[Correlation study of IL-18 expression in HBsAg positive parturients in intrauterine transmission of HBV]

Objective: To investigate the expression of IL-18 in peripheral blood of HBsAg positive parturients in intrauterine transmission of HBV. Methods: A case-control study was conducted in 282 HBsAg positive parturients and 43 health parturients (control group) in Northwest Women and Children Hospital of Shaanxi Province. Enzyme-linked immunosorbent assay (ELISA) was used to detect five serological makers of hepatitis B, real time PCR was used to detect HBV DNA, and flow liquid chip method was used to detect IL-18 levels in peripheral blood of parturients and newborns. Results: The incidence of dominant HBV infection (DBI), occult HBV infection (OBI) and intrauterine transmission of HBV were 8.42 % (24/285), 40.00 % (114/285) and 48.42 % (138/285), respectively. The level of IL-18 in peripheral blood of HBsAg-negative parturients were significantly lower than those of HBsAg-positive parturients ( P =0.001), non-HBV intrauterine transmission (NBIT) group ( P =0.001) and OBI group ( P <0.001). The level of IL-18 in HBeAg negative group was significantly lower than that in HBeAg positive group ( P =0.023). When HBV DNA load was ≥10(3) copies/ml, the level of IL-18 was significantly higher than that in HBsAg-negative group ( P <0.01). With the increase of HBV DNA load in maternal blood, the level of IL-18 increased ( P =0.024). When HBV DNA load was 10(3)-10(6) copies/ml, the level of IL-18 in DBI group was significantly lower than that in NBIT group ( P =0.022), and increased with the increase of HBV DNA load in maternal blood ( P =0.016). With the increased severity of intrauterine transmission of HBV, the level of IL-18 in non-hepatitis B vaccine group decreased significantly ( P =0.044). The level of IL-18 in non-hepatitis B vaccine group and immunoglobulin injection group was significantly higher than that in NBIT group ( P <0.05). Multivariate analysis showed that the linear relationship between maternal HBeAg status and maternal IL-18 levels had statistical significance ( P =0.01). Conclusions: IL-18 is a higher level balance regulator of Th1/Th2 immune network. Monitoring the level of IL-18 in HBsAg-positive parturients can be used not only for predicting the probability of DBI and OBI, but also as an intervention mean, especially for those who are HBeAg-positive and had HBV DNA load ≥10(3) copies/ml, to improve maternal cellular immune function, which is conducive to interrupting intrauterine transmission and providing a theoretical basis for the prevention and control of HBV intrauterine transmission.