Background: Mild cognitive impairment (MCI) is a heterogeneous state between normal ageing and dementia, often considered prodromal to Alzheimer's disease (AD). Progression is variable, and distinguishing stable from progressive MCI remains difficult, particularly in the presence of mixed neuropathology. Blood biomarkers such as phosphorylated tau181 (pTau181), glial fibrillary acidic protein (GFAP), and neurofilament light chain (NfL) demonstrate prognostic value in established AD, but limited performance for prognosticating progression from MCI. Methods: Blood protein biomarkers (pTau181, GFAP, NfL) were integrated with NMR- and LC-MS-derived metabolomic features. In a deeply phenotyped MCI cohort (VITACOG; n=68) with two-year MRI follow-up, cross-validated logistic regression identified discriminative multi-analyte panels to distinguish stable from progressive MCI. Disease progression was defined by worsening cortical atrophy, measured via annualised brain volume loss. Generalisability was tested in a larger community-based cohort from UK Biobank (n=223) and two Oxford Project to Investigate Memory and Ageing (OPTIMA) subsets with histopathological diagnosis (n=61, n=37). Results: Integration of pTau181 with six metabolite features yielded the highest prognostic performance (AUC 0.91; accuracy 80%), with metabolomic findings independently validated in the OPTIMA cohort. A complementary GFAP-NMR panel also performed strongly (AUC 0.80; accuracy 75%). In contrast, individual metabolites, including the atrophy marker homocysteine, and standalone protein biomarkers performed poorly (AUC ≤0.66), as well their combination (AUC 0.68), highlighting the added value of multi-omic integration. In an asymptomatic ageing population (UK Biobank), the models served as a population-level stress test, confirming that multi-omic integration improved specificity for MRI-derived atrophy measures and captured atrophy-related risk in community cohorts. Conclusion: Multi-omic integration of protein and metabolic features markedly improved prognostication of MCI progression by capturing early neurodegenerative signatures, yielding translational panels suitable for scalable risk stratification and early therapeutic intervention in clinical practice. ### Competing Interest Statement A.D.S. and H.R. are named as inventors on two patents held by the University of Oxford on the use of B-vitamins to treat cognitive disorders (US9364497 and US10966947). F.J. is named as an inventor on US10966947. These patents have been licensed to Elysium Health, NY. J.S.O.M. has a research contract and equipment loan from ThermoFisher Scientific, which manufactures IC-MS systems. S. de J., Q. G. and E. S. are employees of Numares AG (Am Biopark 9, 93053 Regensburg-Grass, Germany). All other authors report no conflicts of interest. N.J.A. received consultancy or speaker fees from BioArtic, Biogen, Lilly, Quanterix and Alamar Biosciences. H.Z. has served at scientific advisory boards and/or as a consultant for Abbvie, Acumen, Alector, Alzinova, ALZpath, Amylyx, Annexon, Apellis, Artery Therapeutics, AZTherapies, Cognito Therapeutics, CogRx, Denali, Eisai, Enigma, LabCorp, Merck Sharp & Dohme, Merry Life, Nervgen, Novo Nordisk, Optoceutics, Passage Bio, Pinteon Therapeutics, Prothena, Quanterix, Red Abbey Labs, reMYND, Roche, Samumed, ScandiBio Therapeutics AB, Siemens Healthineers, Triplet Therapeutics, and Wave, has given lectures sponsored by Alzecure, BioArctic, Biogen, Cellectricon, Fujirebio, LabCorp, Lilly, Novo Nordisk, Oy Medix Biochemica AB, Roche, and WebMD, is a co-founder of Brain Biomarker Solutions in Gothenburg AB (BBS), which is a part of the GU Ventures Incubator Program, and is a shareholder of CERimmune Therapeutics (outside submitted work). S. M. S. is co-founder and part-owner of SBGneuro. ### Funding Statement T.K. is funded by an EPSRC Postdoctoral Pathway Scheme (EP/Z534870/1) and EPSRC talent and skills funding and Numares AG (Am Biopark 9, 93053 Regensburg-Grass, Germany). This research was supported in part by the Aqua-Synapse EU framework (2022-2026) to D.A., funded by the European Union's Horizon 2020 Research and Innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 101086453. The authors are solely responsible for the content of this publication, which does not necessarily represent the official views of the European Union or the European Research Executive Agency. H.Z. is a Wallenberg Scholar and a Distinguished Professor at the Swedish Research Council supported by grants from the Swedish Research Council (#2023-00356, #2022-01018 and #2019-02397), the European Union's Horizon Europe research and innovation programme under grant agreement No 101053962, and Swedish State Support for Clinical Research (#ALFGBG-71320). The original VITACOG trial was supported by grants from Charles Wolfson Charitable Trust, Medical Research Council, Alzheimer's Research Trust, Henry Smith Charity, John Coates Charitable Trust, Thames Valley Dementias and Neurodegenerative Diseases Research Network of the National Institute for Health Research, UK, and the Sidney and Elizabeth Corob Charitable Trust. The original OPTIMA cohort was supported by grants from Bristol-Myers Squibb, Medical Research Council and the Charles Wolfson Charitable Trust. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The VITACOG trial was approved by a local NHS Research Ethics Committee (COREC 04/Q1604/100). For the OPTIMA cohort, ethical approval was obtained from the Frenchay Research Ethics Committee (REC Ref 09/H0107/9). All participants provided written informed consent in accordance with the Declaration of Helsinki. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Anonymised data not published within this article will be made available by request from any qualified investigator.

