PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “IgA Deficiency”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2001

Physiology of IgA and IgA deficiency.

Although secretory immunoglobulin A (IgA) is important in mucosal immunity. selective IgA deficiency is the most common primary immunodeficiency of humans. In most cases this defect is not associated with any illness. The reasons for this are unknown, but other immunological compensations might provide sufficient or complete restitution. Alternatively, it is possible that IgA deficiency alone may not predispose to disease, but additional immunological abnormalities might be present in symptomatic individuals. Some IgA-deficient individuals have a reduced antibody response to immunizations (even with normal IgG and IgM levels) and others have deficient responses to bacterial polysaccharides when IgG subclass levels are normal. The physiological role of IgA, the frequency and causes of IgA deficiency, the diseases associated with its absence, and current limited understanding of the pathogenesis of selective IgA deficiency will be reviewed.

Animals↗
PubMed2001

[The current concept of primary IgA deficiency and its prevalence in Iceland.].

IgA deficiency is among the most common primary immune deficiency known. Its prevalence, ranging from 1/324-1/1850, depends upon the study group geographic location and its ethnicity. IgA deficiency is commonly associated with other immune defects such as IgG2, and IgG4 deficiency. In addition, ataxia telangiectasia has been associated with IgA deficiency as well. The clinical significans of IgA deficiency is presently unclear. However, increased susceptibility to atopy, autoimmunity, infections and cancer has been reported. Furthermore, majority of these diseases are bound to the mucosal surfaces; the organ where IgA is thought to have its most protective role. Recent studies focusing on the genealogy of primary IgA deficiency have found linkages to chromosome 6, 14, 18 and 22. In addition, a link to certain HLA haplotypes has been reported. Thus, further studies into the immunogenetics of IgA deficiency are needed, particularly focusing upon the question why some individuals with IgA deficiency are prone to diseases whereas others are not. In this article some of these questions are addressed, and the current literature on the topic reviewed.

English Abstract↗
PubMed1991

C4 polymorphism and major histocompatibility complex haplotypes in IgA deficiency: association with C4A null haplotypes.

IgA-deficient individuals (n = 110) and six families comprising 9 cases of IgA deficiency were typed for HLA-A, -B, -DR, C4 and factor B. Phenotype frequencies were increased for HLA-B8 (p = 0.004), HLA-DR3 (p = 0.001) and homozygous C4AQ0 (p = 0.01) and decreased for HLA-B7 (p = 0.004), HLA-DR2 (p = 0.0001) and C4A3 (p = 0.00007) compared to controls. Homozygous C4A deficiency was found in 20% of IgA-deficient persons. As clearly suggested by investigation of families, the findings could be attributed to high prevalence of the extended major histocompatibility complex (MHC) haplotype [HLA-A1, B8, C4AQ0, C4B1, BfS, DR3] in IgA deficiency. All but 1 of the 9 IgA-deficient persons included in the family study carried this haplotype and 4 of them were homozygous. In the families, 3 persons with normal serum IgA concentrations had the same MHC haplotypes as their IgA-deficient relatives. The findings were also consistent with possible overrepresentation of other MHC haplotypes with aberrant C4 gene organization in IgA deficiency. As previously suggested, the presence of two MHC haplotypes associated with IgA deficiency appears to be a necessary but not sufficient requirement for manifestation of the condition. The putative existence of a recessive gene in the MHC with regulatory function with regard to IgA gene expression is consistent with the findings.

Complement C4↗
PubMedDate not supplied

Measurement of salivary, urinary and fecal secretory IgA levels in children with partial or total IgA deficiency.

We measured salivary, urinary and fecal secretory IgA (sIgA) levels in 11 children with total IgA deficiency and in 6 children with partial IgA deficiency using an ELISA technique. This was based on flexible microplates coated with antisecretory component (SC) and peroxidase-conjugated anti-IgA as a second antibody. Selective IgA deficiency is diagnosed as a serum IgA concentration < or = 0.05 g/l; partial IgA deficiency is diagnosed as a serum concentration of IgA > 0.05 g/l but 2 SD below normal levels. No salivary or fecal sIgA, and only low levels of urinary sIgA, were detected in the selective IgA-deficient group. The partial IgA-deficient children presented with low levels of salivary, urinary and fecal sIgA. Fecal sIgA levels correlated with salivary sIgA levels (p < 0.01) but not with urinary sIgA levels (p > 0.05) in the IgA-deficient patients. We found that all the children with partial IgA deficiency, except one, had detectable, but low values of secretory IgA. Our data suggest that these patients also have a partial mucosal IgA deficiency.

