Clinical and experimental immunology
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Clin. Exp. Immunol. · Sep 1993
Intrathyroidal lymphocyte subsets, including unusual CD4+ CD8+ cells and CD3loTCR alpha beta lo/-CD4-CD8- cells, in autoimmune thyroid disease.
Intrathyroidal lymphocyte subsets were analysed in 13 euthyroid patients with autoimmune thyroid disease by two-colour flow cytometry and compared with subsets in peripheral blood. In both Graves' and Hashimoto's diseases, proportions of intrathyroidal CD5- B cells were higher than in peripheral blood. The numbers of such cells were correlated with serum levels of anti-thyroid microsomal antibodies. ⋯ Proportions of CD5+ B cells were high in Graves' disease, and proportions of CD8+CD11b- cytotoxic T cells were high in Hashimoto's disease. Unexpectedly, CD4+CD8+ cells and CD3loTCR alpha beta lo/-CD4-CD8- cells were present in thyroid tissues of both diseases. These findings suggest that: (i) an imbalance in the numbers of regulatory T cells and of NK cells that had appeared in the thyroid resulted in the proliferation of CD5- B cells, which were related to thyroid autoantibody production; (ii) CD5+ B cells and cytotoxic T cells are important for the different pathological features in Graves' and Hashimoto's diseases, respectively; and (iii) intrathyroidal CD4+CD8+ cells and CD3loTCR alpha beta lo/-CD4-CD8- cells may be related to the pathogenesis of autoimmune thyroid disease.
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Clin. Exp. Immunol. · Dec 1992
Immunoglobulin class and IgG subclass distribution of anticardiolipin antibodies in patients with systemic lupus erythematosus and associated disorders.
The class and subclass distribution of an antibody response may give insight into the stimulating mechanism and likely effector functions. IgA, IgG and IgM anticardiolipin antibodies (aCL) were quantified in a consecutive series of 200 samples sent to an autoimmune serology laboratory to determine the relationships between aCL responses of each of these antibody classes and, in particular, whether there was any utility in the measurement of IgA aCL. Positive results for one of the three aCL isotypes were found in 105 samples (53%), and in 41 samples IgA aCL was detected (21%). ⋯ Amongst the SLE patients IgG1 and IgG3 aCL were the predominant IgG subclasses, consistent with an antigen-driven, T cell-dependent antibody response. However, a subgroup of eight of the autoimmune subjects had predominant elevation of IgG2 aCL, possibly implying a role for T cell-independent antibody production to cardiolipin. Amongst the syphilis patients IgG1 and IgG3 aCL were also the predominant subclasses of aCL but IgG4 aCL were also detected in the majority of subjects, consistent with prolonged antigenic stimulation.
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Clin. Exp. Immunol. · Feb 1992
Subclass composition and J-chain expression of the 'compensatory' gastrointestinal IgG cell population in selective IgA deficiency.
The subclass distribution of IgG-producing immunocytes was examined by two-colour immunohistochemistry in gastrointestinal mucosa of 14 patients with selective serum IgA deficiency providing the following biopsy material: gastric (n = 1); jejunal (n = 12); colonic (n = 1); and rectal (n = 2). All except two patients suffered from various infections, and coeliac disease was observed in six of them. Control reference data were based on biopsies from immunologically intact subjects, including histologically normal jejunal (n = 10) and large bowel (n = 10) mucosa and stomach mucosa with slight chronic gastritis (n = 8). ⋯ J chain appeared to be preferentially expressed by IgG1 cells (75%), but was also found in IgG2 (70%), IgG3 (32%) and IgG4 cells (33%). IgM-producing cells showed a J-chain positivity (99%) in IgA deficiency similar to normal (100%). Our results suggested that the block in mucosal B cell differentiation to IgA expression in the proximal gut is mainly located immediately upstream to the CH alpha 1 gene, giving excessive terminal maturation of J-chain-positive IgG1 immunocytes.
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Clin. Exp. Immunol. · Oct 1989
IgA subclasses of human colostral antibodies specific for microbial and food antigens.
The distribution of total and antigen-specific IgA1 and IgA2 antibodies in human colostrum was determined by ELISA using subclass-specific monoclonal reagents. In 18 samples of colostrum the mean ratio of total IgA1 to IgA2 was found to be 53:47, respectively, but significant individual variations were observed. ⋯ The IgA antibody activity directed against the polysaccharides was almost equally distributed between the two subclasses. However, antibody activity specific for protein antigens was found predominantly in the IgA1 subclass while anti-LPS activity was mostly of the IgA2 subclass.