CROI 2016 Abstract eBook

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Poster Abstracts

at the beginning of the 12 month follow up period (baseline), and 3) among those without vaccination and/or immunity at baseline, during the 12 month follow-up period (recent). We examined factors associated with recent immunity during the 12 months of follow-up using Rao-Scott chi-square tests. Results: Among 8444 MSM and PWID, 64% (95% confidence interval [CI] 59-65) overall had ever been vaccinated against or demonstrated immunity to HAV, including 64% (CI 61-68) of MSM and 72% (CI 66-78) of PWID. At baseline, 59% (CI 56-62) of MSM and 65% (CI 59–71) of PWID had evidence of immunity. Among those without baseline evidence of immunity, 14% (CI 12-16) of MSM and 19% (CI 12-25) of PWID were either vaccinated or developed immunity during 12 months of follow-up. Factors associated with not being immune during follow-up included older age, white race, HIV diagnosis > 5 years, undetectable HIV viral load, not having condomless sex and not being tested for sexually transmitted diseases (Table). Conclusions: Over one third of HIV-infected MSM or PWID in care during 2009-2012 were not vaccinated and demonstrated no immunity to HAV, despite inclusion in the Advisory Committee on Immunization Practices recommendations. This analysis suggests that a sizeable portion of HIV-infected MSM and PWID are at risk and susceptible for HAV infection despite current HAV vaccination recommendations, suggesting a substantial unmet need for this population.

592 Antiretroviral Therapy and Hepatitis Delta Replication in HIV-Coinfected Patients Charles Béguelin 1 ; Darius Moradpour 2 ; Roland Sahli 3 ; Huldrych F. Günthard 4 ; Manuel Battegay 5 ; Alexandra L. Calmy 6 ; Enos Bernasconi 7 ; Andri Rauch 1 ; GillesWandeler 8 ; for the Swiss HIV Cohort Study 1 Bern Univ Hosp and Univ of Bern, Bern, Switzerland; 2 CHU Vaudois, Univ of Lausanne, Lausanne, Switzerland; 3 Inst of Microbiology, CHU Vaudois, Univ of Lausanne, Lausanne, Switzerland; 4 Univ Hosp Zurich, Zurich, Switzerland; 5 Univ Hosp Basel, Basel, Switzerland; 6 Univ Hosp Geneva, Univ of Geneva, Geneva, Switzerland; 7 Regional Hosp Lugano, Lugano, Switzerland; 8 Univ Hosp Bern, Bern, Switzerland Background: Hepatitis delta virus (HDV) infection is present in 5-15% of HIV/hepatitis B virus (HBV)-coinfected individuals and can lead to severe liver disease. Although treatment options remain limited, tenofovir (TDF) has been associated with a reduction in HDV viral load (VL) in recent studies. We explored the virological characteristics of HDV infection in the Swiss HIV Cohort Study and describe treatment outcomes in those treated with a TDF-containing antiretroviral therapy. Methods: We quantitatively assessed HDV RNA in all HIV/HBV-coinfected patients with a positive anti-HDV serology (Diasorin ® ) using real-time polymerase chain reaction. Demographic and clinical characteristics of individuals with and without HDV replication were compared using Chi-square and Mann-Whitney tests. Individuals with an HDV VL > limit of detection (300 cp/ml) at TDF initiation and who had at least one follow-up stored sample were included in the prospective study. HDV VL trajectories were described and the proportion of patients who reached virological suppression on TDF was evaluated. Results: Among 771 HIV/HBV-coinfected patients, 139 (18%) were anti-HDV-positive. Of 122 with a sample available for amplification, 72 (59%) had a detectable HDV RNA. Median HDV VL was 4.7 log cp/ml (interquartile range [IQR]: 0- 7.3 log). At time of measurement, 50% (15/30) of individuals on lamivudine, 54% (19/35) of those on TDF and 56% (38/57) of those with other or no antiretroviral treatment had detectable HDV RNA (p=0.26). Age and sex distribution, as well as CD4 cell counts, stage of HIV disease, hepatitis c antibody-positivity and ethnicity were similar between patients with detectable HDV RNA and those with undetectable levels. In 21 patients included in the prospective study, mean HDV RNA decreased from 8.1 log cp/ml before TDF initiation to 7.2 log cp/ml at the follow-up visit, with a median time of 34 months (IQR 23-35) between the two tests. Eight (38%) patients had a decrease of the HDV VL >1 log during follow-up and HDV RNA became negative in three of them (14%) (Figure). Conclusions: In this nationwide cohort of HIV/HBV-coinfected individuals with positive anti-HDV serology, approximately 60% had detectable HDV RNA. TDF-containing regimens reduced HDV VL in 38% of individuals within three years of treatment initiation.

Poster Abstracts

236

CROI 2016