Simultaneous transient erythroblastopenia and agranulocytosis: IgG-mediated inhibition of erythrogranulopoiesis.

We report a case of simultaneous transient erythroblastopenia and agranulocytosis recovering spontaneously. In vitro study using autologous bone marrow cells after recovery demonstrated IgG-mediated inhibition of both erythropoiesis and granulopoiesis but not megakaryopoiesis. The inhibitory activity disappeared shortly after remission. These findings suggest that IgG-mediated inhibition of hematopoiesis may be pathogenetic for transient bone marrow failure of the patient.