We compared the relative efficacies against simian immunodeficiency virus (SIV) challenge of three vaccine regimens that elicited similar frequencies of SIV-specific CD4+ and CD8+ T-cell responses but differed in the level of antibody responses to the gp120 envelope protein. All macaques were primed with DNA plasmids expressing SIV gag, pol, env, and Retanef genes and were boosted with recombinant modified vaccinia Ankara virus (MVA) expressing the same genes, either once (1 × MVA) or twice (2 × MVA), or were boosted once with MVA followed by a single boost with replication-competent adenovirus (Ad) type 5 host range mutant (Ad5 h) expressing SIV gag and nef genes but not Retanef or env (1 × MVA/Ad5). While two of the vaccine regimens (1 × MVA and 1 × MVA/Ad5) protected from high levels of SIV replication only during the acute phase of infection, the 2 × MVA regimen, with the highest anti-SIV gp120 titers, protected during the acute phase and transiently during the chronic phase of infection. Mamu-A*01 macaques of this third group exhibited persistent Gag CD8+CM9+ effector memory T cells with low expression of surface Programmed death-1 (PD-1) receptor and high levels of expression of genes associated with major histocompatibility complex class I (MHC-I) and MHC-II antigen. The fact that control of SIV replication was associated with both high titers of antibodies to the SIV envelope protein and durable effector SIV-specific CD8+ T cells suggests the hypothesis that the presence of antibodies at the time of challenge may increase innate immune recruiting activity by enhancing antigen uptake and may result in improvement of the quality and potency of secondary SIV-specific CD8+ T-cell responses.
Patients carrying two loss-of-function (or hypomorphic) alleles of STAT1 are vulnerable to intracellular bacterial and viral diseases. Heterozygosity for loss-of-function dominant-negative mutations in STAT1 is responsible for autosomal dominant (AD) Mendelian susceptibility to mycobacterial disease (MSMD), whereas heterozygosity for gain-of-function loss-of-dephosphorylation mutations causes AD chronic mucocutaneous candidiasis (CMC). The two previously reported types of AD MSMD-causing STAT1 mutations are located in the tail domain (p.L706S) or in the DNA-binding domain (p.E320Q and p.Q463H), whereas the AD CMC-causing mutations are located in the coiled-coil domain. We identified two cases with AD-STAT1 deficiency in two unrelated patients from Japan and Saudi Arabia carrying heterozygous missense mutations affecting the SH2 domain (p.K637E and p.K673R). p.K673R is a hypomorphic mutation that impairs STAT1 tyrosine phosphorylation, whereas the p.K637E mutation is null and affects both STAT1 phosphorylation and DNA-binding activity. Both alleles are dominant-negative and result in impaired STAT1-mediated cellular responses to IFN-γ and IL-27. By contrast, STAT1-mediated cellular responses against IFN-α and IFN-λ1 were preserved at normal levels in patients’ cells. We describe here the first dominant mutations in the SH2 domain of STAT1, revealing the importance of this domain for tyrosine phosphorylation and DNA-binding, as well as for anti-mycobacterial immunity.
MSMD; STAT1; osteomyelitis; dominant-negative effect
Glucuronidation is an important phase II pathway responsible for the metabolism of many endogenous substances and drugs to less toxic metabolites, which undergo renal excretion. The aim of the current work was to evaluate genotype and allele frequencies of certain UDP-glucuronosyltransferase 1A1 (UGT1A1) variants in an Arab population.
Material and methods
Genomic DNA was isolated from 192 healthy unrelated Saudi males of various geographic regions and genotyping of UGT1A1*6, *27, *36, *28, *37, and *60 was carried out using polymerase chain reaction (PCR) amplification followed by direct sequencing.
The most common allele for (TA) repeats was the wild type (TA)6 with a frequency of 74.3% followed by the mutant (TA)7 (i.e., UGT1A1*28) with a frequency of 25.7%. The distribution of UGT1A1*60 allele was 62.4% among subjects with the homozygous mutant genotype of 35.4%, while the wild type variant represents 10.6% only. Both UGT1A1*6 and *27 were not detected as all screened subjects showed a homozygous wild type pattern. Similarly, UGT1A1*36* and *37 were either not present or rarely found, respectively. In comparison to other populations, the frequency of UGT1A1*60 and *28 in the studied population was less than that of African Americans but higher than Asians. The geographical origin of the study subjects also implied some differences in genotype distribution of (TA) repeats and UGT1A1*60.
