Serum ERK1/2 proteins fluctuating with HBV infection report frequency of viral-specific CD8+ T cells and predict IFNα therapeutic effect in chronic hepatitis B patients

Abstract Chronic hepatitis B (CHB) is a life-threatening disease caused by HBV infection. Our previous work proved that activation of ERK1/2 and STAT3 signaling was involved in HBV tolerance. We herein investigated clinical significances of serum ERK1/2 and STAT3 proteins in CHB. Results showed that ERK1/2 and STAT3 were fluctuated with natural history of CHB. In addition, STAT3 was found to be positively correlated to the elevation of ALT, AST and GGT, while ERK1 was negatively correlated to decreases of TP and ALB. Also, there was a positive correlation between the anti-HBc antibody and ERK1, ERK2 or STAT3 in HBeAg-negative patients. Strikingly, serum ERK1 and ERK2 could reflect level of HBsAg-specific CD8+ T cells. A model composed with baseline ERK1 and ERK2 levels had a high accuracy to predict the effect of IFNα treatment. In conclusion, serum ERK1, ERK2 and STAT3 could serve as novel biomarkers in chronic HBV infections.