IL-10 secretion from CD14+ peripheral blood mononuclear cells is down regulated in patients with acne vulgaris.:IL-10 is down-regulated in acne patients.

Background: Acne is a common chronic inflammatory dermatosis of the pilosebaceous unit. It is characterized by seborrhoea, comedone formation and an inflammatory response consistent with defective cellular immunity to Propionibacterium acnes. Objective: The objective of this study was to investigate the immune reactivity of patients with acne compared to healthy controls by examining the response of peripheral blood mononuclear cells (PBMC) to stimulation with P. acnes. Particular focus was placed upon the measuring the production of IL-10 which has established immunoregulatory role. Methods and Patients: Venous blood was collected from 47 acne patients and 40 age and sex matched healthy controls with no prior history of acne. PBMC were cultured and their cytokine response to P. acnes investigated. Results: Pro-inflammatory IL-8 and TNF¿ secretion from PBMCs was higher in acne patients when stimulated with P. acnes. In contrast, a statistically significant reduction in PBMC secretion of anti-inflammatory IL-10 in acne patients was identified. The impaired production of IL-10 by PBMCs from acne patients was confined to CD14+ cells presumed to be monocytes. The ability of CD14 cells from acne patients to phagocytose P. acnes bacteria was also observed to be defective but the addition of exogenous IL-10 to PBMC cultures restored phagocytic activity. Conclusions: These data suggest that acne patients have a pro-inflammatory cytokine milieu and crucially are unable to contain early inflammatory changes due to a specific defect in immunosurveillance, namely low monocyte IL-10 production. Our observations raise the possibility that acne therapeutics might profitably target IL-10 both as a regulator of pro-inflammatory cytokines and in augmenting the CD14+ cell phagocytic response.