Calculated Globulin Adds Predictive Value to Hepatitis B Vaccine Response in HIV-infected Persons Independently of HIV Viral load and CD4 Cell Count

BACKGROUND: Response rates to hepatitis B (HBV) virus vaccine are low compared with the general population. Recent data suggest baseline total IgG levels add predictive value for vaccine failure. We retrospectively analyzed the relationship of calculated globulin (CG) levels with HBV vaccine response in participants in the U.S. Military HIV Natural History Study (NHS). METHODS: NHS is a longitudinal observational cohort of DoD active duty and beneficiaries with HIV infection, enrolling since 1986. Inclusion criteria was: (1) no current or past HBV or hepatitis C infection (2) HBV vaccination after positive HIV date, (3) available post-vaccination follow-up serum HBV surface antibody (HBsAb) test, (4) CD4 cell count, HIV RNA viral load (VL), and protein levels within 90 days prior to the last vaccine dose. Using a standard approach, CG levels were derived by subtracting the albumin level from total protein. Variables were analyzed using univariate and multivariate logistic regression model. RESULTS: Data from 674 eligible participants were analyzed. Subjects were 87% male, 44% Caucasian, 41% African-American. At time of last vaccine dose, median values were age, 34 yrs; CD4 cells/uL, 515; nadir CD4 cells/ul, 318. 51% were receiving ART and VL was <400 copies/ml in 51%. Overall, HBV vaccine response rate was 54%. Among CG quartiles, HBV vaccine response was 70%, 60%, 40% and 44% from lowest to highest quartile respectively (P < 0.001). In the multivariate analysis, CD4 cell count, VL and CG were independently associated with vaccine response (Table). CONCLUSION: CG levels at time of last dose independently predicted successful HBV vaccine response in HIV-infected persons. These data suggest B-cell dysfunction, characterized by higher CG levels, may be clinically significant regardless of VL and CD4 cell count. DISCLOSURES: All authors: No reported disclosures.