title: Drug-induced agranulocytosis: in vitro evidence for immune suppression of granulopoiesis and a cross-reacting lymphocyte antibody.
abstract: Two patients with agranulocytosis associated with diphenylhydantoin (DPH) therapy and clinical data suggesting suppression of granulopoiesis were investigated using in vitro culture techniques for committed granulocyte/macrophage precursors. Addition of DPH to cultures containing the patients' sera resulted in significant suppression of colony growth. Extensive studies on the acute serum from one patient revealed the drug-dependent inhibitory activity to be nondialyzable, resistant to chloroform extraction, heat stable, active in the presence of heat-inactivated fetal bovine serum, active against autologous as well as allogeneic cells, and absent from convalescent sera. Drug-dependent bone marrow colony-suppressing activity was removed by absorption on an antiimmunoglobulin-Sepharose column but not by IgG-Sepharose. The serum show non-drug dependent suppression of oxygen consumption by normal polymorphonuclear leukocytes engaged in phagocytosis and also showed evidence of ability to opsonize these cells. When the serum was incubated with mitogen-stimulated lymphocytes, suppression of 3H-thymidine uptake by autologous but not allogeneic cells was noted. Similarly, the serum suppressed short-term 3H-thymidine uptake by autologous but not allogeneic bone marrow. Absorption of the patients' sera with allogeneic polymorphonuclear leukocytes, autologous polymorphonuclear leukocytes, or autologous lymphocytes removed the drug-dependent inhibitory activity, but absorption with allogeneic lymphocytes did not. These data are most consistent with the presence of a noncomplement dependent antibody capable of suppressing granulopoiesis, mediating peripheral destruction of polymorphonuclear leukocytes, and cross-reacting with a lymphocyte antigen of limited population distribution.
mesh_terms: D000380:Agranulocytosis / Q000276:immunology*; D001854:Bone Marrow Cells; D002455:Cell Division; D006410:Hematopoiesis; D006801:Humans; D007165:Immunosuppression Therapy; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology; D009504:Neutrophils / Q000502:physiology; D010101:Oxygen Consumption; D010587:Phagocytosis; D010672:Phenytoin / Q000009:adverse effects*
chemical_list: D010672:Phenytoin