Contact immunotherapy with diphenylcyclopropenone (DCP) in alopecia areata patients and effect of treatment on İL-17 protein levels

In this study we aimed to evaluate the effect of IL-17 in the pathogenesis of AA and DCP treatment mechanism and to evaluate the success of DCP treatment on extensive and chronic AA patients. For this purpose, the study was planned to enroll 50 patients with AA. Ten scalp biopsy specimens obtained by excision of benign lipomatous neoplasm or sebaceous cyst of hair in general surgical clinic were taken to create a control group. Protein quantities obtained from some of the biopsy samples were not sufficient to determine the level. Also patients who didn't come to their pre-treatment biopsy appointments were excluded from the study. Eighteen biopsy samples before treatment, 13 after treatment and 5 of control samples were found available for measurement. IL-17 protein levels were measured by Western blot method and results were evaluated statistically. Cosmetically acceptable hair regrowth was observed in 26.3% of patients after DCP treatment. Although pre-treatment mean IL-17 protein level was higher in AA patients compared to control group, there wasn't a statistically significant difference (p<0,05). However, median IL-17 protein levels were statistically significantly higher in AA patients with active disease compared to stable disease (p= 0.024) and patchy type of AA compared to AU patients (p= 0.039). IL-17 protein levels was not significantly different between post-treatment biopsy samples of AA patients compared to control group and between pre and post-treatment biopsy samples obtained from patients with effective treatment response (p<0,05). If considered only extensive and chronic AA patients were enrolled to our study, we found the treatment success of our study to be consistent with the literature. And we concluded that IL-17 may play a role in active period of disease process. However, we think there is a need for studies with more patients and more budget that consists not only one pathway also final products of other pathways which can influence the pathogenesis. And not only cytokine levels also the place of cytokine-producing cells in the biopsy specimens must be examined to understand interactions between the pathways involved in the inflammatory process and how DCP is effective in the treatment of AA