IgA deficiency in children. A clinical study with special reference to intestinal findings

Clinical manifestation for immunoglobulin A deficiency: a systematic review and meta-analysis

OBJECTIVES

Immunoglobulin A deficiency (IgAD) is a common disease with an unknown genetic defect, characterized by the decreased or absent IgA with other isotypes normal, normal subclasses, and specific antibodies. Patients with this disorder represent a spectrum of clinical manifestations including infections, autoimmune disorders, malignancy, and allergic diseases. The current study aimed to evaluate their prevalence and categorized them.

METHODS

We searched PubMed, Web of Science, and Scopus databases to find eligible studies from the earliest available date to January 2022 with standard keywords. Pooled estimates of clinical manifestations prevalence and the corresponding 95% confidence intervals were calculated using random-effects models.

RESULTS

The most prevalent clinical manifestations belonged to infection (64.8%) followed by allergic diseases (26.16%) and autoimmunity (22.0%), respectively. In selective IgA deficiency patients as the largest group of IgAD in current study, celiac disease (6.57%), Inflammatory bowel disease (4.01%), and rheumatoid arthritis (3.80%) were the most prevalent autoimmunity. Meanwhile, the most frequent infection was respiratory tract infection, fungal infection, and gastrointestinal infection at 50.74%, 18.48%, and 15.79%, respectively. In addition, the pooled prevalence of asthma, allergic rhinitis, and allergic conjunctivitis were 19.06%, 15.46%, and 11.68%, respectively which were reported as the most widespread allergic diseases.

CONCLUSIONS

Our results showed that apart from undiagnosed IgAD patients, IgAD patients represent a wide range of clinical manifestations. Infection, allergy, and autoimmunity are the most common clinical manifestations. The concurrent presence of IgA and IgG subtypes deficiency could be associated with increased susceptibility to infection. Considering the probability of developing new clinical complications during follow-up, periodic assessments of IgAD patients should be inspected.

Innate Mechanisms in Selective IgA Deficiency

Selective IgA deficiency (SIgAD), characterized by a serum IgA level below 0.07 mg/ml, while displaying normal serum levels of IgM and IgG antibodies, is the most frequently occurring primary immunodeficiency that reveals itself after the first four years after birth. These individuals with SIgAD are for the majority healthy and even when they are identified they are usually not investigated further or followed up. However, recent studies show that newborns and young infants already display clinical manifestations of this condition due to aberrancies in their immune defense. Interestingly, there is a huge heterogeneity in the clinical symptoms of the affected individuals. More than 50% of the affected individuals do not have clinical symptoms, while the individuals that do show clinical symptoms can suffer from mild to severe infections, allergies and autoimmune diseases. However, the reason for this heterogeneity in the manifestation of clinical symptoms of the individuals with SIgAD is unknown. Therefore, this review focusses on the characteristics of innate immune system driving T-cell independent IgA production and providing a mechanism underlying the development of SIgAD. Thereby, we focus on some important genes, including TNFRSF13B (encoding TACI), associated with SIgAD and the involvement of epigenetics, which will cover the methylation degree of TNFRSF13B, and environmental factors, including the gut microbiota, in the development of SIgAD. Currently, no specific treatment for SIgAD exists and novel therapeutic strategies could be developed based on the discussed information.

Avoidance of Cow's Milk-Based Formula for At-Risk Infants Does Not Reduce Development of Celiac Disease: A Randomized Controlled Trial

BACKGROUND & AIMS

Feeding during the first months of life might affect risk for celiac disease. Individuals with celiac disease or type 1 diabetes have been reported to have high titers of antibodies against cow's milk proteins. Avoidance of cow's milk-based formula for infants with genetic susceptibility for type 1 diabetes reduced the cumulative incidence of diabetes-associated autoantibodies. We performed a randomized controlled trial in the same population to study whether weaning to an extensively hydrolyzed formula reduced the risk of celiac disease autoimmunity or celiac disease.

METHODS

We performed a double-blind controlled trial of 230 infants with HLA-defined predisposition to type 1 diabetes and at least 1 family member with type 1 diabetes. The infants were randomly assigned to groups fed a casein hydrolysate formula (n = 113) or a conventional formula (control, n = 117) whenever breast milk was not available during the first 6-8 months of life. Serum samples were collected over a median time period of 10 years and analyzed for antibodies to tissue transglutaminase (anti-TG2A) using a radiobinding assay, to endomysium using an immunofluorescence assay, and antibodies to a deamidated gliadine peptide using an immunofluorometry assay. Duodenal biopsies were collected if levels of anti-TG2A exceeded 20 relative units. Cow's milk antibodies were measured during the first 2 years of life.

RESULTS

Of the 189 participants analyzed for anti-TG2A, 25 (13.2%) tested positive. Of the 230 study participants observed, 10 (4.3%) were diagnosed with celiac disease. We did not find any significant differences at the cumulative incidence of anti-TG2A positivity (hazard ratio, 1.14; 95% confidence interval, 0.51-2.54) or celiac disease (hazard ratio, 4.13; 95% confidence interval, 0.81-21.02) between the casein hydrolysate and cow's milk groups. Children who developed celiac disease had increased titers of cow's milk antibodies before the appearance of anti-TG2A or celiac disease.

