CD117 Positive Cells Significantly Exist in Immune-targeted Follicles of Alopecia Areata

Aim: Studying the expression of CD117 (c-kit) in hair follicles of Alopecia Areata (AA).

Place and Duration of Study: Department of dermatology and venereology, Minia university hospital, Egypt and Department of Pathology and laboratory medicine, Western University, Ontario, Canada, between July 2022 and July 2023.

Methodology: This study included 16 AA patients, Skin biopsies were obtained from each participant and stained with hematoxylin and eosin (H&E) and CD117 immune stain, all hair follicles are numbered and evaluated for presence of infiltrates and expression of CD117. Correlation was done between existence of perifollicular inflammatory infiltrate and expression of CD117 in all hair follicles in cross section.

Results: Within 82 follicles examined, CD117 was significantly expressed in immune targeted follicles. The median of positive expression was 2 with interquartile range (IQR) (1-3), the expression decreased in non-infiltrated follicles the median was 1 with IQR (0-1.8) with statistically significant difference (P = 0.001).

Conclusion: CD117 is significantly expressed in hair follicles of AA and is correlated to the immune cytotoxic infiltrates and possibly to the pathogenesis of alopecia areata.