Prevalence of tissue transglutaminase antibodies and IgA deficiency are not increased in juvenile idiopathic arthritis: a case-control study

BACKGROUND

The prevalence of Celiac Disease (CD) in Juvenile Idiopathic Arthritis (JIA) has been reported to be 0.1-7% in various small studies. As a result of the limited number of research and their inconclusive results there are no clear recommendations for routine CD screening in asymptomatic patients with JIA. Our aim is to estimate the prevalence of IgA deficiency and tissue transglutaminase (tTG) IgA in a cohort of JIA followed in two large academic medical centers.

METHODS

Serum was collected and stored from all subjects and analyzed in a reference laboratory for total IgA (Quantitative Nephelometry) and tTG IgA antibody levels (Semi-Quantitative Enzyme-Linked Immunosorbent Assay). Fisher's exact tests were performed for statistical significance. Risk estimates (odds ratios) with 95% confidence intervals were calculated.

RESULTS

808 JIA cases and 140 controls were analyzed. Majority were non-Hispanic whites (72% vs. 68% p = 0.309). A total of 1.2% of cases were IgA deficient compared to none of the controls (p = 0.373). After excluding IgA deficient subjects, 2% of cases had tTG IgA ≥ 4u/mL compared to 3.6% of controls (p = 0.216) (OR = 0.5; 95% C.I = 0.1-1.4); and 0.8% of cases had tTG IgA > 10u/mL compared to 1.4% of controls (p = 0.627) (OR = 0.5; 95%C.I = 0.1-2.9).

CONCLUSIONS

Using the largest JIA cohort to date to investigate prevalence of celiac antibodies, the prevalence of positive tTG IgA was 0.8% and of IgA deficiency was 1.2%. The results did not demonstrate a higher prevalence of abnormal tTG IgA in JIA. The study did not support the routine screening of asymptomatic JIA patients for CD.

Prevalence of neurological diseases among patients with selective IgA deficiency

Background: There are no published epidemiologic studies with regard to the prevalence of neurologic diseases among subjects with selective immunoglobulin A (IgA) deficiency (sIgAD). Objective: To investigate the prevalence of neurologic diseases among the Israeli population with sIgAD. Methods: A population-based case-control study among members of a large nationwide health maintenance organization in Israel providing services to > 700,000 members. The sIgAD group included individuals ≥4 years of age with a serum IgA level of <0.07 g/L and with a diagnosis of sIgAD. The control group was randomly sampled from the entire study population with a case-control ratio of five controls for each case (1:5), with exact matching for age, gender, ethnic group, and socioeconomic status category. Results: A total of 796 subjects ages 20.58 ± 15.46 years; 391 female subjects (49.1%) were identified as having sIgAD. The control group was constituted of 3980 matched subjects. The sIgAD group was characterized by a higher prevalence of autism spectrum disorder and tic disorders. Migraine was less prevalent in the sIgAD group (19 [2.39%]) than in the control group (168 [4.22%]), odds ratio (OR) 0.55 (95% confidence interval {CI}, 0.34-0.90); p = 0.016]. More cases of subjects with epilepsy were observed in the sIgAD group (14 [1.76%]) than in the control group (31 [0.80%]), OR 2.28 (95% CI, 1.12 - 4.44; p = 0.015). Conclusion: Our observation raises the question of the role of IgA in noninfectious diseases of the central nervous system. Further basic studies are needed to explain our observation.

Selective immunoglobulin A deficiency in children with diabetes mellitus: Data from a medical center in Ukraine

The aim of this study was to estimate the prevalence of selective immunoglobulin A deficiency (SIgAD) among children with type 1 diabetes mellitus (DM) in Ternopil region (western Ukraine). Serum IgA levels were measured in 240 patients aged 4-17 years with DM and in 324 children of a control group of the same age. Normal IgA level was observed in 210 (87.5%) patients, increased-in 18 (7.5%), decreased (lower than the age reference value)-in 12 (5.0%) patients with DM. The mean IgA level in patients with DM was 152.11±73.78 mg/dL. SIgAD criteria were met by 7 (2.9%) children with DM, but none of the children of the control group met the SIgAD criteria. Female / male ratio among the patients with SIgAD was 1/6. There was no history of recurrent infections in these patients. No correlation between IgA and HbA1c levels was detected. Autoimmune thyroiditis was observed in 42.9% of patients with DM and SIgAD, and in 3.5% of patients with DM and normal or increased IgA levels. Thus, the prevalence of selective IgA deficiency in children with DM in Ternopil region (Ukraine) is 2.9% (1:34). This study shows that patients with low IgA levels need further re-examination of IgA levels to exclude SIgAD. Children with SIgAD and DM should be monitored for autoimmune manifestations that may affect the course and consequences of the disease.

Selective IgA Deficiency and Allergy: A Fresh Look to an Old Story

Selective IgA deficiency (SIgAD) is the most common human primary immune deficiency (PID). It is classified as a humoral PID characterized by isolated deficiency of IgA (less than 7 mg/dL but normal serum IgG and IgM) in subjects greater than 4 years of age. Intrinsic defects in the maturation of B cells and a perturbation of Th cells and/or cytokine signals have been hypothesized to contribute to SIgAD pathogenesis. The genetic basis of IgA deficiency remains to be clarified. Patients with SIgAD can be either asymptomatic or symptomatic with clinical manifestations including allergy, autoimmunity and recurrent infections mainly of the respiratory and gastrointestinal tract. Studies analyzing allergy on SIgAD patients showed prevalence up to 84%, supporting in most cases the relationship between sIgAD and allergic disease. However, the prevalence of allergic disorders may be influenced by various factors. Thus, the question of whether allergy is more common in SIgAD patients compared to healthy subjects remains to be defined. Different hypotheses support an increased susceptibility to allergy in subjects with SIgAD. Recurrent infections due to loss of secretory IgA might have a role in the pathogenesis of allergy, and vice versa. Perturbation of microbiota also plays a role. The aim of this review is to examine the association between SIgAD and atopic disease and to update readers on advances over time at this important interface between allergy and SIgAD.

[Prevalence and characteristics of selective IgA deficiency in celiac patients]

INTRODUCTION

Celiac disease is a multisystemic autoimmune disease that mainly affects the small intestine. Selective Immunoglobulin A deficiency is the most common primary immunodeficiency in the general population, with an incidence of 1%. It is estimated that it affects 2%-3% of celiac disease and 6.5% of patients with this deficit have celiac disease, observing the important association between both.

OBJECTIVES

To determine the prevalence of selective Immunoglobulin A deficiency in celiac patients. Describe the clinical, serological, and histological presentation and its association with autoimmune diseases.

MATERIALS AND METHODS

Cross-sectional, descriptive, and retrospective study in celiac patients with Immunoglobulin A dosing in the period from March 2005 to March 2020, at the Gastroenterology Clinic, Hospital de Clínicas, Montevideo-Uruguay.

RESULTS

343 patients were included. Seven patients presented selective Immunoglobulin A deficiency (2%). All were female with a mean age of 20 years (4-36). Selective total immunoglobulin A deficiency was observed in 6 patients (85%) and only 1 (15%) had partial deficiency. Tissue transglutaminase antibody immunoglobulin A and antiendomysium antibody were negative in patients with selective total immunoglobulin A deficiency and positive in those with partial deficiency. All presented villous atrophy, gastrointestinal symptoms, and a lower incidence of autoimmune diseases compared to the reference literature.

CONCLUSIONS

The prevalence of selective immunoglobulin A deficiency in this celiac population (2%) is similar to that reported in other populations, reaffirming the importance of including immunoglobulin A dosing for the diagnosis of CD.

