Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder associated with allergic hypersensitivity to food. We interrogated >1.5 million genetic variants in European EoE cases and subsequently in a multi-site cohort with local and out-of-study control subjects. In addition to replication of the 5q22 locus (meta-analysis p = 1.9×10−16), we identified association at 2p23 (encoding CAPN14, p = 2.5×10−10). CAPN14 was specifically expressed in the esophagus, dynamically upregulated as a function of disease activity and genetic haplotype and after exposure of epithelial cells to IL-13, and located in an epigenetic hotspot modified by IL-13. There was enriched esophageal expression for the genes neighboring the top 208 EoE sequence variants. Multiple allergic sensitization loci were associated with EoE susceptibility (4.8×10−2 < p < 5.1×10−11). We propose a model that elucidates the tissue specific nature of EoE that involves the interplay of allergic sensitization with an EoE-specific, IL-13–inducible esophageal response involving CAPN14.
Rationale: In patients with pulmonary alveolar proteinosis (PAP) syndrome, disruption of granulocyte/macrophage colony–stimulating factor (GM-CSF) signaling is associated with pathogenic surfactant accumulation from impaired clearance in alveolar macrophages.
Objectives: The aim of this study was to overcome these barriers by using monocyte-derived induced pluripotent stem (iPS) cells to recapitulate disease-specific and normal macrophages.
Methods: We created iPS cells from two children with hereditary PAP (hPAP) caused by recessive CSF2RAR217X mutations and three normal people, differentiated them into macrophages (hPAP-iPS-Mφs and NL-iPS-Mφs, respectively), and evaluated macrophage functions with and without gene-correction to restore GM-CSF signaling in hPAP-iPS-Mφs.
Measurements and Main Results: Both hPAP and normal iPS cells had human embryonic stem cell–like morphology, expressed pluripotency markers, formed teratomas in vivo, had a normal karyotype, retained and expressed mutant or normal CSF2RA genes, respectively, and could be differentiated into macrophages with the typical morphology and phenotypic markers. Compared with normal, hPAP-iPS-Mφs had impaired GM-CSF receptor signaling and reduced GM-CSF–dependent gene expression, GM-CSF– but not M-CSF–dependent cell proliferation, surfactant clearance, and proinflammatory cytokine secretion. Restoration of GM-CSF receptor signaling corrected the surfactant clearance abnormality in hPAP-iPS-Mφs.
Conclusions: We used patient-specific iPS cells to accurately reproduce the molecular and cellular defects of alveolar macrophages that drive the pathogenesis of PAP in more than 90% of patients. These results demonstrate the critical role of GM-CSF signaling in surfactant homeostasis and PAP pathogenesis in humans and have therapeutic implications for hPAP.
alveolar macrophage; receptor; genetic disease; granulocyte-macrophage colony–stimulating factor; surfactant
Food allergy is a common condition for which there are currently no approved treatments except avoidance of the allergenic food and treatment of accidental reactions. There are several potential treatments that are under active investigation in animal and human studies, but it is not yet clear what the best approach may be. Here, we review approaches that are currently in clinical trials, including oral, sublingual, and epicutaneous immunotherapy, immunotherapy combined with anti-IgE, and Chinese herbal medicine as well as approaches that are in preclinical or early clinical investigation, including modified protein immunotherapy, adjuvants, DNA vaccines, and helminth administration. We discuss the importance of fully exploring the risks and benefits of any treatment before it is taken to general clinical practice and the need for clarity about the goals of treatment.
History and severity of atopic dermatitis (AD) are risk factors for peanut allergy. Recent evidence suggests that children can become sensitized to food allergens through an impaired skin barrier. Household peanut consumption, which correlates strongly with peanut protein levels in household dust, is a risk factor for peanut allergy.
We sought to assess whether environmental peanut exposure (EPE) is a risk for peanut sensitization and allergy and whether markers of an impaired skin barrier modify this risk.