CONCLUSIONS

In a randomized controlled trial of 230 infants with genetic risk factors for celiac disease, we did not find evidence that weaning to a diet of extensively hydrolyzed formula compared with cow's milk-based formula would decrease the risk for celiac disease later in life. Increased titers of cow's milk antibody before anti-TG2A and celiac disease indicates that subjects with celiac disease might have increased intestinal permeability in early life. ClinicalTrials.gov Number: NCT00570102.

Selective IgA Deficiency: Epidemiology, Pathogenesis, Clinical Phenotype, Diagnosis, Prognosis and Management

Selective immunoglobulin A deficiency (SIgAD) is the most common primary antibody deficiency. Although more patients with SIgAD are asymptomatic, selected patients suffer from different clinical complications such as pulmonary infections, allergies, autoimmune diseases, gastrointestinal disorders and malignancy. Pathogenesis of SIgAD is still unknown; however, a defective terminal differentiation of B cells and defect in switching to IgA-producing plasma cells are presumed to be responsible. Furthermore, some cytogenic defects and monogenic mutations are associated with SIgAD. There is no specific treatment for patients with symptomatic IgA deficiency, although prophylactic antibiotic therapy along with circumstantial immunoglobulin replacement with justification and supportive care (using a product that contains minimal IgA) could be helpful for patients with a severe phenotype. The epidemiology, pathogenesis, clinical phenotype, diagnosis, prognosis, management and treatment in patients with SIgAD have been reviewed.

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 and clinical profile of celiac disease in children with type 1 diabetes mellitus

OBJECTIVE

To determine the prevalence of celiac disease (CD) in children with type 1 diabetes mellitus (TIDM) in follow-up in a Tertiary Care Referral Centre in Western India and to describe the clinical features indicative of CD in screened patients of TIDM.

STUDY DESIGN

In this single center observational cross-sectional study, 71 children who were diagnosed with TIDM were subjected to screening for CD with tissue transglutaminase antibody testing. Those who tested positive were offered intestinal biopsy for the confirmation of diagnosis. Clinical profiles of both groups of patients were compared and manifestations of CD were delineated.

RESULTS

The study revealed the prevalence of CD (based on serology) in children with Type 1 diabetes as 15.49%. The prevalence of biopsy-confirmed CD was 7.04%. Of the diagnosed CD patients, one-third were symptomatic at the time of screening while the majority was asymptomatic. The major clinical features indicative of CD were intestinal symptoms, anemia, rickets, and short stature. Autoimmune thyroid disease was prevalent in 29.6% of the patients with TIDM followed by CD.

CONCLUSIONS

The high prevalence of CD in children with Type 1 diabetes emphasizes the need for routine screening programs to be in place for these high-risk populations. The clinical profile of patients with CD further elaborates the indicators of CD and the need to screen for them.

IgA deficiency and autoimmunity

IgA is the most abundant immunoglobulin in the human body, and performs a very specialized role which involves mucosal immunity, development of tolerance and protection against infection. IgA is the key immunoglobulin in the respiratory and gastrointestinal tracts, which provide the most intimate interface between the environment and self. Normal levels of IgA are based on early studies consisting of only small numbers of patients. The international consensus definition of IgA deficiency is a level of 0.07g/l after the age of four years in the absence of IgG and IgM deficiencies. The epidemiology of IgA deficiency reveals interesting variances between geographical regions - the incidence in Caucasians being much higher than that in Asians. IgA deficiency has also been found to co-exist with autoimmune diseases, allergies and malignancies. The association with autoimmunity is particularly interesting because it suggests a common genetic linkage that could potentially also explain the diversity in geoepidemiology. Both MHC and non-MHC associations have been described and the 8.1 haplotype has been significantly associated with autoimmunity in IgA deficiency patients over controls. Non-MHC genetic associations include IFIH1 and CLEC16A. The mutations leading to IgA deficiency have not been defined, but in some cases of IgA deficiency it has been suggested that the pathogenesis involves a failure in switched memory B cells that can lead to this cohort experiencing an increased incidence of recurrent bacterial infections or autoimmune diseases. Attempts to investigate the role of cytokines that can induce IgA synthesis in cells of patients with IgA deficiency, such as IL21 or the combination of CD40L/anti-CD40, IL-4 and IL10, are underway.

Screening for coeliac disease in preschool Greek children: the feasibility study of a community-based project

AIM

Evaluation of the prevalence of coeliac disease (CD) in Greek paediatric population.

METHODS

The project consists of two parts: (i) a pilot study of preschool children aged 2-6 years to test the feasibility and diagnostic accuracy of community-based screening and (ii) a CD prevalence study, by random clustered sampling and proportionate stratification of various geographical areas in Greece. Trained nonmedical staff performed a rapid immunochromatographic test to detect IgA antibodies to tTG-IgA and IgA deficiency. Toddlers with positive results were referred to a paediatric gastroenterologist for further assessment with serum anti-tTG IgA and EMA-IgA. Children with positive serum anti-tTG and anti-EMA underwent upper gastrointestinal tract endoscopy and small bowel biopsy and were subsequently in gluten-free diet.

