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1.  73 IFN-ã Induces Milk Allergen-Specific IL-10-Producing Regulatory B Cells in Non-IGE Mediated Milk Allergy 
Background
Tolerance induction is one of the most important concerns in the treatment of allergies and autoimmune diseases. L-10-producing regulatory B cells (Br1s) seem to have a role in immune tolerance to food allergens. Oral immunotherapy using IFN-gamma has been successful for food allergy treatmen. We were to investigate the effects of IFN-gamma on allergen-specific Br1 responses in milk allergy patients and milk-tolerant subjects to evaluate the mmunomodulatory effects of IFN-gamma on Br1 cell responses.
Methods
The 6 milk allergy patients and 8 milk-tolerant subjects were selected by DBPCFC and clinical characteristics. The PBMCs were stimulated in vitro with casein only, IFN-gamma with casein, or without any stimulant. And the CD19(+) CD5(+) B cells were gated and the expression of IL-10 and Annexin V binding were subsequently analysed.
Results
In milk allergy group, the Br1 fraction decreased from 24.4 to 15.0% (P = 0.002) after casein stimulation and it was recovered to 22.6% in the presence of IFN-gamma (P = 0.006). In milk-tolerant group, the Br1 fraction increased from 9.4 to 17.1% after casein stimulation (P = 0.014) and to 15.7% after IFN-gamma were added (P = 0.066). The proportion of apoptotic Br1s among CD5(+) B cells decreased from 16.5 to 8.1% with casein (P = 0.003) and to 11.8% with IFN-gamma and casein (P = 0.141) in milk allergy group, while in milk-tolerant group, the proportion of apoptotic Br1 increased from 8.2 to 15.0% after casein stimulation (P = 0.014), but was unchanged by casein with IFN-gamma.
Conclusions
Allergen-specific Br1 responses and the apoptotic Br1 fraction were induced by IFN-gamma in milk allergy patients, but were not changed in milk-tolerant subjects. Finally IFN-gamma induced allergen-specific Br1 responses and immune tolerance to specific allergens in milk allergy patients.
doi:10.1097/01.WOX.0000411818.31635.ea
PMCID: PMC3512875
2.  Basophil Reactivity, Wheal Size and Immunoglobulin Levels Distinguish Degree of Cow’s Milk Tolerance 
Background
In our previous study, about 75% of cow’s milk-allergic children tolerated baked-milk products, which improved their prognosis and quality of life.
Objective
We sought to identify biomarkers of varying degrees of clinical tolerance among a cohort of cow’s milk-allergic children.
Methods
132 subjects were initially classified as baked-milk-reactive, baked-milk-tolerant or “outgrown milk allergy” based on oral food challenges. The baked-milk tolerant group was then divided into 3 groups based upon the amount and degree of heat-denatured milk protein that they could tolerate. Serum was analyzed for allergen-specific IgE and IgG4, basophil reactivity was assessed in whole blood stimulated with serial 10-fold dilutions of milk protein, and prick skin tests were performed to commercial milk extract. Activated basophils were defined using flow cytometry as CD63brightCD203c+CD123+HLA-DRdim/−CD41a− lineage−. Data were analyzed using the Jonckheere-Terpstra test.
Results
Significant differences across the five clinical groups were seen for median casein- and milk-specific IgE, casein-specific IgG4 and casein IgE/IgG4; milk-specific to non-specific basophil activation ratio, median basophil reactivity, and spontaneous basophil activation (CD203c expression following stimulation with RPMI); and milk PST wheal diameters. Casein- and milk-specific IgE, milk-specific basophil reactivity and milk prick skin test wheal diameter are all significantly greater among milk-allergic patients who react to baked-milk than among those who tolerate it.
Conclusions
The majority of milk-allergic patients are able to tolerate some forms of baked-milk in their diets. Different phenotypes of cow’s milk-allergic children can be distinguished by casein- and milk-specific IgE, milk-specific basophil reactivity, and milk prick skin test mean wheal diameters. Spontaneous basophil activation is greater among patients with more severe clinical milk reactivity.
doi:10.1016/j.jaci.2012.06.003
PMCID: PMC3493710  PMID: 22819512
Cow’s milk allergy; tolerance; extensively heated; baked; immunotherapy; immunomodulation; biomarker; basophil activation
3.  Immunologic Features of Infants with Milk or Egg Allergy Enrolled in an Observational Study (CoFAR) of Food Allergy 
Background
Immune features of infants with food allergy have not been delineated.
Objectives
To explore basic mechanisms responsible for food allergy and identify biomarkers, e.g. prick skin tests (PST), food-specific IgE, and mononuclear cell responses in a cohort of infants with likely milk/egg allergy at increased risk of developing peanut allergy.
Methods
Infants aged 3–15 months were enrolled with a positive PST to milk or egg and either a corresponding convincing clinical history of allergy to milk or egg, or with moderate to severe atopic dermatitis (AD). Infants with known peanut allergy were excluded.
Results
Overall, 512 infants (67% males) were studied with 308 (60%) having a history of a clinical reaction. Skin tests and/or detectable food-specific IgE revealed sensitization as follows: milk-78%, egg-89% and peanut-69%. PST and food-specific IgE levels were discrepant for peanut: 15% IgE ≥ 0.35 kUA/L/PST- versus 8% PST+/IgE < 0.35, p = 0.001. Mononuclear cell allergen stimulation screening for CD25, CISH, FOXP3, GATA3, IL-10, IL-4, IFN-gamma and TBET expression using casein, egg white and peanut revealed that only allergen-induced IL-4 expression was significantly increased in those with clinical allergy to milk (compared to non-allergic) and in those sensitized to peanut, despite the absence of an increase in GATA-3 mRNA expression.
Conclusions
Infants with likely milk/egg allergy are at considerably high risk of having elevated peanut-specific IgE (potential allergy). Peanut-specific serum IgE was a more sensitive indicator of sensitization than PST. Allergen-specific IL-4 expression may be a marker of allergic risk. Absence of an increase in GATA-3 mRNA expression suggests that allergen-specific IL-4 may not be of T cell origin.
doi:10.1016/j.jaci.2010.02.038
PMCID: PMC2868273  PMID: 20451041
food allergy; sensitization; atopy
4.  Dietary baked-milk accelerates resolution of cow's milk allergy in children 
Background
The majority (∼75%) of cow's milk-allergic children tolerate extensively heated-(baked-) milk products. Long-term effects of inclusion of dietary baked-milk have not been reported.
Objective
We report on the outcomes of children who incorporated baked-milk products into their diets.
Methods
Children evaluated for tolerance to baked-milk (muffin) underwent sequential food challenges to baked-cheese (pizza) followed by unheated-milk. Immunologic parameters were measured at challenge visits. The comparison group were matched to active subjects (using age, sex, and baseline milk-specific IgE) to evaluate the natural history of tolerance development.
Results
Over a median of 37 months (range 8-75 months), 88 children underwent challenges at varying intervals (range 6-54 months). Among 65 subjects initially tolerant to baked-milk, 39 (60%) now tolerate unheated-milk, 18 (28%) tolerate baked-milk/baked-cheese and 8 (12%) chose to avoid milk strictly. Among the baked-milk-reactive subgroup (n=23), 2 (9%) tolerate unheated-milk, 3 (13%) tolerate baked-milk/baked-cheese, while the majority (78%) avoid milk strictly. Subjects who were initially tolerant to baked-milk were 28 times more likely to become unheated-milk-tolerant compared to baked-milk-reactive subjects (P<.001). Subjects who incorporated dietary baked-milk were 16 times more likely than the comparison group to become unheated-milk-tolerant (P<.001). Median casein IgG4 levels in the baked-milk-tolerant group increased significantly (P<.001); median milk IgE values did not change significantly.
