069 Cytotoxic Effects of Alopecia Areata Serum on the Cultured Follicular Outer Root Sheath Cells and Dermal Papilla Cells

Won-Soo Lee, Yun Chul Kang Department of Dermatology, Yonsei University Wonju College of Medicine, Wonju, Korea

The exact primary cell target in the affected hair follicle of alopecia areata(AA) lesion is not definitely known. The possible role of humoral factor(s)/circulating antibodie(s) in inducing hair loss in AA has been suspected for many years. We investigated the effect of serum from AA patients on cultured normal human outer root sheath(ORS) cells and dermal papilla(DP) cells to determine whether it has a role in the process of hair loss and contains any cytotoxic factors to ORS cells and/or DP cells. The ORS cells and DP cells from healthy human occipital scalp hair follicles were isolated and cultured in a defined serum-free media. Sera were obtained from five patients with active AA lesions and added to the single cell suspension of the ORS cells and the DP cells. To determine cytotoxicity, we assessed cell viability by using MTT assay. Cell viability, expressed as percent of control absorbance, showed a typical dose-dependent curves in both ORS and DP cell lines. The decrease in the number of viable cells was statistically significant from the control sera. There were no marked variations in the response between individual patient’s sera or between individual cell lines. Our data suggest that ORS cells and DP cells may somehow be involved in the pathogenesis of AA and provide clear evidence for involvement of circulating factors in AA.