Concomitant JAK2 V617F-positive polycythemia vera and B-cell chronic lymphocytic leukemia in three patients originating from two separate hematopoietic stem cells.

The simultaneous occurrence of polycythemia vera (PV) and chronic lymphocytic leukemia (CLL) is a rare event that offers a possibility to study their common origin. PV originates from self-renewing hematopoietic stem cells (HSC) with both lymphoid and myeloid potential(–3). It has been reported that CLL also originates from self-renewing HSC with a potential for both lymphoid and myeloid differentiation(4, 5).

Intermittent dosage of imatinib mesylate in CML patients with a history of significant hematologic toxicity after standard dosing.

Hematologic toxicity is reported as one of the most important problems connected with imatinib mesylate (IM) treatment in patients with chronic myelogenous leukemia (CML). Withholding the drug or application of growth factors is recommended in this situation. This study introduced a novel approach using intermittent dosage of IM in order to avoid prolonged interruptions in therapy, to allow spontaneous recovery in blood count and, simultaneously, to achieve intermittently therapeutic plasma drug levels.