The Epidemiology and Clinical Manifestations of Autoimmunity in Selective IgA Deficiency

Selective immunoglobulin A deficiency (SIgAD) is the most common primary immunodeficiency, defined as an isolated deficiency of IgA (less than 0.07 g/L). Although the majority of people born with IgA deficiency lead normal lives without significant pathology, there is nonetheless a significant association of IgA deficiency with mucosal infection, increased risks of atopic disease, and a higher prevalence of autoimmune disease. To explain these phenomena, we have performed an extensive literature review to define the geoepidemiology of IgA deficiency and particularly the relative risks for developing systemic lupus erythematosus, hyperthyroidism, hypothyroidism, type 1 diabetes mellitus, Crohn's disease, ulcerative colitis, rheumatoid arthritis, juvenile idiopathic arthritis, ankylosing spondylitis, and vitiligo; these diseases have strong data to support an association. We also note weaker associations with scleroderma, celiac disease, autoimmune hepatitis, immune thrombocytopenic purpura, and autoimmune hemolytic anemia. Minimal if any associations are noted with myasthenia gravis, lichen planus, and multiple sclerosis. Finally, more recent data provide clues on the possible immunologic mechanisms that lead to the association of IgA deficiency and autoimmunity; these lessons are important for understanding the etiology of autoimmune disease.

Prevalence of dermatologic diseases among patients with selective immunoglobulin A deficiency

BACKGROUND

There are no published large-scale epidemiologic studies regarding the prevalence of skin diseases in patients with selective immunoglobulin A (IgA) deficiency (sIgAD). The purpose of this study was to investigate the prevalence of dermatological diseases in patients with sIgAD.

METHODS

This retrospective matched case-control study was based on data from the Leumit Healthcare Services data base (approximately 725,000 residents of Israel), which was searched for all subjects aged ≥12 years who had undergone serum total IgA measurements during 2004-14 for any reason. The case group included subjects with sIgAD. The control A group was randomly sampled from those subjects in whom an IgA was drawn (n ≈ 725,000), with a ratio of 10 controls for every case (1:10). The control A group was randomly sampled from those subjects in whom an IgA was drawn (n = 104,729) and the control B group was randomly sampled from the full study population (n ≈ 725,000), with a ratio of 10 controls for every case (1:10). Comorbidity was compared between the study groups.

RESULTS

The sIgAD group was characterized: 1) By a higher prevalence of atopic dermatitis (AD) (16 [4.6 %]) than the control A group (76 [2.1 %]; p = 0.004 and the control B group (64 [1.9 %]; p = 0.002). 2) By higher prevalence of acne (69 [19.9 %]) than the control A group (516 [13.8 %]; p = 0.013) and control B group (494 [14.2 %]; p < 0.001). 3) By higher rate of chronic spontaneous urticaria (CSU) (17 [4.9 %)] than in the control A group (31 [0.9 %], with odds ratio 5.54 [3.04-10.13]; p < 0.001) and the control B group (28 [0.8 %]; p < 0.001).

CONCLUSIONS

sIgAD is characterized by a higher prevalence of AD, CSU and acne.

Population-Based Screening for Selective Immunoglobulin A (IgA) Deficiency in Lithuanian Children Using a Rapid Antibody-Based Fingertip Test

BACKGROUND Selective immunoglobulin A (IgA) deficiency is the most common inherited immunodeficiency disorder worldwide. An early diagnosis is advocated because of the increased risk of infections, autoimmune diseases, and allergic reactions. We investigated the usefulness of a rapid point-of-care test in detecting for IgA deficiency in a population with a previously unknown prevalence. MATERIAL AND METHODS Altogether, 1000 children aged 11-13 years from randomly selected Lithuanian schools were enrolled. A point-of-care test with a fingertip sample was used to screen for the presence of IgA deficiency in children whose parents gave consent. Those with suspected IgA deficiency were referred to hospital for further clinical examination and confirmation of the diagnosis. In addition, their medical histories were compared with those of 30 age- and sex-matched healthy controls. RESULTS IgA deficiency was suspected in one girl and in three boys on the basis of the rapid test, and the diagnosis was confirmed for all four cases (prevalence 0.4%, 95% confidence interval 0.16-1.02%). There was no difference in disease history or complications between IgA-deficient children and healthy controls. CONCLUSIONS The rapid antibody test is a practical and accurate method to diagnose selective IgA deficiency in children. The prevalence of IgA deficiency among Lithuanian schoolchildren is 1:250.

Prevalence of selective immunoglobulin A deficiency in Greek children and adolescents with type 1 diabetes

BACKGROUND

The association of selective immunoglobulin A (IgA) deficiency with type 1 diabetes (T1D) remains unclear. This study was to evaluate serum IgA concentrations in Greek children and adolescents with T1D.

METHODS

In two hundred individuals with T1D, serum IgA concentrations were quantitatively determined using nephelometry.

RESULTS

Immunoglobulin A deficiency was detected in 6 (3.0%) of 200 patients who were subjected to immunological evaluation. Recurrent infections were not recorded, but human papilloma virus infection was clinically suspected and confirmed by laboratory examination in a 5-year-old girl. In regard to coincidence of selective IgA deficiency with autoimmune diseases, celiac disease was detected in a girl and juvenile idiopathic arthritis in a boy. Serum IgA concentrations differed significantly when patients were grouped according to age at the beginning of the study (P<0.001), age at diagnosis of T1D (P=0.015) and coincidence of celiac disease (CD) (P=0.038). However, when the age of the patients was adjusted, difference in serum IgA concentrations was not statistically significant despite CD was present or not. Moreover, serum IgA concentrations were positively correlated with serum IgG (P<0.001) and IgE (P=0.001) concentrations and negatively correlated with serum antigliadin antibody IgG (P=0.035) concentrations. There was no association or correlation of serum IgA concentrations with glycemic control.

CONCLUSION

The prevalence of selective IgA deficiency in Greek children and adolescents with T1D is high (3.0%). The correlation of serum IgA concentrations with serum IgG, IgE and anti-gliadin antibody IgG concentrations needs further investigation.

[VACCINE-ASSOCIATED PARALYTIC POLIOMYELITIS IN RUSSIAN FEDERATION DURING THE PERIOD OF CHANGES IN VACCINATION SCHEDULE (2006-2013 yy.)]

The results of virologic testing of clinical materials and epidemiological analysis of vaccine-associated paralytic poliomyelitis (VAPP) cases obtained in 2006-2013 during AFP surveillance are presented. Among the 2976 cases of AFP 30 cases were VAPP. 15 cases were observed in OPV recipients, whereas 15 cases were observed in non-vaccinated contacts. The age of the patients varied from 4 months to 5.5 years (13.6 ± 12.4 months old). Children younger than 1 year constituted 63.3% of the group; boys were dominant (73.3%); 53.3% of children were vaccinated with OPV; the time period between receipt of OPV and onset of palsy was from 2 to 32 days (18.7 ± 8.2). Lower paraparesis was documented in 48.3% of patients; lower monoparesis in 37.9%; upper monoparesis, in 6.9%; tetraparesis with bulbar syndrome, in 6%. The majority of the patients (85.7%) had an unfavorable premorbid status. The violations of the humoral immunity were found in 73.9% cases: CVID (52.9%), hypogammaglobulinemia (41.2%); selective lgA deflciency (5.9%). In 70.6% cases damage to humoral immunity was combined with poor premorbid status. The most frequently observed (76%, p < 0.05) represented the single type of poliovirus--type 2 (44%) and type 3 (32%). All strains were of the vaccine origin, the divergence from the homotypic Sabin strains fell within the region of the gene encoding VPI protein, which did not exceed 0.5% of nucleotide substitutions except vaccine derived poliovirus type 2--multiple recombinant (type 2/type 3/ type 2/type 1) with the degree of the divergence of 1.44% isolated from 6-month old unvaccinated child (RUS08063034001). The frequency of the VAPP cases was a total of 1 case per 3.4 million doses of distributed OPV in 2006-2013; 2.2 cases per 1 million of newborns were observed. This frequency decreased after the introduction of the sequential scheme of vaccination (IPV, OPV) in 2008-2013 as compared with the period of exclusive use of OPV in 2006-2007: 1 case per 4.9 million doses, 1.4 cases per million newborns and 1 case per 1.9 million doses, 4.9 cases per 1 million newborns, respectively. The study has been financed from Russian Federation budget within the framework of the Program for eradication of poliomyelitis in the Russian Federation, WHO Polio eradication initiative, WHO's European Regional Bureau, Russian Foundation for Basic Research (project No. 15-15-00147).