Conclusions
Tolerance of baked-milk is a marker of transient IgE-mediated cow's milk allergy whereas reactivity to baked-milk portends a more persistent phenotype. The addition of baked-milk to the diet of children tolerating such foods appears to accelerate development of unheated-milk tolerance compared to strict avoidance.
Clinical implications
Addition of dietary baked-milk is safe, convenient, and well-accepted by patients. Prescribing baked-milk products to milk-allergic children represents an important shift in the treatment paradigm for milk allergy.
Capsule summary
The majority of cow's milk-allergic children tolerate extensively baked-milk products, which is a marker of transient IgE-mediated cow's milk allergy. Dietary baked-milk appears to accelerate development of unheated-milk tolerance compared to strict avoidance.
doi:10.1016/j.jaci.2011.04.036
PMCID: PMC3151608  PMID: 21601913
cow's milk allergy; milk allergy; tolerance; extensively heated; baked; immunotherapy; immunomodulation
5.  The usefulness of casein-specific IgE and IgG4 antibodies in cow's milk allergic children 
Background
Cow's milk allergy is one of the most common food allergies among younger children. We investigated IgE antibodies to milk, and IgE and IgG4 antibodies to casein, α-lactalbumin and β-lactoglobulin in cow's milk allergic (CMA) and non-allergic (non-CMA) children in order to study their clinical usefulness.
Methods
Eighty-three children with suspected milk allergy (median age: 3.5 years, range: 0.8-15.8 years) were diagnosed as CMA (n = 61) or non-CMA (n = 22) based on an open milk challenge or convincing clinical history. Their serum concentrations of allergen-specific (s) IgE and IgG4 antibodies were measured using ImmunoCAP®. For the sIgG4 analysis, 28 atopic and 31 non-atopic control children were additionally included (all non-milk sensitized).
Results
The CMA group had significantly higher levels of milk-, casein- and β-lactoglobulin-sIgE antibodies as compared to the non-CMA group. The casein test showed the best discriminating performance with a clinical decision point of 6.6 kUA/L corresponding to 100% specificity. All but one of the CMA children aged > 5 years had casein-sIgE levels > 6.6 kUA/L. The non-CMA group had significantly higher sIgG4 levels against all three milk allergens compared to the CMA group. This was most pronounced for casein-sIgG4 in non-CMA children without history of previous milk allergy. These children had significantly higher casein-sIgG4 levels compared to any other group, including the non-milk sensitized control children.
Conclusions
High levels of casein-sIgE antibodies are strongly associated with milk allergy in children and might be associated with prolonged allergy. Elevated casein-sIgG4 levels in milk-sensitized individuals on normal diet indicate a modified Th2 response. However, the protective role of IgG4 antibodies in milk allergy is unclear.
doi:10.1186/1476-7961-10-1
PMCID: PMC3398319  PMID: 22212305
casein; cow's milk allergy; IgE; IgG4; ImmunoCAP
6.  The natural history of milk allergy in an observational cohort 
Objective
There are few studies on the natural history of milk allergy. Most are single-site and not longitudinal, and these have not identified a means for early prediction of outcomes.
Methods
Children aged 3 to 15 months were enrolled in an observational study with either (1) a convincing history of egg allergy, milk allergy, or both with a positive skin prick test (SPT) response to the trigger food and/or (2) moderate-to-severe atopic dermatitis (AD) and a positive SPT response to milk or egg. Children enrolled with a clinical history of milk allergy were followed longitudinally, and resolution was established by means of successful ingestion.
Results
The cohort consists of 293 children, of whom 244 were given a diagnosis of milk allergy at baseline. Milk allergy has resolved in 154 (52.6%) subjects at a median age of 63 months and a median age at last follow-up of 66 months. Baseline characteristics that were most predictive of resolution included milk-specific IgE level, milk SPT wheal size, and AD severity (all P < .001). Baseline milk-specific IgG4 level and milk IgE/IgG4 ratio were not predictive of resolution and neither was expression of cytokine-inducible SH2-containing protein, forkhead box protein 3, GATA3, IL-10, IL-4, IFN-γ, or T-bet by using real-time PCR in CD25-selected, casein-stimulated mononuclear cells. A calculator to estimate resolution probabilities using baseline milk IgE level, SPT response, and AD severity was devised for use in the clinical setting. Conclusions: In this cohort of infants with milk allergy, approximately one half had resolved over 66 months of follow-up. Baseline milk-specific IgE level, SPT wheal size, and AD severity were all important predictors of the likelihood of resolution.
doi:10.1016/j.jaci.2012.10.060
PMCID: PMC3691063  PMID: 23273958
Milk allergy; natural history; food allergy; IgE
7.  Intestinal malrotation with suspected cow’s milk allergy: a case report 
BMC Research Notes  2012;5:481.
Background
Intestinal malrotation is an incomplete rotation of the intestine. Failure to rotate leads to abnormalities in intestinal positioning and attachment that leave obstructing bands across the duodenum and a narrow pedicle for the midgut loop, thus making it susceptible to volvulus. One of the important differential diagnoses for malrotation is an allergy to cow’s milk. Several studies have described infants with surgical gastrointestinal diseases and cow’s milk allergy. However, to our knowledge, no study has reported infants with intestinal malrotation who have been symptomatic before surgery was performed and have been examined by allergen-specific lymphocyte stimulation test and food challenge tests with long-term follow-up.
Case presentation
The patient was a Japanese male born at 39 weeks of gestation. He was breast-fed and received commercial cow’s milk supplementation starting the day of birth and was admitted to our hospital at 6 days of age due to bilious vomiting. Plain abdominal radiography showed a paucity of gas in the distal bowel. Because we demonstrated malpositioning of the intestine by barium enema, we repositioned the bowel in a normal position by laparotomy. The patient was re-started on only breast milk 2 days post surgery because we suspected the presence of a cow’s milk allergy, and the results of an allergen-specific lymphocyte stimulation test showed a marked increase in lymphocyte response to kappa-casein. At 5 months of age, the patient was subjected to a cow’s milk challenge test. After the patient began feeding on cow’s milk, he had no symptoms and his laboratory investigations showed no abnormality. In addition, because the patient showed good weight gain and no symptoms with increased cow’s milk intake after discharge, we concluded that the present case was not the result of a cow’s milk allergy. At 1 year, the patient showed favorable growth and development, and serum allergy investigations revealed no reaction to cow’s milk.
Conclusion
When physicians encounter infants with surgical gastrointestinal disease, including intestinal malrotation, they should consider cow’s milk allergy as a differential diagnosis or complication and should utilize food challenge tests for a definitive diagnosis.
doi:10.1186/1756-0500-5-481
PMCID: PMC3490812  PMID: 22943656
Allergen-specific lymphocyte stimulation test; Cow’s milk allergy; Food challenge test; Infant; Intestinal malrotation
8.  Milk-induced eczema is associated with the expansion of T cells expressing cutaneous lymphocyte antigen. 
Journal of Clinical Investigation  1995;95(2):913-918.
