Pure white-cell aplasia. Antibody-mediated autoimmune inhibition of granulopoiesis.

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 . . .