Rapidly progressive autoimmune pancytopenia successfully treated with steroids.

A 73-year-old woman was admitted to our hospital because of pancytopenia. Bone marrow aspiration showed increased cellularity with no dysplastic change. Laboratory tests revealed increased reticulated erythrocytes and reticulated platelets, positive direct Coombs test, and hemolysis. These findings led to the diagnosis of Evans syndrome. Relatively decreased mature neutrophils in the bone marrow aspirate raised the possibility of autoimmune neutropenia. Antineutrophil antibody was detected by the 6 cell-lineage immunofluorescence test, consistent with the diagnosis of autoimmune neutropenia. The patient had no underlying diseases, and was therefore considered to have idiopathic autoimmune pancytopenia. Due to rapid progression of the disease, prednisolone was administered at an initial dose of 0.5 mg/kg per day and the pancytopenia improved promptly.