The extravasation of T cells at sites of inflammation is critically dependent on the activity of homing receptors (HR) involved in endothelial cell recognition and binding. Two such HR (the cutaneous lymphocyte antigen [CLA] and L-selectin) have been shown to be selectively involved in T cell migration to skin and peripheral lymph nodes, respectively. This study was designed to assess the relationship between the organ specificity of an allergic reaction to food and the expression of HR on T cells activated in vitro by the relevant food allergen. Peripheral blood mononuclear cells were isolated from seven milk allergic children with a history of eczema when exposed to milk. All patients had a positive prick skin test and double-blind placebo-controlled food challenge to milk. 10 children with either allergic eosinophilic gastroenteritis or milk-induced enterocolitis and 8 nonatopic adults served as controls. Five-parameter flow cytometry using monoclonal antibodies was used for detection of the specific HR on freshly isolated T cells versus T cell blasts induced by a 6-d incubation with casein, as compared with Candida albicans. After in vitro stimulation with casein, but not C. albicans, patients with milk allergy and atopic dermatitis had a significantly greater percentage of CLA+ T cells (P < 0.01) than controls with milk-induced enterocolitis, allergic eosinophilic gastroenteritis, or nonatopic healthy controls. In contrast, the percentage of L-selectin-expressing T cells did not differ significantly between these groups. These data suggest that after casein stimulation allergic patients with milk-induced skin disease have an expanded population of CLA+ T cells, as compared with nonatopics or allergic patients without skin involvement. We postulate that heterogeneity in the regulation of HR expression on antigen-specific T cells may play a role in determining sites of involvement in tissue-directed allergic responses.
Images
PMCID: PMC295586  PMID: 7532192
9.  Changes in antigen-specific T cell number and function during oral desensitization in cow’s milk allergy enabled with omalizumab 
Mucosal immunology  2012;5(3):267-276.
Food allergy is a major public health problem for which there is no effective treatment. We examined the immunological changes that occurred in a group of children with significant cow’s milk allergy undergoing a novel and rapid high dose oral desensitization protocol enabled by treatment with omalizumab (anti-IgE mAb). Within a week of treatment, the CD4+ T cell response to milk was nearly eliminated, suggesting anergy in, or deletion of, milk-specific CD4+ T cells. Over the following three months while the subjects remained on high doses of daily oral milk, the CD4+ T cell response returned, characterized by a shift from IL-4 to IFN-γ production. Desensitization was also associated with reduction in milk-specific IgE and a 15-fold increase in milk-specific IgG4. These studies suggest that high dose oral allergen desensitization may be associated with deletion of allergen-specific T cells, without the apparent development of allergen-specific Foxp3+ regulatory T cells.
doi:10.1038/mi.2012.5
PMCID: PMC3328586  PMID: 22318492
10.  Presence of functional, autoreactive human milk-specific IgE in infants with cow’s milk allergy 
Summary
Background
Occasionally, exclusively breastfed infants with cow’s milk allergy (CMA) remain symptomatic despite strict maternal milk avoidance.
Objective
To determine whether or not persistence of symptoms could be due to sensitization against endogenous human milk proteins with a high degree of similarity to bovine allergens.
Methods
Ten peptides representing known bovine milk IgE-binding epitopes [α-lactalbumin (ALA), β- and κ-casein] and the corresponding, highly homologous human milk peptides were labelled with sera from 15 breastfed infants with CMA, aged 3 weeks to 12 months, and peptide (epitope)-specific IgE antibodies were assessed. Nine of the 15 breastfed infants became asymptomatic during strict maternal avoidance of milk and other major food allergens; six infants remained symptomatic until weaned. Ten older children, aged 5–15 years, with CMA were also assessed. The functional capacity of specific IgE antibodies was assessed by measuring β-hexosaminidase release from rat basophilic leukaemia cells passively sensitized and stimulated with human and bovine ALA. Results A minimum of one human milk peptide was recognized by IgE antibodies from 9 of 15 (60%) milk-allergic infants, and the majority of older children with CMA. Genuine sensitization to human milk peptides in the absence of IgE to bovine milk was occasionally seen. There was a trend towards specific IgE being detected to more human milk peptides in those infants who did not respond to the maternal milk elimination diet than in those who did (P = 0.099). Functional IgE antibody to human ALA was only detected in infants not responding to the maternal diet.
Conclusions and Clinical Relevance
Endogenous human milk epitopes are recognized by specific IgE from the majority of infants and children with CMA. Such autoreactive, human milk-specific IgE antibodies appear to have functional properties in vitro. Their role in provoking allergic symptoms in infants exclusively breastfed by mothers strictly avoiding dietary milk remains unclear.
doi:10.1111/j.1365-2222.2011.03864.x
PMCID: PMC3780604  PMID: 22092935
atopic eczema; autoreactivity; cow’s milk allergy; cross-reactivity; endogenous protein; human milk; IgE antibodies; infants; RBL assay; sensitization; SPOT method
11.  Extensively hydrolysed casein formula supplemented with Lactobacillus rhamnosus GG maintains hypoallergenic status: randomised double-blind, placebo-controlled crossover trial 
BMJ Open  2012;2(2):e000637.
Objective
To evaluate the hypoallergenicity of an extensively hydrolysed (EH) casein formula supplemented with Lactobacillus rhamnosus GG (LGG).
Design
A prospective, randomised, double-blind, placebo-controlled crossover trial.
Setting
Two study sites in Italy and The Netherlands.
Study participants
Children with documented cow's milk allergy were eligible for inclusion in this trial.
Interventions
After a 7-day period of strict avoidance of cow's milk protein and other suspected food allergens, participants were tested with an EH casein formula with demonstrated hypoallergenicity (control, EHF) and a formula of the same composition with LGG added at 108 colony-forming units per gram powder (EHF-LGG) in randomised order in a double-blind placebo-controlled food challenge (DBPCFC). After absence of adverse reactions in the DBPCFC, an open challenge was performed with EHF-LGG, followed by a 7-day home feeding period with the same formula.
Main outcome measure
Clinical assessment of any adverse reactions to ingestion of study formulae during the DBPCFC.
Results
For all participants with confirmed cow's milk allergy (n=31), the DBPCFC and open challenge were classified as negative.
Conclusion
The EH casein formula supplemented with LGG is hypoallergenic and can be recommended for infants and children allergic to cow's milk who require an alternative to formulae containing intact cow's milk protein.
Trial registration number
http://ClinicalTrials.gov Identifier: NCT01181297.
Article summary
Article focus
Hypoallergenic extensively hydrolysed (EH) cow's milk-based or amino acid-based formulae are recommended for management of cow's milk allergy in formula-fed infants.
Although Lactobacillus rhamnosus GG (LGG) has over 25 years of safe use as a dietary probiotic, the safety and hypoallergenic status of EH casein formula supplemented with LGG has not yet been demonstrated.
Key messages
Supplementing the EH casein formula with LGG to provide additional benefits does not change its hypoallergenic status.
The LGG-supplemented EH formula can be safely used for management of cow's milk allergy in infants and children.
Strengths and limitations of this study
Testing the LGG-supplemented EH formula in a properly designed double-blind placebo-controlled food challenge in accordance with accepted European Society of Pediatric Gastroenterology and Nutrition (ESPGHAN) and American Academy of Pediatrics standards to establish hypoallergenicity is a major strength of this study.
One limitation is the potentially low novelty of our finding. Because LGG is the most used dietary probiotic, accumulated safety data for LGG as a stand-alone dietary supplement in infants and adults are available.
doi:10.1136/bmjopen-2011-000637
PMCID: PMC3298831  PMID: 22396223
Cow's milk protein; cow's milk allergy; extensively hydrolysed formula; double-blind placebo-controlled food challenge; hypoallergenic formula; infant; Lactobacillus GG
12.  IFN-γ production in response to in vitro stimulation with collagen type II in rheumatoid arthritis is associated with HLA-DRB1*0401 and HLA-DQ8 
Arthritis Research  1999;2(1):75-84.
