Acute lymphoblastic leukemia with p190 type bcr/abl chimeric mRNA at relapse

We describe the case of a 23-year-old man with acute lymphoblastic leukemia in whom the Philadelphia chromosome was first detected in the late stage of the disease. At diagnosis, the patient's leukocyte count was 39,400/microliter and leukemic cells were positive for CD10, 19, 20, 33, 34 and HLA-DR. Karyotypic analysis at diagnosis revealed 46,XY. Complete remission was achieved after the first induction therapy, but the disease recurred after 9 months. The patient underwent allogeneic peripheral blood stem cell transplantation from his HLA identical mother, but relapse occurred on day 80. The proportion of bone marrow lymphoblasts decreased transiently after donor lymphocyte infusion but later increased, and the patient died on day 362. The Philadelphia chromosome was first detected by karyotypic analysis on day 256. p190-type bcr/abl mRNA transcripts were negative following RT-PCR at the initial diagnosis, but became positive from the first relapse through the late stage. Generally, the product of the bcr/abl fusion gene has been thought to play an important role in leukemogenesis, however the present case suggests that this gene product is also related to disease progression.