Among 994 patients with essential thrombocythemia (ET) who were genotyped for the MPLW515UK mutation, 30 patients carrying the mutation were identified (3.0%), 8 of whom also displayed the JAK2V671 F mutation. MPLW515UK patients presented lower hemoglobin levels and higher platelet counts than did wild type (wt) MPL; these differences were highly significant compared with MPLwV JAK2V617F-positive patients. Reduced hemoglobin and increased platelet levels were preferentially associated with the W515L and W515K alleles, respectively. MPL mutation was a significant risk factorformicrovesseldisturbances,suggest- ing platelet hyperreactivity associated with constitutively active MPL; arterial thromboses were increased only in comparison to MPLwtlJAK2wt patients. MPLW515UK patients presented reduced total and erythroid bone marrow cellularity, whereas the numbers of megakaryocytes, megakaryocytic clusters, and small-sized megakaryocytes were all significantly increased. These data indicate that MPLW515/K mutations do not define a distinct phenotype in ET, although some differences depended on the JAK2V617F mutational status of the counterpart.
Vannucchi, A., Antonioli, E., Guglielmelli, P., Panerazzi, A., Guerini, V., Barosi, G., et al. (2008). Characteristics and clinical correlates of MPL 515W > L/K mutation in essential thrombocythemia. BLOOD, 112(3), 844-847 [10.1182/blood-2008-01-135897].
Characteristics and clinical correlates of MPL 515W > L/K mutation in essential thrombocythemia
LO COCO, FRANCESCO;
2008-01-01
Abstract
Among 994 patients with essential thrombocythemia (ET) who were genotyped for the MPLW515UK mutation, 30 patients carrying the mutation were identified (3.0%), 8 of whom also displayed the JAK2V671 F mutation. MPLW515UK patients presented lower hemoglobin levels and higher platelet counts than did wild type (wt) MPL; these differences were highly significant compared with MPLwV JAK2V617F-positive patients. Reduced hemoglobin and increased platelet levels were preferentially associated with the W515L and W515K alleles, respectively. MPL mutation was a significant risk factorformicrovesseldisturbances,suggest- ing platelet hyperreactivity associated with constitutively active MPL; arterial thromboses were increased only in comparison to MPLwtlJAK2wt patients. MPLW515UK patients presented reduced total and erythroid bone marrow cellularity, whereas the numbers of megakaryocytes, megakaryocytic clusters, and small-sized megakaryocytes were all significantly increased. These data indicate that MPLW515/K mutations do not define a distinct phenotype in ET, although some differences depended on the JAK2V617F mutational status of the counterpart.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.