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Abstract: PB2304

Type: Publication Only

Background
As per new WHO 2016 classification, polycythemia vera (PV) is suspected once hemoglobin is above 16.5gm/Dl (HCT >49%) in males and 16gm/dL (HCT 48%) in females.  JAK 2 V617F mutation or similar mutations in JAK 2 gene are seen in almost all of the patients with polycythemia vera. Bone marrow examination is required to make a diagnosis of PV and to differentiate it from other myeloproliferative neoplasms. High hemoglobin values more than the above ranges are commonly seen in clinical haematology practice.

Aims
Aim of present study was to evaluate patients presenting with raised hemoglobin and differentiate ideopathic polycythemia and its clinical course from polycythemia vera

Methods
Retrospective review of patients referred to the haematologist in Sir Ganga Ram Hospital, New Delhi, India, for high hemoglobin levels from January 2015 to December 2017 was performed. Demographic characteristics, history (including smoking and alcohol) and general physical examination were noted. All patients were tested for JAK 2 V617F mutation, erythropoietin levels (EPO) and ultrasound whole abdomen for splenohepatomegaly. Patients with PV were treated with phlebotomy, low dose aspirin and cytoreductive therapy with hydroxyurea as per standard guidelines.

Results
A total of 70 patients were found, 65 males: 5 females, 14/70 (20%) were JAK2 V617F positive and rest 56/70 (80%) were negative (table 1). JAK 2 Exon 12 mutations were done in 31 of 56 JAK 2 V617F negative patients and all were negative. Bone marrow examination was done in 28 of 56 JAK 2 V617F negative patients and was normal in all except 2 patients in which panmyelosis was seen. Palpable splenomegaly was seen in 9/14() patients with JAK 2 V617F positive patients while splenomegaly was absent in all JAK2 negative patients. Phlebotomy was done if Hemoglobin was more than 17g/dL in JAK 2 negative patients and low dose aspirin was given if hypertension/hypercholesterolemia/diabetes was present. None of JAK 2 negative patient developed thromboembolism or AML/myelofibrosis during study period with a median follow up of 13.5 months while 2 patients died in JAK 2 positive group (one due to cerebrovasucular accident and other due to development of myelofibrosis.

TABLE 1. COMPARISION OF JAK2 POSITIVE AND JAK 2 NEGATIVE PATIENTS WITH POLYCYTHEMIA

Conclusion
Most of the patients referred for isolated increase in hemoglobin were young males without splenomegaly, had high prevalence of hypertension and were JAK 2 negative. Bone marrow examination was not performed in most of these patients and were treated as idiopathic erythrocytosis and managed conservatively with optimal clinical outcomes. There is a need to review the requirement of doing bone marrow examination in such patients.

Session topic: 16. Myeloproliferative neoplasms - Clinical

Keyword(s): Polycythemia vera