IFN-γ was measured in supernatants after in vitro stimulation of peripheral blood mononuclear cells with collagen type II (CII), purified protein derivative or influenza virus. IFN-γ production in response to CII was similar in rheumatoid arthritis (RA) patients and healthy control individuals. The IFN-γ response to purified protein derivative and influenza virus was lower in RA patients, reflecting a general T-cell hyporesponsiveness in RA. After recalculating the response to CII taking this hyporesponsiveness into account the CII response was higher in RA patients, and was associated with human leucocyte antigen (HLA)-DRB1*0401 and HLA-DQA1*0301-DQB1*0302 (HLA-DQ8). Rheumatoid arthritis patients with elevated serum levels of immunoglobulin (Ig)G anti-CII antibodies had lower CII-induced IFN-γ production than patients with low anti-CII levels. The relative increase in CII-reactivity in RA patients as compared with healthy control individuals, and the association of a higher response with RA-associated HLA haplotypes, suggest the existence of a potentially pathogenic cellular reactivity against CII in RA.
Introduction:
Despite much work over past decades, whether antigen-specific immune reactions occur in rheumatoid arthritis (RA) and to what extent such reactions are directed towards joint-specific autoantigens is still questionable. One strong indicator for antigenic involvement in RA is the fact that certain major histocompatibility complex (MHC) class II genotypes [human leucocyte antigen (HLA)-DR4 and HLA-DR1] predispose for the development of the disease [1]. In the present report, collagen type II (CII) was studied as a putative autoantigen on the basis of both clinical and experimental data that show an increased frequency of antibodies to CII in RA patients [2,3,4] and that show that CII can induce experimental arthritis [5].
It is evident from the literature that RA peripheral blood mononuclear cells (PBMCs) respond poorly to antigenic stimulation [6,7,8], and in particular evidence for a partial tolerization to CII has been presented [9]. The strategy of the present work has accordingly been to reinvestigate T-cell reactivity to CII in RA patients, to relate it to the response to commonly used recall antigens and to analyze IFN-γ responses as an alternative to proliferative responses.
Aims:
To study cellular immune reactivity to CII in patients with RA and in healthy control individuals and to correlate this reactivity to HLA class II genotypes and to the presence of antibodies to CII in serum.
Methods:
Forty-five patients who met the 1987 American College of Rheumatology classification criteria for RA [10] and 25 healthy control individuals of similar age and sex were included. Twenty-six of these patients who had low levels of anti-CII in serum were randomly chosen, whereas 19 patients with high anti-CII levels were identified by enzyme-linked immunosorbent assay (ELISA)-screening of 400 RA sera.
Heparinized blood was density gradient separated and PBMCs were cultured at 1 × 106/ml in RPMI-10% fetal calf serum with or without antigenic stimulation: native or denatured CII (100 μ g/ml), killed influenza virus (Vaxigrip, Pasteur Mérieux, Lyon, France; diluted 1 : 1000) or purified protein derivative (PPD; 10 μ g/ml). CII was heat-denatured in 56°C for 30 min.
Cell supernatants were collected after 7days and IFN-γ contents were analyzed using ELISA. HLA-DR and HLA-DQ genotyping was performed utilizing a polymerase chain reaction-based technique with sequence-specific oligonucleotide probe hybridization. Nonparametric statistical analyses were utilized throughout the study.
Results:
PBMCs from both RA patients and healthy control individuals responded with inteferon-γ production to the same degree to stimulation with native and denatured CII (Fig. 1a), giving median stimulation indexes with native CII of 4.6 for RA patients and 5.4 for healthy control individuals, and with denatured CII of 2.9 for RA patients and 2.6 for healthy control individuals. RA patients with elevated levels of anti-CII had a weaker IFN-γ response to both native and denatured CII than did healthy control individuals (P = 0.02 and 0.04, respectively).
Stimulation with the standard recall antigens PPD and killed influenza virus yielded a median stimulation index with PPD of 10.0 for RA patients and 51.3 for healthy control individuals and with influenza of 12.3 for RA patients and 25.7 for healthy, control individuals. The RA patients displayed markedly lower responsiveness to both PPD and killed influenza virus than did healthy control individuals (Fig. 1b). IFN-γ responses to all antigens were abrogated when coincubating with antibodies blocking MHC class II.
The low response to PPD and killed influenza virus in RA patients relative to that of healthy control individuals reflects a general downregulation of antigen-induced responsiveness of T cells from RA patients [6,7,8]. That no difference between the RA group and the control group was recorded in CII-induced IFN-γ production therefore indicates that there may be an underlying increased responsiveness to CII in RA patients, which is obscured by the general downregulation of T-cell responsiveness in these patients. In order to address this possibility, we calculated the fraction between individual values for the CII-induced IFN-γ production and the PPD-induced and killed influenza virus-induced IFN-γ production, and compared these fractions. A highly significant difference between the RA and healthy control groups was apparent after stimulation with both native CII and denatured CII when expressing the response as a fraction of that with PPD (Fig. 2a). Similar data were obtained using killed influenza virus-stimulated IFN-γ values as the denominator (Fig. 2b).
When comparing the compensated IFN-γ response to denatured CII stimulation between RA patients with different HLA genotypes, highly significant differences were evident, with HLA-DRB1*0401 patients having greater CII responsiveness than patients who lacked this genotype (Fig. 3a). HLA-DQ8 positive patients also displayed a high responsiveness to CII as compared with HLA-DQ8 negative RA patients (Fig. 3b). These associations between the relative T-cell reactivity to denatured CII and HLA class II genotypes were not seen in healthy control individuals. Similar results were achieved using influenza as denominator (P = 0.02 for HLA-DRB1*0401 and P = 0.01 for HLA-DQ8).
Discussion:
No reports have previously systematically taken the general T-cell hyporesponsiveness in RA into account when investigating specific T-cell responses in this disease. In order to address this issue we used the T-cell responses to PPD and killed influenza virus as reference antigens. This was made on the assumption that exposure to these antigens is similar in age-matched and sex-matched groups of RA patients and healthy control individuals. The concept of a general hyporesponsiveness in RA T cells has been documented in several previous reports, in which both nominal antigens [6,7,8] and mitogens [11,12,13] have been used. The fact that a similar functional downregulation in RA PBMCs was obtained with both PPD and killed influenza virus as reference antigens strengthens the validity of our approach.
We identified an association between the IFN-γ response to CII and HLA-DRB1*0401 and HLA-DQ8 in the RA patient group, which is of obvious interest because both these MHC class II alleles have been associated with high responsiveness to CII in transgenic mice that express these human MHC class II molecules [14,15]. There was no association between high anti-CII levels and shared epitope (HLA-DRB1*0401 or HLA-DRB1*0404).
Conclusion:
CII, a major autoantigen candidate in RA, can elicit an IFN-γ response in vitro that is associated with HLA-DRB1*0401 and HLA-DQ8 in RA patients. This study, with a partly new methodological approach to a classical problem in RA, has provided some additional support to the notion that CII may be a target autoantigen of importance for a substantial group of RA patients. Continued efforts to identify mechanisms behind the general hyporesponsiveness to antigens in RA, as well as the mechanisms behind the potential partial anergy to CII, may provide us with better opportunities to study the specificity and pathophysiological relevance of anti-CII reactivity in RA.