Adolescent↗
PubMed1993

IgG subclass concentrations and Gm allotypes in IgA-deficient and normal pregnant women.

IgG subclass concentrations were measured in the serum of 40 IgA-deficient (IgA concentration < 0.01 milligram) and 38 normal women in the second trimester of pregnancy. In the IgA-deficient group, 2 women were also deficient in IgG2 and IgG4, while a further 10 had very low concentrations of serum IgG4 only. These low IgG4 values were unrelated to the presence of anti-IgA antibodies. The incidence of low IgG4 values was significantly greater (p < 0.01) than in the control group where only 1 woman had low IgG4 and none had low IgG2. Mean values for total IgG, IgG1 and IgG3 were very significantly higher (p < 0.001) in the IgA-deficient group than in the control group. These differences were unrelated to Gm phenotype.

Female↗
PubMed2000

Tumor necrosis factor genomic polymorphism in Spanish IGA deficiency patients.

Selective IgA deficiency (IgAD) is the most common form of primary immunodeficiency. Its association with genes within the major histocompatibility complex (MHC) has been repeatedly reported. Recently the susceptibility gene has been located in the class III region, around the tumor necrosis factor (TNF) cluster. In this study we have examined IgAD association with TNF-alpha gene promoter polymorphisms and TNFa and b microsatellites. No significant association was found with the former polymorphisms and the observed associations with TNFa2 allele and haplotypes TNFa2b1 and TNFa2b3 were proven to be secondary to their occurrence on the B14-DR1 and B8-DR3 haplotypes, previously reported to be associated with susceptibility to IgAD. However, a primary negative (protective) association was found between the TNFa10 allele and IgAD.

Alleles↗
PubMed2001

[Role of aspartic acid at position 57 of the HLA-DQ beta chain in sporadic and familial forms of selective IgA deficiency].

BACKGROUND: Selective IgA deficiency (IgAD) is the most frequent primary immunodeficiency in Caucasians. A protective effect of an aspartic acid residue at position 57 of the DQ beta chain against IgAD has been repeatedly described. The aim of our study was to determine, whether the genetic effect of non-aspartic acids (non-Asp) at position 57 of the DQ beta chain is different in familial and non-familial forms of IgAD. METHODS AND RESULTS: Codon 57 genotyping was performed in 59 patients with sporadic from in 28 patients with familial forms of IgAD, and in 162 control persons. Significantly increased occurrence of the non-Asp residues at position 57 in IgAD patients compared to control persons was found, but there was no difference between familial and sporadic forms of IgAD. The association was not proved in six IgAD patients who were relatives of CVID patients. CONCLUSION: The protective effect of non-aspartic acid at position 57 of the DQ beta chain is present in both sporadic and familial form of IgAD. This effect was not observed in IgAD relatives of CVID persons showing that a genetic background of this form might be different than in other forms of IgAD.

Amino Acid Sequence↗
PubMed2003

Cytokine genotyping (TNF and IL-10) in patients with celiac disease and selective IgA deficiency.

OBJECTIVE: Selective IgA deficiency (IgAD) and celiac disease (CD) are frequently associated and share the ancestral haplotype human leukocyte antigen (HLA)-8.1, which is characterized by a peculiar cytokine profile. The aim of this study was to evaluate the role of tumor necrosis factor (TNF) and interleukin (IL)-10 alleles in CD and CD-IgAD. METHODS: The distribution of some biallelic polymorphisms of both cytokine promoters (-308G-->A and -863C-->A at TNF promoter sequence and -1082G-->A, -819C-->A, and -592C-->T at IL-10 promoter) were typed using biotilinated specific probes in 32 celiac patients, in 34 CD-IgAD patients, and in 96 healthy controls. RESULTS: In CD and CD-IgAD, the -308A allele was significantly more frequent than in controls, whereas no significant differences were observed for the biallelic polymorphisms at the -863 and for the three IL-10 promoter polymorphisms. The evaluation of combined TNF and IL-10 genotypes showed in CD-IgAD a significant reduction of -308G/-1082G homozygous subjects and both in CD and CD-IgAD groups an increase of 308AA/1082GG. Accordingly, CD-IgAD patients positive both for -308A TNF and -1082A IL-10 showed an increase of TNF-alpha and a reduction of IL-10 serum levels. CONCLUSIONS: Genetically determined increased production of TNF-alpha and reduction of IL-10 may be relevant for susceptibility to CD, mainly in IgAD, as the different allele expression at TNF and IL-10 loci seems to influence cytokine production profile.