Lassa fever is a zoonotic disease identified by the World Health Organization (WHO) as having pandemic potential. This study estimates the health-economic burden of Lassa fever throughout West Africa and projects impacts of a series of vaccination campaigns. We also model the emergence of 'Lassa-X'-a hypothetical pandemic Lassa virus variant-and project impacts of achieving 100 Days Mission vaccination targets. Our model predicted 2.7 million (95% uncertainty interval: 2.1-3.4 million) Lassa virus infections annually, resulting over 10 years in 2.0 million (793,800-3.9 million) disability-adjusted life years (DALYs). The most effective vaccination strategy was a population-wide preventive campaign primarily targeting WHO-classified 'endemic' districts. Under conservative vaccine efficacy assumptions, this campaign averted $20.1 million ($8.2-$39.0 million) in lost DALY value and $128.2 million ($67.2-$231.9 million) in societal costs (2021 international dollars ($)). Reactive vaccination in response to local outbreaks averted just one-tenth the health-economic burden of preventive campaigns. In the event of Lassa-X emerging, spreading throughout West Africa and causing approximately 1.2 million DALYs within 2 years, 100 Days Mission vaccination averted 22% of DALYs given a vaccine 70% effective against disease and 74% of DALYs given a vaccine 70% effective against both infection and disease. These findings suggest how vaccination could alleviate Lassa fever's burden and assist in pandemic preparedness. A modeling study quantifies the health-economic burden of Lassa virus infection across West Africa and projects impacts of a series of reactive and preventive vaccination campaigns against the disease, presenting substantial impacts in terms of averted disability-adjusted life years and healthcare cost reductions.

Background: World Health Organization has called for research into predictive factors for selecting persons who could be successfully treated with shorter durations of direct-acting antiviral (DAA) therapy for hepatitis C. We evaluated early virological response as a means of shortening treatment and explored host, viral and pharmacokinetic contributors to treatment outcome. Methods: Duration of sofosbuvir and daclatasvir (SOF/DCV) was determined according to day 2 (D2) virologic response for HCV genotype (gt) 1- or 6-infected adults in Vietnam with mild liver disease. Participants received 4- or 8-week treatment according to whether D2 HCV RNA was above or below 500 IU/ml (standard duration is 12 weeks). Primary endpoint was sustained virological response (SVR12). Those failing therapy were retreated with 12 weeks SOF/DCV. Host IFNL4 genotype and viral sequencing was performed at baseline, with repeat viral sequencing if virological rebound was observed. Levels of SOF, its inactive metabolite GS-331007 and DCV were measured on days 0 and 28. Results: Of 52 adults enrolled, 34 received 4 weeks SOF/DCV, 17 got 8 weeks and 1 withdrew. SVR12 was achieved in 21/34 (62%) treated for 4 weeks, and 17/17 (100%) treated for 8 weeks. Overall, 38/51 (75%) were cured with first-line treatment (mean duration 37 days). Despite a high prevalence of putative NS5A-inhibitor resistance-associated substitutions (RASs), all first-line treatment failures cured after retreatment (13/13). We found no evidence treatment failure was associated with host IFNL4 genotype, viral subtype, baseline RAS, SOF or DCV levels. Conclusions: Shortened SOF/DCV therapy, with retreatment if needed, reduces DAA use in patients with mild liver disease, while maintaining high cure rates. D2 virologic response alone does not adequately predict SVR12 with 4-week treatment. Funding: Funded by the Medical Research Council (Grant MR/P025064/1) and The Global Challenges Research 70 Fund (Wellcome Trust Grant 206/296/Z/17/Z).