Peanut protein in household dust (in micrograms per gram) was assessed in highly atopic children (age, 3-15 months) recruited to the Consortium of Food Allergy Research Observational Study. History and severity of AD, peanut sensitization, and likely allergy (peanut-specific IgE, ≥5 kUA/mL) were assessed at recruitment into the Consortium of Food Allergy Research study.
There was an exposure-response relationship between peanut protein levels in household dust and peanut skin prick test (SPT) sensitization and likely allergy. In the final multivariate model an increase in 4 log2 EPE units increased the odds of peanut SPT sensitization (1.71-fold; 95% CI, 1.13- to 2.59-fold; P = .01) and likely peanut allergy (PA; 2.10-fold; 95% CI, 1.20- to 3.67-fold; P < .01). The effect of EPE on peanut SPT sensitization was augmented in children with a history of AD (OR, 1.97; 95% CI, 1.26-3.09; P < .01) and augmented even further in children with a history of severe AD (OR, 2.41; 95% CI, 1.30-4.47; P < .01); the effect of EPE on PA was also augmented in children with a history of AD (OR, 2.34; 95% CI, 1.31-4.18; P < .01).
Exposure to peanut antigen in dust through an impaired skin barrier in atopically inflamed skin is a plausible route for peanut SPT sensitization and PA.
Atopic dermatitis; peanut sensitization; peanut allergy; environmental peanut exposure; dust; AD, Atopic dermatitis; CoFAR, Consortium of Food Allergy Research; EPE, Environmental peanut exposure; FLG, Filaggrin; IQR, Interquartile range; LLQ, Lower limit of quantitation; LR, Logistic regression; OR, Odds ratio; PA, Peanut allergy; sIgE, Specific IgE; SPT, Skin prick test
Food allergy is an important public health problem that affects children and adults and may be increasing in prevalence. Despite the risk of severe allergic reactions and even death, there is no current treatment for food allergy: the disease can only be managed by allergen avoidance or treatment of symptoms. The diagnosis and management of food allergy also may vary from one clinical practice setting to another. Finally, because patients frequently confuse nonallergic food reactions, such as food intolerance, with food allergies, there is an unfounded belief among the public that food allergy prevalence is higher than it truly is. In response to these concerns, the National Institute of Allergy and Infectious Diseases, working with 34 professional organizations, federal agencies, and patient advocacy groups, led the development of clinical guidelines for the diagnosis and management of food allergy. These Guidelines are intended for use by a wide variety of health care professionals, including family practice physicians, clinical specialists, and nurse practitioners. The Guidelines include a consensus definition for food allergy, discuss comorbid conditions often associated with food allergy, and focus on both IgE-mediated and non-IgE-mediated reactions to food. Topics addressed include the epidemiology, natural history, diagnosis, and management of food allergy, as well as the management of severe symptoms and anaphylaxis. These Guidelines provide 43 concise clinical recommendations and additional guidance on points of current controversy in patient management. They also identify gaps in the current scientific knowledge to be addressed through future research.
food; allergy; anaphylaxis; diagnosis; disease management; guidelines
Sensitive diagnostic tests for infectious diseases often employ nucleic acid amplification technologies (NAATs). However, most NAAT assays, including many isothermal amplification methods, require power-dependent instrumentation for incubation. For use in low resource settings (LRS), diagnostics that do not require consistent electricity supply would be ideal. Recombinase polymerase amplification (RPA) is an isothermal amplification technology that has been shown to typically work at temperatures ranging from 25–43°C, and does not require a stringent incubation temperature for optimal performance. Here we evaluate the ability to incubate an HIV-1 RPA assay, intended for use as an infant HIV diagnostic in LRS, at ambient temperatures or with a simple non-instrumented heat source. To determine the range of expected ambient temperatures in settings where an HIV-1 infant diagnostic would be of most use, a dataset of the seasonal range of daily temperatures in sub Saharan Africa was analyzed and revealed ambient temperatures as low as 10°C and rarely above 43°C. All 24 of 24 (100%) HIV-1 RPA reactions amplified when incubated for 20 minutes between 31°C and 43°C. The amplification from the HIV-1 RPA assay under investigation at temperatures was less consistent below 30°C. Thus, we developed a chemical heater to incubate HIV-1 RPA assays when ambient temperatures are between 10°C and 30°C. All 12/12 (100%) reactions amplified with chemical heat incubation from ambient temperatures of 15°C, 20°C, 25°C and 30°C. We also observed that incubation at 30 minutes improved assay performance at lower temperatures where detection was sporadic using 20 minutes incubation. We have demonstrated that incubation of the RPA HIV-1 assay via ambient temperatures or using chemical heaters yields similar results to using electrically powered devices. We propose that this RPA HIV-1 assay may not need dedicated equipment to be a highly sensitive tool to diagnose infant HIV-1 in LRS.