Immunoglobulin A deficiency in celiac disease in the United States

BACKGROUND AND AIMS

Multiple European studies report increased prevalence of selective immunoglobulin A deficiency (SIgAD) and partial immunoglobulin A deficiency (PIgAD) in patients with celiac disease (CD). However; prospective data representing North American adults are lacking. While SIgAD precludes the use of IgA-tissue-transglutaminase antibody (IgA-tTG), the effect of PIgAD on IgA-tTG sensitivity is not well documented. We aim to determine the prevalence and impact of IgA deficiency on CD presentation and diagnosis in North American adult patients.

METHODS

We reviewed 1000 consecutive patients undergoing IgA-tTG testing and 243 healthy controls. Eligible sera were tested for IgA-tTG, serum immunoglobulins, and IgA/IgG-deamidated gliadin peptide (IgA/IgG-DGP).

RESULTS

Prevalence of SIgAD was marginally higher in patients with CD (1.9%) compared with healthy controls (0.4%, P = 0.24) and patients without CD (0.7%, P = 0.173). Prevalence of PIGAD was similar in patients with CD (4.8%) compared with healthy controls (5.9%, P = 0.57) and patients without CD (7.2%, P = 0.22). One (16.7%) of 6 patients with CD with SIgAD and all 15 (100%) with PIGAD tested IgA-tTG positive prior to gluten-free diet initiation. Patients with CD with SIGAD showed lower frequency of gastrointestinal symptoms (33% vs 82%, P = 0.01) and more co-morbid autoimmune disease (67% vs 23%, P = 0.03) when compared with patients with CD with normal IgA.

CONCLUSIONS

The prevalence of SIgAD in North American patients with CD is comparable with European data but not significantly different than control populations. Patients with CD with SIgAD exhibit decreased IgA-tTG sensitivity and lack of gastrointestinal symptoms. PIgAD is common in patients with gastrointestinal disorders but does not alter CD presentation or IgA-tTG sensitivity.

IgA deficiency in wolves from Canada and Scandinavia

Immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in both humans and selected breeds of domestic dogs. In both species, IgAD is associated with recurrent infections and immune mediated diseases. Previous results imply that IgAD is also common in the wild ancestor of domestic dogs, the gray wolf. Here, we report that serum IgA concentrations are significantly different in Scandinavian and Canadian wolves (p = 3.252e-15) with an increased prevalence for IgAD in Scandinavian wolves (60%), which is as high as those found in high-risk dog breeds.

IgA deficiency and risk of cancer: a population-based matched cohort study

PURPOSE

To investigate the risk of cancer in individuals with IgA deficiency compared with the general population.

METHODS

Prospective nationwide population-based cohort study. We identified 2320 individuals with IgA deficiency (IgA levels < 0.07 g/L) diagnosed between 1980 and 2010 in six Swedish university hospitals. Individuals with IgA deficiency were then matched on age, sex, place of residence, and year of diagnosis with up to 10 general population controls (n = 23,130). Through linkage with the Swedish Cancer Register we calculated conditional hazard ratios (HRs) for cancer diagnosed after IgA deficiency diagnosis in patients without a previous cancer diagnosis.

RESULTS

During follow-up, 125 individuals with IgA deficiency (61/10,000 person-years) and 984 controls (47/10,000 person-years) developed cancer (HR 1.31; 95%CI = 1.09-1.58). In cause-specific analyses, we found an increased risk of any gastrointestinal cancer (HR = 1.64; 95%CI = 1.07-2.50), but not for lymphoproliferative malignancy (HR 1.68; 95%CI = 0.89-3.19). Relative risk estimates for overall cancer were very high in the first year of follow-up (overall: HR = 2.80; 95%CI = 1.74-4.49), but failed to reach statistical significance thereafter. IgA deficiency diagnosed in childhood (n = 487) was not associated with overall cancer (HR = 3.26; 0.88-12.03).

CONCLUSIONS

Individuals with IgA deficiency are at a moderately increased risk of cancer, with excess risks of gastrointestinal cancer. This excess risk is highest just after diagnosis suggesting a degree of surveillance bias. Children with IgA deficiency were at no increased risk of cancer but the statistical power was limited in subanalyses.

Bronchial hyperreactivity in children with antibody deficiencies

BACKGROUND

Antibody deficiency comprises a heterogeneous group of disorders characterised by the body's inability to mount an effective antibody response to pathogens. Although it has been reported that asthma and allergic disease are frequent in antibody deficiencies, there are no data that evaluate and compare bronchial hyperreactivity (BHR) in all groups of antibody deficiencies. In this study, we aimed to evaluate and compare the frequency of BHR in patients with different antibody deficiencies.

METHODS

The study was carried out on 113 patients between ages 5 and 18 diagnosed with antibody deficiencies. The patients and their families were questioned on their history of asthma and allergic diseases. Allergic skin prick tests and non-specific bronchial provocation test with methacholine was done for all patients. Complete blood count and serum total IgE levels were measured.

RESULTS

The mean age of the patients was 10.8 ± 3.8 years and 66.4% were male. Within the study group 41.6% of the patients had selective IgA deficiency, 24.8% had IgG subclass deficiency, 14.2% had partial IgA deficiency, 10.6% had common variable immunodeficiency, 6.2% had transient hypogammaglobulinaemia and 2.7% X-linked agammaglobulinaemia. In total group, 42.5% had bronchial hyperreactivity with methacholine challenge test. BHR was more significant in both patients with selective IgA deficiency and partial IgA deficiency compared to those with IgG subclass deficiency (P=0.041 and P=0.038, respectively).

CONCLUSION

BHR was high in antibody deficiencies, especially selective IgA deficiency compared to IgG subclass deficiency.

Autoimmunity in patients with selective IgA deficiency

BACKGROUND AND OBJECTIVE

Selective immunoglobulin A deficiency (SIgAD) is the most common primary antibody deticiency. Patients with SIgAD have a greater risk of concomitant autoimmune disorders than healthy individuals. The exact mechanism underlying the relationship between autoimmunity and SIgAD is not fully understood. The aim of this study was to evaluate potential associations between autoimmunity and specific clinical or immunological findings in patients with SIgAD.

METHODS

The study population comprised 57 symptomatic patients (65% males) with confirmed SIgAD who were referred to our center. Demographic data and history of autoimmunity were recorded both for patients and for their relatives. Comprehensive clinical and laboratory examinations were performed to investigate autoimmune complications in all the patients.

RESULTS

Autoimmune disorders were documented in 17 cases (29.8%; 9 males and 8 females). The most common manifestations were thyroiditis, vitiligo, and hemolytic anemia (3 cases each). Ten patients (17.5%) had a family history of autoimmunity. Significant associations were detected between autoimmunity and increased duration of follow-up (P = .003), serum level of IgM (P = .01), regulatory T-cell count (P = .03), and class-switched memory B-cell count (P = .01). Four cases of autoimmune SIgAD (23.5%) progressed to common variable immunodeficiency during the follow-up period (P = .006).