Our data indicate that Saudis harbor some important UGT1A1 mutations known to affect enzyme activity. Additional studies are warranted to assess the clinical implications of these gene polymorphisms in this ethnic group.
glucuronidation; UDP-glucuronosyltransferase 1A1; gene polymorphism; Saudi Arabians
Clinical immunology has traditionally relied on accurate phenotyping of the patient’s immune dysfunction for the identification of a candidate gene or genes for sequencing and molecular confirmation. Although this is also true for other branches of medicine, the marked variability in immune-related phenotypes and the highly complex network of molecules that confer normal host immunity are challenges that clinical immunologists often face in their quest to establish a specific genetic diagnosis.
We sought to identify the underlying genetic cause in a consanguineous family with chronic inflammatory bowel disease–like disorder and combined immunodeficiency.
We performed exome sequencing followed by autozygome filtration.
A truncating mutation in LPS-responsive beige-like anchor (LRBA), which abolished protein expression, was identified as the most likely candidate variant in this family.
The combined exome sequencing and autozygosity mapping approach is a powerful tool in the study of atypical immune dysfunctions. We identify LRBA as a novel immunodeficiency candidate gene the precise role of which in the immune system requires future studies.
LPS-responsive beige-like anchor (LRBA); chronic diarrhea; common variable immunodeficiency; autoimmunity
In the course of primary infection with herpes simplex virus 1 (HSV-1), children with inborn errors of TLR3 immunity are prone to HSV-1 encephalitis (HSE) 1–3. We tested the hypothesis that the pathogenesis of HSE involves non hematopoietic central nervous system (CNS)-resident cells. We derived induced pluripotent stem cells (iPSCs) from the dermal fibroblasts of TLR3- and UNC-93B-deficient patients and from controls. These iPSCs were differentiated into highly purified populations of neural stem cells (NSCs), neurons, astrocytes and oligodendrocytes. The induction of IFN-β and/or IFN-γ1 in response to poly(I:C) stimulation was dependent on TLR3 and UNC-93B in all cells tested. However, the induction of IFN-β and IFN-γ1 in response to HSV-1 infection was impaired selectively in UNC-93B-deficient neurons and oligodendrocytes. These cells were also much more susceptible to HSV-1 infection than control cells, whereas UNC-93B-deficient NSCs and astrocytes were not. TLR3-deficient neurons were also found to be susceptible to HSV-1 infection. The rescue of UNC-93B- and TLR3-deficient cells with the corresponding wild-type allele demonstrated that the genetic defect was the cause of the poly(I:C) and HSV-1 phenotypes. The viral infection phenotype was further rescued by treatment with exogenous IFN-α/β, but not IFN-γ1.Thus, impaired TLR3- and UNC-93B-dependent IFN-α/β intrinsic immunity to HSV-1 in the CNS, in neurons and oligodendrocytes in particular, may underlie the pathogenesis of HSE in children with TLR3 pathway deficiencies.
Subepithelial fibrosis is one of the most critical structural changes affecting bronchial airway function during asthma. Eosinophils have been shown to contribute to the production of pro-fibrotic cytokines, TGF-β and IL-11, however, the mechanism regulating this process is not fully understood.
In this report, we investigated whether cytokines associated with inflammation during asthma may induce eosinophils to produce pro-fibrotic cytokines.
Eosinophils were isolated from peripheral blood of 10 asthmatics and 10 normal control subjects. Eosinophils were stimulated with Th1, Th2 and Th17 cytokines and the production of TGF-β and IL-11 was determined using real time PCR and ELISA assays.