Oral immunotherapy; food allergy; cow's milk; long-term outcomes
Immunotherapy for peanut allergy may be limited by the risk of adverse reactions.
To investigate the safety and immunologic effects of a vaccine containing modified peanut proteins.
This was a Phase 1 trial of EMP-123, a rectally administered suspension of recombinant Ara h 1, Ara h 2 and Ara h 3, modified by amino acid substitutions at major IgE binding epitopes, encapsulated in heat/phenol killed E. coli. Five healthy adults were treated with 4 weekly escalating doses after which 10 peanut allergic adults received weekly dose escalations over 10 weeks from 10mcg to 3063mcg, followed by 3 biweekly doses of 3063 mcg.
There were no significant adverse effects in the healthy volunteers. Of the 10 peanut allergic subjects [4 with intermittent asthma, median peanut-IgE 33.3kUA/L (7.2–120.2), median peanutskin prick test wheal 11.3mm (6.5–18)], 4 experienced no symptoms, one had mild rectal symptoms, and the remaining 5 experienced adverse reactions preventing completion of dosing. Two were categorized as mild but the remaining three were more severe, including one moderate reaction and two anaphylactic reactions. Baseline peanut IgE was significantly higher in the 5 reactive subjects (median 82.4 versus 17.2kUA/L, p=0.032), as was baseline anti-Ara h 2 IgE (43.3 versus 8.3, p=0.036). Peanut skin test titration and basophil activation (at a single dilution) were significantly reduced after treatment but no significant changes were detected for total IgE, peanut IgE, or peanut IgG4.
Rectal administration of EMP-123 resulted in frequent adverse reactions, including severe allergic reactions in 20%.
Allergic transfusion reactions (ATRs) are a spectrum of hypersensitivity reactions that are the most common adverse reaction to platelets and plasma, occurring in up to 2% of transfusions. Despite the ubiquity of these reactions, little is known about their mechanism. In a small subset of severe reactions, specific antibody has been implicated as causal, although this mechanism does not explain all ATRs. Evidence suggests that donor, product, and recipient factors are involved, and it is possible that many ATRs are multi-factorial. Further understanding of the mechanisms of ATRs is necessary so that rationally designed and cost-effective prevention measures can be developed.
allergy; transfusion reaction; platelets; plasma; red cell; hypersensitivity; urticaria; pruritus
Current studies indicate that older Mexican Americans take fewer calcium or calcium/vitamin D supplements than do older non-Hispanic whites. Factors associated with calcium supplement use are not completely understood in this ethnic group.
The purpose of this article was to determine the prevalence of calcium or calcium/vitamin D supplementation and factors associated with their use in older Mexican Americans.
A cross-sectional survey was conducted in a random sample of older Mexican Americans residing in the southwestern United States who had participated in the Hispanic Established Populations for the Epidemiologic Study of the Elderly. Self-identified Mexican Americans ≥75 years of age were enrolled through household interviews in 2004–2005. Each subject was asked to bring all prescription and nonprescription medications that they had used regularly during the previous 2 weeks to allow the interviewer to record the product names. Dosages were not recorded. Subjects were assigned to 1 of 3 categories based on their use of calcium or calcium/vitamin D supplements during the previous 2 weeks: (1) calcium supplement only, (2) calcium/vitamin D supplement, or (3) vitamin D supplement only. The subjects’ sociodemographic and cultural factors, self-reported health and functional status, cognitive status, number of comorbidities, and use of antiosteoporosis medications were recorded.