CONCLUSIONS

Autoimmune disorders, autoimmune cytopenia, and Ig subclass deficiency can lead to severe clinical manifestations in patients with SIgAD. Therefore, immunologists and pediatricians should be aware of these conditions.

[Primary immunodeficiencies are a topical problem of modern medicine]

AIM

To analyze the incidence of primary immunodeficiencies (PIDs), to reveal the specific features of the course of this condition at the present stage, and to estimate the quality of health care to patients with PIDs.

SUBJECTS AND METHODS

An open-label prospective trial was performed in 94 patients with different forms of PIDs (63 with selective immunoglobulin A (IgA) deficiency and 31 with other more severe primary immunodeficiencies) who had been permanent residents in the Perm Territory in the period 1990 to 2012.

RESULTS

The registered PID cases were noted to be lower than the estimated ones. Over 22 years of follow-ups, the death rates for this group of patients with these diseases were 11%, and the disability rates were 27%. In severe PIDs (exclusive of selective IgA deficiency), these rates were as high as 35.5 and 96%, respectively. The rate of untimely diagnosis of severe PIDs was high (43%). Molecular genetic studies were conducted in only one tenth of the patents with this disease. PID treatment generally complied with the accepted medical standards. However, all patients with X-linked agammaglobulinemia were observed to have periodic irregularities of replacement therapy with intravenous immunoglobulins, which was a cause of death in 2 patients. Adult patients with common variable immune deficiency received no adequate replacement therapy. Timely diagnosis and adequate therapy could not only preserve the life of many patients with severe PIDs (64.5% survived), but could achieve its relatively satisfactory quality.

CONCLUSION

As of now, PIDs ceased to be fatal diseases. To improve the quality of health care to patients with this pathology, there is a need to increase the awareness of the diagnosis and treatment of immunodeficiencies among physicians of different specialties, to extend the application of molecular genetic techniques, including those for prenatal diagnosis, and to continuously provide patients with essential drugs.

Asthma and risk of selective IgA deficiency or common variable immunodeficiency: a population-based case-control study

OBJECTIVE

To determine the association between a history of asthma and a diagnosis of selective IgA deficiency (sIgAD)/common variable immunodeficiency (CVID).

PATIENTS AND METHODS

This population-based case-control study included residents of Olmsted County, Minnesota, who met the Pan-American Group for Immunodeficiency/European Society for Immunodeficiencies diagnostic criteria for sIgAD/CVID between January 1, 1964, through December 31, 2008. Each case had 4 age- and sex-matched controls (2 from the community and 2 from a list of individuals who had undergone an immune work-up). We ascertained asthma status by applying predetermined criteria for asthma.

RESULTS

We identified 39 cases: 26 (66.7%) had sIgAD and 13 (33.3%) had CVID. Of the 39 cases, 51.3% were men (n=20) and 97.1% were white (33 of 34 patients). The mean age at the index date (the time when criteria were met) of sIgAD/CVID was 34.2 years. Of the 39 cases, 9 (23.1%) had a history of asthma before the index date of sIgAD/CVID; of the 156 controls, 16 (10.3%) had a history of asthma before the index date (odds ratio, 2.77; 95% CI, 1.09-7.06; P=.03). A history of asthma (before or after the index date of sIgAD/CVID) was more prevalent in sIgAD/CVID cases (30.8%; n=12) than in matched controls (11.5%; n=18) (odds ratio, 3.57; 95% CI, 1.50-8.51; P=.01).

CONCLUSION

Asthmatic patients are more likely to have a diagnosis of sIgAD/CVID than nonasthmatic individuals. This association may potentially account for the increased risks of bacterial infections in some individuals with asthma.

Serological testing for coeliac disease in Type 1 diabetes mellitus: is immunoglobulin A level measurement necessary?

AIMS

Immunoglobulin A (IgA) measurement is advocated when case finding for coeliac disease in patients with Type 1 diabetes mellitus. Currently, there is a paucity of contemporary studies assessing IgA deficiency in Type 1 diabetes. This study evaluates the prevalence of IgA deficiency in individuals with Type 1 diabetes, compared with patients with coeliac disease and control subjects. In addition, we evaluate whether routine IgA measurement is justifiable when case finding for coeliac disease in patients with Type 1 diabetes.

METHODS

All patients were assessed using IgA endomysial antibodies, IgA anti-tissue transglutaminase antibodies and total IgA levels. Altogether, 2434 individuals were tested: 1000 patients with Type 1 diabetes, 234 patients with coeliac disease and 1200 population control subjects. Definitive IgA deficiency was defined as total IgA levels < 0.07 g/l.

RESULTS

The prevalence of IgA deficiency was significantly more common in patients with Type 1 diabetes (0.9%, n = 9/1000; P = 0.036) and coeliac disease (1.29%, n = 3/234; P = 0.041) when compared with population control subjects (prevalence of 0.17%, 2/1200). No statistical difference between Type 1 diabetes and coeliac disease for IgA deficiency was identified (P = 0.87). Of patients in the group with Type 1 diabetes, 3.3% (33/1000) had coeliac disease, and of those only one patient had IgA deficiency leading to an antibody-negative presentation. Both IgA-deficient individuals within the population control subjects had normal duodenal biopsies and no relevant symptoms.

CONCLUSIONS

IgA deficiency is more common in Type 1 diabetes compared with population control subjects. Despite this, very few individuals with Type 1 diabetes and IgA deficiency appear to have villous atrophy on biopsy. These outcomes question the practice of routine IgA measurement when case finding for coeliac disease in patients with Type 1 diabetes.

Genome-wide association study identifies TNFSF13 as a susceptibility gene for IgA in a South Chinese population in smokers

IgA is an important factor in our immune system. There are many diseases associated with it, such as IgA nephropathy, IgA deficiency, and so on. In order to describe the relationship between the genes and the IgA level, we performed a genome-wide association study of serum IgA with 1,999 healthy Chinese men in the first stage and replicated on an independent Chinese sample with 1,496 subjects in the second stage. Association between each SNP with IgA was estimated by multivariate linear regression analysis conditioned on age and smoke. Haplotype analysis for the block around the top SNP was performed. In the first stage, one genomic locus was identified to be significantly associated with IgA. The loci is TNFSF13 (17p13.1; rs3803800; P = 6.26 × 10(-8)). In smoke-specific analysis, rs3803800 was approximately significantly associated with IgA levels in smokers (P = 3.96 × 10(-7)), while no association was observed in nonsmokers (P = 2.28 × 10(-1)). In addition, we performed the haplotype analysis on chromosome 17 with the SNPs around rs3803800. Although the total P value for the haplotype did not acquire significant difference, three haplotypes (TGAG, CACG, and CACA) reached significant (P < 0.05). In conclusion, TNFSF13 could be a susceptible gene which was discovered having relationship with serum IgA level, and smoke might be a factor infecting the IgA level.

Prevalence of primary immunodeficiency in Korea

This study represents the first epidemiological study based on the national registry of primary immunodeficiencies (PID) in Korea. Patient data were collected from 23 major hospitals. A total of 152 patients with PID (under 19 yr of age), who were observed from 2001 to 2005, have been entered in this registry. The period prevalence of PID in Korea in 2005 is 11.25 per million children. The following frequencies were found: antibody deficiencies, 53.3% (n = 81), phagocytic disorders, 28.9% (n = 44); combined immunodeficiencies, 13.2% (n = 20); and T cell deficiencies, 4.6% (n = 7). Congenital agammaglobulinemia (n = 21) and selective IgA deficiency (n = 21) were the most frequently reported antibody deficiency. Other reported deficiencies were common variable immunodeficiencies (n = 16), X-linked agammaglobulinemia (n = 15), IgG subclass deficiency (n = 4). Phagocytic disorder was mostly chronic granulomatous disease. A small number of patients with Wiskott-Aldrich syndrome, hyper-IgE syndrome, and severe combined immunodeficiency were also registered. Overall, the most common first manifestation was pneumonia. This study provides data that permit a more accurate estimation PID patients in Korea.

