CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

HBV-RNA is an emerging biomarker reflecting the activity of intrahepatic HBV reservoir. The aim of the study was to describe HBV seroconversion (HBV-S) rate in HIV/ HBV subjects on HBV-active therapy and to analyse markers of HBV activity after achieving HBsAg loss. Methods: HIV/HBV individuals attending Modena HIV Clinic since 1985 with at least two HBV serology measurements and a follow-up (FU) of at least 6 months were included. Anti-HBV regimens during FU were collected. HBV-S was defined as HBsAb>10UI/ml in presence of HBsAg loss. HBV-DNA and -RNA were quantified in subjects with HBsAg loss by highly-sensitive assays based on digital droplet PCR (LLOQ: 1IU and 2IU/ml, respectively) at last available FU. Subjects were compared according to HBV-S using univariate analysis and multivariate logistic regression. Results: Overall, 163 HBV/HIV subjects were included (77% males, 31% intravenous drug users, HIV and HBV duration of 16 [IQR 9-25] and 10 [IQR 5-19] years, respectively) (Table 1): 32 (20%) had HBsAg loss and 19 (12%) had HBV-S (incident rate: 0.26 per 10,000 PYFU). HBV-S occurred more frequently if positive HCV-Ab (p=0.004), in liver transplant recipients (p=0.016) and on TDF-based regimen (p=0.013). Individuals without HBV-S had shorter exposure to TAF (p=0.025) and more frequently past AIDS events (p=0.011). HBV-DNA and –RNA were available for 15(47%) subjects with HBsAg loss (8 with also HBV-S): of those, 12(80%) had residual HBV activity. In detail, 4(33%) had a positivity to both HBV-DNA and -RNA and 8(67%) to HBV-RNA alone. Notably, higher rate of positive HBV-RNA was found in subjects with HBV-S (8/8 [100%] vs 4/7 [57%], p=0.038). HCV co-infection was associated with HBV-S (adjusted OR 6.4, 95% CI 2.2-19.1, p=0.001), while history of AIDS reduced the probability of HBV-S (aOR 0.1, 95%CI 0.01-0.61, p 0.016). No association with any HBV active regimen was found. Conclusions: One out of 10 individuals with HIV/HBV co-infection in our cohort reached HBV seroconversion, in line with literature. Previous AIDS-related events did not favour seroconversion, while HCV co-infection seemed to be associated with the outcome. A residual HBV activity persisted despite HBsAg loss during active HBV therapy: tenofovir discontinuation should be carefully evaluated in those patients and, if pursued, a proper monitoring of HBV markers should not be missed.

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Increased Detection of HBV DNA and Mutational Analysis in HBsAg Negative Specimens at NHLS/DGM Nondumiso A. Nkosi 1 , Omphile E. Simani 2 , Gloria S. Selabe 2 1 Sefako Makgatho Health Sciences University, Ga-Rankuwa, South Africa, 2 Sefako Makgatho Health Sciences University, Pretoria, South Africa Background: The disease burden associated with Hepatitis B (HBV) necessitates accurate diagnosis and it is important for effective disease management and prevention. The standard approach to HBV diagnosis is hepatitis B surface antigen (HBsAg) screening. However, the rising detection of HBV DNA in HBsAg negative specimens indicates a challenge. The underdiagnosis of HBV due to reliance on HBsAg screening poses a significant public health risk, as individuals with undetected HBV infection unknowingly transmit the virus. Moreover, these individuals remain at risk of liver disease progression without appropriate intervention. Addressing this diagnostic gap is critical for improving patient outcomes, enhancing the accuracy of HBV surveillance, and reducing the overall disease burden associated with HBV. The aim of this study was to investigate HBV DNA and mutations in HBsAg negative specimens at Dr George Mukhari National Health Laboratory Services (NHLS/ DGM). Methods: The study included 444 stored residual serum samples that tested negative for HBsAg during routine diagnosis, from March 2021 to May 2022 at National Health Laboratory Services, Dr George Mukhari (NHLS/DGM). Majority (33%) of the samples were from the 20-29 age group. Two hundred and fourteen (68%) were females. HIV status was known in 158 of 320 samples, of which 92% (146/158) were HIV positive and 8% (12/158) were HIV negative. HBV DNA was detected using real-time polymerase chain reaction (rt-PCR) with a 45 IU/ml (252 copies/ml) detection limit. Subsequently, conventional PCR was performed to amplify and sequence the surface region. Results: Sixty-nine of 444 (16 %) samples tested positive for HBV DNA. Of these, 28 (41%) had viral loads (VL) below 200 IU/ml with a median VL of 80 IU/ ml [61 IU/ml -129 IU/ml], while the remaining 41 (59%) had VL above 200 IU/ml with a median VL of 688 IU/ml [383 IU/ml -7101 IU/ml]. Sequences mutational analysis identified L209V as the most prevalent mutation in 61.3% of sequences, along with D144A causing epitope conformational changes. Immune escape mutations, influencing HBsAg antigenicity such as D144A, Y100C, P142L, N131S and P120T were identified. Genotyping identified six sequences as genotype A1, 20 genotype A2, and four genotype G. Conclusions: These findings suggest revising HBV diagnostic criteria, recommending that diagnosis should not solely rely on HBsAg screening. Alternatively diagnostic assays, as cost effective as HBsAg screening but with more sensitivity are needed. HBV Seroconversion in People With HIV: Relevance of Clinical History and Viral Markers Monitoring Marianna Menozzi 1 , Adriana Cervo MD 2 , Gianluca Cuomo 1 , Mattia Simion 2 , Alessandra Soffritti 2 , Lorenzo Piermatteo 3 , Stefano D'Anna 3 , Romina Salpini 3 , Valentina Svicher 3 , Cristina Mussini 2 1 AOU Policlinico di Modena, Modena, Italy, 2 University of Modena and Reggio Emilia, Modena, Italy, 3 University of Rome Tor Vergata, Rome, Italy Background: Treatment including tenofovir disoproxil (TDF) or alafenamide (TAF) is the standard of care in people living with HIV/HBV infection. Serum

Poster Abstracts

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