Lesional and circulating levels of interleukin-17 and 25-hydroxycholecalciferol in active acne vulgaris: Correlation to disease severity.

Objectives: The immunological aspects of inflammatory acne are still incompletely understood, so this study aimed to investigate the possible role of IL-17 and 25 hydroxycholecalciferol (25(OH)D3) in the disease pathogenesis and progression.

Materials And Methods: Across-sectional study has been conducted on 135 patients with active acne vulgaris of various severities and 150 matched controls. ELISA assays of serum and tissue levels of IL-17 and 25(OH)D3, also immunohistochemical and Western blotting demonstration of the expression patterns of lesional IL-17 in comparison with control group, were performed.

Results: The mean serum levels of IL-17 were 544.2 pg/mL ± 477.4 SD and 42.2 pg/mL ± 8.1 SD for acne patients and controls, respectively, with significantly higher levels among the patient group (P < 0.05). Higher IL-17 expression levels in active acne lesions when compared with its level in healthy skin of the controls. The mean serum levels of 25(OH)D3 among patients and controls were 33.3 ng/mL ± 9.7 SD and 51.7 ng/mL ± 2.7 SD, respectively, with significantly lower levels among the patient group (P < 0.05). There were significantly negative correlations between IL-17 and 25(OH)D3 levels (P < 0.001 for both).

Conclusions: Deficiency of vitamin D3 accompanied with higher IL-17 in an inverse pattern may have a possible role in active acne vulgaris.