A total of 2069 older Mexican Americans (1272 women, 797 men; mean age, 81.9 years) were enrolled. The overall prevalence of calcium supplement use was 10.6% (weighted). Calcium supplements were used more often by women (odds ratio [OR] = 1.76; 95% CI, 1.17–2.63), subjects with multiple comorbidities (OR = 1.29; 95% CI, 1.10–1.50), those who interviewed in English (OR = 1.59; 95% CI, 1.06–2.40), and those who used antiosteoporosis medications (OR = 3.57; 95% CI, 1.85–6.89).
Use of calcium or calcium/vitamin D supplements was low (<60%) among this group of older Mexican Americans. Men are particularly at risk. More should be done to raise awareness regarding the benefits of calcium supplementation in this ethnic group.
Mexican American; aged; calcium; supplement use
Classic ways to determine MHC restriction involve inhibition with locus specific antibodies and antigen presentation assays with panels of cell lines matched or mismatched at the various loci of interest. However, these determinations are often complicated by T-cell epitope degeneracy and promiscuity. We describe selection of 46 HLA DR, DQ and DP specificities that provide worldwide population (phenotypic) coverage of almost 90% at each locus, and account for over 66% of all genes at each locus. This panel afforded coverage of at least four HLA class II alleles in over 95% of the individuals in four study populations of diverse ethnicity from the US and South Africa. Next, a panel of single HLA class II transfected cell lines, corresponding to these 46 allelic variants was assembled, consisting of lines previously developed and 15 novel lines generated for the present study. The novel lines were validated by assessing their HLA class II expression by FACS analysis, the in vitro peptide binding activity of HLA molecules purified from the cell lines, and their antigen presenting capacity to T-cell lines of known restriction. We also show that these HLA class II transfected cell lines can be used to rapidly and unambiguously determine HLA restriction of epitopes recognized by an individual donor in a single experiment. This panel of lines will enable high throughput determination of HLA restriction, enabling better characterization of HLA class II-restricted T-cell responses and facilitating the development of HLA tetrameric staining reagents.
HLA Class II; restriction; transfectants; epitopes; population coverage; polymorphism
Treatment of oral mucositis (OM) is challenging. In order to develop and test useful treatment approaches, the development of reliable, reproducible and simpler methods than are currently available for assessment of OM is important. A Patient-Reported Oral Mucositis Symptom (PROMS) scale was assessed in patients with head and neck cancer to determine if the patient-reported OM experience, as determined by using the PROMS scale, correlate with OM assessed by clinician-based scoring tools.
Materials and Methods
Fifty patients with head and neck cancer and undergoing radiotherapy consented to participate. They were examined before cancer treatment and twice weekly during 6–7 weeks of therapy and once 4–6 weeks after therapy. Signs of OM were evaluated using the 3 clinician-based scoring tools; NCI-CTCAE v.3, the OMAS criteria and the Total VAS-OMAS. The participants' OM experiences were recorded using PROMS-questionnaires consisting of 10 questions on a visual analogue scale. Spearman rank correlation test were applied between the PROMS scale values and the clinician-determined scores. Repeated measures mixed linear models were applied to appraise the strengths of correlation at the different time points throughout the observation period.
Thirty-three participants completed all stages of the study. The participant experience of OM using the PROMS scale demonstrates good correlations (Spearman's Rho 0.65–0.78, p<0.001) with the clinician-determined scores on the group level over all time points and poor to good correlations (Spearman's Rho -0.12–0.70, p<0.001) on the group level at different time points during and after therapy. When mouth opening was problematic, i.e. during the 6th and 7th week after commencing cancer treatment, the Spearman's Rho varied between 0.19 and 0.70 (p<0.001).
Patient experience of OM, as reported by the PROMS scale may be a feasible substitute for clinical assessment in situations where patients cannot endure oral examinations.