[Selective immunoglobulin A deficiency]

Immunoglobulin class A is the main protein of the mucosal immune system. Selective immunoglobulin A deficiency (sIgAD) is the most common primary immunodeficiency in Caucasians. sIGAD is strongly associated with the certain major histocompatibility complex region. Most individuals with sIgAD are asymptomatic and identified coincidentally. However, some patients may present with recurrent infections, allergic disorders and autoimmune manifestations. Several autoimmune diseases, such as systemic lupus erythematosus, diabetes mellitus type 1, Graves disease and celiac disease, are associated with an increased prevalence of sIgAD. Screening for sIgAD in coeliac disease is essential. Patients need treatment of associated diseases. It is also known that IgA deficiency may progress into a common variable immunodeficiency (CVID). Pathogenesis and molecular mechanism involved in sIgAD should be elucidated in the future.

Lack of association between IgA deficiency and respiratory atopy in young male adults

BACKGROUND

The issue of atopy and increased serum IgE in IgA deficiency is still a matter of debate. The aim of this study was to evaluate the prevalence of IgA deficiency and its relationship with respiratory atopy.

MATERIALS AND METHODS

A retrospective study on 4700 consecutive young males (age range 18-23), who underwent a health screen for admission to the Italian Airforce Academy between 1993 and 1995 was conducted. Serum IgA was measured by immunoturbidimetry and total and specific IgE by fluorescent enzyme immunoassay (Phadiatop FEIA, Pharmacia Cap System). Airway responsiveness was assessed by methacholine challenge.

RESULTS

IgA deficiency was detected in 0.34% (16/4700) subjects and atopy was detected in 8.6% (406/4700). The mean IgA was 243 mg/dl (95% CI 107, 442) in the 406 atopic subjects and 238 mg/dl (95% CI 100, 441) in 1544 controls. Only 6 (37.5%) of the IgA deficient subjects had subnormal IgE levels and 6 were positive in the fluorescent EIA. None of the IgA deficient patients presented with respiratory hyper-reactivity.

CONCLUSION

Atopy is not more prevalent in young male adult IgA deficient subjects, who rather display a high frequency of recurrent sinusitis.

Selective IgA deficiency in autoimmune diseases

Selective immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. It has previously been suggested to be associated with a variety of concomitant autoimmune diseases. In this review, we present data on the prevalence of IgAD in patients with Graves disease (GD), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), celiac disease (CD), myasthenia gravis (MG) and rheumatoid arthritis (RA) on the basis of both our own recent large-scale screening results and literature data. Genetic factors are important for the development of both IgAD and various autoimmune disorders, including GD, SLE, T1D, CD, MG and RA, and a strong association with the major histocompatibility complex (MHC) region has been reported. In addition, non-MHC genes, such as interferon-induced helicase 1 (IFIH1) and c-type lectin domain family 16, member A (CLEC16A), are also associated with the development of IgAD and some of the above diseases. This indicates a possible common genetic background. In this review, we present suggestive evidence for a shared genetic predisposition between these disorders.

Prevalence of selective immunoglobulin A deficiency in healthy Turkish school children

Immunoglobulin A (IgA) deficiency is the most common primary deficiency. We aimed to define the prevalence of IgA deficiency among healthy school children in Turkey and the differences between geographical regions. Blood samples were collected from 20,331 healthy school children from all regions across Turkey. The serum IgA levels were tested through nephelometric method, and all 108 samples with IgA levels lower than 5 g/L were tested through ELISA for IgG and IgM levels. All IgG and IgM values were within the normal range in all cases, and no concomitant deficiency was observed. Our study results showed that the selective IgA deficiency incidence was 0.52% (1:188). The highest incidence, of 1:128.7, was observed in children from the Marmara region; the Black Sea Region levels (1:132.7) were lower, and the Mediterranean levels (1:365.7) were the lowest.

Prevalence of IgA deficiency in adult systemic lupus erythematosus and the study of the association with its clinical and autoantibody profiles

INTRODUCTION

IgA deficiency (IgAD) is the most common primary immunodeficiency, which can cause frequent infections. The association of IgA deficiency with systemic lupus erythematosus (SLE) is very important because of the high morbidity and mortality rates of infections in patients with this disease.

OBJECTIVES

To study the prevalence of IgA deficiency in SLE patients from southern Brazil and to compare the clinical and autoantibody profiles of SLE patients with and without IgA deficiency.

PATIENTS AND METHODS

One hundred and eighty-nine SLE patients were submitted to serum IgA measurement by nephelometry. Levels of IgA below 50mg/dL were considered to be IgAD. Demographic data, clinical profile (presence of arthritis, psychosis, seizures, stroke, serositis, hemolytic anemia, leucopenia, thrombocytopenia, and nephritis) and autoantibody profiles (ANA, anti-Ro, anti-La, anti-Sm, anti-DNA, anti-RNP, lupus anticoagulant, and anticardiolipin IgG and IgM) were obtained from reviewing medical records. As control, we used literature data from another study performed in the same geographical area. Data were analyzed through contingency and frequency tables, applying the Chi-square, Fisher, and Mann Whitney tests.

RESULTS

IgA deficiency was found in 11 (6.17%) patients (P < 0.001 in relation to controls). The association between IgA deficiency and clinical or autoantibody profile was not significant.

CONCLUSION

We concluded that a higher prevalence of IgA deficiency was observed in lupus patients than in controls. Deficiency of IgA did not have any particular laboratory or clinical effects on this population.

[IgE deficiency: a forgotten disease?]

BACKGROUND

Selective IgE deficiency is a profound deficiency (< 5 UI/mL) or absence of serum IgE levels without other immunologic abnormalities. It is usually asymptomatic, but may be associated with recurrent respiratory infections, chronic fatigue, and musculoskeletal complaints.

OBJECTIVE

To describe the evolution and treatment in patients with selective IgE deficiency.

PATIENTS AND METHOD

In selective IgE's deficiency patients identification note, atopy history, concurrent diseases, clinic of allergic diseases, Prick test and prior response to treatment were analyzed.

RESULTS

Eleven patients were included, five women and six men within 16 months to 10 years old. The patients had serum IgE levels < 5 UI with other immunoglobulins and sub-classes in normal levels; except a patient with concomitant IgA and IgE deficiency. The treatment administered was since prophylactic antibiotic to intravenous gammaglobulin.

DISCUSSION

We established the diagnosis of selective IgE deficiency in patient with serum IgE levels < 5 UI/mL associated with recurrent respiratory infections.

CONCLUSIONS

We need more clinic studies to document with precision the selective IgE deficiency.