RESULTS

In this project participated 1136 toddlers, who were tested at school. The prevalence of positive rapid anti-tTG screening was 1:154, of IgA deficiency 1:120 and of biopsy-proven CD 1:154. The prevalence of CD from this pilot study served as expected prevalence value for sample size calculation for the main prevalence study.

CONCLUSION

This protocol using rapid immunochromatographic test for the detection of both IgA deficiency and CD is easy to be performed by nonmedical staff in a community setting, enabling the accurate identification of new CD cases among asymptomatic population.

Immunoglobulin A deficiency in celiac disease

GOALS

To determine the prevalence and significance of immunoglobulin A (IgA) deficiency and partial deficiency in patients with celiac disease (CD).

BACKGROUND

Selective IgA deficiency is a common primary immunoglobulin deficiency and has a higher prevalence in patients with CD. The prevalence and significance of IgA deficiency and partial deficiency in patients with CD in the United States has not previously been examined.

STUDY

A retrospective, cohort study of 1498 adults and 317 children seen in a University Medical Center was conducted.

RESULTS

There were 26 patients (22 adults, 4 children) with CD who were IgA deficient and 11 (9 adults, 2 children) with CD who were partially IgA deficient. The prevalence of IgA deficiency/partial deficiency was similar among adults and children (2.1% and 1.9%, respectively, P=0.99). Among adults, concomitant autoimmune disease was present in 29% of IgA-deficient/partially deficient patients versus 12% of CD patients with normal IgA levels (P=0.0081). All 4 IgA-deficient patients who had persistently positive IgG celiac serologies while adherent to a gluten-free diet and were rebiopsied had a normal repeat biopsy. Both positive tissue transglutaminase IgG and antigliadin IgG were found in these patients.

CONCLUSIONS

Selective IgA deficiency/partial deficiency is present in 2% of CD patients at this referral center and is equally prevalent among adults and children. IgA-deficient/partially deficient adults had a higher prevalence of concomitant autoimmune disease than those without IgA deficiency. In patients who are IgA deficient, IgG serologies may be persistently elevated despite histologic recovery.

Presentation of celiac disease

The mode of presentation of patients with celiac disease has changed dramatically over the recent decades, with diarrheal or classic presentations becoming less common. This trend is most markedly seen in children, whose main presentations include recurrent abdominal pain, growth issues, and screening groups at risk. Among adults, presentations include diarrhea, anemia, osteoporosis, and recognition at endoscopy performed for gastroesophageal reflux disease, as well as screening. The groups most commonly screened include family members of patients with celiac disease, Down syndrome, and autoimmune diseases.

Epidemiology and clinical presentations of celiac disease

Evidence of the prevalence of celiac disease comes from serological screening studies. These have revealed that celiac disease is common, occurring in about 1 % of the population worldwide. There are some countries with higher prevalence rates such as Finland and others with lower rates, for example Germany. The disease is found in most continents and appears to be increasing. Most people with the disease are not currently diagnosed though women are diagnosed more frequently than men. The mode of presentation has changed both in children and adults with diarrhea and a malabsorption syndrome becoming less common. Abdominal pain and growth issues are major modes of presentation in children, while anemia, osteoporosis, and recognition at endoscopy performed for GERD are seen as modes of presentation in adults. Screening of at risk groups is a major mode of presentation for both adults and children.

Recognizing gastrointestinal and hepatic manifestations of primary immunodeficiency diseases

Given the complex immune function of the gastrointestinal (GI) tract, it is not surprising that many children with primary immunodeficiencies present with GI tract manifestations. Although many immunodeficiency disorders present with overt evidence of immune dysregulation, a few can present in older children with more subtle signs and symptoms. Such children may present first to a gastroenterologist with common symptoms, including malabsorption, diarrhea, hepatomegaly, or inflammatory bowel disease, which may actually be a manifestation of their underlying immune disorder. A thorough clinical history in combination with a careful review of histology from biopsies may reveal clues that one is dealing with a disease entity outside the norm and may prompt additional laboratory studies beyond the usual set of screening laboratory tests. Once the true underlying diagnosis is revealed, more appropriate therapy can be initiated. Additionally, more appropriate anticipatory guidance regarding the expected disease course, response to medications, and any additional risks that therapy may entail can be provided to the family.

Reversible IgA deficiency after severe Gram-negative bacteria infection in a patient with systemic sclerosis

A 43-year-old woman with systemic sclerosis (SSc) developed IgA deficiency (IgAD) after cholecystitis. The severe decrease of IgA (<10 mg/dl) partially recovered after 5 years. She had repeated episodes of infection during IgAD. Anti-IgA antibody was not detected. Flow cytometric analysis showed that peripheral CD19(+)IgA(+) and CD38(+)IgA(+) cells were normally present. Although the mechanism of secondary IgAD is still vague, its association with autoimmune diseases including SSc and also with bacterial infection is discussed.

Selective IgA deficiency in early life: association to infections and allergic diseases during childhood

Selective IgA deficiency in early life is quite common in Caucasian populations, but it is unclear whether it increases the risk of infections and allergic diseases during childhood. Serum IgA levels were measured in 2423 children at 4 years of age in a Swedish population based birth cohort (BAMSE). Parental questionnaires were repeatedly sent out during the child's first 8 years of life, collecting information about infections and allergic diseases. 14 children (1:173) were found to be IgA deficient at 4 years of age. These children had an increased risk of pseudocroup at year 1 (p<0.01) and food hypersensitivity at year 4 (p<0.05) as compared to IgA sufficient children. No increased risk was observed in the partial IgA deficiency group. The findings suggest that selective IgA deficiency may increase the risk of parentally reported pseudocroup and food hypersensitivity during early childhood.

