BCR-ABL1 transcript levels increase in peripheral blood but not in granulocytes after physical exercise in patients with chronic myeloid leukemia

AbstractIn chronic myeloid leukemia (CML) treatment response is determined by measurements of BCR-AB1L transcripts in peripheral blood by quantitative real-time PCR (qRT-PCR) and a 2–5 fold increase is considered a warning sign. The BCR-ABL1 gene is mainly expressed in myeloid cells whereas quantification of BCR-ABL1 is performed on the nucleated cell fraction of peripheral blood. Hence, leukocyte composition of the nucleated cell fraction may affect the result of BCR-ABL1 quantification. The aim of this study was to investigate if changes in leukocyte composition of peripheral blood had any effect on BCR-ABL1 transcript levels in CML patients. Six CML patients in complete cytogenetic remission (CCgR) performed a maximal physical exercise test. Blood samples were collected before exercise, at maximal exhaustion and after exercise. A biphasic increase in leukocyte count was observed and the relative proportion of granulocytes in peripheral blood changed significantly after exercise compared with baseline (...