The purpose of the current study is to describe the factors associated with Mexican American elders who have spent time in a SNF compared to those who have not in the Southwestern United States.
Data were collected on the Mexican American elders who reported a SNF stay within 10 years of baseline.
A probability sample of 3050 Mexican American elders from five Southwestern states followed from 1993 to 2005 were examined.
Variables examined included socio-demographics, language of interview, disabilities with Instrumental Activities of Daily Living (IADLs), Activities of Daily Living (ADLs), selfreported health, cognitive status and depression.
A total of 78 (3.9%) out of 2020 subjects resided in SNF’s. Using univariate analyses older age, English-language interview, poorer cognitive status, and functional disabilities were independently associated with Skilled Nursing Facility (SNF) admissions. Logistic regression analyses controlling for age reveal that SNF patients were older (OR =1.08, p=0.001), have an ADL disability (OR=4.94, p<0.001), scored in the Geriatric Depression Scale depressed range (OR=2.72, p=0.001) and were more likely to interview in English (OR=1.95, p=0.042), when compared to community counterparts.
Mexican American elders resided in a SNF at some point in the previous ten years were older and more likely to be functionally impaired. They also were more likely to prefer English as their primary language indicating they were more likely to agree to a SNF stay than their Spanish speaking counterparts.
Long Term Care; Disparities; Skilled Nursing Facilities
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.
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.
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.
Milk allergy; natural history; food allergy; IgE
Monoclonal antibodies directed at IgE demonstrate clinical efficacy in subjects with peanut allergy, but previous studies have not addressed the kinetics of the clinical response or the role of mast cells and basophils in the food-induced allergic response.
We sought to determine the kinetics of the clinical response to omalizumab and whether clinical improvement is associated with either mast cell or basophil suppression.
Subjects with peanut allergy were treated with omalizumab for 6 months and assessed for clinical and cellular responses. At baseline, subjects had a double-blind, placebo-controlled oral food challenge (OFC), skin prick test titration (SPTT), and basophil histamine release (BHR) to peanut. BHR was repeated at week 2 and then weekly until it decreased to less than 20% of baseline values. The OFCs and SPTTs were repeated after the BHR reduction (or at week 8 if BHR did not decrease) and again at 6 months.
Fourteen subjects enrolled in the study. At the second food challenge, there was a significant increase in the threshold dose of peanut inducing allergic symptoms (80 to 6500 mg, P < .01). Peanut-induced BHR was either completely suppressed (n = 5) or 10-fold more allergen was required to induce maximal BHR (n = 9), and SPTT responses were not significantly changed from baseline. After 6 months of omalizumab, further changes in the OFC threshold dose or BHR were not observed, but a significant suppression in SPTTs was identified.
The clinical response to omalizumab occurs early in treatment when the basophil, but not the mast cell, is suppressed, supporting a role for the basophil in acute food reactions.
Omalizumab; peanut allergy; oral food challenge; basophil; mast cell
Transforming growth factor–β (TGFβ) is a multifunctional cytokine that plays diverse roles in physiologic processes as well as human disease, including cancer, heart disease, and fibrotic disorders. In the immune system, TGFβ regulates regulatory T cell (Treg) maturation and immune homeostasis. Although genetic manipulation of the TGFβ pathway modulates immune tolerance in mouse models, the contribution of this pathway to human allergic phenotypes is not well understood. We demonstrate that patients with Loeys-Dietz syndrome (LDS), an autosomal dominant disorder caused by mutations in the genes encoding receptor subunits for TGFβ, TGFBR1 and TGFBR2, are strongly predisposed to develop allergic disease, including asthma, food allergy, eczema, allergic rhinitis, and eosinophilic gastrointestinal disease. LDS patients exhibited elevated immunoglobulin E levels, eosinophil counts, and T helper 2 (TH2) cytokines in their plasma. They had an increased frequency of CD4+ T cells that expressed both Foxp3 and interleukin-13, but retained the ability to suppress effector T cell proliferation. TH2 cytokine–producing cells accumulated in cultures of naïve CD4+ T cells from LDS subjects, but not controls, after stimulation with TGFβ, suggesting that LDS mutations support TH2 skewing in naïve lymphocytes in a cell-autonomous manner. The monogenic nature of LDS demonstrates that altered TGFβ signaling can predispose to allergic phenotypes in humans and underscores a prominent role for TGFβ in directing immune responses to antigens present in the environment and foods. This paradigm may be relevant to nonsyndromic presentations of allergic disease and highlights the potential therapeutic benefit of strategies that inhibit TGFβ signaling.