Celiac disease and IgA deficiency: complications of serological testing approaches encountered in the clinic

BACKGROUND

IgA deficiency causes false-negative IgA-based celiac serology results in patients with celiac disease. Using a case-finding strategy, we examined the prevalence of IgA deficiency, physician evaluation, and management of IgA deficiency during serological testing for celiac disease.

METHODS

We reviewed consecutive IgA-endomysial antibody (EMA) and serum IgA results from the laboratory database over 17 months. We cross-referenced seronegative patients with IgA deficiency (IgA <0.06 g/L) to the pathology database to evaluate intestinal biopsy results. Ordering physicians received a questionnaire regarding the management of seronegative patients with IgA deficiency who had no biopsy record.

RESULTS

Among the 9533 patients tested for IgA-EMA, 4698 (49%) were tested for IgA deficiency. IgA deficiency occurred in 35 of 4698 (0.75%) patients screened for IgA deficiency. Only 19 of 35 (54%) IgA-deficient patients were diagnosed appropriately with either intestinal biopsy (17 patients) or measurement of IgG-tissue transglutaminase (2 patients). Thirteen (76%) of the 17 IgA-deficient patients who underwent upper endoscopy with or without colonoscopy displayed gastrointestinal pathology on biopsies, including 3 (18%) with celiac disease. No further evaluation to exclude celiac disease was performed for the remaining 16 of 35 (46%) IgA-deficient, EMA-negative patients because of inappropriate management (6 patients), administrative error (7 patients), or patient/physician refusal (3 patients).

CONCLUSIONS

IgA deficiency occurred in 1:131 patients tested for celiac disease, and celiac disease occurred in 1:6 of those properly evaluated. Inadequate evaluation of IgA deficiency while testing for celiac disease occurred frequently and resulted in the underdiagnosis of both. Changes in testing algorithms and reporting of results were made to improve testing for celiac disease and IgA deficiency.

Elevation of IgG antibodies against tissue transglutaminase as a diagnostic tool for coeliac disease in selective IgA deficiency

BACKGROUND

IgA serum autoantibodies against tissue transglutaminase (tTG) have an established diagnostic value in coeliac disease, and high efficacy tests are widely available for their detection. However, serological evaluation of IgA deficient subjects is still difficult.

AIMS

To evaluate the diagnostic potential of IgG class anti-tTG autoantibodies measured quantitatively using an enzyme linked immunosorbent assay (ELISA) compared with immunofluorescent detection of coeliac autoantibodies.

PATIENTS

We tested serum samples from 325 IgA deficient subjects, including 78 patients with coeliac disease, 73 disease controls, and 174 blood donors.

METHODS

IgG antibodies against human recombinant tTG were measured with an ELISA. IgG antiendomysium antibodies (EMA) were assayed by indirect immunofluorescence on human jejunum and appendix sections.

RESULTS

The IgG anti-tTG ELISA had a sensitivity of 98.7% and a specificity of 98.6%, and the correlation with IgG EMA titres was high (r(s)=0.91). One coeliac patient, initially negative in all autoantibody tests, displayed both IgG anti-tTG antibodies and IgG EMA during later gluten exposure. IgG anti-tTG antibodies and EMA titres showed significant decreases (p<0.001) in treated patients. The frequency of IgG anti-tTG autoantibody positivity was 9.8% among IgA deficient blood donors and 11 of the 12 positive subjects with known HLA-DQ haplotypes carried DQ2 or DQ8 alleles.

CONCLUSIONS

IgG anti-tTG and IgG EMA autoantibody tests are highly efficient in detecting coeliac disease in IgA deficient patients. The high prevalence of coeliac antibodies among symptom free IgA deficient blood donors who also carry coeliac-type HLA-DQ genes indicates that all IgA deficient persons should be evaluated for coeliac disease.

Fasting plasma nitric oxide products in coeliac disease

OBJECTIVES

In coeliac disease, inducible nitric oxide synthase activity in the duodenal mucosa is greatly increased, resulting in increased production of nitric oxide. We investigated whether this resulted in increased plasma concentrations of its stable end products (nitrate/nitrite: NOx).

METHODS

Fasting plasma NOx was determined in 66 patients attending for upper gastrointestinal endoscopy. Of these, 21 had coeliac disease (nine were on a gluten-free diet). The remainder had a variety of other gastrointestinal disorders. NOx was determined using the Griess reaction. Distal duodenal biopsies for coeliac patients were graded according to the Marsh score.

RESULTS

Patients with untreated coeliac disease had a higher fasting NOx concentration (mean 117.5 microM) than either those with coeliac disease taking a gluten-free diet (mean 71.2 microM) or those with other diseases (mean 33.5 microM; one-way analysis of variance, P < 0.001). Coeliac patients with higher fasting NOx concentrations had more marked histological changes (P < 0.05).

CONCLUSION

Fasting plasma NOx is significantly elevated in untreated coeliac disease and correlates with histological grade. The potential clinical utility of serial NOx measurements to monitor improvement on a gluten-free diet requires further study.

