Acute Promyelocytic Leukemia with Marrow Fibrosis at Initial Presentation: Possible Involvement of Transforming Growth Factor-β<sub>1</sub>

Abstract

Although the occurrence of marrow fibrosis in acute myeloid leukemia has been described, there have been no reports of acute promyelocytic leukemia (APL) associated with marrow fibrosis. Here we describe an APL patient with severe marrow fibrosis at initial presentation. He had the typical manifestations of APL, except for marrow fibrosis. Complete remission was achieved by treatment with all-trans retinoic acid plus chemotherapy, and his marrow fibrosis gradually improved concomitantly with the decrease in leukemic cells. To clarify the mechanism of marrow fibrosis in this patient, we investigated the expression of genes for several cytokines promoting fibrosis by the reverse transcriptase polymerase chain reaction methods. An overexpression of transforming growth factor-beta(1) was noted in his leukemic cells at initial presentation, whereas no increase in expression was observed at the time of relapse when he no longer had marrow fibrosis. These findings suggest that overexpression of transforming growth factor-beta(1) was involved in the development of marrow fibrosis in this APL patient.