PMCID: PMC17806  PMID: 11219392
collagen type II; human leucocyte antigen-DR; IFN-γ; rheumatoid arthritis; T cell
13.  Allergen-Specific Basophil Activation Associated with Clinical Tolerance in Patients with Milk Allergy 
Background
Milk-allergic children who tolerate heat-denatured milk (HM) have less severe reactions and outgrow the condition earlier than those who react to HM, which may be related to differences in IgE-dependent effector cell function.
Objective
To apply a novel assay to test the hypothesis that HM-tolerant children have suppressed IgE-mediated basophil responses.
Methods
Allergic, HM-tolerant, Outgrown or Control subjects were defined by oral food challenges. Whole blood cells were stimulated in vitro with a range of milk allergen doses in the presence or absence of autologous serum or with dilutions of autologous serum. Activated basophils were identified by flow cytometry as CD63bright CD123+ CD203c+ HLA-DR- CD41a-.
Results
HM-tolerant subject basophils were significantly less responsive to milk allergen stimulation at all doses than were basophils from HM reactive (Allergic) individuals. In the absence of autologous serum, HM-tolerant subject basophils were significantly more reactive at low allergen concentrations. To a lesser extent, autologous serum also inhibited IL-3- and anti-IgE-induced, but not fMLP-induced responses. The allergen-specific responsiveness of HM-tolerant subject basophils increased with dilution of autologous serum with normal pooled serum.
Conclusion
Milk-allergic children with a favorable prognosis have evidence of extrinsically suppressed allergen-specific effector cell reactivity.
doi:10.1016/j.jaci.2008.12.1128
PMCID: PMC2831768  PMID: 19348919
milk allergy; basophils; basophil activation test; oral tolerance; cow’s milk allergy
14.  Elevated Antigen-Driven IL-9 Responses Are Prominent in Peanut Allergic Humans 
PLoS ONE  2012;7(10):e45377.
Food allergies, and peanut allergy in particular, are leading causes of anaphylactic fatalities worldwide. The immune mechanisms that underlie food allergy remain ill-defined and controversial, in part because studies in humans typically focus on analysis of a limited number of prototypical Th1/Th2 cytokines. Here we determine the kinetics and prevalence of a broad panel of peanut-driven cytokine and chemokine responses in humans with current peanut allergy vs those with stable, naturally occurring clinical tolerance to peanut. Our primary focus is identification of novel indicators of immune dysregulation. Antigen-specific cytokine mRNA and protein responses were elicited in primary culture via peanut or irrelevant antigen (Leishmania extract, milk antigens) mediated stimulation of fresh peripheral blood cells from 40 individuals. Peanut extract exposure in vitro induced a broad panel of responses associated with Th2/Th9-like, Th1-like and Th17-like immunity. Peanut-dependent Type 2 cytokine responses were frequently found in both peanut allergic individuals and those who exhibit clinical tolerance to peanut ingestion. Among Th2/Th9-associated cytokines, IL-9 responses discriminated between allergic and clinically tolerant populations better than did commonly used IL-4, IL-5 or IL-13 responses. Comparison with responses evoked by unrelated control antigen-mediated stimulation showed that these differences are antigen-dependent and allergen-specific. Conversely, the intensity of IL-12, IL-17, IL-23 and IFN-γ production was indistinguishable in peanut allergic and peanut tolerant populations. In summary, the ability to generate and maintain cytokine responses to peanut is not inherently distinct between allergic and peanut tolerant humans. Quantitative differences in the intensity of cytokine production better reflects clinical phenotype, with optimally useful indicators being IL-9, IL-5, IL-13 and IL-4. Equivalent, and minimal, Ag-dependent pro-inflammatory cytokine levels in both healthy and peanut allergic volunteers argues against a key role for such cytokines in maintenance of clinical tolerance to food antigens in humans.
doi:10.1371/journal.pone.0045377
PMCID: PMC3469559  PMID: 23071516
15.  Anti-Interferon Autoantibodies in Autoimmune Polyendocrinopathy Syndrome Type 1 
PLoS Medicine  2006;3(7):e289.
Background
The autoimmune regulator (AIRE) gene influences thymic self-tolerance induction. In autoimmune polyendocrinopathy syndrome type 1 (APS1; OMIM 240300), recessive AIRE mutations lead to autoimmunity targetting endocrine and other epithelial tissues, although chronic candidiasis usually appears first. Autoimmunity and chronic candidiasis can associate with thymomas as well. Patients with these tumours frequently also have high titre immunoglobulin G autoantibodies neutralising type I interferon (IFN)–α and IFN-ω, which are secreted signalling proteins of the cytokine superfamily involved in both innate and adaptive immunity.
Methods and Findings
We tested for serum autoantibodies to type I IFNs and other immunoregulatory cytokines using specific binding and neutralisation assays. Unexpectedly, in 60/60 Finnish and 16/16 Norwegian APS1 patients with both AIRE alleles mutated, we found high titre neutralising immunoglobulin G autoantibodies to most IFN-α subtypes and especially IFN-ω (60% homologous to IFN-α)—mostly in the earliest samples. We found lower titres against IFN-β (30% homologous to IFN-α) in 23% of patients; two-thirds of these (from Finland only) also had low titres against the distantly related “type III IFN” (IFN-λ1; alias interleukin-29). However, autoantibodies to the unrelated type II IFN, IFN-γ, and other immunoregulatory cytokines, such as interleukin-10 and interleukin-12, were much rarer and did not neutralise.
Neutralising titres against type I IFNs averaged even higher in patients with APS1 than in patients with thymomas. Anti–type I IFN autoantibodies preceded overt candidiasis (and several of the autoimmune disorders) in the informative patients, and persisted for decades thereafter. They were undetectable in unaffected heterozygous relatives of APS1 probands (except for low titres against IFN-λ1), in APS2 patients, and in isolated cases of the endocrine diseases most typical of APS1, so they appear to be APS1-specific.
Looking for potentially autoimmunising cell types, we found numerous IFN-α+ antigen-presenting cells—plus strong evidence of local IFN secretion—in the normal thymic medulla (where AIRE expression is strongest), and also in normal germinal centres, where it could perpetuate these autoantibody responses once initiated. IFN-α2 and IFN-α8 transcripts were also more abundant in antigen-presenting cells cultured from an APS1 patient's blood than from age-matched healthy controls.
Conclusions
These apparently spontaneous autoantibody responses to IFNs, particularly IFN-α and IFN-ω, segregate like a recessive trait; their high “penetrance” is especially remarkable for such a variable condition. Their apparent restriction to APS1 patients implies practical value in the clinic, e.g., in diagnosing unusual or prodromal AIRE-mutant patients with only single components of APS1, and possibly in prognosis if they prove to predict its onset. These autoantibody responses also raise numerous questions, e.g., about the rarity of other infections in APS1. Moreover, there must also be clues to autoimmunising mechanisms/cell types in the hierarchy of preferences for IFN-ω, IFN-α8, IFN-α2, and IFN-β and IFN-λ1.
Almost all of nearly 100 APS1 patients studied made large amounts of auto-antibodies that blocked the function of IFN-α and IFN-ω. The antibodies appeared early during development of the disease and may play a role in its etiology.
Editors' Summary
Background.