Background: To determine the impact of the COVID-19 pandemic on the population with chronic Hepatitis B virus (HBV) infection under hospital follow-up in the UK, we quantified the coverage and frequency of measurements of biomarkers used for routine surveillance (alanine transferase [ALT] and HBV viral load). Methods: We used anonymized electronic health record data from the National Institute for Health Research (NIHR) Health Informatics Collaborative (HIC) pipeline representing five UK National Health Service (NHS) Trusts. Results: We report significant reductions in surveillance of both biomarkers during the pandemic compared to pre-COVID-19 years, both in terms of the proportion of patients who had ≥1 measurement annually, and the mean number of measurements per patient. Conclusions: These results demonstrate the real-time utility of HIC data in monitoring health-care provision, and support interventions to provide catch-up services to minimise the impact of the pandemic. Further investigation is required to determine whether these disruptions will be associated with increased rates of adverse chronic HBV outcomes.

Chronic hepatitis B virus (HBV) infection is associated with significant global morbidity and mortality. Low treatment rates are observed in patients living with HBV; the reasons for this are unclear. This study sought to describe patients’ demographic, clinical and biochemical characteristics across three continents and their associated treatment need. This retrospective cross-sectional post hoc analysis of real-world data used four large electronic databases from the United States, United Kingdom and China (specifically Hong Kong and Fuzhou). Patients were identified by first evidence of chronic HBV infection in a given year (their index date) and characterized. An algorithm was designed and applied, wherein patients were categorized as treated, untreated but indicated for treatment and untreated and not indicated for treatment based on treatment status and demographic, clinical, biochemical and virological characteristics (age; evidence of fibrosis/cirrhosis; alanine aminotransferase [ALT] levels, HCV/HIV coinfection and HBV virology markers). In total, 12,614 US patients, 503 UK patients, 34,135 patients from Hong Kong and 21,614 from Fuzhou were included. Adults (99.4

Purpose The National Institute for Health Research (NIHR) Health Informatics Collaborative (HIC) was established to enable re-use of routinely collected clinical data across National Health Service (NHS) Trusts in the United Kingdom to support translational research. Viral hepatitis is one of the first five exemplar themes and hepatitis B virus (HBV) is the current focus of the theme. The NIHR HIC HBV dataset, derived from the central data repository of NIHR HIC viral hepatitis theme, aims to describe and characterise HBV infection in secondary care in the United Kingdom, and provides a resource for translational research. Participants The dataset comprises >5000 individuals (99% adults aged ≥18, 1% children aged <18) with chronic HBV (CHB) infection from five NHS Trusts across England, representing clinical data collected between August 1994 and August 2021. Findings to date Data on demographics, laboratory tests, antiviral treatment, elastography scores, imaging/biopsy reports, death information, and potential risk factors for liver disease have been collected. Data are captured by electronic patient record (EPR) systems, and records are updated prospectively as new results are added. This cohort profile describes the dataset in its current form. Among the adults, 55% are male, and the median age at index date (defined as the first recorded positive hepatitis B virus surface antigen (HBsAg) or HBV DNA in EPR systems) was 40 years (interquartile range [IQR]: 32-50). For those individuals with ethnicity reported, 30% were Asian, 24% were Black, 30% were White, and the remaining 16% were mixed or other ethnic groups. Currently, the median follow-up duration of the adult patients in this dataset was 5.0 (IQR: 2.7-7.5) years, with 9.3 (95% CI: 8.2-10.5) deaths per 1,000 person-years. We have already conducted several analyses using subsets of this dataset including an evaluation of distribution and trajectories of HBsAg and HBV viral load in CHB, reviewing the use of antiviral treatment, quantifying the burden of liver disease in the untreated population, and studying the use of laboratory biomarkers to improve stratification and surveillance. Future plans Longitudinal data collection is continuing, with the sample growing in size, more parameters being collected, average follow-up increasing, and more NHS Trusts participating. This dataset offers important opportunities for epidemiological studies and biomedical informatics research, as well as characterising an HBV population for clinical trials through external collaborations with industry.

Background To determine the impact of the COVID-19 pandemic on the population with chronic Hepatitis B virus (HBV) infection under hospital follow-up in the UK, we quantified the coverage and frequency of measurements of biomarkers used for routine surveillance (alanine transferase [ALT] and HBV viral load). Methods We used anonymized electronic health record data from the National Institute for Health Research (NIHR) Health Informatics Collaborative (HIC) pipeline representing five UK National Health Service (NHS) Trusts. Results We report significant reductions in surveillance of both biomarkers during the pandemic compared to pre-COVID-19 years, both in terms of the proportion of patients who had ≥1 measurement annually, and the mean number of measurements per patient. Conclusions These results demonstrate the real-time utility of HIC data in monitoring health-care provision, and support interventions to provide catch-up services to minimise the impact of the pandemic. Further investigation is required to determine whether these disruptions will be associated with increased rates of adverse chronic HBV outcomes.

