The effects of mutational profiles on phenotypic presentation of myeloproliferative neoplasm subtypes in Bosnia: 18 year follow-up

The identification of mutually exclusive somatic mutations shared among myeloproliferative neoplasm (MPN) subtypes has provided a powerful tool for studying disease evolution. Clinical features, gene mutations, and survival over 18 years were analyzed in MPN patients. One hundred thirty-eight MPN patients were subcategorized according to MPN subtypes: essential thrombocythemia (ET, n = 41), polycythemia vera (PV, n = 56), primary myelofibrosis (PMF, n = 10), and MPN unclassified (MPN-U, n = 31). Patient characteristics included clinical parameters, overall survival (OS), and mutational status of the Janus kinase 2 (JAK2), calreticulin (CALR), and myeloproliferative leukemia virus oncogene (MPL) genes. We compared hematologic and clinical features of JAK2(V617F)-ET vs. CALR-mutated ET vs. JAK2(V617F)-PV patients. JAK2(V617F)-patients had higher values of erythrocytes, hemoglobin, and hematocrit compared to CALR-mutated patients (p < 0.05). The mutant allele burden in JAK2(V617F)-PV and JAK2(V617F)-ET patients directly correlated with erythrocyte, hemoglobin, and hematocrit values, but it inversely correlated with platelet count. Thus, mutant allele burden was an indicator of the clinical phenotype in JAK2(V617F)-MPN patients. OS was not affected by the mutational status. In general, mutated JAK2, CALR, and MPL genes left specific hematological signatures.