The human body is under constant attack by viruses, bacteria, fungi, and parasites, but the immune system usually prevents these pathogens from causing disease. To be effective, the immune system has to respond rapidly to foreign antigens (bits of protein specific to pathogens) while ignoring self-antigens. If tolerance to self-antigens breaks down, autoimmunity develops, often causing disease. There are many common autoimmune diseases—type I diabetes and multiple sclerosis, for example—but because these involve defects in many genes as well as environmental factors, the details of how autoimmunity develops remain unclear. Autoimmune polyendocrinopathy syndrome type 1 (APS1), however, is caused by defects in a single gene. Patients with this rare disease characteristically have defects (or mutations) in both copies of a gene called AIRE (for autoimmune regulator). In normal people, the protein product of this gene helps to establish tolerance to a subset of self-antigens. People carrying AIRE mutations make an autoimmune response against some of their own tissues, typically the endocrine (hormone-producing) tissues that control body metabolism. A major component of this autoimmune response are “autoantibodies” (antibodies are immune molecules that normally recognize and attack foreign substances, whereas autoantibodies are directed against the body's own molecules).
Why Was This Study Done?
For a diagnosis of APS1, a patient must have at least two of the following symptoms: recurrent, localized yeast infections (usually the first symptom of the disease to appear in early childhood), hypoparathyroidism (failure of the gland that controls calcium levels in the body), and Addison disease (failure of the steroid-producing adrenal glands, which help the body respond to stress). The researchers who did this study had previously noticed that these yeast infections and autoimmunity (usually against muscle) can also occur in patients with tumors of the thymus (thymomas). The thymus is the organ that generates immune cells called T cells. Generation of the T cell repertoire in the thymus involves selection of those T cells that recognize only foreign substances. T cells that can react against self-antigens are eliminated, and the AIRE gene is thought to be involved in this “education process.” Like those with APS1, patients with thymomas make autoantibodies not only against target organs (especially muscle in their case), but also against interferon alpha (IFN-α) and interferon omega (IFN-ω), two secreted immune regulators. The researchers wanted to know if patients with APS1 also make autoantibodies against interferons, because this could provide insights into how autoimmunity develops in APS1 and other autoimmune diseases.
What Did the Researchers Do and Find?
The researchers tested blood from nearly 100 APS1 patients for antibodies to IFN-α, IFN-ω, and other immunoregulatory cytokines. They found that almost all patients made large amounts of antibodies that blocked the function of IFN-α and IFN-ω; some also made lower amounts of antibodies against two related interferons, but none made blocking antibodies against unrelated interferons or other immune regulators. For many patients, serum samples were available at different times during their disease, which allowed the researchers to show that the antibodies appeared early in disease development, before the onset of yeast infections or damage to endocrine tissues, and their production continued for decades as the patient aged. Furthermore, only patients with APS1 made these antibodies—they were absent in patients with Addison disease alone, for example.
What Do These Findings Mean?
The discovery that autoantibodies to IFN-α and IFN-ω are made persistently in patients with APS1 suggests ways in which autoimmunity develops in these patients. These can now be investigated further both in patients and in animal models of the disease. The discovery also has practical implications. Measurement of these autoantibodies might help some APS1 patients by allowing earlier diagnosis—and prompter treatment—than in current practice. The levels of these autoantibodies might also help to predict the time course of APS1 in individual patients, although more studies will be needed to check this out. Finally, if future studies show that interferon autoantibodies are responsible for the patients' susceptibility to yeast infections (which seems plausible), treatment with IFN-γ, an interferon to which APS1 patients do not make autoantibodies, might provide an alternative way to deal with this problem.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0030289.
• MedlinePlus pages on autoimmune diseases
• Online Mendelian Inheritance in Man page on APS1
• Links to patient information on APS1 from the Stanford Health Library
• Wikipedia page on autoendocrine polyendocrinopathy (note: Wikipedia is a free online encyclopedia that anyone can edit)
• Information on autoimmunity from the American Autoimmune Related Diseases Association
doi:10.1371/journal.pmed.0030289
PMCID: PMC1475653  PMID: 16784312
16.  495 Milk, the Most Commonly Undeclared Food Allergen Causing Unexpected Allergic Reactions in Sweden between 2004 and 2011 
Background
Allergy to milk proteins is a common allergic manifestation, especially among children. Different types of food products could be a risk factor for milk allergic individuals. According to the European Community Directive 2000/13/EC the list of ingredients shall include all the ingredients of the foodstuff, however with some exceptions. In 2003 Directive 2003/89/EC entered into force stating that milk and other ingredients, which are common elicitors of food allergic reactions, shall always be declared in the labeling.
Objective
To investigate which undeclared food allergen that most commonly has caused unexpected allergic reactions in Sweden between 2004 and 2011, ie, since 2003/89/EC entered into force, and to compile data regarding the reactions to this food allergen.
Methods
The medical care, school personnel and control authorities have since 1990 been encouraged to report allergic reactions to foods, which do not declare the ingredient causing the allergic reaction, to the Swedish National Food Administration. Also, the suspected foods have been provided for analyses. Food allergens, e.g. caseins (a group of milk proteins), were analyzed with Enzyme Linked Immunosorbent Assay and/or Rocket Immunoelectrophoresis.
Results
Forty-eight cases of unexpected allergic reactions to foods, in which the causing food allergen was detected, were reported between 2004 and 2011. The most commonly detected food allergen was milk (21) followed by peanut (9), egg (6) and wheat (5). The persons who suffered from unexpected allergic reactions to milk were all children or teenagers. Mild symptoms were reported as well as anaphylactic reactions. One death was most likely caused by an allergic reaction to bread contaminated with milk. The lowest doses eliciting allergic reactions were calculated to be 2 to 6 mg casein. The types of foods causing the reactions were chocolate, ready-made meals, meat products, sauces, bread and a vegetarian milk substitute. The unexpected allergic reactions to milk were caused by mislabeling in 7 cases and to contamination in 14 cases.
Conclusions
Although rare, allergic reactions to undeclared food allergens may occur. Milk was the most commonly undeclared food allergen causing allergic reactions in Sweden between 2004 and 2011.
doi:10.1097/01.WOX.0000411610.80926.6a
PMCID: PMC3512776
17.  Targeting a Cross-Reactive Gly m 5 Soy Peptide as Responsible for Hypersensitivity Reactions in a Milk Allergy Mouse Model 
PLoS ONE  2014;9(1):e82341.
Background
Cross-reactivity between soybean allergens and bovine caseins has been previously reported. In this study we aimed to map epitopes of the major soybean allergen Gly m 5 that are co-recognized by casein specific antibodies, and to identify a peptide responsible for the cross-reactivity.
Methods
Cow's milk protein (CMP)-specific antibodies were used in different immunoassays (immunoblotting, ELISA, ELISA inhibition test) to evaluate the in vitro recognition of soybean proteins (SP). Recombinant Gly m 5 (α), a truncated fragment containing the C-terminal domain (α-T) and peptides of α-T were obtained and epitope mapping was performed with an overlapping peptide assay. Bioinformatics tools were used for epitope prediction by sequence alignment, and for modelling the cross-recognized soy proteins and peptides. The binding of SP to a monoclonal antibody was studied by surface Plasmon resonance (SPR). Finally, the in vivo cross-recognition of SP was assessed in a mouse model of milk allergy.
Results
Both α and α-T reacted with the different CMP-specific antibodies. α-T contains IgG and IgE epitopes in several peptides, particularly in the peptide named PA. Besides, we found similar values of association and dissociation constants between the α-casein specific mAb and the different milk and soy components. The food allergy mouse model showed that SP and PA contain the cross-reactive B and T epitopes, which triggered hypersensitivity reactions and a Th2-mediated response on CMP-sensitized mice.