Endocrinological disorders and celiac disease

Celiac disease is a permanent intolerance to dietary gluten. Its well known features are abdominal symptoms, malabsorption of nutrients, and small-bowel mucosal inflammation with villous atrophy, which recover on a gluten-free diet. Diagnosis is challenging in that patients often suffer from subtle, if any, symptoms. The risk of clinically silent celiac disease is increased in various autoimmune conditions. The endocrinologist, especially, should maintain high suspicion and alertness to celiac disease, which is to be found in 2-5% of patients with insulin-dependent diabetes mellitus or autoimmune thyroid disease. Patients with multiple endocrine disorders, Addison's disease, alopecia, or hypophysitis may also have concomitant celiac disease. Similar heredity and proneness to autoimmune conditions are considered to be explanations for these associations. A gluten-free diet is essential to prevent celiac complications such as anemia, osteoporosis, and infertility. The diet may also be beneficial in the treatment of the underlying endocrinological disease; prolonged gluten exposure may even contribute to the development of autoimmune diseases. The diagnosis of celiac disease requires endoscopic biopsy, but serological screening with antiendomysial and antitissue transglutaminase antibody assays is an easy method for preliminary case finding. Celiac disease will be increasingly detected provided the close association with autoimmune endocrinological diseases is recognized.

New diagnostic findings in coeliac disease

Coeliac disease, a life-long gluten-sensitive disorder, characterized by malabsorption, villous atrophy and crypt hyperplasia, is well recognized. However, the disease is evidently underdiagnosed, and the classic forms constitute only the tip of the 'coeliac iceberg'. Patients with coeliac disease can have subtle symptoms, if any. Diagnostic difficulties may further emerge when minor mucosal changes are found. In coeliac screening and case-finding a novel test, the antitissue transglutaminase test, has proven promising with a sensitivity and specificity of over 95 %. Genetic and immunohistological research has taken a great leap forward. Coeliac disease is strongly associated with HLA-DQ2, coded by the DQA1*0501 and DQB1*02 alleles, or the DQ8 (DQA1*03, DQB1*0302 alleles). The disease is rare in patients who do not share these alleles, a circumstance which can be utilized in diagnostics. An increase in small bowel intraepithelial lymphocytes especially gammadelta+ T-cell receptor-bearing cells is typical, albeit not pathognomonic, for coeliac disease. Combining new symptoms, humoral immunity, genetics and immunohistological staining can today offer a greater diagnostic scope for coeliac disease, especially in cases where clinical presentation and small bowel biopsy findings remain doubtful.

Prevalence and clinical features of selective immunoglobulin A deficiency in coeliac disease: an Italian multicentre study. Italian Society of Paediatric Gastroenterology and Hepatology (SIGEP) and "Club del Tenue" Working Groups on Coeliac Disease

BACKGROUND

Selective immunoglobulin A (IgA) deficiency (SIgAD) is associated with coeliac disease (CD).

AIM

To make a retrospective study of the association of SIgAD with CD in Italy.

METHODS

Hospital medical records of 2098 patients consecutively diagnosed as having CD were reviewed.

RESULTS

Of 2098 patients with CD, 54 (2.6%) had SIgAD, representing a 10-16-fold increase over that in the population in general. This increase was not influenced by age or geographical factors. Patients with SIgAD had a higher incidence of silent forms (7/54, 13%), recurrent infections (16/54, 29.6%), and atopic diseases (7/54, 13%) than those without. The association with autoimmune and malignant diseases and the outcome after eating a gluten free diet were similar in patients with or without SIgAD. In all patients with SIgAD, antibodies for IgA gliadin and endomysium were absent, but serum levels of IgG anti-gliadin antibodies were high in almost all of them (51/54).

CONCLUSIONS

Serum IgA should be measured in order to be able to interpret negative results for IgA anti-gliadin antibodies and anti-endomysial antibodies in patients being screened for CD. Since some patients with CD and SIgAD may be negative for IgG anti-gliadin antibodies, an intestinal biopsy should be performed in all suspected cases.

Celiac disease and selective immunoglobulin A deficiency

Selective IgA deficiency was observed in 12 of 688 (1.7%) patients with celiac disease who were clinically undistinguishable from patients with celiac disease with normal IgA levels. This high prevalence of IgA deficiency in patients with celiac disease makes serum IgA assay advisable when screening for celiac disease is performed by measurement of antigliadin antibodies or anti-IgA endomysium antibodies. Similarly, subjects with IgA deficiency should be considered at risk of celiac disease.

Addison's disease and selective IgA deficiency in two coeliac patients

Coeliac disease is associated with selective IgA deficiency and various autoimmune disorders. An association between Addison's disease and coeliac disease has been documented previously in the literature but never heretofore in coeliac patients with selective IgA deficiency. From a coeliac registry of over 700 biopsy-proven coeliac patients, studied closely over a 25-year period at University College Hospital, Galway, we now report the finding of Addison's disease and selective IgA deficiency in two patients with established coeliac disease. Previous reports of Addison's disease in coeliac patients were sporadic, and it was felt that the association between the two conditions was fortuitous. We now believe that coeliac patients, especially those who are selectively deficient in serum IgA, should be followed up with increased vigilance, as the association between IgA-deficient coeliac patients and Addison's disease is greater than can be explained by chance. Furthermore, we suggest that patients with established Addison's disease may have subclinical coeliac disease and should be screened with anti-reticulin or anti-endomyseal antibodies.

