Interleukin-31 is associated with uremic pruritus in patients receiving hemodialysis.

ABSTRACT

BACKGROUND: Interleukin (IL)-31 induces severe pruritus and dermatitis in transgenic mice, and is associated with many itching skin diseases. OBJECTIVE: We sought to investigate the association of serum IL-31 levels with uremic pruritus in patients undergoing hemodialysis. METHODS: Patients receiving maintenance hemodialysis in a referral medical center were recruited. Serum IL-31 levels were determined by the enzyme-linked immunosorbent assay methodology. The various characteristics of pruritus were assessed using an interview questionnaire. RESULTS: Among the 178 study participants, 34.8% had uremic pruritus. The patients with pruritus had higher serum IL-31 levels than those without pruritus symptoms (median 8.68 [first quartile 0.43, third quartile 35.04] vs 4.91 [0, 15.78], P = .04). A multivariate linear regression analysis showed that higher serum levels of IL-31, high-sensitivity C-reactive protein, and alanine transaminase, and a lower dialysis dose assessed by Kt/V, were independent predictors for higher pruritus intensity. The generalized additive model also showed a positive exposure-response relationship between serum levels of IL-31 and visual analog scale scores of pruritus intensity. LIMITATIONS: The cause-effect relationship between IL-31 and uremic pruritus could not be assessed by the cross-sectional study design. CONCLUSION: IL-31 may play an important role in the pathophysiology of uremic pruritus.