Activation of Janus kinase signaling pathway in acne lesions.

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway has been linked to the pathogenesis of many inflammatory skin diseases; however, the role of JAKs in the pathogenesis of acne vulgaris has not been previously elucidated. We aimed to analyze the cutaneous expression of JAK1/2/3 proteins in acne vulgaris and investigate the possible role of JAK signaling in acne pathogenesis. This case-control study was carried out on 28 patients with inflammatory acne vulgaris vs 20 age- and sex-matched healthy volunteers. Acne severity was assessed using Global acne severity grading system (GAGS). Skin biopsies were collected from lesional and non-lesional skin of patients and from control group. The expression of JAK1/2/3 proteins was examined by real-time quantitative polymerase chain reaction. JAK1 and JAK3 were overexpressed in acne lesions, compared to non-lesional skin and the control group. No significant difference was found in JAK2 expression between patients and controls. JAK1 and JAK3 showed no significant relation with the patients' age, sex, family history, duration of acne, or GAGS score. Our results suggest the activation of JAK pathway in acne lesions, indicating that it may play a pivotal role in the inflammatory disease process. JAK1 and JAK3 may be possible new targets for acne therapy.

Cryopeeling versus trichloroacetic acid peeling in the treatment of solar lentigines: Effect on epidermal Langerhans cells.

Trichloroacetic acid (TCA) peeling may be effective in solar lentigines, but with concerns regarding potential tumorigenesis. Cryopeeling would be better with improving the whole sun-damaged skin. We aimed to compare the efficacy and safety of cryopeeling and TCA 35% peeling for treatment of solar lentigines and assess their influence on the number of epidermal Langerhans cells (LC). Twenty-five patients were treated with TCA 35% and cryopeeling on the right and left hands, respectively. Two sessions were done 3 weeks apart. Evaluations were scheduled at weeks 0, 3, and 6. Skin biopsies, taken before and after treatment, were evaluated histologically and immunohistochemically for the number of CD1a + epidermal LCs. Lentigines decreased after cryopeeling from the first session (p < .001), but after the second session with TCA peeling (p = .004). Cryopeeling produced significant lightening, compared with TCA (p = .015). Blistering, hyper/hypopigmentation were reported with cryopeeling, whereas only hyperpigmentation was noted after TCA peeling. The LCs remained at about the pretreatment number after cryopeeling (p = .058), though they decreased after TCA (p = .002). Cryopeeling provided faster and superior improvement of lentigines compared with TCA peeling. Furthermore, TCA seems to suppress LCs raising the concern for carcinogenic potential.