Prevalence and diagnosis of celiac disease in IgA-deficient children

BACKGROUND

Reported frequencies of celiac disease in selective IgA deficiency in childhood vary widely and this is probably due to the different characteristics of the patients studied and to the different criteria used for intestinal biopsy: all patients or only those with symptoms of malabsorption. Diagnosis of celiac disease is of considerable importance in IgA deficiency because of its increased frequency and also because avoidance of dietary gluten permits elimination of the symptoms and complications of celiac disease.

OBJECTIVES

To obtain a more reliable estimate of the incidence of celiac disease in childhood IgA deficiency jejunal biopsies were performed in 65 consecutively diagnosed IgA-deficient children whose parents consented. Some clinical and laboratory parameters including IgA-antigliadin and IgG-antigliadin antibodies were evaluated to predict their usefulness in selecting IgA-deficient patients for intestinal biopsy.

METHODS

All IgA-deficient patients had serum IgA levels below 5 mg/dL and salivary IgA below 0.5 mg/dL. Jejunal biopsy was performed using a peroral Watson capsule and IgA-antigliadin and IgG-antigliadin antibodies were performed by an ELISA assay.

RESULTS

Biopsy findings of severe villous atrophy permitted diagnosis of celiac disease in 7.7% (5/65 children). IgG-antigliadin antibody levels, elevated in 16 patients including all five celiacs, were the best parameter for predicting celiac disease and gave no false negatives.

CONCLUSIONS

The 7.7% frequency of celiac disease observed in these IgA-deficient children is about 20 times higher than in the general Italian population, and the lowest among the studies biopsying all patients; this is probably attributable to the presence of a substantial proportion of healthy children (20/65) and very few (2/65) with autoimmune disorders. The elevated sensitivity and negative-predictive value of IgG-antigliadin antibodies lead us to suggest that positive IgG-antigliadin antibodies can be used to select IgA-deficient children for jejunal biopsy with a very low probability of missing celiac disease while allowing a drastic reduction in the number of biopsies performed.

Long-term follow-up of health in blood donors with primary selective IgA deficiency

A 20-year health follow-up study of 159 initially healthy blood donors with a severe deficiency of serum IgA ( < 0.05 x 10(-3) g/L) and of 45 donors with decreased serum IgA (0.05 x 10(-3)-0.8 g/L) was carried out. The findings indicate that persons with a severe deficiency of and decreased serum IgA who are healthy as young adults have an increased susceptibility to pneumonia and recurrent episodes of other respiratory infections and a higher risk of developing autoimmune diseases in middle age. Vitiligo, autoimmune hypothyreosis, milk intolerance, and possible rheumatoid arthritis were associated with severe IgA deficiency, but otherwise different degrees of IgA deficiency seem to be similar with respect to the appearance of diseases. Regardless of the fact that a total of 163 (80%) of the 204 IgA-deficient subjects had-episodes of infections, drug allergy, or autoimmune or atopic disease, the finding of primary, selective IgA deficiency in a healthy adult per se does not seem to predict severe life-threatening illnesses at least during 20 years of life.

Gluten-sensitive enteropathy

Gluten-sensitive enteropathy is induced by dietary wheat gliadin and related proteins in genetically susceptible individuals. Most evidence suggests that the mucosal lesion represents an immunologically mediated injury triggered by gluten in the context of a particular assortment of major histocompatibility complex genes. The amino acid residues of gliadin and related proteins responsible for toxicity have not been identified; in vitro systems are available, but definitive conclusions must rely on in vivo jejunal challenges. At a conservative estimate, symptomatic gluten-sensitive enteropathy affects approximately 1 in 1000 individuals in Europe; however, it is now becoming clear that a greater proportion of individuals has clinically silent disease, and probably many others have a minor form of the the enteropathy. In most countries, the clinical presentation has changed over the past few years coming closer to the adult type of the disease, and the age of onset of symptoms is shifting upward. Liver, joint, hematologic, dental, and neurologic symptoms are increasingly being recognized. Several diseases are associated the gluten-sensitive enteropathy, such as IgA deficiency, insulin-dependent diabetes mellitus, and a range of other autoimmune diseases. Tests based on the measurement of antigliadin and antiendomysium antibodies have gained success as noninvasive screening tests; however, the ultimate diagnosis still is based on the finding of a severe histologic lesion of the jejunum while the patient is on a gluten-containing diet and on its disappearance once the gluten is excluded from the diet. A lifelong, strict GFD is mandatory for celiac children. Among other long-term problems, an increased risk of intestinal lymphoma has been reported in patients on a normal gluten-containing diet.