The basal expression levels of eosinophil derived TGF-β and IL-11 cytokines were comparable between asthmatic and healthy individuals. Stimulating eosinophils with Th1 and Th2 cytokines did not induce expression of pro-fibrotic cytokines. However, stimulating eosinophils with Th17 cytokines resulted in the enhancement of TGF-β and IL-11 expression in asthmatic but not healthy individuals. This effect of IL-17 on eosinophils was dependent on p38 MAPK activation as inhibiting the phosphorylation of p38 MAPK, but not other kinases, inhibited IL-17 induced pro-fibrotic cytokine release.
Th17 cytokines might contribute to airway fibrosis during asthma by enhancing production of eosinophil derived pro-fibrotic cytokines. Preventing the release of pro-fibrotic cytokines by blocking the effect of Th17 cytokines on eosinophils may prove to be beneficial in controlling fibrosis for disorders with IL-17 driven inflammation such as allergic and autoimmune diseases.
Asthma; Eosinophils; Th17 cytokines; Pro-fibrotic cytokines; TGF-β; IL-11
Acute asthma attacks remain a frequent cause of emergency department (ED) visits and hospital admission. Many factors encourage patients to seek asthma treatment at the emergency department. These factors may be related to the patient himself or to a health system that hinders asthma control. The aim of this study was to identify the main factors that lead to the frequent admission of asthmatic patients to the ED.
A cross-sectional survey of all the patients who visited the emergency room with bronchial asthma attacks over a 9-month period was undertaken at two major academic hospitals. The following data were collected: demographic data, asthma control in the preceding month, where and by whom the patients were treated, whether the patient received education about asthma or its medication and the patients’ reasons for visiting the ED.
Four hundred fifty (N = 450) patients were recruited, 39.1% of whom were males with a mean age of 42.3 ± 16.7. The mean duration of asthma was 155.90 ± 127.13 weeks. Approximately half of the patients did not receive any information about bronchial asthma as a disease, and 40.7% did not receive any education regarding how to use asthma medication. Asthma was not controlled or partially controlled in the majority (97.7%) of the patients preceding the admission to ED. The majority of the patients visited the ED to receive a bronchodilator by nebuliser (86.7%) and to obtain oxygen (75.1%). Moreover, 20.9% of the patients believed that the ED managed them faster than the clinic, and 21.1% claimed that their symptoms were severe enough that they could not wait for a clinic visit. No education about asthma and uncontrolled asthma are the major factors leading to frequent ED visits (three or more visits/year), p-value = 0.0145 and p-value = 0.0003, respectively. Asthma control also exhibited a significant relationship with inhaled corticosteroid ICS use (p-value =0.0401) and education about asthma (p-value =0.0117).
This study demonstrates that many avoidable risk factors lead to uncontrolled asthma and frequent ED visits.
Asthma; Control; Inhaled cortisone; Emergency department
Inhaled corticosteroids represent the most common treatment for asthma. Although most asthmatic patients respond well, a significant proportion of severe asthmatics require higher doses or even fail to respond to oral or inhaled corticosteroids. We previously reported that glucocorticoid receptor-beta is associated with corticosteroid resistance in airway epithelial cells from asthmatic patients and that Th-17 cytokines increase steroid insensitivity via a mechanism involving GR-beta upregulation. We aim to investigate whether IL-17A and F cytokines enhance steroid unresponsiveness in PBMCs from normal subjects and severe asthmatics via the upregulation of GR-beta isoform.
PBMCs were cultured for 48 hours in the presence or absence of IL-2, IL-4, IL-17A, IL-17F or IL-23 cytokines. Expression of GR-alpha, GR-beta, GILZ and IL-6 was determined using Q-RT-PCR and/or Western blotting. Response to Dexamethasone was determined on the inhibition of PHA-induced proliferation by Dexamethasone (IC50) using either 3H-thymidine or CFSE-labelled cells. Response of the cells to Dexamethasone-induced apoptosis was determined by Annexin-V staining.
