Acquired amegakaryocytic thrombocytopenic purpura (AATP): a study of autologous megakaryocyte progenitors and the effect of patients plasma on normal marrow megakaryocyte colony formation.

Abstract

Megakaryocyte progenitors (Colony Forming Unit-Megakaryocyte, CFU-Mk) and the effect of plasma on megakaryocyte colony formation in normal human marrow (Plasma Factor Index-Megakaryocyte, PFI-Mk) were studied in six patients with acquired amegakaryocytic thrombocytopenic purpura (AATP) and in ten normal subjects. Assay was based on the method of Messner. In one AATP marrow culture four CFU-Mk were found, in the other two a single CFU-Mk were present, and in the remaining three samples no megakaryocyte colonies were observed. PFI-Mk in AATP patients was significantly higher than in normal subjects. No correlation was found between PFI-Mk and platelet count in either group. The results of this study indicate the presence of an intrinsic defect at the level of CFU-Mk in AATP marrow. PFI-Mk in AATP patients relate to changes in marrow megakaryocyte number rather than to peripheral blood platelet count.