There are presently no available therapeutic options for peanut-allergic patients.
To investigate the safety, efficacy, and immunologic effects of peanut sublingual immunotherapy (SLIT).
After a baseline oral food challenge (OFC) of up to 2g of peanut powder (~50% protein) (median successfully consumed dose [SCD] 46mg), 40 subjects, aged 12–37 (median 15) years, were randomized 1:1 across 5 sites to daily peanut or placebo SLIT. A 5g OFC was performed after 44 weeks followed by unblinding; placebo subjects then crossed over to higher dose peanut SLIT, followed by a subsequent crossover Week 44 5g OFC. Week 44 OFCs from both groups were compared to baseline OFCs; subjects successfully consuming 5g or at least 10-fold more peanut powder than the baseline OFC threshold were considered responders.
After 44 weeks of SLIT, 14/20 (70%) subjects receiving peanut SLIT were responders compared to 3/20 (15%) subjects receiving placebo (p<0.001). In peanut-SLIT responders, median SCD increased from 3.5mg to 496mg. After 68 weeks of SLIT, median SCD significantly increased to 996mg (compared to week 44, p=0.05). The median SCD at the Week 44 crossover OFC was significantly higher than baseline (603mg vs 71mg; p=0.02). 7/16 (44%) crossover subjects were responders; median SCD increased from 21mg to 496mg among responders. Of 10,855 peanut doses through Week 44 OFCs, 63.1% were symptom-free; excluding oral/pharyngeal symptoms, 95.2% were symptom-free.
Peanut SLIT safely induced a modest level of desensitization in a majority of subjects compared to placebo. Longer duration of therapy showed statistically significant increases in the SCD.
peanut allergy; sublingual immunotherapy; desensitization; food allergy
A novel robotic sensor is proposed to measure both the contact angle and the force acting between the tip of a surgical robot and soft tissue. The sensor is manufactured using a planar lithography process that generates microchannels that are subsequently filled with a conductive liquid. The planar geometry is then molded onto a hemispherical plastic scaffolding in a geometric configuration enabling estimation of the contact angle (angle between robot tip tangent and tissue surface normal) by the rotation of the sensor around its roll axis. Contact force can also be estimated by monitoring the changes in resistance in each microchannel. Bench top experimental results indicate that, on average, the sensor can estimate the angle of contact to within ±2° and the contact force to within ±5.3 g.
Background. The risk of developing childhood asthma
has been linked to the severity and etiology of viral respiratory illnesses in early
childhood. Since inner-city infants have unique environmental exposures, we hypothesized
that patterns of respiratory viral infections would also be distinct.
Methods. We compared the viral etiology of respiratory
illnesses in 2 groups: a cohort of 515 infants from 4 inner-city areas and a cohort of 285
infants from mainly suburban Madison, Wisconsin. Nasal secretions were sampled during
periods of respiratory illness and at 1 year of age and were analyzed for viral pathogens
by multiplex polymerase chain reaction.
Results. Overall, inner-city infants had lower rates
of viral detection. Considering specific viruses, sick urban infants had lower rates of
detectable rhinovirus or respiratory syncytial virus infection and higher rates of
adenovirus infection. Every urban site had a higher proportion of adenovirus-positive
samples associated with illnesses (10%–21%), compared with Madison
Conclusions. These findings provide evidence that
inner-city babies have different patterns of viral respiratory illnesses than babies who
grow up in a more suburban location. These findings raise important questions about the
etiology of virus-negative illnesses in urban infants and the possibility of long-term
consequences of early life infections with adenovirus in this population.