Treatment of PBMCs with IL-17A+IL-17F combined significantly decreased the mRNA expression of GR-alpha while that of GR-beta was significantly upregulated. IL-2+IL-4 in combination significantly decreased GR-alpha expression but had no effect on GR-beta receptor expression. IL17A+IL17F+IL23 combined induced the highest ratio of GR-beta/GR-alpha in PBMC from normal subjects. Either IL-17A+F or IL-2+IL-4 combinations significantly decreased the inhibitory effect of Dexamethasone on PBMC proliferation (IL-17A+F IC50 = 190 nM Dex; IL-2+4 IC50 = 1060 nM Dex), when compared to the control without cytokine stimulation. In the presence of Dexamethasone, IL-2+IL-4 but not IL-17A+IL-17F, inhibited the expression of the glucocorticoid-inducible leucine zipper gene (GILZ) in PBMCs from both normal (60%) and asthmatics (45–50%), which was correlated with significantly higher apoptosis in cells stimulated with IL-2+IL-4.
IL-17A, IL-17F, IL-2, and IL-4, which are known to be upregulated in the blood and lung tissue of asthmatics, contribute to steroid insensitivity of severe asthmatic patients by modulating the expression of GR-alpha and GR-beta receptors on peripheral blood PBMCs. GR-beta could protect PBMCs from Dex-induced apoptosis. Furthermore, the increased GR-beta/GR-alpha ratios by both IL-17A+F and IL-2+4 cytokines correlates with the decreased inhibitory effect of Dexamethasone on PHA-induced PBMC proliferation.
B lymphocytes are known to be important cytokine sources in inflammation and play a pathogenic role by producing autoantibodies in a number of chronic immunological diseases. However, B cell depletion therapy induced an exacerbation of symptoms in some patients with autoimmune disorders, revealing that B cells play a critical anti-inflammatory role mediated by IL-10 release. We therefore investigated the human B cell regulatory subset producing IL-10 in response to stimulation.
Highly purified B cells were obtained from tonsils by using a multiple-step separation procedure which included rosette depletion, adherence depletion, CD3+ cell magnetic-activated depletion and CD19+ magnetic-activated positive cell selection. CD20+ purity was verified by flow cytometry. The CD19+CD20+ B cells were stimulated with CpG oligonucleotide, IL-4, IFN-gamma, anti-CD40, IL-17A and IL-17F, either alone or in combination. The expression of both IL-6 and IL-10 mRNA was analyzed by quantitative RT-PCR and by ELISA. B regulatory cell subsets expressing IL-10 and the markers CD5 and CD1d were quantified by FACS analysis. B cell proliferation was determined by 3H thymidine incorporation or CFSE labeling.
Expression of IL-10 mRNA and protein in purified B cells from tonsils was weakly stimulated by anti-CD40 antibody, CpG oligonucleotide or with IL-17. When B cells were simultaneously stimulated with IL-17, anti-CD40 antibody and CpG oligonucleotide, the mRNA and protein expression of IL-10 was strongly increased (n = 3; P ≤ 0.001). B cells proliferation was also significantly increased. In contrast, stimulation with IL-4 alone or in combination with anti-CD40 antibody, decreased the expression of IL-10 (n = 3; P ≤ 0.001).
TLR9 receptor stimulation synergizes with CD40 and IL-17 receptors stimulation in the induced proliferation and potent release of IL-10 cytokine while decreasing IL-6 production in B cells. These novel findings provide evidence that B lymphocytes might be an important source of the anti-inflammatory IL-10 cytokine, and provide novel evidence that stimulation of B lymphocytes with IL-17 cytokine could be an important regulatory mechanism in immune responses.
Asthma is a chronic inflammatory disorder of the lung airways that is associated with airway remodeling and hyperresponsiveness. Its is well documented that the smooth muscle mass in asthmatic airways is increased due to hypertrophy and hyperplasia of the ASM cells. Moreover, eosinophils have been proposed in different studies to play a major role in airway remodeling. Here, we hypothesized that eosinophils modulate the airways through enhancing ASM cell proliferation. The aim of this study is to examine the effect of eosinophils on ASM cell proliferation using eosinophils isolated from asthmatic and normal control subjects.