Conclusions
Gly m 5 is a cross-reactive soy allergen and the α-T portion of the molecule contains IgG and IgE immunodominant epitopes, confined to PA, a region with enough conformation to be bound by antibodies. These findings contribute to explain the intolerance to SP observed in IgE-mediated CMA patients, primarily not sensitised to SP, as well as it sets the basis to propose a mucosal immunotherapy for milk allergy using this soy peptide.
doi:10.1371/journal.pone.0082341
PMCID: PMC3886974  PMID: 24416141
18.  Early recovery from cow's milk allergy is associated with decreasing IgE and increasing IgG4 binding to cow's milk epitopes 
Background
Dynamics and balance of allergen specific IgE, IgG4 and IgA binding may contribute to the development of tolerance in cow's milk allergy. Profiling of antibody binding to cow's milk protein epitopes may help in predicting natural history of allergy.
Objective
To investigate differences in IgE, IgG4 and IgA binding to cow's milk epitopes over time between patients with early recovery or with persisting cow's milk allergy.
Methods
We studied serum samples at the time of diagnosis (mean age 7 months), one year later and at follow-up (mean age 8.6 years) from 11 patients with persisting IgE-mediated cow's milk allergy at age 8-9 years, and 12 patients who recovered by age 3 years. We measured the binding of IgE, IgG4 and IgA antibodies to sequential epitopes derived from five major cow's milk proteins with a peptide microarray-based immunoassay. We analyzed the data with a novel image processing method together with machine learning prediction.
Results
IgE epitope binding patterns were stable over time in patients with persisting cow's milk allergy, whereas binding decreased in patients who recovered early. Binding patterns of IgE and IgG4 overlapped. Among patients who recovered early, the signal of IgG4 binding increased while that of IgE decreased over time. IgE and IgG4 binding to a panel of αs1-, αs2-, β-and κ-casein regions predicted outcome with significant accuracy.
Conclusions
Attaining tolerance to cow's milk is associated with decreased epitope binding by IgE and a concurrent increase in corresponding epitope binding by IgG4.
doi:10.1016/j.jaci.2010.03.025
PMCID: PMC3289532  PMID: 20462631
cow's milk allergy; tolerance; epitope; IgE; IgG4; IgA
19.  Prevention of Birch Pollen-Related Food Allergy by Mucosal Treatment with Multi-Allergen-Chimers in Mice 
PLoS ONE  2012;7(6):e39409.
Background
Among birch pollen allergic patients up to 70% develop allergic reactions to Bet v 1-homologue food allergens such as Api g 1 (celery) or Dau c 1 (carrot), termed as birch pollen-related food allergy. In most cases, specific immunotherapy with birch pollen extracts does not reduce allergic symptoms to the homologue food allergens. We therefore genetically engineered a multi-allergen chimer and tested if mucosal treatment with this construct could represent a novel approach for prevention of birch pollen-related food allergy.
Methodology
BALB/c mice were poly-sensitized with a mixture of Bet v 1, Api g 1 and Dau c 1 followed by a sublingual challenge with carrot, celery and birch pollen extracts. For prevention of allergy sensitization an allergen chimer composed of immunodominant T cell epitopes of Api g 1 and Dau c 1 linked to the whole Bet v 1 allergen, was intranasally applied prior to sensitization.
Results
Intranasal pretreatment with the allergen chimer led to significantly decreased antigen-specific IgE-dependent β-hexosaminidase release, but enhanced allergen-specific IgG2a and IgA antibodies. Accordingly, IL-4 levels in spleen cell cultures and IL-5 levels in restimulated spleen and cervical lymph node cell cultures were markedly reduced, while IFN-γ levels were increased. Immunomodulation was associated with increased IL-10, TGF-β and Foxp3 mRNA levels in NALT and Foxp3 in oral mucosal tissues. Treatment with anti-TGF-β, anti-IL10R or anti-CD25 antibodies abrogated the suppression of allergic responses induced by the chimer.
Conclusion
Our results indicate that mucosal application of the allergen chimer led to decreased Th2 immune responses against Bet v 1 and its homologue food allergens Api g 1 and Dau c 1 by regulatory and Th1-biased immune responses. These data suggest that mucosal treatment with a multi-allergen vaccine could be a promising treatment strategy to prevent birch pollen-related food allergy.
doi:10.1371/journal.pone.0039409
PMCID: PMC3387141  PMID: 22768077
20.  Allergen-responsive CD4+CD25+ Regulatory T Cells in Children who Have Outgrown Cow's Milk Allergy 
The Journal of Experimental Medicine  2004;199(12):1679-1688.
Cow's milk allergy in children is often of short duration, which makes this disorder an interesting clinical model for studies of tolerance to dietary antigens. Here, we studied T cell responses in 21 initially allergic children who, after a milk-free period of >2 mo, had cow's milk reintroduced to their diet. Children who outgrew their allergy (tolerant children) had higher frequencies of circulating CD4+CD25+ T cells and decreased in vitro proliferative responses to bovine β-lactoglobulin in peripheral blood mononuclear cells (PBMCs) compared with children who maintained clinically active allergy. No significant difference in proliferative activity stimulated by the polyclonal mitogen phytohemagglutinin was observed between the two groups. Depletion of CD25+ cells from PBMCs of tolerant children led to a fivefold increase in in vitro proliferation against β-lactoglobulin. This suggests that tolerance is associated with the appearance of circulating CD4+CD25+ regulatory T (Treg) cells that are capable of suppressing the effector T cells generated 1 wk after reintroduction of cow's milk. The suppressive function of the CD4+CD25+ Treg cells was shown to be partly cell contact dependent. Collectively, our study provides human data to suggest that mucosal induction of tolerance against dietary antigens is associated with the development of CD4+CD25+ Treg cells.
doi:10.1084/jem.20032121
PMCID: PMC2212808  PMID: 15197226
human; oral tolerance; regulatory T cells; food allergy; cytokines
21.  Long term outcome of acquired food allergy in pediatric liver recipients: a single center experience 
Pediatric Reports  2012;4(1):e6.
Food induced sensitization has been reported in pediatric liver recipients. However long term follow up has not been established so far.
We report here our experience regarding 3 pediatric patients who developed acquired food allergy after liver transplantation. The first patient suffered from persistent diarrhea and eczema. The second one presented with abdominal pain with no signs of rejection, abdominal discomfort, vomiting when ingesting milk proteins and responded well to the elimination diet. The third patient presented with facial angioedema and hoarseness of voice. She had multiple food allergies and reacted to milk, egg and sesame. All the patients had elevated total Immunoglobulin E (IgE) and elevated specific IgE antibodies to the implicated food allergens. The first patient presented clinical manifestations of allergy when she was 19 months old. The second patient became allergic at the age of 16 and the third patient at the age of 3. The symptoms of food allergy persisted for 8 years in the first case and for 2 years in the other two cases. Low levels of specific IgE antibodies to the implicated food allergens and an enhanced T-helper 1 cell immune response toward interferon-gamma production were markers of tolerance acquisition. The long term prognosis in our cases was excellent. Food allergy resolved in all the patients. The long term prognosis of acquired food allergy after liver transplantation is currently obscure. More studies would be needed including greater number of patients to determine whether acquired food allergy is transient in pediatric liver recipients.
doi:10.4081/pr.2012.e6
PMCID: PMC3357619  PMID: 22690312
liver transplantation; acquired food allergy; children; long term follow up.
22.  437 Association between Cows Milk Allergy and Gastroesophageal Reflux Disease on Mexican People 
Background
The World Allergy Organization estimates 520 million people with food allergy on the world. The data that support the prevalence fluctuate in relation of the method employed to obtain these, for example, questionnaires, measurements of IgE-specific, oral challenges; the last one is considerate the gold standard. Similar situation occur to allergy to cow´s milk (CMA), the prevalence reported is 1 to 17.5% in preschoolers, 1 to 13.5% in 5 to 16-year-olds, and 1 to 4% in adults. About 40% of infants referred for specialist management of Gastroesophageal Reflux Disease (GERD) have CMA. This situation increases to 56% in severe cases. These allergic reactions are typically not IgE-mediated. The gold standard for GERD is the pH measurement in 24 hours (specificity 100%), exist other test more accessible, with considerable sensivity (80%) like scintigraphy.
