Clinical features of childhood Ph1 positive acute leukemia

Clinical, immunologic, cytogenetic and molecular studies were performed on 9 patients with childhood Ph1 positive acute leukemia. FAB-L1 was found in 2 patients, L2 in 5 patients, and M1 and M2 in each patient. Six patients were older than 10 years old, and white blood cell count of 5 patients was more than 10(5)/microliters. All but one patient have died within 18 months. Immunologic analysis revealed that leukemic cells from all patients expressed lymphoid antigens CD10 and CD19, and myeloid antigen, CD13, was expressed on leukemic cells from 3 patients initially, and from 6 patients after short term in vitro culture without stimulation. bcr rearrangements were not observed in 3 patients tested. RNA analysis showed that 5 patients expressed P190bcr-abl pattern and one patient expressed P210bcr-abl pattern using polymerase chain reaction study. We conclude that Ph1 positive acute leukemia had a poor prognosis and differentiate into both myeloid and lymphoid lineages as well as chronic myelogenous leukemia (CML), and that this disease could not be possibly distinguished from CML by use of the molecular studies.