Eosinophils were isolated from peripheral blood of 6 mild asthmatics and 6 normal control subjects. ASM cells were incubated with eosinophils or eosinophil membranes and ASM proliferation was estimated using thymidine incorporation. The mRNA expression of extracellular matrix (ECM) in ASM cells was measured using quantitative real-time PCR. The effect of eosinophil-derived proliferative cytokines on ASM cells was determined using neutralizing antibodies. The role of eosinophil derived Cysteinyl Leukotrienes in enhancing ASM was also investigated.
Co-culture with eosinophils significantly increased ASM cell proliferation. However, there was no significant difference in ASM proliferation following incubation with eosinophils from asthmatic versus normal control subjects. Co-culture with eosinophil membranes had no effect on ASM proliferation. Moreover, there was no significant change in the mRNA expression of ECM proteins in ASM cells following co-culture with eosinophils when compared with medium alone. Interestingly, blocking the activity of cysteinyl Leukotries using antagonists inhibited eosinophil-derived ASM proliferation.
Eosinophils enhances the proliferation of ASM cells. This role of eosinophil does not seem to depend on ASM derived ECM proteins nor on Eosinophil derived TGF-β or TNF-α. Eosinophil seems to induce ASM proliferation via the secretion of Cysteinyl Leukotrienes.
Interleukin-12 receptor β1 (IL-12Rβ1) deficiency is the most common form of Mendelian susceptibility to mycobacterial disease (MSMD). We undertook an international survey of 141 patients from 102 kindreds in 30 countries. Among 102 probands, the first infection occurred at a mean age of 2.4 years. In 78 patients, this infection was caused by Bacille Calmette-Guérin (BCG; n = 65), environmental mycobacteria (EM; also known as atypical or nontuberculous mycobacteria) (n = 9) or Mycobacterium tuberculosis (n = 4). Twenty-two of the remaining 24 probands initially presented with nontyphoidal, extraintestinal salmonellosis. Twenty of the 29 genetically affected sibs displayed clinical signs (69%); however 8 remained asymptomatic (27%). Nine nongenotyped sibs with symptoms died. Recurrent BCG infection was diagnosed in 15 cases, recurrent EM in 3 cases, recurrent salmonellosis in 22 patients. Ninety of the 132 symptomatic patients had infections with a single microorganism. Multiple infections were diagnosed in 40 cases, with combined mycobacteriosis and salmonellosis in 36 individuals. BCG disease strongly protected against subsequent EM disease (p = 0.00008). Various other infectious diseases occurred, albeit each rarely, yet candidiasis was reported in 33 of the patients (23%). Ninety-nine patients (70%) survived, with a mean age at last follow-up visit of 12.7 years ± 9.8 years (range, 0.5-46.4 yr). IL-12Rβ1 deficiency is characterized by childhood-onset mycobacteriosis and salmonellosis, rare recurrences of mycobacterial disease, and more frequent recurrence of salmonellosis. The condition has higher clinical penetrance, broader susceptibility to infections, and less favorable outcome than previously thought.
BACKGROUND AND OBJECTIVES:
Human metapneumovirus (hMPV) and the Netherlands human coronavirus (HCoV-NL63) have been isolated from children with respiratory tract infection. The prevalence of these viruses has not been reported from Saudi Arabia. We sought to determine whether hMPV and HCoV-NL63 are responsible for acute respiratory illness and also to determine clinical features and severity of illness in the hospitalized pediatric patient population.
DESIGN AND SETTING:
Prospective hospital-based study from July 2007 to November 2008.
PATIENTS AND METHODS:
Nasopharyngeal specimens from children less than 16 years old who were suffering from acute respiratory diseases were tested for hMPV and HCoV-NL63 by reverse transcriptase–polymerase chain reaction. Samples were collected from July 2007 to November 2008.