e13564 Background: Immune checkpoint inhibitor (ICI) therapies have shown impressive results in treating oncology patients. However, some patients exhibit immune-related adverse events (irAE-s), one significant irAE is autoimmune hepatitis. Oncologists routinely screen for hepatic toxicity with a complete metabolic panel prior to each ICI administration. Predictive modeling of irAE-s based on patient factors has the potential to help guide treatment selection and monitoring protocols. We have developed a widely usable model based on patient history and routinely collected standard blood panels that can predict whether a patient will experience hepatitis with ICI administration. Methods: We defined irAE hepatitis as any single value of AST, ALT, or alkaline phosphatase three-times the upper limit of normal (ULN) as following ICI treatment. The goal was to determine whether the level of the biomarkers exceed this threshold within certain, pre-defined time-windows, as determined by medical experts. We used feature engineering to compress the time-series of lab panels into single meaningful statistical descriptors, such as mean or maximum of these vectors. The dataset was highly unbalanced with many more negative cases (out of the 3231 patients, depending on the window length used for feature generation, 100-400 positives were found), which warranted the application of synthetic resampling methods. Finally, we trained various ensemble models ( e.g., random forest, gradient boosting), on both the resampled and original dataset, to obtain the final, predictive model for the likelihood of irAE hepatitis. Models were tuned to favor high recall and lower precision (identification of patients for increased monitoring) or moderate recall and moderate precision (maximizing F1-score). Results: We explored several modelling methods, such as KNN, Logistic Regression, Random Forests (RF), Gradient Boosting (GB), and stacking. GB without resampling produced the best model with the moderate recall and precision. To achieve high recall with low precision, we needed to resample the dataset with random majority class under sampling and then use RF (see table below for exact results). Conclusions: In this study, we show contemporary machine learning methods can be used as a screening tool for patients at risk for irAE hepatitis. This method could be used to identify patients who would benefit from additional laboratory monitoring between ICI administrations or guide clinical decisions about therapy cessation in advance of toxicity. Additionally, these methods may be further developed and adapted to improve clinical trial exclusion criteria for patients most likely to develop irAE hepatitis.[Table: see text]

e13565 Background: Hepatitis toxicity is one of the most important adverse effects of immune checkpoint inhibitor (ICI) therapy, occurring in approximately 10% of patients. However, when identified early, it can be managed clinically, potentially allowing continuation of ICI treatment. The goal of the study was to evaluate the feasibility and clinical usefulness of an artificial intelligence (AI) model to predict the risk of developing hepatitis toxicity during the course of ICI treatment from routine bloodwork values. Methods: Our model uses a clinical dataset of 2438 patients who received ICI treatment at the Vanderbilt University Medical Center prior to the end of 2020. Hepatitis toxicity was defined as one or more of ALT, AST, ALKPHOS, BILIRUBIN values exceeding 2.5-times the upper limit of normal value. The available feature set was limited to the routinely available blood test values. All features were normalized to the upper limit of normal and transformed to a discretized symbolic representation, a modified version of Symbolic Aggregate ApproXimation. Motifs were extracted as n-grams from the symbol series, and the counts were used as input features for the predictive model. The study uses standard data science model training and evaluation concepts: train, validation, and test splits were created randomly on the patient level; the reported evaluation metrics are median AUC, TPR, TNR, PPV, NPV over 10 sampling runs. The final, best-performing model architecture is a boosted decision tree model (XGBoost) trained on the last four blood tests to predict hepatitis at the next blood sampling timepoint (i.e., at the time of the next ICI treatment appointment). Results: The best model uses the following eight blood values as features: ALT, AST, ALKPHOS, BILIRUBIN, ALBUMIN, CO2, CALCIUM, and BUN, and achieves an AUC of 0.82 (std. 0.01), with TPR = 0.32 (0.03), TNR = 0.97 (0.005), PPV = 0.18 (0.03), and NPV = 0.99 (0.002). It finds 32% of the timepoints where the patient is going to develop hepatitis toxicity prior to their next treatment, and about 1 in 5 positive predictions are correct. It is important to note that only about 1% of all ‘sequences’ of four consecutive blood tests are followed by hepatitis at the next test. That is, while a relatively large proportion of patients are going to develop hepatitis toxicity during their ICI treatment, the timepoint at which this happens is very uncertain. Conclusions: We demonstrate that an AI model built using only already available patient laboratory data could provide clinically useful input for clinicians to support their ICI treatment decisions to reduce the occurrence of hepatitis toxicity. The dynamic nature and below-patient-level granularity of the model would allow a clinician / clinical trial investigator to make adjustments to the therapy based on individual patient reaction over time.

