The Serum Level of IL-31 in Patients with Chronic Kidney Disease-Associated Pruritus: What Can We Expect?

Abstract

Chronic-kidney-disease-associated pruritus (CKD-aP) is one of the most common and burdensome dermatological symptoms affecting patients undergoing dialysis, and its etiopathogenesis has still not been fully discovered. This study was designed to investigate the possible contribution of interleukin-31 (IL-31) to the pathogenesis of itch in patients undergoing maintenance hemodialysis (HD). We evaluated the serum level of IL-31 in HD patients with pruritus, in HD patients without pruritus and in healthy controls, as well as its correlation to the severity of itch. The study enrolled 175 adult subjects. The participants were divided into three groups. Group A included 64 patients on maintenance HD with CKD-aP, Group B included 62 patients on maintenance HD not reporting CKD-aP and Group C included 49 healthy controls. Pruritus severity was assessed using the Numerical Rating Scale (NRS), and the serum levels of IL-31 were measured. The results showed that the IL-31 serum level was significantly higher in the itchy group (p < 0.001) in comparison to the patients free from pruritus. Moreover, a marginal trend towards significance (r = 0.242, p = 0.058) was observed between the IL-31 serum level and itch intensity. Our study supports earlier findings on the extended role of IL-31 in the development of CKD-aP.