Adult↗
PubMed1982

IgA-containing plasma cells in the intestinal mucosa of children with selective IgA deficiency.

In 8 children with selective IgA deficiency (serum IgA less than 5 mg/dl, secretory IgA less than 0.5 mg/dl in unstimulated saliva) immunofluorescent staining of intestinal biopsy specimens revealed the presence of IgA-containing plasma cells. This finding supports the hypothesis that in the intestinal mucosa of patients with IgA deficiency B lymphocytes undergo "sterile" differentiation into IgA-containing plasma cells probably incapable of secreting the IgA synthesized.

B-Lymphocytes↗
PubMed1990

Central MHC genes, IgA deficiency and autoimmune disease.

IgA deficiency is a common immunological disorder that is sometimes associated with an immunodeficiency syndrome, allergic disease, autoimmune disease and gluten enteropathy. Many subjects with this deficiency, however, are healthy, at least for many decades. Analysis of the immunological and genetic abnormalities found in IgA deficiency and in some of the associated disorders has led to the postulate that a genetically determined defect of immunoregulation underlies all of these diseases. Here, Martyn French and Roger Dawkins propose that the products of genes located within the central region of the major histocompatibility complex (MHC) regulate B cells and/or antibody production. Particular MHC ancestral haplotypes contain specific alleles and arrangements of these genes, thereby explaining associations with either increased or decreased production of immunoglobulin isotypes by B cells.

Agammaglobulinemia↗
PubMed1988

Anti-IgA antibodies in IgA-deficient children.

IgG and IgM isotype antibodies to polyclonal human IgA, myeloma IgA1, and myeloma IgA2 were estimated in 38 IgA-deficient children aged between 0.9 and 15 years. All children had IgM anti-IgA antibodies. IgG antibodies against either polyclonal IgA, IgA1, or IgA2 were present in 63% of the IgA-deficient children. IgG anti-IgA antibodies were detected against all three antigens in 8 of 11 severely IgA-deficient children and in 7 of 27 partially IgA-deficient children, but in only 1 of 23 healthy adult controls. The proportion of children with IgG anti-IgA antibodies was significantly greater in the severely IgA-deficient group in comparison with the partially IgA-deficient group and the adult controls (chi-square test, P less than 0.01 and P less than 0.005, respectively). There was a strong correlation within each IgG subclass between antibody responses toward each of the three IgA antigens. Twenty-four children were followed over a period ranging from 0.9 to 11 years (mean, 2.3 years). Three children who were initially IgG anti-IgA antibody negative became antibody positive and three who were antibody positive became antibody negative. Five children with severe IgA deficiency remained severely IgA deficient and IgG antibodies to IgA persisted in all five at follow-up. The presence of IgG anti-IgA antibodies did not influence the normalization of serum IgA at follow-up in 14 of 19 children who were initially partially IgA deficient.

Adolescent↗
PubMed1996

Coexistent IgG2 and IgA deficiencies in blood donors.

BACKGROUND: To meet the transfusion requirements of IgA-deficient patients with anti-IgA, blood services screen random donors to identify potential donors of IgA-deficient blood components. New information reveals that some IgA-deficient persons may also be deficient in IgG2 and may be at increased risk for bacterial infections. STUDY DESIGN AND METHODS: Serum samples from IgA-deficient blood donors and patients were tested for IgG2 concentration by radial immunodiffusion using monospecific anti-IgG2. RESULTS: Four (9.0%) of 44 IgA-deficient blood donors and 14 (31.5%) of 44 IgA-deficient patients had coexistent IgG2 and IgA deficiencies. Follow-up interviews with the 4 donors who had coexistent IgG2 and IgA deficiencies revealed that 3 had recurrent respiratory infections and had been hospitalized at least once for pneumonia. The fourth donor did not report a history suggestive of recurrent infections. CONCLUSION: Some blood donors, recruited specifically because they are IgA deficient, may also be deficient in IgG2. Persons identified by donor screening programs as being IgA deficient should be tested for IgG2. If deficient in IgG2, they should be evaluated for a history of recurrent bacterial infections and counseled accordingly.