Background There is an emerging understanding that coronavirus disease 2019 (COVID-19) is associated with increased incidence of pneumomediastinum (PTM). We aimed to determine its incidence among patients hospitalised with COVID-19 in the UK and describe factors associated with outcome. Methods A structured survey of PTM and its incidence was conducted from September 2020 to February 2021. UK-wide participation was solicited via respiratory research networks. Identified patients had severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and radiologically proven PTM. The primary outcomes were to determine incidence of PTM in COVID-19 and to investigate risk factors associated with patient mortality. Results 377 cases of PTM in COVID-19 were identified from 58 484 inpatients with COVID-19 at 53 hospitals during the study period, giving an incidence of 0.64%. Overall 120-day mortality in COVID-19 PTM was 195 out of 377 (51.7%). PTM in COVID-19 was associated with high rates of mechanical ventilation. 172 out of 377 patients (45.6%) were mechanically ventilated at the point of diagnosis. Mechanical ventilation was the most important predictor of mortality in COVID-19 PTM at the time of diagnosis and thereafter (p<0.001), along with increasing age (p<0.01) and diabetes mellitus (p=0.08). Switching patients from continuous positive airway pressure support to oxygen or high-flow nasal oxygen after the diagnosis of PTM was not associated with difference in mortality. Conclusions PTM appears to be a marker of severe COVID-19 pneumonitis. The majority of patients in whom PTM was identified had not been mechanically ventilated at the point of diagnosis.

Persistent hepatitis C virus (HCV) infection is a major cause of chronic liver disease, worldwide. With the development of direct-acting antivirals, treatment of chronically infected patients has become highly effective, although a subset of patients responds less well to therapy. Sofosbuvir is a common component of current de novo or salvage combination therapies, that targets the HCV NS5B polymerase. We use pre-treatment whole-genome sequences of HCV from 507 patients infected with HCV subtype 3a and treated with sofosbuvir containing regimens to detect viral polymorphisms associated with response to treatment. We find three common polymorphisms in non-targeted HCV NS2 and NS3 proteins are associated with reduced treatment response. These polymorphisms are enriched in post-treatment HCV sequences of patients unresponsive to treatment. They are also associated with lower reductions in viral load in the first week of therapy. Using in vitro short-term dose-response assays, these polymorphisms do not cause any reduction in sofosbuvir potency, suggesting an indirect mechanism of action in decreasing sofosbuvir efficacy. The identification of polymorphisms in NS2 and NS3 proteins associated with poor treatment outcomes emphasises the value of systematic genome-wide analyses of viruses in uncovering clinically relevant polymorphisms that impact treatment.

Background: The World Health Organization (WHO) has identified the need for a better understanding of which patients with hepatitis C virus (HCV) can be cured with ultrashort course HCV therapy. Methods: A total of 202 individuals with chronic HCV were randomised to fixed-duration shortened therapy (8 weeks) vs variable-duration ultrashort strategies (VUS1/2). Participants not cured following first-line treatment were retreated with 12 weeks’ sofosbuvir/ledipasvir/ribavirin. The primary outcome was sustained virological response 12 weeks (SVR12) after first-line treatment and retreatment. Participants were factorially randomised to receive ribavirin with first-line treatment. Results: All evaluable participants achieved SVR12 overall (197/197, 100% [95% CI 98-100]) demonstrating non-inferiority between fixed-duration and variable-duration strategies (difference 0% [95% CI -3.8%, +3.7%], 4% pre-specified non-inferiority margin). First-line SVR12 was 91% [86%-97%] (92/101) for fixed-duration vs 48% [39%-57%] (47/98) for variable-duration, but was significantly higher for VUS2 (72% [56%-87%] (23/32)) than VUS1 (36% [25%-48%] (24/66)). Overall, first-line SVR12 was 72% [65%-78%] (70/101) without ribavirin and 68% [61%-76%] (69/98) with ribavirin (p=0.48). At treatment failure, the emergence of viral resistance was lower with ribavirin (12% [2%-30%] (3/26)) than without (38% [21%-58%] (11/29), p=0.01). Conclusions: Unsuccessful first-line short-course therapy did not compromise retreatment with sofosbuvir/ledipasvir/ribavirin (100% SVR12). SVR12 rates were significantly increased when ultrashort treatment varied between 4-7 weeks rather than 4-6 weeks. Ribavirin significantly reduced resistance emergence in those failing first-line therapy. ISRCTN Registration: 37915093 (11/04/2016).

Background: The World Health Organization (WHO) has identified the need for a better understanding of which patients with hepatitis C virus (HCV) can be cured with ultrashort course HCV therapy. Methods: A total of 202 individuals with chronic HCV were randomised to fixed-duration shortened therapy (8 weeks) vs variable-duration ultrashort strategies (VUS1/2). Participants not cured following first-line treatment were retreated with 12 weeks’ sofosbuvir/ledipasvir/ribavirin. The primary outcome was sustained virological response 12 weeks (SVR12) after first-line treatment and retreatment. Participants were factorially randomised to receive ribavirin with first-line treatment. Results: All evaluable participants achieved SVR12 overall (197/197, 100% [95% CI 98-100]) demonstrating non-inferiority between fixed-duration and variable-duration strategies (difference 0% [95% CI -3.8%, +3.7%], 4% pre-specified non-inferiority margin). First-line SVR12 was 91% [86%-97%] (92/101) for fixed-duration vs 48% [39%-57%] (47/98) for variable-duration, but was significantly higher for VUS2 (72% [56%-87%] (23/32)) than VUS1 (36% [25%-48%] (24/66)). Overall, first-line SVR12 was 72% [65%-78%] (70/101) without ribavirin and 68% [61%-76%] (69/98) with ribavirin (p=0.48). At treatment failure, the emergence of viral resistance was lower with ribavirin (12% [2%-30%] (3/26)) than without (38% [21%-58%] (11/29), p=0.01). Conclusions: Unsuccessful first-line short-course therapy did not compromise retreatment with sofosbuvir/ledipasvir/ribavirin (100% SVR12). SVR12 rates were significantly increased when ultrashort treatment varied between 4-7 weeks rather than 4-6 weeks. Ribavirin significantly reduced resistance emergence in those failing first-line therapy. ISRCTN Registration: 37915093 (11/04/2016).

BackgroundThe WHO has identified the need for a better understanding of which patients can be cured with ultrashort course hepatitis C (HCV) therapyMethods202 individuals with chronic HCV were randomised to fixed-duration shortened therapy (8 weeks) vs variable-duration ultrashort strategies (VUS1/2). Participants not cured following first-line treatment were retreated with 12 weeks’ sofosbuvir/ledipasvir/ribavirin. Primary outcome was sustained virological response 12 weeks (SVR12) after first-line treatment and retreatment. Participants were factorially randomised to receive ribavirin with first-line treatment.ResultsAll evaluable participants achieved SVR12 overall (197/197, 100%[95%CI 98-100]) demonstrating non-inferiority between fixed-duration and variable-duration strategies (difference 0% [95%CI −3.8%,+3.7%], 4% pre-specified non-inferiority margin). First-line SVR12 was 91%[86%-97%] (92/101) for fixed-duration vs 48%[39%-57%] (47/98) for variable-duration, but was significantly higher for VUS2 (72% [56%-87%] (23/32)) than VUS1 (36% [25%-48%] (24/66)). Overall first-line SVR12 was 72%[65%-78%] (70/101) without ribavirin and 68%[61%-76%] (69/98) with ribavirin (p=0.48). At treatment failure, the emergence of viral resistance was lower with ribavirin (12% [2%-30%] (3/26)) than without (38% [21%-58%] (11/29), p=0.01).ConclusionsUnsuccessful first-line short-course therapy did not compromise retreatment with sofosbuvir/ledipasvir/ribavirin (100% SVR12). SVR12 rates were significantly increased when ultrashort treatment varied between 4-7 weeks rather than 4-6 weeks. Ribavirin significantly reduced resistance emergence in those failing first-line therapy.RegistrationISRCTN 37915093.FundingNational Institutes of Health Research.

Abstract Background Genotype 6 is the most genetically diverse lineage of hepatitis C virus, and it predominates in Vietnam. It can be treated with sofosbuvir with daclatasvir (SOF/DCV), the least expensive treatment combination globally. In regional guidelines, longer treatment durations of SOF/DCV (24 weeks) are recommended for cirrhotic individuals, compared with other pangenotypic regimens (12 weeks), based on sparse data. Early on-treatment virological response may offer means of reducing length and cost of therapy in patients with liver fibrosis. Methods In this prospective trial in Vietnam, genotype 6-infected adults with advanced liver fibrosis or compensated cirrhosis were treated with SOF/DCV. Day 14 viral load was used to guide duration of therapy: participants with viral load <500 IU/mL at day 14 were treated with 12 weeks of SOF/DCV and those ≥500 IU/mL received 24 weeks. Primary endpoint was sustained virological response (SVR). Results Of 41 individuals with advanced fibrosis or compensated cirrhosis who commenced treatment, 51% had genotype 6a and 34% had 6e. The remainder had 6h, 6k, 6l, or 6o. One hundred percent had viral load <500 IU/mL by day 14, meaning that all received 12 weeks of SOF/DCV. One hundred percent achieved SVR12 despite a high frequency of putative NS5A inhibitor resistance-associated substitutions at baseline. Conclusions Prescribing 12 weeks of SOF/DCV results in excellent cure rates in this population. These data support the removal of costly genotyping in countries where genotype 3 prevalence is <5%, in keeping with World Health Organization guidelines. NS5A resistance-associated mutations in isolation do not affect efficacy of SOF/DCV therapy. Wider evaluation of response-guided therapy is warranted.

