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

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. 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.