IL-10-592 polymorphism is associated with IL-10 expression and severity of enterovirus 71 infection in chinese children

•IL-10-592 C allele is related to critical EV71 infection.•IL-10-592 A/A could decrease IL-10 level.•IL-10 in plasma was elevated in critical EV71 infection cases.

BackgroundEnterovirus 71 (EV71) infection results in some severe complications with high mortality and disability in Hand, Foot and Mouth Disease (HFMD) in children. Recent studies have shown that cytokine genetic predispositions have associations with both the development of EV71 infection and severity of HFMD.ObjectiveThis study was designed to investigate whether the IL-10-592 polymorphism is associated with IL-10 levels and disease severity in Chinese children with EV71 infection.Study designIn patients selected, there were 378 cases with EV71 infection (including 291 mild cases, 70 severe cases and 17 critical cases), as well as 406 health controls. EV71 in serum was tested by RT-PCR, and IL-10-592 genotype was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis techniques.ResultThe IL-10-592C allele was observed with higher frequency in patients with critical EV71 infection (70.59%) compared with severe EV71 infection (41.43%, P < 0.01), mild EV71 infection (43.81%, P < 0.01) and healthy children (44.46%, P < 0.01). The blood IL-10 levels of critical cases were significantly higher than severe cases, mild cases, and healthy children. Among all of the four groups, IL-10 levels in patients with genotype AA were significantly lower than those with genotypes AC + CC (t = 4.86, P < 0.05; t = 2.30, P < 0.05; t = 3.44, P < 0.05; t = 5.58, P < 0.05).ConclusionIL-10-592C allele is associated with IL-10 expressions and the severity of EV71 infection in Chinese patients.