Evaluation of interleukin-23 plasma levels in patients with polycythemia vera and essential thrombocythemia.

Essential thrombocythemia (ET), polycythemia vera (PV) and myelofibrosis share the same acquired genetic lesion, JAK2V617F. It is believed that cytokines participate in the activation of JAK2V617F. In this study, we analyzed the plasma levels of interleukin (IL)-23, IL-10 and IL-22 in patients with PV and ET. In the same subjects we also performed analysis of the JAK2V617F mutation, and evaluated a possible relationship between interleukin levels and thrombotic complications or with the symptom pruritus. Plasma levels of IL-23 were significantly increased in all patients with MPN in comparison to controls. Moreover, there was a significant difference between the levels of IL-23 in patients affected by PV and those measured in controls (8.57 ± 3.69 pg/mL vs. 6.55 ± 4.125 pg/mL; p < 0.03). No difference was found between IL-23 levels in ET patients and controls. No statistically significant differences were found between the levels of IL-23, Il-22 or IL-10 in PV or ET subjects with or without thrombosis, in patients with or without pruritus, or according the JAK2V617F burden. In PV patients the JAK2 burden and Hb levels correlated with occurrence of pruritus. Our study seems to point out a possible involvement of IL-23 in the pathogenesis of PV.