Low prevalence of selective IgA deficiency in infected children born to HIV-seropositive mothers: an in vivo model for speculation on selective IgA deficiency pathogenesis

Anecdotal reports of restored immunoglobulin production in individuals with common variable immunodeficiency after acquiring HIV infection suggest that perturbation of the immune system occurring during HIV infection may force some underlying functional defects. These findings raise intriguing questions about the pathogenesis of common variable immunodeficiency. No study has investigated the possible influence of HIV infection on the development of selective IgA deficiency, a primary immunologic defect genetically related to common variable immunodeficiency. IgA serum levels were evaluated in a large cohort of children born to HIV-infected mothers from 1985 to 2006. To avoid differences possibly due to different follow-up durations we considered only infected and non-infected children aged over 4 years at last-follow-up. The study included 1,157 non-infected children and 964 infected children, aged ≥ 4 years at last-follow-up and with availability of two or more serum IgA determinations over six months of age. No child displayed immunoglobulin values compatible with diagnosis of common variable immunodeficiency. However, 0/964 infected children vs. 5/1157 non-infected children had selective IgA deficiency (P=0.048). It may be speculated that several immunological alterations, occurring simultaneously in perinatal HIV infection, surpass the functional defect exhibited in some children with selective IgA deficiency. Our data may shed light on the pathogenesis of selective IgA deficiency.

Immunologic evaluation of patients with recurrent ear, nose, and throat infections

PURPOSE

In this study, we aimed to study the frequency of possible underlying immunodeficiency responsible for susceptibility to ear, nose, and throat (ENT) infection.

MATERIALS AND METHODS

One hundred three (72 males and 31 females) consecutive children and adult patients with history of recurrent or chronic ENT infections, referred by otolaryngologists to the Department of Allergy and Clinical Immunology, Children's Medical Center, Tehran University of Medical Sciences (Tehran, Iran), were enrolled to the study from March 2003 to March 2006. For each patient, demographic information and medical histories of any ENT infections were collected by reviewing the patient's records. We measured immunoglobulin isotype concentrations and immunoglobulin (Ig) G subclasses by nephelometry and enzyme-linked immunosorbent assay methods, respectively. Of 103 patients, 75 received unconjugated pneumococcus polyvalent vaccine, and blood samples were taken before and 21 days after vaccination. Specific antibodies against whole pneumococcal antigens were measured using enzyme-linked immunosorbent assay method. Existence of bronchiectasis was confirmed in each patient using high resolution computed tomography scan.

RESULTS

Among 103 patients, 17 (16.5%) patients were diagnosed to have defects in antibody-mediated immunity including 6 patients with immunoglobulin class deficiency (2 common variable deficiency and 4 IgA deficiency), 3 with IgG subclass deficiency (2 IgG2 and 1 IgG3), and 8 with specific antibody deficiency against polysaccharide antigens. In our series, bronchiectasis was detected in 5 cases associated with primary immunodeficiency.

CONCLUSIONS

Long-standing history of ENT infections could be an alarm for ENT infections associated with primary antibody deficiency.

Selective IgA deficiency in children and adults with systemic lupus erythematosus

The objective of this study was to determine the frequency and clinical characteristics of selective IgA deficiency (SIgAD) in children and adults with systemic lupus erythematosus (SLE), and evaluate potential differences in presentation and course of the SLE. IgA deficiency was defined as a serum IgA concentration < or =0.01 mg/mL determined on two sera by radial diffusion. SLE was classified by the 1982 criteria of the American College of Rheumatology. Seventy-seven children with SLE followed prospectively for > or =20 years and 152 adults surveyed during a one-year period were assayed for serum IgA levels. Disease characteristics were compared among the deficient patients and the IgA-normal patients. Twelve patients with SIgAD were identified: 1) Juvenile(J)-SLE: four children with juvenile onset (< or =18 years) and four others encountered as adults; and 2) Adult(A)-SLE: four patients with adult onset. No significant differences were found in clinical presentation or course except for a possible increase in recurrent infections and the observation that there were only two African-Americans. Five patients had received blood transfusions with no reactions; three of these patients had serum anti-IgA antibodies. One pediatric patient developed low levels of IgA (<or =1 mg/mL) during a follow-up of three years. Two adult patients died (septicemia, carcinoma); one was on dialysis. SIgAD was identified in 5.2% of children and 2.6% of adults with SLE for an estimated 35-fold increase in frequency. This small number of patients did not appear to have an altered clinical presentation or course from that expected in patients with SLE who did not have SIgAD.

Alterations in humoral immunity in relatives of patients with common variable immunodeficiency

BACKGROUND AND OBJECTIVES

It has been reported that there is a high prevalence of immunodeficiency and autoimmunity in relatives of patients with common variable immunodeficiency (CVID). The aim of this study was to determine the prevalence of immunoglobulin deficiency in relatives of patients with CVID in Iran, where there is a high rate of consanguineous marriage.

METHODS

A descriptive study was undertaken in 64 family members of 23 unrelated CVID patients. The group contained 17 fathers, 18 mothers, 18 sisters, 9 brothers, and 2 children. Serum immunoglobulin levels were measured by nephelometry. Immunoglobulin (Ig) G subclass levels were measured in a subgroup of 36 individuals. Serum IgA levels were confirmed by enzyme-linked immunosorbent assay for subjects with suspected IgA deficiency.

RESULTS

The rate of consanguineous marriage in families containing relatives with antibody deficiencies was significantly higher than in those families in whom relatives did not have immune deficiencies. IgA deficiency was observed in 2 relatives of patients with CVID. Also CVID was observed in 2 family members. In 3 fathers and 1 brother, IgM levels were lower than normal. Three relatives had IgG4 deficiency and 1 person had combined IgG4 and IgG2 deficiency. Twenty percent of the relatives had hypogammaglobulinemia (including IgA deficiency, CVID, decreased levels of IgM, and IgG subclass deficiencies).

CONCLUSION

In our study, alteration in humoral immunity in relatives of CVID patients was higher than previously reported, and this could be attributed to the high rate of consanguineous marriage in Iran. Since the family members of CVID patients are at high risk of hypogammaglobulinemia, it is advisable that they be evaluated for immunodeficiency disorders and monitored throughout their lifetimes.

Decreased B cells and IgA-secreting B cells partially explain the high prevalence of IgA deficiency in dialysis patients

AIMS

We previously reported 2 hemodialysis (HD) patients with recurrent infections and selective immunoglobulin A deficiency (IgAD). We further demonstrated that serum IgA levels were lower and the prevalence of IgAD was higher in uremic patients. The exact mechanisms of IgAD in uremic patients largely remained unclear. In some patients, it was caused by anti-IgA antibody neutralization and subsequent destruction. We performed the present study to survey if there is any defect in IgA production.

MATERIALS AND METHODS

288 patients were initially included for examination of serum immunoglobulins. 16 normal persons, 16 dialysis patients without IgAD, and 12 dialysis patients with IgAD were enrolled after the initial examination. Blood was drawn into heparinized tubes. WBC counts and lymphocyte percentage were examined by a CBC counter. Lymphocytes were separated by the Ficoll-Paque method. Flow cytometry was utilized to isolate the B cell and IgA-secreting B cell after staining with CD 19 phycoerythrin and FITC-conjugated rabbit anti-human IgA antibody.

RESULTS

There is no significant difference between WBC counts or total lymphocyte counts of these 3 groups. However, we found a lower percentage of total lymphocyte counts in dialysis patients, either with or without IgAD. The total B cell numbers were lower in dialysis patients with IgAD. In addition, there were fewer IgA-secreting B cells in dialysis patients with IgAD.

CONCLUSION

Decreased B cell and IgA-secreting B cell counts are seen in uremic patients with IgAD. This, in turn, indicates that there might be a defect of IgA production in some patients, rather than IgA destruction by anti-IgA antibodies as seen in some other patients. Further study is needed to investigate the mechanisms of decreased B cells and IgA-secreting B cells.

Low prevalence of IgA deficiency in north Indian population

BACKGROUND AND OBJECTIVES

IgA deficient patients are at risk of severe anaphylactic reaction on being transfused blood and blood products, and its prevalence varies in different parts of the world. No data are available from India. We did a blood donor survey to look for prevalence of IgA deficiency in north India.

