Immunoglobulin synthesis in a patient with C4 deficiency: functional immaturity of peripheral blood lymphocytes.
Peripheral blood lymphocytes from a systemic lupus erythematosus patient with homozygous C4 deficiency were stimulated in vitro. Although T cell independent stimulation (Epstein-Barr virus) induced normal proportions of IgM secreting cells. IgG and IgA secreting cells were almost absent. Virtually no immunoglobulin secretion was obtained after T cell dependent stimulation (pokeweed mitogen). Cell fractionation experiments indicated that the low pokeweed mitogen response, at least with regard to IgG and IgA production, was mainly due to impaired B-lymphocyte function. The serum IgG subclass distribution pattern of specific antibodies against certain carbohydrate antigens demonstrated a relative lack of IgG2 antibodies. The findings were consistent with functional immaturity of B lymphocytes in the patient.
D001402:B-Lymphocytes / Q000276:immunology; D002648:Child; D003181:Complement C4 / Q000172:deficiency*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007136:Immunoglobulins / Q000096:biosynthesis*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
D003181:Complement C4; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins