A new T helper 17 cytokine in hidradenitis suppurativa: antimicrobial and proinflammatory role of interleukin-26.

Our findings suggest that infection susceptibility in HS might be related to IL-26. Although the role of bacteria remains controversial in HS, this paper supports that there is a defect of antimicrobial response in these patients. What's already known about this topic? Interleukin (IL)-26 is a T helper 17 cytokine described as an antimicrobial and proinflammatory mediator. IL-26 has been reported in immune-mediated inflammatory diseases, but its involvement in inflammatory skin disorders remains unclear. Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder characterized by deficiency of IL-20 and IL-22 (a close homologue of IL-26), which causes antimicrobial peptide pauperization leading to severe and recurrent skin infections. What does this study add? IL-26 plasma levels are higher in patients with HS than in healthy control individuals. The antimicrobial activity of IL-26 might be ineffective in patients with HS. What is the translational message? Cutaneous antimicrobial incompetence in HS could be related to IL-26.