Dietary Habits in Japanese Patients with Alopecia Areata.

PURPOSE: Alopecia areata (AA) is characterized by non-scarring, patchy hair loss caused by autoimmune reactions to anagen hair follicles. The pathogenesis of AA may be affected by the diet. However, the dietary habits of patients with AA have not been precisely examined. Therefore, the aim of this study was to investigate the dietary habits of patients with AA in comparison to those of healthy controls. PATIENTS AND METHODS: We evaluated the dietary habits of 70 adult Japanese patients with AA using a brief-type self-administered diet history questionnaire and compared them to the habits of age- and sex-matched healthy controls. RESULTS: Japanese patients with AA had a higher body mass index (BMI) and higher intakes of vitamin C and fruit than the controls. Logistic regression analysis showed that AA was associated with BMI. Retinol intake was positively correlated with severity of alopecia tool (SALT) score, and linear regression analysis revealed that retinol intake was a predictor of SALT score. Retinol intake among patients with moderate to severe AA (ie, a SALT score >25) was higher than that in patients with mild AA (a SALT score ≤25). The mean age of AA patients with atopic dermatitis (AD) was lower than that of AA patients without AD; however, there were no differences in nutrient or food intake between these two groups. Logistic regression analysis showed that the comorbidity AD was negatively associated with age. CONCLUSION: AA was associated with a high BMI, and high retinol intake was a predictor of SALT score. Further studies should be conducted to clarify whether dietary intervention to reduce BMI or limit retinol intake can alter the development or severity of AA.

Toll­like receptor 4 plays a tumor­suppressive role in cutaneous squamous cell carcinoma.

Toll­like receptor 4 (TLR4), a key regulator of the innate immune system, is expressed not only in immune cells, but also in a number of cancer cells. A biological role for TLR4 in cutaneous squamous cell carcinoma (SCC), however, is unclear. In this study, we first examined TLR4 expression and localization in cases of SCC, actinic keratosis (AK) and Bowen's disease (BD) by immunohistochemistry. TLR4 expression was significantly higher in the SCC than in the AK or BD tissues. We then determined the TLR4 expression level in vivo, in 3 histological subtypes of SCC. TLR4 expression in poorly differentiated SCC was significantly lower compared with that of the moderately and well­differentiated type. In addition, the CD44 immunoreactivity tended to be high in the cell membrane of poorly differentiated SCC. Of note, poorly differentiated SCC is a risk factor of unfavorable outcomes in affected patients. We then assessed the biological role of TLR4 in HSC­1 and HSC­5 SCC cells and HaCaT human keratinocytes. TLR4 knockdown by transfection with siRNA accelerated HSC­1 and HaCaT cell migration and invasion compared to the control siRNA­transfected cells. TLR4 knockdown resulted in an increased CD44 expression and in an enhanced filopodia protrusion formation, particularly in HSC­1. On the whole, these results suggest that a reduced TLR4 expression enhances the malignant features in SCC cases and cultured SCC cell lines. TLR4 may thus play an anti­tumor role in cutaneous SCC.