Combination of FLG mutations and SNPs of IL-17A and IL-19 influence on atopic dermatitis occurrence

Postepy Dermatol Alergol. 2022 Feb;39(1):200-208. doi: 10.5114/ada.2021.105412. Epub 2021 Apr 16.

Abstract

Introduction: Atopic dermatitis (AD) is a heterogeneous inflammatory skin disease. A fresh look on the AD pathophysiology has focused on the skin barrier defect and immune dysfunctions. IL-17A and IL-19 seem to play role in AD pathogenesis.

Aim: The aim was to investigate associations of SNPs of IL-17A (rs2275913) and IL-19 (rs22431188) with AD features, course and occurrence. Searching for prognostic panels composed of FLG (2282del4, R501X) mutations with IL-17A and IL-19 polymorphisms.

Material and methods: Blood samples were collected from 239 patients with AD and 170 controls. Two SNPs, IL-17A and IL-19 and FLG null mutations were analyzed. PCR and RFLP restriction fragment length polymorphism analysis were used. SCORAD score to establish AD severity, VAS to estimate pruritus.

Results: None polymorphisms of studied cytokines caused more frequent AD occurrence compared to controls. We found no associations between IL-17A and IL-19 gene polymorphisms and AD severity (respectively p = 0.954; p = 0.498), IgE level (p = 0.707; p = 0.584), VAS (p = 0.953; p = 0.478), concomitant asthma (p = 0.488, p = 0.764). The G/G genotype in IL-17A (rs2275913) occurrence with coexisting 2282del4 FLG gene mutation increased the AD frequency 9 times (p = 0.0266).

Conclusions: The SNPs of IL-17A rs2275913 and IL-19 rs22431188 SNP seem not to have influence on AD course and occurrence while studied alone. The coexistence of GG genotype of IL-17A and 2282del4 FLG mutation may play a role as prognostic AD factor.

Keywords: IL-17A; IL-19; SNP; atopic dermatitis; filaggrin.