METHODS

A sensitive enzyme linked immunosorbent assay developed in-house was used to detect IgA deficiency in a total of 3818 blood donors. Complete IgA deficiency was defined as value less than 5 mg/dl whereas partial IgA deficiency was defined as value between 5-30 mg/dl.

RESULTS

Of the 3818 blood donors screened, 3640 (95.3%) were males with a mean age of 31.2 yr. No donor was found to have complete IgA deficiency; however, 257 (6.7%) had partial IgA deficiency.

INTERPRETATION AND CONCLUSION

Our study shows that IgA deficiency is rare in north India.

Bronchial hyper-responsiveness in selective IgA deficiency

Secretory IgA in mucosal secretions has a broad protective function. The insufficient protection provided by the respiratory mucosa in children with selective IgA deficiency (sIgAD) might facilitate the development of bronchial hyper-responsiveness (BHR) and consequently asthma symptoms. This study was conducted to clarify the prevalence of BHR in sIgAD children and the relationship with atopic status. A cohort of 20 children (group A) aged 6.4-20.1 yr (median: 12.6) with sIgAD (serum IgA <6 mg/dl) were evaluated for BHR using inhaled hypertonic saline test as well as for atopy by skin prick testing (SPT) to eight common aero-allergens. Seventy other children with normal levels of serum IgA, but sensitized to aero-allergens (group B) and 102 with normal IgA and negative SPTs (group C) were also evaluated. Baseline spirometry demonstrated that forced vital capacity (FVC) values in group A were significantly lower than in C. Forced expiratory volume in 1 s values were similar in all groups, but impairment of the forced expiratory flow over the middle half of the FVC was detected in group B. The prevalence of BHR was similar among group A (30.0%) and group B (35.7%) (p = 0.79) but they differed from group C (5.9%) (p = 0.005). An association between BHR and reported current (p = 0.001) but not lifetime asthma symptoms among group A was also observed. There was no association between atopy and BHR in group A but only to mites' sensitization (p = 0.03). In conclusion, these results indicate that sIgAD constitutes a risk factor for development of BHR but it appears to be related to sensitization to mites.

Selective IgA deficiency in children with recurrent parotitis of childhood

Recurrent parotitis of childhood is defined as the relapsing form of juvenile (idiopathic) parotitis and represents a rare inflammatory disorder of the parotid gland with potentially significant morbidity. We reviewed the charts of patients who were diagnosed with inflammatory parotid diseases in our institution between 1992 and 2002. There were 91 patients presenting with juvenile parotitis (1 of 6117 of all clinical visits). Of these 91 cases, 23 patients (28%) had the relapsing form of juvenile parotitis, and the median number of episodes was 5 (range, 2-20). Laboratory investigations revealed that 5 patients had selective IgA deficiency. The prevalence (22%) is different from the cumulative prevalence of IgA deficiency in a healthy population (0.3%; P < 0.001).

[Autoimmune disease in primary antibody deficiencies]

BACKGROUND

Immunodeficiency and autoimmune phenomena may occur concomitantly in the same individual. Many immune deficiency syndromes, mainly humoral defects, are associated with autoimmune disorders. In the present study, we describe the frequency of autoimmune disorders in these patients.

METHODS AND RESULTS

We performed a retrospective review of the medical records of a cohort of 152 patients with primary antibody deficiency in the Clinical Immunology Unit of the Gregorio Maranon University Hospital in Madrid: common variable immunodeficiency (CVID) (n = 35), IgA deficiency (n = 43), specific IgG subclass deficiency (n = 56), antibody deficiency with normal immunoglobulin (n = 14) and X-linked agammaglobulinemia (n = 4). Of the 152 patients with primary antibody deficiencies, autoimmune disorders were found in 35 (23 %). Autoimmune hematologic disease was found in 14 patients (9.2 %), autoimmune diseases of the gastrointestinal tract in eight (5.3 %), autoimmune endocrine diseases in six (3.9 %), autoimmune rheumatic diseases in six (3.9 %) and vitiligo in four. Autoimmune diseases were more frequent in CVID patients (37.1 %) than in those with selective IgA deficiency (25.5 %) or selective IgG subclass deficiency (12.5 %). Thirty-seven percent of autoimmune episodes occurred prior to the diagnosis of primary antibody deficiency. Sixteen patients (10.5 %) had autoantibodies without clinical data of an autoimmune disease.

CONCLUSIONS

Primary antibody deficiencies have variable autoimmune manifestations. For early detection and appropriate treatment, autoimmune disease should be suspected in patients with immunodeficiency.

Gender, age and seasonal effects on IgA deficiency: a study of 7293 Caucasians

BACKGROUND

The frequency of serum IgA deficiency (SIgAD) differs between populations. We examined the prevalence of SIgAD in healthy Caucasians.

MATERIALS AND METHODS

Serum immunoglobulin A (SIgA) was measured in 7293 volunteers (2264 women, 5029 men) aged 30 +/- 14.2 years (mean +/- SD; range: 12-66). Serum immunoglobulin A and subnormal SIgA levels were defined by a SIgA level < 0.07 g L(-1), and between 0.07 and 0.7 g L(-1), respectively. Means were compared by analysis of variance (anova) and analysis of covariance (ancova); frequencies by the chi(2) test.

RESULTS

Fifteen subjects (0.21%; one woman, 14 men) had SIgAD. Subnormal SIgA levels were found in 155 persons (2.13%): 21 females (0.93% of the females) and 134 males (2.66% of the males; difference: 1.74%; 95% CI: 1.12-2.33%; P < 0.001). Males were more likely to have subnormal SIgA levels or SIgAD (odds ratio 3.09, 95% CI: 1.97-4.85). The prevalence of SIgAD and subnormal SIgA was lowest in winter (chi(2) = 14.8; P = 0.002; 3 d.f.; and chi(2) = 43.2; P < 0.001; 3 d.f., respectively). Serum immunoglobulin A concentrations were significantly higher during winter. Serum immunoglobulin A levels increased with age on average by 0.2 +/- 0.06 g L(-1) per decade of life (P < 0.001). Taking into account the influence of age, SIgA concentration was lower in females as compared with males.

CONCLUSION

The prevalence of SIgAD and subnormal SIgA levels is increased in males. There exists a significant influence of gender, age and seasons on SIgA levels.

Juvenile idiopathic polyarticular arthritis and IgA deficiency in the 22q11 deletion syndrome

Five patients with the 22q11 deletion syndrome (velocardiofacial syndrome) developed chronic inflammatory polyarticular arthritis. These new cases add to 8 previously reported and confirm the association. The arthritis in all cases was moderate to severe, but at least partially responsive to methotrexate and/or corticosteroids, and was clinically indistinguishable from juvenile idiopathic arthritis (JIA). Analysis of the total 13 patients indicates that 2 are rheumatoid factor positive, 6 are antinuclear antibody positive, 5 have subtle T cell deficiencies, and 6 have hypergammaglobulinemia. Of particular interest is the occurrence of IgA deficiency in 4 patients, including 2 from our own series. Although IgA deficiency is seen in both JIA (2-4%) and 22q11 deletion syndrome (2-4%), the prevalence of low IgA in this series (31%) is much greater than expected. This phenomenon and the true association of inflammatory arthritis and a chromosome deletion disorder provides further evidence of important genetic factors in the pathogenesis of JIA.

[Clinical relevance of immunoglobulin A deficiency in celiac disease]

BACKGROUND

To determine the prevalence of the IgA deficiency in patients with celiac disease and its influence on the presentation and evolution of celiac disease.

PATIENTS AND METHOD

47 patients with clinical and histological diagnosis of celiac disease were included. Seric immunoglobulin levels were determined in all patients.

