Pro-inflammatory levels of interleukin-1α-like bioactivity are present in the majority of open comedones in acne vulgaris

Abstract

The factors that initiate the inflammatory response in acne are not known. The presence of pro-inflammatory cytokines in acne comedones was therefore investigated. One hundred eight open comedones were collected from 18 untreated acne patients (10 male, 8 female). Each comedone was homogenized and centrifuged, and the supernatant was analyzed for bioactive and immunochemically detectable IL-α1, IL-1β, and TNFα. Viable counts of propionibacteria, staphylococci, and Malassezia spp. were determined in the comedone pellet. Bioactive IL-1α-like material was demonstrated in 76% of open comedones (range of 23-4765 pg IL-1α-like bioactivity/mg of comedone material). In 58% of comedones, levels exceeded 100 pg/mg. There was no correlation between IL-1α-like bioactivity and IL-1α determined immunochemically. Bioactive IL-1β was not detected in any comedones. Twenty-four percent contained low levels of immunochemical IL-1β (range 12-103 pg IL-1β/mg comedone material). Bioactive TNFα was detected in three comedones with a further five comedones containing immunochemical TNFα (range of 61-820 pg TNFα/mg comedone material). The majority of open comedones (97%) contained microorganisms. There was, however, no significant correlation (Spearman's rank) between levels of any cytokine, in particular IL-1α-like bioactivity, and numbers of microorganisms. Thus, bioactive IL-1α-like material in the majority of open comedones may be concerned in the initiation of inflammation in acne following spongiosis or rupture of the pilosebaceous follicle wall. © 1992.