Philadelphia-positive chronic myelogenous leukemia with a 5q-abnormality in a patient following interferon-alpha therapy

In this report, we describe a rare 5q-/CML association in a patient with ph -positive chronic myelogenous leukemia (CML) who achieved complete cytogene tic response on interferon-alpha (IFN-alpha) treatment, hut who developed a new clone in the blastic crisis. The patient was treated with interferon-a lpha beginning in 1996 and a serial chromosome and molecular study was perf ormed over the clinical course of the disease. The patient remained in comp lete hematologic and cytogenetic remission until November 1998. when a reve rse transcriptase PCR study performed on the bone marrow and peripheral blo od cells was negative for chimeric BCR/ABL mRNA. The treatment was disconti nued until April 1999. when the patient developed acute transformation of t he disease. In June 1999. cytogenetic examination showed the development of a new clone, consisting of the deletion of the long arm of chromosome 5 in addition to the standard Ph translocation. The unusual association of a Ph with an abnormality usually observed in a secondary myeloproliferative dis ease raises the question of whether the new finding is treatment-induced or part of the disease process and casually related to the acute transformati on. (C) 2001 Elsevier Science Inc., All rights reserved.