title: T- and B-cell functions in IgA-deficient patients.
abstract: In vitro lymphocyte function of 60 IgA-deficient patients (IgAdp) were studied. In the mitogen-induced lymphocyte activation test, peripheral blood mononuclear cells (PBMC) of IgAdp showed a weaker response to pokeweed mitogen (PWM) than those of controls (P less than 0.05), and the responses to phytohaemagglutinin (PHA) and concanavalin A (Con A) were normal. The amounts of IgA, IgG, and IgM secreted by PBMC from controls and IgAdp were measured in vitro by enzyme immunoassay. B cells were activated by PWM with or without hydrocortisone (HC) to inhibit HC-sensitive suppressor cells. Lymphocytes of IgA-deficient patients synthesized only minute amounts of IgA in vitro and the amounts of IgA synthesized correlated well with the serum IgA levels. Both IgG and IgM secretion by PWM-stimulated PBMC of IgAdp were also subnormal. The lymphocyte subset analysis in the peripheral blood revealed normal numbers and ratios of T cells, but IgAdp had reduced percentages of surface IgA-bearing cells. Co-culture experiments with isolated B cells, CD4- and CD8+ cells from IgAdp. and controls showed low B-cell capacity for IgA production as the most constant finding. Defects in T-cell functions or changes in the proportions of surface antigen-carrying lymphocytes (other than IgA-) were infrequent and were not associated with any particular group of patients or type of IgAd (primary, acquired, or transient).
authors.affiliation: Children's Hospital, University of Helsinki, Finland.
authors.forename: T K
authors.initials: TK
authors.lastname: Klemola
authors.forename: J
authors.initials: J
authors.lastname: Eskola
authors.forename: E
authors.initials: E
authors.lastname: Savilahti
mesh_terms: D000293:Adolescent; D000328:Adult; D001402:B-Lymphocytes / Q000145:classification / Q000276:immunology* / Q000378:metabolism; D002474:Cell-Free System; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D004406:Dysgammaglobulinemia / Q000097:blood / Q000276:immunology*; D005260:Female; D006801:Humans; D017098:IgA Deficiency; D007070:Immunoglobulin A / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008297:Male; D010641:Phenotype; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M