Serum level of interleukin‐22 in patients with cutaneous warts: A case‐control study

Background Warts are viral cutaneous infections caused by human papilloma virus (HPV), presented by verrucous growth over the skin surface. The immune response is considered to play a crucial role in HPV clearance. It depends on intact cellular immunity including natural killer (NK) cell and cytotoxic T cells. It has been clarified that T‐helper (Th) 1 cytokines (interleukin (IL)‐2, interferon‐γ, and tumor necrosis factor‐a) and IL‐17 are involved in HPV clearance. IL‐22 is one of IL‐10 family of cytokines produced by NK cells, Th1, Th17, and Th22 cells. In the skin, IL‐22 reduces keratinocyte cornification and enhances keratinocyte production of antimicrobial peptides. IL‐22 overexpression has been demonstrated in various viral infections and skin inflammatory disorders. Aim The aim of this study was to assess serum levels of IL‐22 in patients with warts and its association with their different clinical characteristics. Methods The study included 20 patients with warts and 20 control subjects. Serum concentration of IL‐22 was measured by enzyme‐linked immune sorbent assay. Results Serum levels of IL‐22 were significantly higher in patients with warts than in control subjects (P