Role of gene polymorphisms/haplotypes and serum levels of interleukin-17A in susceptibility to viral myocarditis.

Interleukin-17A (IL-17A) has been implicated in the pathogenesis of viral myocarditis (VMC). However, the role of IL-17A polymorphisms in susceptibility to VMC has not been reported to date. The aim of this study was to explore the association between IL-17A variants as well as serum IL-17 levels with VMC. Three single-nucleotide polymorphisms (SNPs) (rs2275913, rs3819025, and rs3748067) were analyzed by the polymerase chain reaction-restriction fragment length polymorphism method in 236 VMC patients and 259 controls from China. Serum IL-17A levels were measured by enzyme-linked immunosorbent assay kits. Multivariable logistic regression analysis that the rs2275913 AA genotype and the haplotype -197A/+45G/+1249G (AGG) were associated with an increased risk of VMC (all P < 0.05). Consistent with these findings, the rs2275913 AA genotype was linked to higher serum IL-17A compared to GG/AG genotype (all P < 0.001). We observed no associations between the other two SNPs and risk of VMC. Serum IL-17A levels were significantly higher in the VMC group than controls (P < 0.001) and gradually increased with the increase of New York Heart Association grade in VMC patients (P < 0.05). Spearman correlation test revealed that the serum IL-17A level was correlated with the cardiac damage and left ventricular systolic functions among VMC patients (all P < 0.05). Our study reveals that IL-17A expression may contribute to the development and severity of VMC. The SNP rs2275913 in the IL-17A gene might exert influence on susceptibility to VMC via linking with the serum IL-17A level.