Polycythemia vera: Correlation of JAK2V617F mutation with clinicohematologic characteristics. A single centre experience.

Abstract

Introduction Janus kinase2 (JAK2) V617F mutation in myeloid cells has been reported from the majority of patients with Polycythemia vera (PV). Materials & Methods A cross sectional study was conducted to review clinical records of 93 cases of erythrocytosis who were evaluated for JAK2V617F mutation by Amplification Refractory Mutation System polymerase chain reaction at our institution. The significance of this mutation in the context of clinical & hematological features in cases that fulfilled World Health Organisation 2008 diagnostic criteria for PV was investigated. Results 66(71%) patients fulfilled the WHO diagnostic criteria for PV. Erythrocytosis could be attributed to secondary causes in 20(21.5%) cases and in seven (7.5%) cases, erythrocytosis was idiopathic. The JAK2V617F mutant allele was detected in 61 of the 66 patients (92.4%) with 19(31.1%) showing homozygosity. A comparison between JAK2V617F mutation positive and JAK2V617F wild type PV patients at presentation revealed that the JAK2V617F mutation positive patients were older(P=0.05), with significantly lesser mean values of hemoglobin (P= 0.02). Compared with heterozygote counterparts, JAK2V617F homozygotes showed significantly higher hemoglobin (P=0.03), incidence of thrombosis(P=0.04) and transformation to myelofibrosis(P=0.02). Conclusions This is the largest Indian study correlating JAK2V617F mutation status with clinicohematologic characteristics in PV patients and reveals that prevalence of JAK2V617F mutational status is 92.4% in PV patients with 31.1% homozygosity. JAK2V617F homozygosity is associated with significantly higher hemoglobin values, and, confers higher risk of thrombosis and progression to myelofibrosis.

Keywords

• Erythrocytosis
• Polycythemia
• JAK2 mutation