Análises de mutações no gene JAK2 em pacientes com diagnóstico clínico de Policitemia Vera atendidos em um único centro da cidade de Juiz de Fora

Abstract

Myeloproliferative neoplasms (MPN) are caused by a clonal proliferation of a hematopoietic progenitor. First described in 1951 as “Myeloproliferative Diseases” and reevaluated by the World Health Organization in 2011 (WHO, 2011), the Myeloproliferative Neoplasms gather the Polycythemia Vera, Essential Thrombocythemia and Primary Mielofibrose in a subgroup called negative BCR-ABL. According to WHO the revised diagnosis criteria for myeloproliferative neoplasms, the presence of JAK2 V617F mutation, is considered the most important criterion for the diagnosis of negative BCR-ABL subgroup representing a clonal marker. The Polycythemia Vera is primarily diagnosed by an independent stimulating factor in red cells mass increasing, followed by an increase of leukocytes in peripheral blood, spleen and thrombocytosis. It usually occurs in men and women of all age groups with higher incidence in 60-year-old patients ranging from 0.7 to 2.6/ 100.000 hab/year. The V617F mutation in the JAK2 gene produces an altered protein that activates constitutively the JAK-STAT pathway and other pathways downstream as a result the protein transcriptional activation and signal transduction (STAT) are subsequently phosphorylated causing impact in the expression of genes involved in regulation of apoptosis and regulatory proteins, as well as altering the rate of proliferation of hematopoietic cells. In this study 26 patients with Polycythemia Vera were selected in Juiz de Fora, Minas Gerais. The peripheral blood was used for genetic material isolation (JAK2 mutation). The clinical data of each patient were related to each other and correlated with the molecular data.