Liver elastography scores in a large population cohort in rural Uganda: Uganda Liver Disease Study (ULiDS) Sheila F Lumley1,2*, Beatrice Kimono3*, Joseph Mugisha3, Brian Ssengendo3, Elizabeth Waddilove4, Richard Ndungutse3, Moses Kwizera Mbonye3, Ponsiano Ocama5, Philippa C Matthews4,6,7 ^, Robert Newton3^ * joint first, ^ joint senior 1 Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, South Parks Road, Oxford OX1 3SY, UK, 2 Department of Infectious Diseases and Microbiology, Oxford University Hospitals NHS Foundation Trust, 3 MRC/UVRI/LSHTM Uganda Research Unit, 4 The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK, 5 Makerere University College of Health Sciences in Kampala, Uganda, 6 Division of Infection and Immunity, University College London, Gower St, London WC1E 6BT, UK, 7 Department of Infection, University College London Hospitals, 235 Euston Rd, London NW1 2BU, UK Contact: sheila.lumley@gtc.ox.ac.uk, philippa.matthews@crick.ac.uk INTRODUCTION - Chronic liver disease (CLD) represents an increasing healthcare burden in many global settings. - In many populations in the WHO Africa region, the prevalence, aetiology and outcomes of CLD represent a neglected challenge. - Hepatitis B virus (HBV) and Human immunodeficiency virus (HIV) are associated with liver fibrosis. - Non-invasive tests (NITs) such as liver elastography act as a surrogate measure of fibrosis. Aims: (1) estimate the prevalence of liver disease in a large population cohort in rural Southern Uganda using elastography (2) define the distribution of elastography scores in a subset of HBV or HIV infected individuals. METHODS - Between April - June 2023, we performed a cross-sectional study (Uganda Liver Disease Study - ULiDs) nested within the Kyamulibwa Uganda MRC General Population cohort (GPC), a well established rural cohort of ~22,000 individuals in Kalungu District. - 517 adults including a subgroup with known HBV infection were selected from the GPC. Pregnant women were not eligible to participate in the study. - We performed a questionnaire to identify exposure to known CLD risk factors, anthropometric measures, bloods for HIV, HBV, HCV and malaria infection status and liver elastography (Fibroscan, Echosens, Paris). - Elastography score was expressed in kilopascal (kPa) as a median of 10 successful acquisitions, scores with interquartile range/median >0.30 were excluded. - We applied the following thresholds to interpret elastography score: - Analysis was performed using R v 4.2.2 (https://www.R-project.org/Licenses) RESULTS (1) Demographics We reviewed 517 adults, the median age of participants was 53 years (IQR 44-63, range 23-96) there were 216 males and 301 females. Current alcohol consumption was reported by 221/517 individuals (42.7%). Median BMI was 21.01 (IQR 18.77 – 23.57). 23 had HBV infection and 64 HIV infection (one individual had HBV/HIV co-infection). (Table 1) Table 1: Demographics for ULiDS cohort Elastography scores In the absence of chronic BBV infection, median elastography score was 5.3 (IQR 4.4 - 6.2), scores were >7kPa in 59/431 (13.7%) and >12kPa in 4/431 (0.9%), compared to (5/23 (21.7%) vs. 1/23 (4.3%) in HBV and 11/64 (17.1%) vs. 2/64 (3.1%) in HIV respectively. Figure 1: Distribution of liver elastography scores across subpopulations with differing BBV infection status In a univariate analysis, elastography scores were higher in males (p=0.003) and chronic HBV infection (median 6.4, IQR 5.7-6.7, p = 0.042). DISCUSSION 112 Elastography score (kPa) Interpretation <7 CLD excluded 7-12 Indeterminate >12 CLD likely - In this rural East African population, elastography data suggest potential associations between liver fibrosis and HBV, male sex and low BMI. - Male sex has been previously identified as a clinical predictor of elevated liver stiffness in HBV infected individuals. - Low BMI may be associated with high levels of liver steatosis in metabolic liver diseas