COCULTURE STUDIES OF 16 UNTRANSFUSED PATIENTS WITH APLASTIC-ANEMIA

Abstract

The effects of peripheral blood lymphocytes from 16 untransfused patients with severe aplastic anemia (AA) of diverse etiologies on the growth of granulocyte-macrophage colonies from normal marrows were studied. Normal lymphocytes in this system increased the number of granulocytic colonies by 31 .+-. 6% (mean .+-. SEM [SE of the mean]). Lymphocytes from 3 of 16 untransfused AA patients significantly inhibited growth in HLA-matched sibling marrows (-30%, -40% and -37% P < 0.01). Although these results suggest that the majority of cases of AA are not mediated by a coculture-detectable immunologic mechanism, studies using lymphocytes obtained from AA patients before transfusions may detect the subpopulation whose disease is immune-mediated and who may respond to immunosuppressive therapy.