[DBMP-85 was effective at diagnosis and LVP was effective at relapse in a case of acute mixed leukemia]

A 16 year-old boy was admitted to our hospital in April 1985, because of bilateral submandibular swellings. Hematological examination revealed Hb was 7.3 g/dl, WBC was 89,000/microliters (76% blast), and platelet was 154,000/microliters. His bone marrow was hypercellular and consisted with 91% blasts. Myeloperoxidase staining was positive for 38% of blasts. Auer rods were seen in some of blasts. Thus, the diagnosis was M1 according to FAB classification. Cytogenetic studies of 20 marrow cells were performed and all cells had 46, XY, -1, -7, 3q-, 7q-, 17q+, +2mar. Eighty five percent of blasts expressed HLA-DR and 43% of blasts expressed CD2 and CD13 simultaneously. Thus, this leukemia was considered as the hybrid type of acute mixed leukemia by surface marker analysis. DBMP-85 regimen, the chemotherapy for AML, was started after admission and complete remission (CR) was attained in June 1985. After 4 courses of post remission chemotherapy, he discharged in December 1985 and was followed at our outpatient clinic without chemotherapy. His disease was relapsed in June 1986, and the combination chemotherapy with mitoxantrone, etoposide and Ara-C was applied to him but failed to attain CR. Then, LVP protocol, the chemotherapy for ALL, was started and CR was achieved. The blasts at relapse had morphologically myeloid features, and expressed HLA-DR, CD2 and CD13 as well as at diagnosis. Cytogenetic studies at relapse showed some karyotype except gaining 12p- anomaly. Therefore, same blasts were considered to emerge at relapse. Our case suggests that LVP therapy may be effective for AML expressing myeloid and lymphoid surface markers.