A Study of 8 Patients with Polycythaemia Vera: The Impact of JAK2 (V617F) Mutation on Diagnosis

M.B. Ino-Ekanem, I.A. Ibanga and E.H. Jumbo

Background: The discovery of the Janus Kinase 2 (JAK2) gene mutation provides a new molecular approach for the diagnosis of polycythaemia vera (PV).

We studied retrospectively patients with a diagnosis of PV at initial presentation to the hospital. They were followed up for an initial period of 2 months.

Objective: The objectives were to access the clinicopathological characteristics, impact of identification of JAK2 mutation on diagnosis and treatment strategies.

Result: Of the 6 patients with complete medical records, 3 were males (50%). The mean haematocrit values were 59.7%, males had a value of 60.3% while females a values of 59.0%. The total WBC count was 8.8 x 10⁹/L while the platelet count was 463.5 x 10⁹/L. None of the patients’ had splenomegaly, all had pruritus. During follow up the mean haematocrit values were 52.3%, males had a value of 55.8% while females a values of 48.7%. The total WBC count was 11.1 x 10⁹/L while the platelet count was 652.1 x 10⁹/L. There was a reduction in the haematocrit value but the white blood cell and platelet counts remained high.

Of the 5 patients who had molecular analysis done, 4(80%) had the JAK2 mutation while in 1 (20%) the mutation was not detected. The results of the molecular analysis done in a regional laboratory were received after an average of 21 days.

The patients were treated with phlebotomy and hydroxyurea. One patient with increasing thrombocytosis had clopidogrel initiated. 3 patients were lost in the follow-up period once there was clinical improvement, at 6 months and 1 year only 1 patient was left in follow-up.

Conclusion: The lag time for obtaining results of molecular analysis was long, which made diagnosis and management on clinicalbasis.