CHRONIC MYELOID-LEUKEMIA WITH THROMBOCYTHEMIC ONSET MAY BE ASSOCIATEDWITH DIFFERENT BCR ABL VARIANT TRANSCRIPTS/

Ph-positive chronic myeloid leukemia (CML) mimicking essential thrombo cythemia (ET) at onset seems to be a distinct clinical entity. Whether this rare clinical form of CML is associated with single, specific va riants of BCR/ABL transcripts is a matter of debate. Among 82 consecut ive patients with Ph-positive CML, we identified 3 patients in which t he disease mimicked ET at presentation, because-of marked thrombocytos is and moderate leukocytosis, with few immature myeloid cells in perip heral blood and blood basophilia in 2 of them. Molecular analysis with the reverse transcriptase-polymerase chain reaction technique showed the presence of b2a2, b3a2, and b3a2-b2a2 transcript variants in the t hree patients, respectively. The results of our study together with a review of literature data suggest that different BCR/ABL transcript va riants may occur in CML mimicking ET, without an apparently significan t prevalence of one type. (C) Elsevier Science Inc., 1998.