Both viruses were found among Saudi children with upper and lower respiratory tract diseases during the autumn and winter of 2007 and 2008, contributing to 11.1% of all viral diagnoses, with individual incidences of 8.3% (hMPV) and 2.8% (HCoV-NL63) among 489 specimens. Initial symptoms included fever, cough, and nasal congestion. Lower respiratory tract disease occurs in immunocompromised individuals and those with underlying conditions. Clinical findings of respiratory failure and culture-negative shock were established in 7 children infected with hMPV and having hematologic malignancies, myelofibrosis, Gaucher disease, and congenital immunodeficiency; 2 of the 7 patients died with acute respiratory failure. All children infected with HCoV-NL63 had underlying conditions; 1 of the 4 patients developed respiratory failure.
hMPV and HCoV-NL63 are important causes of acute respiratory illness among hospitalized Saudi children. hMPV infection in the lower respiratory tract is associated with morbidity and mortality in immunocompromised children. HCoV-NL63 may cause severe lower respiratory disease with underlying conditions.
Chronic mucocutaneous candidiasis disease (CMCD) is characterized by recurrent or persistent infections of the skin, nails, oral and genital mucosae caused by Candida albicans and, to a lesser extent, Staphylococcus aureus, in patients with no other infectious or autoimmune manifestations. We report two genetic etiologies of CMCD: autosomal recessive deficiency in the cytokine receptor, interleukin-17 receptor A (IL-17RA), and autosomal dominant deficiency of the cytokine IL-17F. IL-17RA deficiency is complete, abolishing cellular responses to IL-17A and IL-17F homo- and heterodimers. By contrast, IL-17-F deficiency is partial, with mutant IL-17F-containing homo- and heterodimers displaying impaired, but not abolished activity. These experiments of nature indicate that human IL-17A and IL-17F are essential for mucocutaneous immunity against C. albicans, but otherwise largely redundant.
IFN-γ has been used in the treatment of IL-12Rβ1 deficiency patients with disseminated BCG infection (BCGosis), but the optimal dose to reach efficacy is not clear. We used IFN-γ in the treatment of a 2.7-year-old patient with IL-12Rβ1 deficiency and refractory BCG-osis. IFNγ was started at a dose of 50 μg/m2 3 times per week. The dose was upgraded to 100 mcg/m2 after 3 months, then to 200 mcg/m2 6 months afterwards. Serum mycobactericidal activity and lymphocytes number and function were evaluated throughout the study. There was no clinical response to IFN-γ with 50 or 100 μg/m2 doses. However, there was some response to the 200 μg/m2 dose with no additional adverse effects. The serum mycobactericidal activity was not significantly different during the whole treatment period. Lymphocytes proliferation in response to PHA was significantly higher after 3 months of using the highest dose as compared to the lowest dose. The tuberculin skin test reaction remained persistently negative. We conclude that in a patient with IL-12Rβ1 deficiency, IFN-γ at a dose of 200 μg/m2, but not at lower dosages, was found to have a noticeable clinical effect with no additional adverse effects.
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disorder caused by mutations in the autoimmune regulator gene (AIRE). Terminal 4q deletion is also a rare cytogenetic abnormality that causes a variable syndrome of dysmorphic features, mental retardation, growth retardation, and heart and limb defects. We report a 12-year-old Saudi boy with mucocutaneous candidiasis, hypoparathyroidism, and adrenocortical failure consistent with APECED. In addition, he has dysmorphic facial features, growth retardation, and severe global developmental delay. Patient had late development of chronic renal failure. The blastogenesis revealed depressed lymphocytes' response to Candida albicans at 38% when compared to control. Chromosome analysis of the patient revealed 46,XY,del(4)(q33). FISH using a 4p/4q subtelomere DNA probe assay confirmed the deletion of qter subtelomere on chromosome 4. Parental chromosomes were normal. The deleted array was further defined using array CGH. AIRE full gene sequencing revealed a homozygous mutation namely 845_846insC. Renal biopsy revealed chronic interstitial nephritis with advanced fibrosis. In addition, there was mesangial deposition of C3, C1q, and IgM. This is, to the best of our knowledge, the first paper showing evidence of autoimmune nephropathy by renal immunofluorescence in a patient with APECED and terminal 4q deletion.