A case of protein-losing enteropathy in idiopathic thrombocytopenic purpura with decreased IgA

A young woman presented with high fever and edema in January, 1984, and was diagnosed as having systemic lupus erythematosus. Prednisolone administration failed to improve her symptoms. In May she was admitted to hospital because of elevated erythrocyte sedimentation rate (ESR), hypoproteinemia, hypogammaglobulinemia, hypocomplementemia, positive antinuclear antibody, elevated immune complex level, and diarrhea. Edema disappeared following administration of diuretics and albumin, although the pathogenesis was still undetermined. In September, she was referred to our institution because of severe watery diarrhea and hypoproteinemia. Endoscopic examination showed a diffuse inflammatory lesion in the duodenum and the colon. Radioisotopic 51Cr-albumin study results were compatible with protein-losing enteropathy. Hypoproteinemia and inflammatory changes of the intestine were improved by antibiotics, suggesting that the inflammatory lesion was caused by bacterial infection. Despite the improvements in clinical symptoms and laboratory findings, the serum IgA level was still low and the thrombocytopenia remained. The morphological characteristics of the megakaryocytes were consistent with idiopathic thrombocytopenic purpura. In May, 1986, the thrombocytopenia deteriorated, causing purpura. Prednisolone was administered again, and this resulted in normalization of the platelet count, although the IgA level remained low. Finally the prednisolone was stopped, and the IgA level gradually recovered, with the improvement of the enterocolitis. The exact pathogenesis of the whole picture in this case is unclear, but an 8-year-long clinical course suggests that the protein-losing was caused by an infectious enterocolitis superimposed on IgA deficiency.

Selective IgA deficiency and coeliac disease

Twenty-five children and adults with concomitant coeliac disease and selective IgA deficiency are described. IgG-class reticulin antibodies were positive in 94%. The clinical course of coeliac disease did not differ from that of patients with normal serum IgA level. Patients with IgA deficiency also had other concomitant diseases, especially autoimmune diseases. Patients with selective IgA deficiency have at least a tenfold risk of coeliac disease compared with the population in general.

Surgery of the immunodeficient child

A great deal has been learned about the surgery of immunodeficient patients. If one assesses the problem and follows the surgical principles described, in most instances one can solve the problem and be a great help to the oncologist and immunotherapist. A team approach is most important.

The relationship between atopy and salivary IgA deficiency in infancy

In a prospective study, infants born to atopic parents had a significantly higher prevalence of salivary IgA deficiency at all ages studied than control infants, and the mean non zero IgA level of the potentially atopic infants was significantly lower at 8 and 12 months than of control infants. Of the infants with atopic parents, the prevalence of IgA deficiency was not significantly greater in those who manifested atopic disease during the study period than in those who did not, but the levels were significantly lower at 4 months.

Fatal unresponsive villous atrophy of the jejunum, connective tissue disease and diabetes in a girl with intestinal epithelial cell antibody

The patient presented with a diabetes at the age of 3 years. At the age of 5 years she got persistent diarrhoea, lost weight and showed symptoms or arthritis and pericarditis. She was found to have total villous atrophy of the jejunum, which did not respond to dietary treatment, total parental nutrition, prednisone and cyclophosphamide medication. She had high titres of antinuclear antibodies and elevated serum IgG, but antibodies to DNA and to ribonuclearprotein were negative. A low titre of antibodies to human intestinal epithelial cells was found. The patient died of overwhelming fungal sepsis. We propose that the intestinal damage is part of the autoimmune disease. Careful study of jejunal biopsy specimens is helpful in distinguishing this type of patient from patients with coeliac disease.

Immunoglobulin levels and function in pre-school children with recurrent respiratory infections

Thirty pre-school children with recurrent respiratory infections had a higher age adjusted mean serum IgG level than their siblings or a reference group. One index child had persistently low serum IgA, but mean serum IgA and IgM levels for the index children were normal. All of the 23 index children and 17 siblings studied had a four-fold or greater rise in virus neutralizing antibody titre. There was no correlation between serum immunoglobulin levels and frequency of infections. There was, however, a significant inverse correlation between salivary IgA levels when healthy and the number of infections experienced by each child in the study year. Salivary IgA levels rose considerably during acute infections.

Gastrointestinal complications of congenital immunodeficiency states. The surgeon's role

Ninety-one congenitally immunodeficient patients treated from 1972 to 1981 were reviewed to assess the incidence and nature of gastrointestinal complications. Thirty-three of these patients (36%) developed 59 complications. Patients with immunodeficiencies characterized by neutrophil dysfunction--chronic granulomatous disease (20 patients) and cyclic neutropenia (eight patients)--developed 22 surgical infections, 22 of which required operation. In patients with neutrophil defects, postoperative morbidity was frequent and severe. Gastrointestinal symptoms were common in patients with isolated defects of B or T lymphocytes. Ten of forty-one patients with congenital hypogammaglobulinemia developed gastrointestinal complications, as did one of four patients with DiGeorge Syndrome, and the single patient with secretory IgA deficiency. However, operation was not required for these patients with isolated disorders of lymphocyte function. Patients with combined B and T cell disorders developed gastrointestinal disease, requiring operative therapy at intermediate rates. Gastrointestinal symptoms developed in four of nine patients with severe combined immunodeficiency and three of eight with Wiskott-Aldrich syndrome. Operative therapy was required in two of these seven symptomatic patients.

