Pure White-Cell Aplasia

THE development of techniques for the in vitro clonogenic assay of hematopoietic progenitors1 has allowed investigation of clinical syndromes associated with immunologic injury to human stem cells.2 T-lymphocyte suppression of granulopoiesis has been described in patients with Felty's syndrome,3 and humoral inhibition of granulocyte-progenitor cells has been reported in patients with drug-associated agranulocytosis.4 Spontaneously arising (non-drug-associated) antibodies directed against human myeloid progenitors in patients with neutropenia have only recently been recognized.2 , 5 6 7 8 The antigenic and cellular specificity of these inhibitors, however, have not been well characterized, and the failure to demonstrate serum inhibitory activity against autologous granulocyte progenitors raises questions about . . .