Role of serum erythropoietin, erythropoietin-independent erythroid colony formation, and bone marrow assessment in the diagnosis of polycythemia vera in patients with JAK2 V617F mutation

Abstract

7085 Background: The discovery of the JAK2 V617F mutation in over 95% of polycythemia vera (PV) patients has led to the development of the new 2008 World Health Organization diagnostic criteria for PV. These specify a requirement for an elevated hemoglobin (Hb, males: >185 g/L, females: >165 g/L) and either evidence of JAK2-mutant cells plus any one of the following minor criteria: a below normal level of serum erythropoietin (Epo), detectable Epo-independent erythroid colony (EEC) formation in vitro, or panmyelosis in the bone marrow, or two of the latter in the absence of detectable JAK2-mutant cells. However, in patients with an elevated Hb and JAK2V617F positivity, there are few data to determine whether any of the 3 minor criteria actually add an independent contribution to the diagnosis of PV. Methods: We performed a retrospective chart review of 77 patients who had an elevated Hb and were positive for the JAK2 V617F mutation and who also had a test for at least one of the 3 minor criteria (serum Epo level: n = 53; EEC formation: n = 66; bone marrow examination: n = 16) to determine the frequency of cases who might lack one or more of these. Results: Although the number of patients with a complete set of data was limited, the results, nevertheless, were sufficient to show that all 3 minor criteria were highly represented and all 77 of the patients analyzed (100%) were positive for at least one of them; i.e., 47 of 53 tested (89%) had a reduced serum Epo level; 65 of 66 tested (98%) had EECs and 15 of 16 tested (94%) had evidence of bone marrow panmyelosis. Conclusions: Neither the Epo level, nor the presence of EECs nor evidence of bone marrow panmyelosis provided additional diagnostic specificity in a population of 77 patients with both JAK2 V617F-positive cells and an elevated Hb. Consideration should be given to limiting serum Epo, EEC, and bone marrow assessments to JAK2 mutant-negative patients. No significant financial relationships to disclose.