PRO-INFLAMMATORY LEVELS OF INTERLEUKIN-1-ALPHA-LIKE BIOACTIVITY ARE PRESENT IN THE MAJORITY OF OPEN COMEDONES IN ACNE-VULGARIS

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-1-alpha, IL-1-beta, and TNF-alpha. Viable counts of propionibacteria, staphylococci, and Malassezia spp. were determined in the comedone pellet. Bioactive IL-1-alpha-like material was demonstrated in 76% of open comedones (range of 23-4765 pg IL-1-alpha-like bioactivity/mg of comedone material). In 58% of comedones, levels exceeded 100 pg/mg. There was no correlation between IL-1-alpha-like bioactivity and IL-1-alpha determined immunochemically. Bioactive IL-1-beta was not detected in any comedones. Twenty-four percent contained low levels of immunochemical IL-1-beta (range 12-103 pg IL-1-beta/mg comedone material). Bioactive TNF-alpha was detected in three comedones with a further five comedones containing immunochemical TNF-alpha (range of 61-820 pg TNF-alpha/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-1-alpha-like bioactivity, and numbers of microorganisms. Thus, bioactive IL-1-alpha-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.