Most patients with autoimmune polyendocrine syndrome type I (APS-I) display chronic mucocutaneous candidiasis (CMC). We hypothesized that this CMC might result from autoimmunity to interleukin (IL)-17 cytokines. We found high titers of autoantibodies (auto-Abs) against IL-17A, IL-17F, and/or IL-22 in the sera of all 33 patients tested, as detected by multiplex particle-based flow cytometry. The auto-Abs against IL-17A, IL-17F, and IL-22 were specific in the five patients tested, as shown by Western blotting. The auto-Abs against IL-17A were neutralizing in the only patient tested, as shown by bioassays of IL-17A activity. None of the 37 healthy controls and none of the 103 patients with other autoimmune disorders tested had such auto-Abs. None of the patients with APS-I had auto-Abs against cytokines previously shown to cause other well-defined clinical syndromes in other patients (IL-6, interferon [IFN]-γ, or granulocyte/macrophage colony-stimulating factor) or against other cytokines (IL-1β, IL-10, IL-12, IL-18, IL-21, IL-23, IL-26, IFN-β, tumor necrosis factor [α], or transforming growth factor β). These findings suggest that auto-Abs against IL-17A, IL-17F, and IL-22 may cause CMC in patients with APS-I.
Severe combined immunodeficiency (SCID) is a primary immunodeficiency disorder with heterogenous genetic etiologies. We describe a typical case in a 9-year-old boy that was masked by a clinically functional maternal T cell engraftment leading to late presentation with Pneumocystis jiroveci pneumonia and cytomegalovirus infection, probably following exhaustion of maternally engrafted cells. Based on immunological findings, he had a T- B+SCID phenotype. This report suggests that in rare cases, engrafted maternal T cell might persist for long time leading to partial constitution of immune function and delayed clinical presentation of SCID.
Primary immune deficiency diseases (PIDs) are a heterogeneous group of inherited diseases characterized by variable genetic immune defects, conferring susceptibility to recurrent infections. They have a vast array of manifestations some of which involve the gastrointestinal and hepatobiliary systems. These complications can be the consequence of five different factors, namely, infection, autoimmune process, unregulated inflammation, malignancies and complications of therapeutic intervention. They may precede the PID diagnosis and, once developed, they pose high risk of morbidity. Untrained clinicians may treat these manifestations only at the level of their presentation, leaving the PIDs dangerously undiagnosed. In fact, early diagnosis of PIDs and accompanied gastrointestinal and hepatic complications clearly require appropriate treatment, and in-turn lead to an improved quality of life for the patient. To improve the awareness of gastroenterologists and related health care providers about these diseases, we have reviewed herein the complications of different PIDs focusing on gastrointestinal and hepatic manifestation.
Chronic granulomatous disease; colitis; common variable immunodeficiency; gastrointestinal manifestation; hepatic involvement; primary immune deficiency diseases; Saudi Arabia
Children with Severe Combined Immunodeficiency (SCID) lack autologous T lymphocytes and present with multiple infections early in infancy. Omenn syndrome is characterized by the sole emergence of oligoclonal auto-reactive T lymphocytes, resulting in erythroderma and enteropathy. Omenn syndrome (OS) shares the genetic aetiology of T-B-NK+ SCID, with mutations in RAG1, RAG2, or DCLRE1C.
Patients diagnosed with T-B-NK+ SCID or phenotypes suggestive of Omenn syndrome were investigated by molecular genetic studies using gene tightly linked microsatellite markers followed by direct sequencing of the coding regions and splice sites of the respective candidate genes.
We report the molecular genetic basis of T-B-NK+ SCID in 22 patients and of OS in seven patients all of Arab descent from Saudi Arabia. Among the SCID patients, six (from four families) displayed four homozygous missense mutations in RAG1 including V433M, R624H, R394W, and R559S. Another four patients (from three familes) showed 3 novel homozygous RAG2 mutations including K127X, S18X, and Q4X; all of which predict unique premature truncations of RAG2 protein. Among Omenn patients, four (from two families) have S401P and R396H mutations in RAG1, and a fifth patient has a novel I444M mutation in RAG2. Seven other patients (six SCID and one OS) showed a gross deletion in exons 1-3 in DCLRE1C. Altogether, mutations in RAG1/2 and DCLRE1C account for around 50% and 25%, respectively, in our study cohort, a proportion much higher than in previous reported series. Seven (24%) patients lack a known genetic aetiology, strongly suggesting that they carry mutations in novel genes associated with SCID and Omenn disorders that are yet to be discovered in the Saudi population.
