A thrombocytosis occurring in Philadelphia positive CML in molecular response to imatinib can reveal an underlying JAK2V617F myeloproliferative neoplasm

Coexistance of JAK2V617F mutation and BCR/ABL translocation in one patient

“…5 In contrast with these reports, more recently, several cases with the coexistence of BCR-ABL fusion gene and JAK2V617F mutation in blood and bone marrow samples were reported. [6][7][8][9][10][11][12][13] We report here a new case with concomitant BCR-ABL rearrangement and JAK2V617F mutation, and compare our findings with those of similar reports.…”

“…13 In contrast with other reports; 7-12 after the partial cytogenetic response to imatinib treatment, JAK2 mutation was disappeared. Therefore, they have firstly hypothesized that imatinib treatment have caused the regression of CML clone, as well as JAK2 mutated cells, and that JAK2 mutation can be acquired by Ph + cells , 13 But in most cases, as described previously, imatinib mesylate therapy did not effect the coexisting and/or acquired JAK2 clone, [7][8][9][10][11][12] Moreover, owing to a proliferative advantage, JAK2 mutated hematopoiesis could overwhelm the BCR-ABL translocated hematopoiesis. To our knowledge, it seems more likely that there are two independent growing aberrant stem cell clones.…”

“…The unexpected hematological responses (including thrombocytosis), 7 or erythrocytosis, 8,9 evolving myelofibrosis, 10,11 and/or persisting spleen enlargement, 7,12 under imatinib mesylate treatment led some physicians to detect for JAK2 mutation in either peripheral blood or bone marrow. Probably, imatinib therapy suppresses the BCR-ABL clone, enabling the proliferation of JAK2V617F mutated cells.…”

Thrombocytosis and STAT5 activation in chronic myelogenous leukaemia are not associated withJAK2V617F or calreticulin mutations

“…We were unable to retrospectively determine whether the JAK2 V617F mutation was present at diagnosis of CML. Comparison with similar cases in the literature10 22 23 suggests two possible scenarios: either both mutations occur sequentially in the same progenitor cell ( JAK2 followed by BCR-ABL1 ) with disease manifesting as CML,24 or the mutations occur independently in two distinct clones. In either situation, TKI therapy would be expected to suppress growth of BCR-ABL1 + cells with re-emergence of the JAK2+ clone.…”

Two Cases of Myeloproliferative Neoplasm with a ConcurrentJAK2V617FMutation andBCR/ABLTranslocation without Chronic Myelogenous Leukemia Phenotype Acquisition during Hydroxyurea Treatment

“…Among these reports, the majority of the patients either had pre-existing BCR/ABL -positive CML and developed JAK2 V617F mutation while undergoing tyrosine kinase inhibitor treatment [4-7] or developed BCR/ABL -positive CML with a pre-existing JAK2 V617F mutation-positive MPN [8-12]. In contrast, a small number of patients showed simultaneous occurrence of both JAK2 V617F mutation and BCR/ABL translocation, with a CML phenotype in the bone marrow (BM) with development of symptoms or morphology associated with JAK2 V617F mutation, and with MPN only after imatinib treatment [3, 6, 13-15].…”