title: In-vitro analysis of defective IgA production in selective IgA deficiency in childhood.
abstract: IgA production from B cells can be driven by three signals (anti-Ig antibody, B cell growth factor and helper T cell factor). It was thought that this three signal system might be a way other than the mitogen-stimulated system, to access B cell differentiation into Ig-producing cells. Seven children with IgA deficiency were investigated by this method. In all cases B cell differentiation was defective when using this three signal system. In one case, IgA producing cells were generated in normal number from B cells when stimulated with pokeweed mitogen in the presence of normal T cells. Definite abnormality of regulatory T cells in the IgA production was observed in only one case. These observations suggested that the main cause of IgA deficiency in most cases is the defect of B cells to differentiate into IgA secreting cells.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology* / Q000473:pathology; D002454:Cell Differentiation; D002648:Child; D002675:Child, Preschool; D004406:Dysgammaglobulinemia / Q000276:immunology*; D005260:Female; D006133:Growth Substances / Q000494:pharmacology; D006801:Humans; D017098:IgA Deficiency; D007070:Immunoglobulin A / Q000096:biosynthesis; D007136:Immunoglobulins / Q000096:biosynthesis; D015847:Interleukin-4; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008222:Lymphokines / Q000494:pharmacology; D008297:Male; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D006133:Growth Substances; D007070:Immunoglobulin A; D007136:Immunoglobulins; D008222:Lymphokines; D015847:Interleukin-4