Lower baseline germinal center activity and preserved th1 immunity are associated with hepatitis b vaccine response in treated hiv infection

Background: Why HIV-infected individuals have poor responses to standard dose and schedule hepatitis B virus immunization is not well understood. Methods: We compared the serologic and cellular immune profiles of treated HIV-infected individuals with similar durations of infection and preserved CD4 counts (> 350 cells/microliter) by hepatitis B vaccine (HBV) response before and after vaccination. Results: Similar levels of immune activation and plasma cytokine profile were found between non-responders and responders. The baseline plasma levels of CXCL-13, a surrogate of germinal center reactivity, were significantly lower in HBV responders compared to HBV non-responders and were a predictor of both vaccine response and titer. Furthermore, response to HBV vaccination was associated with a significantly higher frequency of circulating IgG^high memory B cells post vaccination and preserved Th1 antigen-specific T-cell responses. Conclusions: Taken together, our data suggest that preserved Th1 responses are associated with hepatitis B vaccine response in treated HIV infection.