Methods
The objective was determinate the frequency of GERD in patients with IgE-mediated CMA. We evaluated retrospectively 20 patients with IgE-mediated CMA of a group of 47 patients with food allergy between 6 months to 39 years aged. They had one or more IgE-specific to proteins that are considered major allergens: casein, beta-lactoglobulin (BLG) or alpha-lactalbumin (A-LA). All the patients had study to discard GERD, through by scintigraphy (study with more access in our Institute). Patients with CMA and negative scintigraphy, had pH measurement. We made 3 groups each one to represent the positivity of IgE-specific to major allergens and these were associated with the presence or absence of GERD.
Results
GERD was found in 80% of patient with CMA. 77.8% of patients with IgE to casein had GERD diagnosed by scintigraphy (P < 0.008) Likelihood ratio obtained for this relationship was 7; 70% of patients with IgE to A-LA have GERD (P < 0.03), the likelihood ratio was 4. No significant difference was found between the presence of IgE to BLG and GERD. Additionally, we found that 40% of patients with food allergy without CMA presented GERD.
Conclusions
We found high association between IgE-mediated CMA and evidence of GERD on Mexican people opposed to previous literature.
doi:10.1097/01.WOX.0000412200.68444.0f
PMCID: PMC3512898
23.  Epitope-specific T cell tolerance to phospholipase A2 in bee venom immunotherapy and recovery by IL-2 and IL-15 in vitro. 
Journal of Clinical Investigation  1996;98(7):1676-1683.
Bee venom phospholipase A2 (PLA) is the major allergen in bee sting allergy. It displays three peptide and a glycopeptide T cell epitopes, which are recognized by both allergic and non-allergic bee venom sensitized subjects. In this study PLA- and PLA epitope-specific T cell and cytokine responses in PBMC of bee sting allergic patients were investigated before and after 2 mo of rush immunotherapy with whole bee venom. After successful immunotherapy, PLA and T cell epitope peptide-specific T cell proliferation was suppressed. In addition the PLA- and peptide-induced secretion of type 2 (IL-4, IL-5, and IL-13), as well as type 1 (IL-2 and IFN-gamma) cytokines were abolished, whereas tetanus toxoid-induced cytokine production and proliferation remained unchanged. By culturing PBMC with Ag in the presence of IL-2 or IL-15 the specifically tolerized T cell response could be restored with respect to specific proliferation and secretion of the type 1 T cell cytokines, IL-2 and IFN-gamma. In contrast, IL-4, IL-5, and IL-13 remained suppressed. Treatment of tolerized T cells with IL-4 only partially restored proliferation and induced formation of distinct type 2 cytokine pattern. In spite of the allergen-specific tolerance in T cells, in vitro produced anti-PLA IgE and IgG4 Ab and their corresponding serum levels slightly increased during immunotherapy, while the PLA-specific IgE/IgG4 ratio changed in favor of IgG4. These findings indicate that bee venom immunotherapy induces a state of peripheral tolerance in allergen-specific T cells, but not in specific B cells. The state of T cell tolerance and cytokine pattern can be in vitro modulated by the cytokines IL-2, IL-4, and IL-15, suggesting the importance of microenvironmental cytokines leading to success or failure in immunotherapy.
PMCID: PMC507602  PMID: 8833918
24.  Correlation of IgE/IgG4 milk epitopes and affinity of milk-specific IgE antibodies with different phenotypes of clinical milk allergy 
Background
Results from large-scale epitope mapping using peptide microarray have been shown to correlate with clinical features of milk allergy.
Objectives
We sought to assess IgE and IgG4 epitope diversity and IgE affinity in different clinical phenotypes of milk allergy and identify informative epitopes that may be predictive of clinical outcomes of milk allergy.
Methods
Forty-one subjects were recruited from a larger study on the effects of ingesting heat-denatured milk proteins in milk-allergic individuals. Using food challenges, subjects were characterized as clinically reactive to all forms of milk (n = 17), tolerant to heated milk (HM) products (n = 16), or outgrown their milk allergy (n = 8). Eleven non-milk allergic, healthy volunteers served as controls. Peptide microarray was performed using the previously published protocol.
Results
Milk allergic subjects had increased epitope diversity as compared to those who outgrew their allergy. HM tolerant subjects had IgE binding patterns similar to those who had outgrown their allergy, but IgG4 binding patterns that were more similar to the allergic group. Binding to higher numbers of IgE peptides was associated with more severe allergic reactions during challenge. There was no association between IgG4 peptides and clinical features of milk allergy. Using a competitive peptide microarray assay, allergic patients demonstrated a combination of high and low affinity IgE binding whereas HM tolerant subjects and those who had outgrown their milk allergy had primarily low affinity binding.
Conclusions
Greater IgE epitope diversity and higher affinity as determined by peptide microarray were associated with clinical phenotypes and severity of milk allergy.
doi:10.1016/j.jaci.2009.12.017
PMCID: PMC2841053  PMID: 20226304
Milk allergy; Peptide microarray; IgE pitope; IgE affinity; IgG4 epitope
25.  Changes in Holstein cow milk and serum proteins during intramammary infection with three different strains of Staphylococcus aureus 
Background
Staphylococcus aureus is one of the most prevalent pathogens to cause mastitis in dairy cattle. Intramammary infection of dairy cows with S. aureus is often subclinical, due to the pathogen's ability to evade the innate defense mechanisms, but this can lead to chronic infection. A sub-population of S. aureus, known as small colony variant (SCV), displays atypical phenotypic characteristics, causes persistent infections, and is more resistant to antibiotics than parent strains. Therefore, it was hypothesized that the host immune response will be different for SCV than its parental or typical strains of S. aureus. In this study, the local and systemic immune protein responses to intramammary infection with three strains of S. aureus, including a naturally occurring bovine SCV strain (SCV Heba3231), were characterized. Serum and casein-depleted milk cytokine levels (interleukin-8, interferon-γ, and transforming growth factor-β1), as well as serum haptoglobin concentrations were monitored over time after intramammary infection with each of the three S. aureus strains. Furthermore, comparative proteomics was used to evaluate milk proteome profiles during acute and chronic phases of S. aureus intramammary infection.
Results
Serum IL-8, IFN-γ, and TGF-β1 responses differed in dairy cows challenged with different strains of S. aureus. Changes in overall serum haptoglobin concentrations were observed for each S. aureus challenge group, but there were no significant differences observed between groups. In casein-depleted milk, strain-specific differences in the host IFN-γ response were observed, but inducible IL-8 and TGF-β1 concentrations were not different between groups. Proteomic analysis of the milk following intramammary infection revealed unique host protein expression profiles that were dependent on the infecting strain as well as phase of infection. Notably, the protein, component-3 of the proteose peptone (CPP3), was differentially expressed between the S. aureus treatment groups, implicating it as a potential antimicrobial peptide involved in host defense against S. aureus intramammary infection.
Conclusions
Intramammary infection of dairy cattle with S. aureus causes an up-regulation of serum and milk immune-related proteins, and these responses vary depending on the infecting strain.
doi:10.1186/1746-6148-7-51
PMCID: PMC3179444  PMID: 21884610

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