Topical ALA-Photodynamic Therapy for Acne Can Induce Apoptosis of Sebocytes and Down-regulate Their TLR-2 and TLR-4 Expression

The study from 2011 investigated the effects of aminolevulinic acid photodynamic therapy (ALA-PDT) on patients with mild to moderate acne. It involved 12 patients and used clinical assessments, sebum measurements, and biopsies to evaluate the therapy's efficacy. The results showed a significant reduction in inflammatory acne lesions and sebum secretion, with a 53% decrease in lesions after three treatment sessions, maintained for 8 weeks. Biopsies revealed increased apoptosis in sebocytes and a decrease in TLR-2 and TLR-4 expression by 50% and 30%, respectively. Despite the small sample size, the study concluded that ALA-PDT can induce sebocyte apoptosis and down-regulate TLR expression, which may contribute to acne improvement. Side effects included transient erythema, edema, and hyperpigmentation. Further research was recommended to better understand the treatment's mechanisms.