Association Between Inflammatory Acne and Cutibacterium Acnes

A recent study, published in the Journal of the European Academy of Dermatology and Venereology, shed new light on the significant role of Cutibacterium acnes (C. acnes) and the Th17 inflammatory pathway in the development of acne.

Researchers aimed to provides insights into the role of the Th17 inflammatory pathway in acne development. C. acnes has been shown to self-organize in biofilms, leading to increased virulence. There is a loss of C. acnes phylotype diversity during acne development, with a specific predominance of the pro-pathogenic phylotype IA1. Also, the activation of the Th17 pathway has been found to play a central role in the immuno-inflammatory response during acne development.

The dysbiosis of C. acnes phylotypes and the subsequent induction of the Th17 pathway have been identified as key factors in acne inflammation. The pro-pathogenic phylotype IA1 of C. acnes is primarily responsible for stimulating the production of the inflammatory cytokine IL-17 via CD4+ T cells in patients with acne. The induction of the Th17-mediated immuno-inflammatory response involves various skin cells, including keratinocytes, monocytes, and sebocytes.

These findings have paved the way for novel diagnostic biomarkers and treatment approaches. Traditional acne treatments that target C. acnes using topical antibiotics often lead to cutaneous dysbiosis and antimicrobial resistance. Future treatments will focus on maintaining a balanced skin microbiota and restoring C. acnes phylotype diversity, rather than simply eradicating the bacteria. This new direction in treatment aims to promote tissue homeostasis and minimize inflammation.

"The overproduction of IL-17 from Th17 cells in the immune response has been shown to play a pivotal role in the development of acne," concluded the study authors. "This has enabled the identification of biomarkers and prognostic predictors of disease pathogenesis as well as the development of targeted therapies for acne."

Reference

Mias C, Mengeaud V, Bessou-Touya S, Duplan H. Recent advances in understanding inflammatory acne: deciphering the relationship between Cutibacterium acnes and Th17 inflammatory pathway. J Eur Acad Dermatol Venereol. 2023;37(Suppl 2):3-11. doi:10.1111/jdv.18794