Levels of IL-12, IL-17, and LL-37 in acne vulgaris

Introduction: Acne vulgaris (AV) is a chronic inflammatory disease of the pilosebaceous unit with a multifactorial pathogenesis, which includes colonization of Propionibacterium acnes (P. acnes). Increased P. acnes colonization causes a Toll-like receptor (TLR)-2-dependent increase in the production of interleukin (IL)-12 and cathelicidin (LL-37), and a Th-17-dependent increase in interleukin (IL)-17. This study aimed to investigate the relationship between IL-12, IL-17, and LL-37 from patient’s serum and various severities of AV. Materaials and Methods: This study was an analytic observational cross-sectional study. Subjects were enrolled using the consecutive sampling method and assigned according to the Global Acne Grading System (GAGS) criteria. Statistical analysis was performed with one-way analysis of variance and Kruskal-Wallis tests. Results: Mean levels of IL-12, IL-17, and LL-37 in the serum in mild AV were 50.65±6.38, 119.07±24.61, and 180.26±112.92 IU/mL, respectively. The mean levels of IL-12, IL-17, and LL-37 in moderate AV were 47.82±6.51, 132.52±19.41, and 165.91±82.08 IU/mL, respectively. The mean levels of IL-12, IL-17, and LL-37 in severe AV were 48.78±4.93, 208.34±35.38, and 259.50±130.88 IU/mL, respectively. In very severe AV IL-12, IL-17, and LL-37 levels were 39.63, 251.29, and 113 IU/mL, respectively. There were no significant differences between the serum levels of IL-12 (p=0.157) and LL-37 (p=0.434) in the different severities of AV, whereas there was a significant association between the serum levels of IL-17 and the severity of AV (p<0.001). Conclusion: IL-17 is associated with severity of acne vulgaris, while no-association was found between the severity of the disease and IL-12 or LL-37.