Mutation-free patients who lack a known genetic aetiology are likely to carry mutations in the regulatory elements in the SCID-causing genes or in novel genes that are yet to be discovered. Our efforts are underway to investigate this possibility by applying the whole genome scans on these cases via the use of Affymetrix high density DNA SNP chips in addition to homozygosity mapping.
A 10- year-old female, known to have bronchial asthma, presented with an unusual laryngeal lesion, eventually diagnosed as Churg-Strauss syndrome (CSS). She was referred to our hospital with history of recurrent stridor. On endoscopyhe, the larynx showed signs similar to recurrent respiratory papillomatosis (RRP). CSS is a systemic disorder and is now defined as one of the ANCA (antineutrophil cytoplasmic antibodies)-associated vasculitides. CSS is a systemic disease that may involve unusual sites like the larynx. Such an unusual presenatation of CSS should be kept in mind, especially in patients with history of asthma.
PEANUT ALLERGY ACCOUNTS FOR THE MAJORITY of severe food-related allergic reactions. It tends to present early in life, and affected individuals generally do not outgrow it. In highly sensitized people, trace quantities can induce an allergic reaction. In this review, we will discuss the prevalence, clinical characteristics, diagnosis, natural history and management of peanut allergy.
Uncontrolled asthma remains a frequent cause of emergency department (ED) visits and hospital admissions. Improper asthma inhaler device use is most likely one of the major causes associated with uncontrolled asthma and frequent ED visits.
To evaluate the inhaler technique among asthmatic patients seen in ED, and to investigate the characteristics of these patients and factors associated with improper use of inhaler devices and its relationship with asthma control and ED visits.
A cross-sectional study of all the patients who visited the ED with bronchial asthma attacks over a 9-month period was undertaken at two major academic hospitals in Saudi Arabia. Information was collected about demographic data and asthma management and we assessed the inhaler techniques for each patient using an inhaler technique checklist.
A total of 450 asthma patients were included in the study. Of these, 176(39.1%) were males with a mean age of 42.3 ±16.7 years and the mean duration of asthma was 155.9 ± 127.1 weeks. The improper use of asthma inhaler devices was observed in 203(45%) of the patients and was associated with irregular clinic follow-ups (p = 0.0001), lack of asthma education (p = 0.0009), uncontrolled asthma ACT (score ≤ 15) (p = 0.001), three or more ED visits (p = 0.0497), and duration of asthma of less than 52 weeks (p = 0.005). Multiple logistic regression analysis revealed that a lack of education about asthma disease (OR =1.65; 95% CI: 1.07, 2.54) or a lack of regular follow-up (OR =1.73; 95% CI: 1.08, 2.76) was more likely to lead to the improper use of an asthma inhaler device.
Improper asthma inhaler device use is associated with poor asthma control and more frequent ED visits. We also identified many avoidable risk factors leading to the improper use of inhaler devices among asthma patients visiting the ED.
Asthma control; Inhaled corticosteroid; Emergency department; Inhaler devices; Asthma education
ISG15 is an interferon (IFN)-α/β-inducible, ubiquitin-like intracellular protein. Its conjugation to various proteins (ISGylation) contributes to antiviral immunity in mice. We describe human patients with inherited ISG15 deficiency and mycobacterial, but not viral diseases. The lack of intracellular ISG15 production and protein ISGylation was not associated with cellular susceptibility to any viruses tested, consistent with the lack of viral diseases in these patients. By contrast, the lack of mycobacterium-induced ISG15 secretion by leukocytes — granulocytes in particular — reduced the production of IFN-γ by lymphocytes, including natural killer cells, probably accounting for the enhanced susceptibility to mycobacterial disease. This experiment of Nature shows that human ISGylation is largely redundant for antiviral immunity, but that ISG15 plays an essential role as an IFN-γ-inducing secreted molecule for optimal antimycobacterial immunity.