The association of liver biochemistry with clinical outcomes of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection is currently unclear, and the utility of longitudinally measured liver biochemistry as prognostic markers for mortality is unknown. We aimed to determine whether abnormal liver biochemistry, assessed at baseline and at repeat measures over time, was associated with death in hospitalized patients with COVID‐19 compared to those without COVID‐19, in a United Kingdom population. We extracted routinely collected clinical data from a large teaching hospital in the United Kingdom, matching 585 hospitalized patients who were SARS‐CoV‐2 real‐time reverse transcription‐polymerase chain reaction (RT‐PCR) positive to 1,165 hospitalized patients who were RT‐PCR negative for age, sex, ethnicity, and preexisting comorbidities. A total of 26.8% (157/585) of patients with COVID‐19 died compared to 11.9% (139/1,165) in the group without COVID‐19 (P < 0.001). At presentation, a significantly higher proportion of the group with COVID‐19 had elevated alanine aminotransferase (20.7% vs. 14.6%, P = 0.004) and hypoalbuminemia (58.7% vs. 35.0%, P < 0.001) compared to the group without COVID‐19. Within the group with COVID‐19, those with hypoalbuminemia at presentation had 1.83‐fold increased hazards of death compared to those with normal albumin (adjusted hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.25‐2.67), while the hazard of death was ~4‐fold higher in those aged ≥75 years (adjusted HR, 3.96; 95% CI, 2.59‐6.04) and ~3‐fold higher in those with preexisting liver disease (adjusted HR, 3.37; 95% CI, 1.58‐7.16). In the group with COVID‐19, alkaline phosphatase (ALP) increased (R = 0.192, P < 0.0001) and albumin declined (R = −0.123, P = 0.0004) over time in patients who died. Conclusion: In this United Kingdom population, liver biochemistry is commonly deranged in patients with COVID‐19. Baseline hypoalbuminemia and rising ALP over time could be prognostic markers for death, but investigation of larger cohorts is required to develop a better understanding of the relationship between liver biochemistry and disease outcome.

Background: High cure rates with licensed durations of therapy for chronic hepatitis C virus suggest that many patients are overtreated. New strategies in individuals who find it challenging to adhere to standard treatment courses could significantly contribute to the elimination agenda. Objectives: To compare cure rates using variable ultrashort first-line treatment stratified by baseline viral load followed by retreatment, with a fixed 8-week first-line treatment with retreatment with or without adjunctive ribavirin. Design: An open-label, multicentre, factorial randomised controlled trial. Randomisation: Randomisation was computer generated, with patients allocated in a 1 : 1 ratio using a factorial design to each of biomarker-stratified variable ultrashort strategy or fixed duration and adjunctive ribavirin (or not), using a minimisation algorithm with a probabilistic element. Setting: NHS. Participants: A total of 202 adults (aged ≥ 18 years) infected with chronic hepatitis C virus genotype 1a/1b or 4 for ≥ 6 months, with a detectable plasma hepatitis C viral load and no significant fibrosis [FibroScan® (Echosens, Paris, France) score F0–F1 or biopsy-proven minimal fibrosis], a hepatitis C virus viral load < 10,000,000 IU/ml, no previous exposure to direct-acting antiviral therapy for this infection and not pregnant. Patients co-infected with human immunodeficiency virus were eligible if human immunodeficiency virus viral load had been < 50 copies/ml for > 24 weeks on anti-human immunodeficiency virus drugs. Interventions: Fixed-duration 8-week first-line therapy compared with variable ultrashort first-line therapy, initially for 4–6 weeks (continuous scale) stratified by screening viral load (variable ultrashort strategy 1, mean 32 days of treatment) and then, subsequently, for 4–7 weeks (variable ultrashort strategy 2 mean 39 days of duration), predominantly with ombitasvir, paritaprevir, ritonavir (Viekirax®; AbbVie, Chicago, IL, USA), and dasabuvir (Exviera®; AbbVie, Chicago, IL, USA) or ritonavir. All patients in whom first-line treatment was unsuccessful were immediately retreated with 12 weeks’ sofosbuvir, ledipasvir (Harvoni®, Gilead Sciences, Inc., Foster City, CA, USA) and ribavirin. Main outcome measure: The primary outcome was overall sustained virological response (persistently undetectable) 12 weeks after the end of therapy (SVR12). Results: A total of 202 patients were analysed. All patients in whom the primary outcome was evaluable achieved SVR12 overall [100% (197/197), 95% confidence interval 86% to 100%], demonstrating non-inferiority between fixed- and variable-duration strategies (difference 0%, 95% confidence interval –3.8% to 3.7%, prespecified non-inferiority margin 4%). A SVR12 following first-line treatment was achieved in 91% (92/101; 95% confidence interval 86% to 97%) of participants randomised to the fixed-duration strategy and by 48% (47/98; 95% confidence interval 39% to 57%) allocated to the variable-duration strategy. However, the proportion achieving SVR12 was significantly higher among those allocated to variable ultrashort strategy 2 [72% (23/32), 95% confidence interval 56% to 87%] than among those allocated to variable ultrashort strategy 1 [36% (24/66), 95% confidence interval 25% to 48%]. Overall, a SVR12 following first-line treatment was achieved by 72% (70/101) (95% confidence interval 65% to 78%) of patients treated with ribavirin and by 68% (69/98) (95% confidence interval 61% to 76%) of those not treated with ribavirin. A SVR12 with variable ultrashort strategies 1 and 2 was 52% (25/48) (95% confidence interval 38% to 65%) with ribavirin, compared with 44% (22/50) (95% confidence interval 31% to 56) without. However, at treatment failure, the emergence of viral resistance was lower with ribavirin [12% (3/26), 95% confidence interval 2% to 30%] than without [38% (11/29), 95% confidence interval 21% to 58%; p = 0.01]. All 10 individuals who became undetectable at day 3 of treatment achieved first-line SVR12 regardless of treatment duration. Five participants in the variable-duration arm and five in the fixed-duration arm experienced serious adverse events (p = 0.69), as did five participants receiving ribavirin and five participants receiving no ribavirin. Conclusions: SVR12 rates were significantly higher when ultrashort treatment varied between 4 and 7 weeks, rather than between 4 and 6 weeks. We found no evidence of ribavirin significantly affecting first-line SVR12, with unsuccessful first-line short-course therapy also not compromising subsequent retreatment with sofosbuvir, ledipasvir and ribavirin. Future work: A priority for future work needs to be the development and evaluation of robust predictive measures to identify those patients who can be cured with ultrashort courses of therapy. Trial registration: Current Controlled Trials ISRCTN37915093, EudraCT 2015-005004-28 and CTA 19174/0370/001-0001. Funding: This project was funded by the Efficacy and Mechanism Evaluation programme, a MRC and National Institute for Health Research (NIHR) partnership. This will be published in full in Efficacy and Mechanism Evaluation; Vol. 8, No. 17. See the NIHR Journals Library website for further project information.

