Tissue expression of IL-17A and FOXP3 in acne vulgaris patients

CD4⁺  T helper (Th) cells through its pro-inflammatory cell type, interleukin-17 (IL-17)-generating cells and its anti-inflammatory category forkhead box P3-positive (FOXP3⁺ ) regulatory T (Treg) cells, play a vital role in the immune balance in inflammatory disorders. Therefore, assessment of both IL-17 and FOXP3 in acne vulgaris (AV), a chronic inflammatory disease of the pilosebaceous unit, could be of value in understanding AV pathogenesis. This study aimed to investigate the immunohistochemical expression of IL-17A and FOXP3 in acne vulgaris lesions versus normal skin.

Forty-five AV patients and 25 controls were included in this case-control study. Biopsies from participants were analyzed for IL-17A and FOXP3 immunohistochemical profiles using IL-17A and FOXP3 polyclonal antibodies.

Compared to controls, AV patients exhibited a significant increase of IL-17A percent of expression in epidermis (P ≤ .001), in lymphocytes in papillary dermis (P ≤ .001), and in perifollicular lymphocytic inflammatory infiltrate in AV lesions. Also, there was a significant elevation in FOXP3 percent of expression in epidermis (P = .049) and in lymphocytes in papillary dermis (P ≤ .027) in acne patients than control. A significant positive correlation between IL-17A expression in papillary lymphocytes and in epidermal keratinocyte was observed (r = .537, P = .001). In acne vulgaris patients, the associations between IL-17A and FOXP3 expressions could not reach level of significance.

There was an up-regulation of IL-17A and FOXP3 in acne vulgaris development, but with independent roles. Moreover, targeting of IL-17A and FOXP3 may open the door for development of new therapeutic agents in acne vulgaris treatment.