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7th Annual Conference Of The British HIV Association [BHIVA]27 – 29 April 2001, The Hove Centre, Brighton |
[AUTHOR(S):] RM Lascar1, RJC Gilson1, R Johnstone1, R Bertoletti2, MK Maini1
1 Department of Sexually Transmitted Diseases and the 2 Institute of Hepatology, Royal Free and University College Medical School, London, UK
BHIVA Conf 2001 Apr 27-29;7:O31
OBJECTIVE: To investigate the effect of HIV-related immunodepletion on the specific immune response against a common co-infection. The HBV-specific CD8 response has a critical role in controlling HBV infection, but there are no data on how this is affected by the presence of HIV infection.
METHODS: We are using four human leucocyte antigen (HLA)-A2- peptide tetramers to quantify HBV-specific CD8 responses in HIV/HBV co-infected patients. The functional capacity of HBV-specific cells is being analysed with intracellular staining for interferon (IFN)γ following specific stimulation with 10 HLA-A2-restricted peptides. This allows direct ex-vivo evaluation of the HBV-specific CD8 response.
RESULTS: We studied 16 patients with natural immunity following HBV infection (nine HIV-negative and seven HIV co-infected). The HIV-infected subjects have a median CD4 count of 400 cells/µl and are antiretroviral therapy-naïve. Persistent multispecific HBV-specific CD8 responses are detectable both by tetramer and intracellular cytokine staining in the HBV-immune HIV-negative group but they have not been detected in the HIV-infected group. Similarly, HBV-specific CD8 responses were not detected in a group of HIV-positive HBV coinfected carriers of low infectivity (e-antigen negative).
CONCLUSION: These data suggest impairment of the size, multispecificity and function of the HBV-specific CD8 response in HIV-infected patients. This impairment of the CD8 response to HBV could be due to impaired CD4 help. The impact of highly active antiretroviral therapy on HBV-specific immune responses will be analysed prospectively.
PRESENTING AUTHOR: RM Lascar
010427
O31
Copyright © 2001 - British HIV Association (BHIVA) Reproduction of this abstract (other than one copy for personal reference) must be cleared through the BHIVA Organising Secretariat 1 Mountview Court, 310 Friern Barnet Lane, London N20 0LD