[Role of IL-17A and neutrophilic granulocytes in the pathogenesis of psoriasis].

Objective: To study the expression of IL-17A in the inflammatory infiltrating cells in the plaques as one of the key points in the pathological process in moderate to severe psoriasis.

Material And Methods: The material obtained from 50 patients with moderate and severe psoriasis was examined by an indirect immunofluorescence assay to determine the composition of cell infiltrate and the type of IL-17A-producing cells in the foci of lesion. The markers of lymphocytes (CD3), dendritic cells (CD11c), neutrophilic granulocytes (Mpo), and mast cells (Trp) were used. The proliferative activity of basal keratinocytes (Ki-67), the expression of IL-17A, and the co-expression of IL-17A, Mpo, and Trp were also studied.

Results: A positive correlation was established between the count of neutrophilic granulocytes in the infiltrate, the expression of IL-17A, and the number of neutrophils expressing IL-17A with the duration of the disease and the severity of the patient's condition.

Conclusion: Neutrophilic granulocytes and their expression of IL-17A play one of the key roles in the pathogenesis of psoriasis.