Serum levels of IL-12 and IL-23 in psoriatic patients with or without concomitant hepatitis C: a comparative study

Background A role for hepatitis C virus (HCV) infection in psoriasis has been proposed, but the underlying pathogenic mechanisms are still undetermined. Interleukin (IL)-12 and IL-23 dysregulation may be involved. Objective To compare the serum levels of IL-12 and IL-23 in psoriatic patients with and without concomitant hepatitis C and investigate their relationship with both disease processes. Patients and methods Forty-nine psoriatic patients attending the Dermatology Outpatient Clinic in our hospital from January to December 2013 were included in the study. Psoriasis area and severity index scores were calculated. Serum levels of IL-12 (IL-12p70) and IL-23 were assessed and compared with 49 age-matched and sex-matched healthy individuals. All participants were tested for HCV infection. Results Serum IL-12 and IL-23 were significantly increased in psoriatic patients compared with controls (P = 0.004 and 0.001, respectively). Only IL-23 was significantly higher in HCV-positive than in HCV-negative psoriatic patients (P = 0.026) and positively correlated with psoriasis severity (psoriasis area and severity index) and alanine aminotransferase levels (P= 0.01 for both). Conclusion IL-23 overproduction in psoriasis appears to be accentuated by concomitant HCV infection.