Serum IL‐36 Cytokine Profile in Adult Patients With Acne Vulgaris: A Case–Control Study

Introduction and Objective Acne vulgaris (AV) is a chronic inflammatory disease of the pilosebaceous unit characterized by complex immunological mechanisms. The interleukin‐36 (IL‐36) cytokine family has been implicated in various inflammatory skin disorders; however, its role in adult AV remains insufficiently defined. This study aimed to evaluate serum IL‐36 cytokine profiles in adult AV patients and to investigate their associations with demographic and clinical characteristics. Materials and Methods This cross‐sectional case–control study included 70 adult AV patients and 70 healthy controls. Serum levels of IL‐36 α , IL‐36β, IL‐36 γ , and the IL‐36 receptor antagonist (IL‐36Ra) were measured using ELISA. Demographic data (including BMI, smoking, and alcohol status), disease severity, duration, and treatment history were recorded. Group differences were evaluated using adjusted and unadjusted analyses. Results Serum IL‐36 α levels were significantly higher, whereas IL‐36Ra levels were significantly lower in AV patients compared to controls (adjusted p = 0.011 and p < 0.001, respectively). Although IL‐36β levels were lower in unadjusted analyses, this difference was not significant after covariate adjustment. No significant difference was observed for IL‐36 γ . IL‐36Ra demonstrated the highest discriminative ability (AUC = 0.717), followed by IL‐36 α (AUC = 0.642). No consistent associations were identified between IL‐36 cytokines and disease severity or clinical parameters after correction for multiple testing. The differences in IL‐36 α and IL‐36Ra remained significant after adjustment for confounders. Conclusion This study demonstrates an imbalance in IL‐36 cytokine profiles in adult AV patients, characterized by elevated IL‐36 α and reduced IL‐36Ra levels. These findings suggest a potential role for IL‐36‐mediated pathways in the inflammatory milieu of AV, although further prospective studies with tissue‐level analyses are needed to clarify their pathophysiological relevance.