Expression of innate defense antimicrobial peptides in hidradenitis suppurativa

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory disorder of apocrine gland-bearing skin. It is associated with alterations in innate immunity and frequent bacterial infections. Objective: We investigated the expression of innate defense antimicrobial peptides in patients with HS and different grades of severity. Methods: Skin biopsy specimens and sweat were collected from 36 patients with HS and 57 healthy control subjects for analysis of epithelial antimicrobial peptides by real-time reverse transcription-polymerase chain reaction, immunohistochemistry, enzyme-linked immunosorbent assay, and surface-enhanced laser desorption ionization time-of-flight mass spectrometry. Results: We provide evidence that human beta-defensin-3 expression is induced in lesional HS skin on transcriptional and protein levels, yet, this up-regulation was not detectable in patients with severe HS (Hurley grade III). In contrast, messenger RNA expression of ribonuclease 7 was significantly diminished in lesional HS skin specimens irrespective of HS severity. Overall levels of dermcidin/dermcidin-derived peptides in sweat and messenger RNA expression of psoriasin in skin biopsy specimens did not differ between patients with HS and healthy control subjects. Limitation: The relatively small number of samples, in particular in the group of patients with HS and Hurley grade III, is a limitation. Conclusion: Deficient constitutive production of ribonuclease 7 and, in severe HS, reduced human b-defensin-3 induction may contribute to impaired immunity within the hair follicle and thereby boost HS inflammation and severity. (J Am Acad Dermatol 2012;66:966-74.)