THE USEFULNESS OF BCR ABL REARRANGEMENT I N THE DIAGNOSIS AND EVOLUTION OF CHRONIC MYELOID-LEUKEMIA

BACKGROUND: The rearrangement of the bcr/abl gene constitutes the mole cular substrate of the Philadelphia chromosome (Ph'). The aim of this study was to analyze the usefulness of bcr/abl rearrangement in the di agnosis and evolution of chronic myeloid leukemia (CML). METHODS: The rearrangement of the bcr/abl gene was studied in 81 cases of which 34 corresponded to patients with CML (29 Ph' positive chromosome, 2 Ph' n egative chromosome and 3 without karyotype), 2 patients with Ph' posit ive acute lymphoblastic leukemia, 15 patients with chronic myeloprolif erative syndromes different from CML and 30 controls. Of the patients with CML, 6 were reevaluated when a blastic crisis was developed, 2 af ter receving interferon treatment and 1 following allogeneic bone marr ow transplantation. The technique used was that of Southern blotting u sing the restriction enzymes Bgl II and BamHI and the transprobe. RESU LTs: Rearrangement of the bcr/abl gene was observed in all the patient s with CML except in one with Ph' negative chromosome. In the remainin g cases bcr/abl rearrangement was not observed. CONCLUSIONs: The South ern blotting technique for the study of the bcr/abl gene rearrangement is a sensitive and specific method in the diagnosis of chronic myeloi d leukemia constituting a valid alternative to chromosomic study when this cannot be carried out or is not conclusive. It may also be used f or the control of treatment in chronic myeloid leukemia.