Oligoadenylate synthetase 3 S381R gene polymorphism is associated with severity of EV71 infection in Chinese children

Background: Oligoadenylate synthetase 3 (OAS3) is interferon-induced antiviral enzyme, playing a significant role in the innate immune response. Genetic polymorphism in OAS3 gene has been reported to be a susceptibility factor in many infected diseases, but evidence of its effect on enterovirus 71 (EV71) infection is still lacking. Objectives: An attempt study was made to investigate whether genetic polymorphism of OAS3 S381R is associated with the severity of EV71 infection in Chinese children. Study design: Retrospectively sumed up the clinical onsets and experimental results for 249 cases with EV71 infection (including 151 mild cases and 98 severe cases) and 243 controls. An improved multiplex ligation detection reaction (iMLDR) technique was carried out to analyze polymorphism in OAS3 S381R G/C gene for genetic association analyses. The plasma levels of IFN-gamma were determined by enzyme-linked immunosorbent assays. Results: The distribution of OAS3 S381R CC genotype (73.47%) and C allele (85.20%) in severe cases was markedly higher than in mild cases (45.70%, P < .01; 67.88%, P < .01). The blood IFN-gamma levels of severe cases were significantly lower in CC genotype (131.66 +/- 10.84 pg/mL) compared to GG (183.37 +/- 24.50 pg/mL, p < .01) and GC genotype (168.48 +/- 26.57 pg/mL, p < .01). Conclusions: Carrying the C allele of the OAS3 S381R gene could be a susceptibility factor in the development of severe EV71 infection in Chinese children.