[IL-35 level of peripheral blood is correlated with the immune response to hepatitis B vaccine]

To investigate the relationship of IL-35 level in peripheral blood mononuclear cells (PBMCs) and immune response to hepatitis B vaccine and explore the factors influencing vaccine immune reaction.

Our follow-up study enrolled 400 healthy volunteers who had received a standard course of immunization with hepatitis B vaccine. Chemiluminescence method was carried out to quantitatively detect hepatitis B virus surface antibody (HBsAb). PBMCs were isolated from 8 cases of non- or hypo-responders and 8 cases of moderate or hyper-responders, and the total RNA was extracted. Real-time quantitative PCR was performed to detect Epstein-Barr virus (EBV)-induced gene 3 (EBI3) and IL-12p35 mRNA levels. Finally, serum IL-35 level was compared using ELISA between 40 cases of non- or hypo-responders and 40 cases of moderate or hyper-responders randomly selected from the healthy volunteers to analyze the association with HBsAb level.

The levels of EBI3 and IL-12p35 mRNAs in PBMCs in moderate or hyper-responders were significantly higher than those in non- or hypo-responders, and the former was (12.73 ± 2.26) and (7.93 ± 1.06) folds the latter, respectively. The serum IL-35 level in moderate or hyper-responders [(111.50 ± 49.53) ng/L] was significantly higher than that in non-or hypo-responders [(15.01 ± 12.82) ng/L]; and IL-35 level was positively correlated with HBsAb level (r=0.84).

Peripheral blood IL-35 level was closely correlated with the immune response to hepatitis B vaccine and low IL-35 level might be one of possible reasons or mechanisms underlying non-response or hypo-response to hepatitis B vaccine immunization.