RESULTS

Five patients presented a low level of IgA (IgA-deficient group) and 42 patients presented normal levels (non-IgA-deficient group). The age and the relation male/female were similar between both groups. Presentation, clinical manifestations, analytic data of intestinal malabsorption, and the radiologic pattern were also similar between both groups of patients. There were bronchiectasies in two out of 5 IgA-deficient patients and in only one out of 42 non-IgA- deficient patients (p < 0.05). None of the IgA-deficient group showed complications due to the celiac disease, meanwhile 3 non-IgA deficient patients developed intestinal lymphoma (p = NS).

CONCLUSIONS

The IgA deficiency is frequently associated to celiac disease. This association does not seem to influence in a significant way the presentation or the evolution of celiac disease.

IgA deficiency in Czech healthy individuals and selected patient groups

BACKGROUND

Selective IgA deficiency (IgAD) is the most common immunoglobulin deficiency with a variety of clinical manifestations. The frequency of IgAD differs depending on the ethnic origin and clinical symptoms of investigated persons.

METHODS

The prevalence of IgAD (serum IgA level <0.05 g/l) was determined in 5,310 Czech blood donors, 10,326 patients who had undergone immunological investigation, and 246 first-degree relatives of IgAD and common variable immunodeficiency (CVID) patients.

RESULTS

IgAD was detected in 13 (1/408; 0.24%) of the blood donors. The prevalence of IgAD was increased both in children (48/3,113; 1.5%) and adults (33/3,824; 0.9%) referred for frequent respiratory tract infections (in both cases p<0.001) compared to the healthy population. The frequency of IgAD was 12/189 (6%) in first-degree relatives of IgAD patients and 9/57 (16%) in relatives of CVID patients, with the highest frequency observed in children of CVID patients.

CONCLUSIONS

The prevalence of IgAD in the Czech healthy population is comparable to that in other Caucasians. The frequency is increased in children with recurrent respiratory tract infections and especially in relatives of patients with immunoglobulin deficiencies.

[Frequency of selective IgA deficiency in Basque Country]

BACKGROUND

To evaluate the frequency of IgA deficiency in the Basque Country, Spain, and establish a file of IgA-deficient blood donors, using a self laboratory test and checking medical records.

MATERIALS AND METHODS

A screening radial immunodiffusion system was used on 2.607 blood donors samples. A search on the patients laboratory results was realized.

RESULTS

Five blood donors were detected, and 2 of 30 patients fulfilled criteria for donation.

CONCLUSIONS

The frequency obtained of IgA deficiency in the Basque Country was 1/521. The used method is economical and optimum to create a file of IgA-deficient blood donors.

Distribution of primary immunodeficiency diseases diagnosed in a pediatric tertiary hospital

BACKGROUND

Advances in immunologic techniques in recent years have led to increased recognition of primary immunodeficiency disorders, with IgA deficiency the most common phenotype reported by most registries. There have also been reports of increased associated incidence of autoimmunity, allergy, and other diseases.

OBJECTIVES

We wished to determine the percentage of different primary immunodeficiency disorders seen in a pediatric tertiary hospital and to determine the association of primary immunodeficiency disorders with other diseases that are not part of classic immunodeficiency disorders.

METHODS

We performed a retrospective review of the patients referred to our allergy/immunology clinic for immunologic evaluation of recurrent infections during an 8-year period. We also reviewed pathology reports with postmortem diagnosis of immunodeficiencies not identified while patients were alive.

RESULTS

Of the 91 patients with primary immunodeficiency disorders evaluated, the majority had predominantly antibody deficiencies (67%). The most common phenotype was specific antibody deficiency with normal immunoglobulins (23.1%), defined as inability to mount an adequate response to pneumococcal polysaccharides followed by IgG2 subclass deficiency (17.6%). These two phenotypes were diagnosed mostly in the last 2 years of the survey. Associated diseases, found in 40% of patients, were mostly allergic conditions followed by syndromic/chromosomal disorders.

CONCLUSION

The study reveals that specific antibody deficiency with normal immunoglobulins followed by IgG2 subclass deficiency was the most frequently diagnosed primary immunodeficiency disorder in our patient population. It also indicates that immunodeficiency disorders should be considered in patients with other abnormalities like allergic and syndromic/chromosomal disorders that present with recurrent infections.

The prevalence of celiac disease in at-risk groups of children in the United States

OBJECTIVE

In contrast to its prevalence in Europe, celiac disease (CD) is considered rare in the United States. We aimed to determine the prevalence of CD in children presenting with symptoms or conditions associated with CD.

STUDY DESIGN

Individuals aged 6 months to 20 years were screened for IgG and IgA antigliadin (AGA-IgG and AGA-IgA) and antiendomysium (EMA) antibodies. Those with only elevated AGA-IgG were screened for selective IgA deficiency. Patients with elevated EMA, or AGA-IgG elevation and selective IgA deficiency, were advised to undergo small intestinal biopsy.

RESULTS

A total of 1200 individuals were studied; 34 were EMA positive-26 (19 EMA positive) consented to biopsy and 21 had CD, giving a prevalence of 1 in 57 (21/1200). Including the 15 EMA positive patients who refused a biopsy, the prevalence of CD in this study could be as high as 1 in 33 (36/1200).

CONCLUSIONS

CD is not rare in the United States and may be as common as in Europe. AGA and EMA are useful for identifying patients who should undergo a small intestinal biopsy.

Increased prevalence of immunoglobulin A deficiency in patients with the chromosome 22q11.2 deletion syndrome (DiGeorge syndrome/velocardiofacial syndrome)

We wished to determine the prevalence of immunoglobulin A (IgA) deficiency in patients with the chromosome 22q11.2 deletion syndrome. A total of 32 patients with the chromosome 22q11.2 deletion were examined for IgA deficiency. We report a 13% (n = 4) prevalence of IgA deficiency in patients with this syndrome. The odds ratio of IgA deficiency in this population is 14.20 (P < 0.0001). This confirms the occurrence of significant humoral deficits in this predominantly cellular immunodeficiency.

Evaluation of IgA deficiency in Sardinians indicates a susceptibility gene is encoded within the HLA class III region

IgA deficiency (IgA-D) has been associated with the HLA region, in particular with the North European haplotype HLA-A1, -B8, -DR3, but the exact location of the susceptibility gene(s) is unknown. Some reports suggest that a susceptibility gene is encoded in the class II region, while others implicate the class III region. We exploited differences between the common Sardinian and North European HLA-DR3 haplotypes to help localize the IgA-D susceptibility gene(s). With the knowledge that approximately 13% of HLA-DR3 homozygous individuals of North European origin are IgA-D, we examined 43 HLA-DR3 homozygous Sardinians to find that all had normal serum IgA, IgG and IgM levels. A detailed analysis of their MHC haplotypes indicated a common Sardinian HLA-DR3 haplotype TAP1A, TAP2A, HLA-DQB1*0201, -DQA1*0501, -DRB1*0301, LH1-(Z + 2), D3A-(Z + 2), C4B-0, C4A-L, G11-15, Bf-0-4, C2-a, HSP70-7.5, 9N3-(Z + 10), 82I-(Z - 2), TNFalpha-9, 62-(Z - 20), HLA-B18, -Cw5, -A30 which diverges from the common North European HLA-DR3 haplotype telomeric to the HLA-DR region. In parallel studies of five Sardinians with IgA-D, two of the 10 HLA haplotypes (20%) contained HLA-DR3, a frequency similar to that observed in the background population. One of these was the HLA-DR3- B8 North European haplotype, which occurs rarely in Sardinia. Our data favour the hypothesis that a class III region allele, present on the common North European but not on the Sardinian HLA-DR3 haplotype, confers susceptibility to IgA-D.