Investigate the correlation between the presence of the JAK2V617F mutation and laboratorial, morphological and clinical findings.

This is a retrospective, observational, single-center cohort-study involving adults with classic BCR-ABL negative MPN and myelofibrosis secondary to them (n = 119), in a Brazilian universitary hospital. It were evaluated hematological parameters and nonspecific inflammatory biomarkers such as LDH, CRP, ESR, and ferritin, in peripheral blood, as well as the occurrence of thrombo-hemorrhagic events or death, by consulting medical records.

Patients diagnosed with ET (n = 75), and JAK2V617F -positive (n = 69; 92,0%) had significantly higher values of marrow cellularity, hemoglobin, hematocrit, neutrophil to lymphocyte ratio (N/L ratio), ferritin, also higher RBC and WBC counts. Besides a higher occurrence of thrombotic and/or hemorrhagic events (p = 0.006). A positive correlation (Spearman) was observed between the JAK2V617F mutation and thrombo-hemorrhagic events, bone marrow cellularity, RBC count, hemoglobin concentration, hematocrit, WBC count, N/L ratio, and ferritin dosage.

Patients with ET positive for JAK2V617F mutation showed a “PV-like” profile with higher values of hemoglobin, hematocrit, hematimetry, LDH, and higher medullary cellularity in addition to, lower platelet values and higher incidence of thrombotic events, as suggested by previous studies. After all, JAK2V617F status is incorporated into the International Prognostic Score for Thrombosis in ET (IPSET). Besides demonstrating the clinical, epidemiological, laboratory profile, and mutational status in Brazilian patients in a university hospital, our study points to the need to reinforce the orientation about certain exams. It is essential to evaluate not only the incorporation of ESR in the routine investigation of patients in whom there is suspicion of classic MPN BCR-ABL negative, especially PV, but also the inclusion of CRP dosage in the prognostic evaluation of patients with ET and PV.

There is a correlation between the JAK2V617F mutation and higher values of RBC count, WBC count, N/L ratio, and ferritin, in addition to greater cellularity in the bone marrow. A “PV-like” profile was also observed in JAK2-positive TE patients.