Blood Donors↗
PubMed2005

Immunoglobulin G (IgG) anti-tissue transglutaminase antibodies used as markers for IgA-deficient celiac disease patients.

The role of immunoglobulin A (IgA) anti-tissue transglutaminase antibodies (IgA-tTG) as predictors of untreated celiac disease (CoD) is well documented, and the presence and levels of these antibodies are most accurately monitored with native or recombinant human antigens. However, IgA-deficient CoD patients are not identified by IgA serology, and conflicting results concerning the diagnostic validity of IgG antibodies against gliadin (IgG-AGA), endomysium (IgG-EmA), and tTG (IgG-tTG) have been reported. The aim of the present study was to evaluate the utility of IgG-tTG for the detection of CoD in IgA-deficient patients. Samples from 115 IgA-deficient and 200 IgA-sufficient subjects were collected and tested for the presence of IgA and IgG antibodies against tTG, EmA, and AGA. Antibodies against tTG were measured by an enzyme-linked immunosorbent assay based on recombinant human tTG, and antibodies against EmA were determined by immunofluorescence. The values for IgG-tTG showed a higher correlation (correlation coefficient [r] = 0.91) with those for IgG-EmA for the IgA-deficient subjects than for the IgA-sufficient subjects (r = 0.88). The overall concordance of the positive and negative results between IgG-tTG and IgG-EmA was 97%, and the IgG-tTG assay discriminated between IgG-EmA-positive and -negative subjects with IgA deficiency at a rate of 100%. Elevated levels of IgG-tTG and IgG-EmA were measured in 70% of the IgA-sufficient subjects. IgG-tTG detection with recombinant human tTG is a good alternative to IgG-EmA detection, and the addition of IgG-tTG assessment to present screening methods may improve the ability to identify IgA-deficient subjects with CoD.

Biomarkers↗
PubMed1984

Fluctuating levels of serum IgA in individuals with selective IgA deficiency.

Monitoring of donors with selective IgA deficiency, i.e., with less than 0.5 mg IgA/l, led to the observation that serum IgA levels wer not constant. Small but significant fluctuations in IgA levels were noted (coefficient of variance: 143%) which were greater than the variability inherent in the testing methodology (coefficient of variance: 10%). These fluctuations created difficulties in terms of defining IgA-deficient blood products and had implications with respect to the mechanisms involved in IgA deficiency. With respect to supplying IgA-deficient blood products, in our experience a cutoff level of 0.5 mg/l should be the maximum permissible IgA concentration in order to ensure that no adverse reactions occur in individuals with class-specific anti-IgA.

Autoantibodies↗
PubMedDate not supplied

Selective and partial IgA deficiency in an adolescent male with bronchiectasis.

Selective IgA deficiency is the most common primary immunodeficiency. Two types of selective IgA deficiency may be distinguished: the complete form, with IgA level less than 5 mg/dl, and the partial IgA deficiency, with level greater than 5 mg/dl but less than 2 standard deviations below the age-adjusted mean level; 50% of the cases belong to the partial type and half of them may be considered as transient clinical form. Patterns of this condition, are very unsteady: while some patients remain without any symptoms, others present recurrent respiratory and gastrointestinal tract infections. Though respiratory tract infections are the most frequent diseases, and in very few patients are associated bronchiectasis. A twelve-year-old patient with permanent partial IgA deficiency was treated for bronchiectasis in our pneumology and allergy pediatric center. The other serum immunoglobulins, IgG subclass, lymphocytes sub-populations, cell with expression of DR markers and proliferative response to PHA of peripheral blood lymphocytes, were normal. The alpha-1-antitrypsin, Mantoux test (negative), sweat chloride concentration and ciliated nasal epithelium were also normal. Pneumonia, bronchiectasis and meningitis are found in the complete IgA deficiency. The greater part of studies confirm that this severe, chronic and/or recurrent lower respiratory tract diseases are scarcely found in children with partial selective IgA deficiency, although our case states that it can be found. We think that in every patient with bronchiectasis the selective IgA deficiency complete or partial, has to be considered as an isolated etiologic factor.

Bronchiectasis↗
PubMed2006

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.

Adolescent↗