Aim Current clinical recommendations suggest treating chronic hepatitis B virus (HBV) infection in a minority of cases, but more data are needed to determine the benefits and risks of Tenofovir disoproxil fumarate (TDF) therapy. We aimed to assess the impact of TDF on liver disease, and the risk of nephrotoxicity. Method We studied a longitudinal UK chronic HBV (CHB) cohort attending out-patient clinics between 2005 and 2018, analysing data for 206 ethnically diverse adults (60 on TDF, 146 untreated), with median follow-up 3.3±2.8 years. Results Patients prescribed TDF were older (39 vs. 35 years, p=0.004) with a male excess (63% vs. 47%, p=0.04) compared to untreated patients. Reflecting treatment eligibility criteria, at baseline, treated patients were more likely to have elevated ALT (p<0.001), higher HBV DNA viral load (VL) (p<0.001), and higher elastography scores (p=0.002), but with no difference in renal function (p=0.6). In the TDF group, VL declined significantly between baseline and subsequent time points (all p<0.0001) with VL suppressed in 94% at three years, while in the untreated group viraemia was unchanged from baseline. In the TDF group, ALT and elastography scores normalised during treatment and by three years were equivalent to those in the untreated group. Progression of liver fibrosis did not occur in the TDF group but arose in 7.4% of untreated patients, although this difference was non-significant. There was no significant difference in renal impairment during follow-up between two groups. Conclusion TDF may have long-term benefits for a wider pool of the CHB population. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work has been supported by the National Institute for Health Research (NIHR) Biomedical Research Centre (BRC) at Oxford and funded by the NIHR Health Informatics Collaborative (HIC). C.C reports funding from GlaxoSmithKline. E.B is supported by the Oxford NIHR Biomedical Research Centre and is an NIHR Senior Investigator. P.C.M is supported by a Wellcome intermediate fellowship (grant ref 110110/Z/15/Z). The views expressed in this article are those of the author and not necessarily those of the NHS, the NIHR, or the Department of Health. The authors would like to thank all the research nurses and research admin staff at the contributing site for their help in data collection and Gail Roadknight for her work supporting the NIHR HIC. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The research database for the NIHR HIC viral hepatitis theme was approved by South Central - Oxford C Research Ethics Committee (REF Number: 15/SC/0523). All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes No additional data are available.