title: Effects of long-term procainamide therapy on immunoglobulin synthesis.
abstract: Procainamide is a potent inducer of autoantibodies. In order to evaluate the immunologic effects of this drug in vivo, 23 cardiac disease patients who had received procainamide for at least 6 months and an equal number of matched cardiac disease control subjects were studied, and percentage of circulating T cell subsets, concanavalin A-induced suppressor cell activity, and pokeweed mitogen--stimulated generation of immunoglobulin-secreting cells was quantitated. There was no significant difference between patient and control groups in the percentage of T cell subsets defined by OKT4 and OKT8 monoclonal antibodies or in concanavalin A-induced suppressor cell activity. The numbers of pokeweed mitogen--induced immunoglobulin-secreting cells were markedly decreased in the patient group, as measured by the protein A-augmented reverse hemolytic plaque assay (3,000 +/- 644, mean +/- SEM in patients versus 10,826 +/- 1,529, mean +/- SEM in control subjects, P less than 0.005). Removal of the adherent cell fraction did not improve the hyporesponsiveness. When B and T cell fractions of 6 patients were mixed with normal T and B cell fractions, all of the patients demonstrated diminished B cell responses, and one-half also had diminished T cell responses. Addition of patient adherent cells to a co-culture of normal B cells with deficient patient T cells restored plaque formation to normal levels, suggesting that the T cell defect was correctable by a macrophage-derived factor. The data obtained suggest that procainamide exerts an immuno-suppressive action on both B and T cell function in patients receiving this drug.
authors.forename: C L
authors.initials: CL
authors.lastname: Yu
authors.forename: M
authors.initials: M
authors.lastname: Ziff
mesh_terms: D000368:Aged; D000911:Antibodies, Monoclonal; D000921:Antibody-Producing Cells / Q000276:immunology; D003327:Coronary Disease / Q000188:drug therapy; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D007136:Immunoglobulins / Q000096:biosynthesis*; D007700:Kinetics; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011043:Pokeweed Mitogens / Q000276:immunology; D011342:Procainamide / Q000627:therapeutic use*; D013601:T-Lymphocytes / Q000145:classification; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D007136:Immunoglobulins; D011043:Pokeweed Mitogens; D011342:Procainamide