Credit: AFIP
New research has revealed a molecular method for classifying patients with polycythemia vera (PV).
Investigators identified 102 genes that can be used to distinguish patients with aggressive PV from those with indolent disease.
The 2 patient groups exhibited significant differences with regard to leukemic transformation, disease duration, survival, hemoglobin level, thrombosis, splenomegaly, splenectomy, and chemotherapy exposure.
Jerry L. Spivak, MD, of the Johns Hopkins University School of Medicine in Baltimore, and his colleagues conducted this research and recounted the results in NEJM.
The researchers analyzed gene expression in CD34+ cells from 19 patients with PV and compared the results to healthy control subjects of the same sex.
Males with PV had roughly twice as many differentially regulated genes as females with PV—571 and 253, respectively.
The investigators subtracted the genes with sex-specific expression and were left with 102 genes that were differentially regulated (68 upregulated and 34 downregulated) between PV patients and controls.
And the team found they could use these genes to separate patients with indolent PV from those with aggressive disease, as the expression of the genes differed markedly between the 2 groups.
The 2 groups also differed significantly with regard to a number of clinical characteristics. The median disease duration was 14 years for patients with aggressive disease and 6 years for those with indolent disease (P=0.05).
The number of patients who transformed to acute leukemia was 4 and 1, respectively (P=0.04). And the number of patients who were still alive at the time of analysis was 1 and 11, respectively (P=0.001).
There were also significant differences with regard to hemoglobin level (P=0.007), the incidence of thromboembolic events (P=0.04), the frequency of palpable splenomegaly (P=0.03), the rate of splenectomy (P=0.007), and chemotherapy exposure (P=0.03).
However, there were no significant differences between the 2 groups with regard to age, JAK2 V617F neutrophil allele burden, white cell count, or platelet count.
