Efficacy of vaccination against hepatitis B in HIV-infected patients in northern Greece
Abstract number: R2490
Pape M., Mandraveli K., Kollaras P., Kazakos E.I., Nikolaidis P., Alexiou-Daniel S.
Objective: Several studies have shown that HIV-positive patients with HBV co-infection have higher HBV replication, lower rates of seroconversion to anti-Hbe and anti-Hbs, and show accelerated progression towards cirrhosis. Since HIV and hepatitis B share epidemiological risks, it is essential to prevent hepatitis B by vaccination. The aim of this study was to evaluate the antibody response rates to HBV by immunisation in HIV-infected patients as compared to HIV-uninfected healthcare professionals and to identify differences in responsiveness correlating to CD4 counts in the HIV-infected group.
Methods: 158 HIV-infected patients and 480 HIV-uninfected healthcare professionals, tested negative for hepatitis B surface antigen (HBsAg) and antibody to HBsAg (anti-HBs) received vaccination with hepatitis B vaccine (Engerix). All subjects received three standard doses of the vaccine at 01-6 months. Upon completion of vaccination anti-HBs levels were examined by ELISA (AXSYM, Abbott) and a positive response was defined as an anti-HBs titer of 10 IU/L. CD4 cells measurements were done by flow cytometry. Patients and healthy individuals were divided into two groups according to the magnitude of response to vaccination.
Results: Protective antibody titres were evident in 37% (n = 58) of patients with a mean CD4 cell count of 749.36 (±-259.1)/mm3. Interestingly, in 13.8% (8/58) of those subjects, CD4 cells did not exceed 500/mm3.
The remaining 63% (n = 100) showed inadequate seroconversion titres. Mean CD4 cell count among HIV-infected non-responders was 621.1 (±306.43)/mm3, while 50% of those patients had a CD4 count of >500/mm3. Statistical analysis using Student's t test, revealed that overall differences in CD4 counts between responders and non-responders are significant (p = 0.0126). Protective antibody titres were found in 88.2% of healthy controls.
Conclusion: Efficacy of current HBV vaccination schedule is low among HIV-infected patients. Despite significant differences observed in CD4 counts in relation to antibody response, the former cannot be used as the sole marker of immune system activation. Failure to generate an antibody reaction maybe due to other factors as inferred by the high percentage (11.8%) of non-responders in the control group. Alternative strategies such as higher hepatitis B vaccine doses, prolongation of the vaccination schedule, or both, as prescribed for many patients with non-HIV-related immune deficiencies, may be considered.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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