Selective IgA deficiency: clinical and immunological evaluation of 50 pediatric patients

Fifty children with IgA deficiency were folllowed for 1 to 4 years from 1975 to 1978. Thirty-five had complete deficiency of serum IgA (less than 2.5 IU/ml) and 15 partial deficiency (serum IgA below the 10th centile for age). Patients with another associated immunodeficiency, such as ataxia-telangiectasia, were not included. Most children with complete deficiency of IgA had recurrent respiratory and/or gastrointestinal infections, about half with onset in the first year of life, while partial deficiency of IgA has probably little if any importance for anti-infectious immunity but is important in the pathogenesis of atopy. Atopic diseases were frequent in both groups. Chromosomal abnormalities were found in 2 patients: trisomy 21 in one and in the other a ring chromosome 18. No important defects in cellular immunity were detected but some isolated, borderline abnormalities were often present.

Yeast opsonisation in children with chronic diarrhoeal states

Four patients with defective yeast opsonisation and protracted diarrhoea are reported. Plasma infusions improved the opsonising function in all 4 and the diarrhoea in 3. This immunological abnormality was assessed in 100 sequential patients with chronic diarrhoea associated with various gastrointestinal disorders; 52 with protracted diarrhoea and failure to thrive of undetermined cause, 26 with 'toddler diarrhoea', 8 with coeliac disease, 5 with chronic inflammatory bowel disease, and 9 with miscellaneous disorders. 23% of the patients with protracted diarrhoea of undetermined cause had defective opsonisation, a greater proportion (P less than 0.05) than that in 'toddler diarrhoea' or the remaining patients, in whom the frequency (4%) was similar to that (5%) in healthy populations. We suggest that yeast opsonisation be tested in children with protracted diarrhoea, as plasma infusions can be an effective form of treatment.

Clinical findings and intestinal immunoglobulins in children with partial IgA deficiency

We studied the intestinal morphology, and the jejunal and rectal immunoglobulins of 16 children with partial IgA deficiency, defined as serum IgA concentration more than two standard deviations below the mean for age, but higher than the lower limit of sensitivity of single radial immunodiffusion (0.02 g/l). Five of the patients had been treated with phenytoin, 2 had juvenile rheumatoid arthritis, 2 had ulcerative colitis and 5 had recurrent upper respiratory tract infections. The jejunal morphology was normal in every case. In 6 cases normalization of serum IgA occurred during the follow-up, while in one patient with ulcerative colitis the concentration fell below 0.02 g/l. In patients with recurrent infections, there was a decreased frequency of infections when the level of serum igA increased. In 4 patients, IgM-containing cells prodominated in both the jejunal and rectal mucosa, and IgM was increased in the intestinal juice. In 6 patients a significant increase in IgM-containing cells or a decrease in IgA-containing cells or both were seen in either the rectal or jejunal mucosa. There was no correlation between the number of IgA-containing cells in the intestinal mucosa and the serum level of IgA.

Hypothyroidism and coeliac disease-A family study

A family of ten children is described. Five were hypothyroid and two had coeliac disease, both disorders coexisting in one child. IgA deficiency was present in the mother and one child.

Antigen absorption from the small intestine and gastrointestinal disease

In this article, I have attempted to summarize the concept of intestinal permeability to antigens such as ingested food proteins, bacterial breakdown products, endotoxins, and enzymes. The mature gut retains the capacity to absorb macromolecules by a pinocytotic mechanism which is more pronounced during the neonatal period. The vast majority of individuals have no ill effects from the intestinal transport of large molecules. However, when increased quantities of toxic or antigenic macromolecules gain access to the body because of a derangement in the intraluminal digestive process or because of a defect in the mucosal barrier, antigen absorption may be altered and result in either local intestinal or systemic disorders. The speculative concepts suggesting that clinical disease states may be associated with altered mucosal permeability have been discussed.

Immunological abnormalities in the sera of IgA-deficient blood donors

Immunological abnormalities of 163 IgA-deficient blood donors were studied. Anti-IgA antibodies were found in 15, anti-IgG antibodies (measured by the Ripley test) in 34, latex test positivity in 21, anti-IgM antibodies in 9 and antibodies against bovine milk in 41 sera. These numbers differed significantly from the control groups of normal blood donors. In the studies of thyroglobulin antibodies, antinuclear antibodies and blood group A and B isoagglutinins there was no difference from the controls. Interrelationships of all findings were studies by statistical analysis. Correlations were found between latex and Ripley tests and rheumatic disorders as well as between high age and anti-IgA antibodies. Male subjects had antibodies against bovine milk more often than females. Otherwise no striking findings were brought up by the statistical analysis.

Selective IgA deficiency in blood donors

The frequency of selective deficiency of serum IgA was determined in a population of 64,588 new Finnish blood donors by Ouchterlony's double diffusion with 10 mug/ml as the limit of detection. The incidence was 1:396. Those found IgA-deficient were retested by hemagglutination inhibition and by radioimmunoassay. The calculated incidences of IgA levels below 0.5 and 0.015 mug/ml were 1:500 and 1:800, respectively. Statistically significant compensatory elevation of serum IgG was observed in the IgA-deficient donors. The IgM levels were not changed. Among 9,920 hospital patients, the incidence of IgA deficiency was 1:660. The age structure of the IgA-deficient patients was similar to that of the IgA-deficient healthy blood donors but lower than that of hospital patients in general. No difference was observed between the clinical history of IgA-deficienct blood donors and of the controls.