An infantile case of cytomegalovirus induced idiopathic thrombocytopenic purpura with predominant proliferation of CD10 positive lymphoblast in bone marrow

Abstract
An infant with cytomegalovirus infection (CMV) developed idiopathic thrombocytopenic purpura (ITP) at 4 months of age. A bone marrow (BM) aspiration showed a remarkable increase of immature megakaryocytes and prominent proliferation of lymphoblasts. Flow cytometric analysis of the bone marrow cells showed that the predominant cells in the lymphocyte cluster were of B-lineage (CD19) with CD10 (common acute lymphoblastic leukemia antigen) positive. Virus study showed a higher titer of CMV antibody. Cytomegalovirus DNA was detected by the polymerase chain reaction (PCR) method in urine, peripheral cells and marrow cells. Low-grade fever, diarrhea and petechiae were accompanied by mild liver dysfunction. Complete remission was made with intravenous high-dose immunoglobulin (IVIg) without progression to overt acute leukemia. The percentage of CD10+/CD19+ lymphocytes in bone marrow also diminished. We postulated that the proliferation of immature lymphocytes and megakaryocytes in bone marrow was caused by maturation arrest that might result from CMV infection.