Single-cell atlas of the liver myeloid compartment before and after cure of chronic viral hepatitis.

BACKGROUND & AIMS: Chronic viral infections present serious public health challenges; however, direct-acting antivirals (DAAs) are now able to cure nearly all patients infected with hepatitis C virus (HCV), representing the only cure of a human chronic viral infection to date. DAAs provide a valuable opportunity to study immune pathways in the reversal of chronic immune failures in an in vivo human system. METHODS: To leverage this opportunity, we used plate-based single-cell RNA-seq to deeply profile myeloid cells from liver fine needle aspirates in patients with HCV before and after DAA treatment. We comprehensively characterised liver neutrophils, eosinophils, mast cells, conventional dendritic cells, plasmacytoid dendritic cells, classical monocytes, non-classical monocytes, and macrophages, and defined fine-grained subpopulations of several cell types. RESULTS: We discovered cell type-specific changes post-cure, including an increase in MCM7+STMN1+ proliferating CD1C+ conventional dendritic cells, which may support restoration from chronic exhaustion. We observed an expected downregulation of interferon-stimulated genes (ISGs) post-cure as well as an unexpected inverse relationship between pre-treatment viral load and post-cure ISG expression in each cell type, revealing a link between viral loads and sustained modifications of the host's immune system. We found an upregulation of PD-L1/L2 gene expression in ISG-high neutrophils and IDO1 expression in eosinophils, pinpointing cell subpopulations crucial for immune regulation. We identified three recurring gene programmes shared by multiple cell types, distilling core functions of the myeloid compartment. CONCLUSIONS: This comprehensive single-cell RNA-seq atlas of human liver myeloid cells in response to cure of chronic viral infections reveals principles of liver immunity and provides immunotherapeutic insights. CLINICAL TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov (NCT02476617). IMPACT AND IMPLICATIONS: Chronic viral liver infections continue to be a major public health problem. Single-cell characterisation of liver immune cells during hepatitis C and post-cure provides unique insights into the architecture of liver immunity contributing to the resolution of the first curable chronic viral infection of humans. Multiple layers of innate immune regulation during chronic infections and persistent immune modifications after cure are revealed. Researchers and clinicians may leverage these findings to develop methods to optimise the post-cure environment for HCV and develop novel therapeutic approaches for other chronic viral infections.

Preemptive antiviral therapy in lung transplantation from hepatitis C donors results in a rapid and sustained virologic response.

Objective: The study objective was to assess the safety and efficacy of a preemptive direct-acting antiviral therapy in lung transplants from hepatitis C virus donors to uninfected recipients. Methods: This study is a prospective, open-label, nonrandomized, pilot trial. Recipients of hepatitis C virus nucleic acid test positive donor lungs underwent preemptive direct-acting antiviral therapy with glecaprevir 300 mg/pibrentasvir 120 mg for 8 weeks from January 1, 2019, to December 31, 2020. Recipients of nucleic acid test positive lungs were compared with recipients of lungs from nucleic acid test negative donors. Primary end points were Kaplan-Meier survival and sustained virologic response. Secondary outcomes included primary graft dysfunction, rejection, and infection. Results: Fifty-nine lung transplantations were included: 16 nucleic acid test positive and 43 nucleic acid test negative. Twelve nucleic acid test positive recipients (75%) developed hepatitis C virus viremia. Median time to clearance was 7 days. All nucleic acid test positive patients had undetectable hepatitis C virus RNA by week 3, and all alive patients (n = 15) remained negative during follow-up with 100% sustained virologic response at 12 months. One nucleic acid test positive patient died of primary graft dysfunction and multiorgan failure. Three of 43 nucleic acid test negative patients (7%) had hepatitis C virus antibody positive donors. None of them developed hepatitis C virus viremia. One-year survival was 94% for nucleic acid test positive recipients and 91% for nucleic acid test negative recipients. There was no difference in primary graft dysfunction, rejection, or infection. One-year survival for nucleic acid test positive recipients was similar to a historical cohort of the Scientific Registry of Transplant Recipients (89%). Conclusions: Recipients of hepatitis C virus nucleic acid test positive lungs have similar survival as recipients of nucleic acid test negative lungs. Preemptive direct-acting antiviral therapy results in rapid viral clearance and sustained virologic response at 12 months. Preemptive direct-acting antiviral may partially prevent hepatitis C virus transmission.

Peginterferon lambda for the treatment of hospitalized patients with mild COVID-19: A pilot phase 2 randomized placebo-controlled trial.

Background: This study aimed to investigate the efficacy and safety of subcutaneous injection of peginterferon lambda in patients hospitalized with COVID-19. Methods: In this study (NCT04343976), patients admitted to hospital with COVID-19 confirmed by RT-PCR from nasopharyngeal swab were randomly assigned within 48 h to receive peginterferon lambda or placebo in a 1:1 ratio. Participants were subcutaneously injected with a peginterferon lambda or saline placebo at baseline and day 7 and were followed up until day 14. Results: We enrolled 14 participants; 6 participants (85.7%) in the peginterferon lambda group and 1 participant (14.3%) in the placebo group were treated with remdesivir prior to enrollment. Fifty percent of participants were SARS-CoV-2 RNA negative at baseline although they tested SARS-CoV-2 RNA positive within 48 h of randomization. Among participants who were SARS-CoV-2 positive at baseline, 2 out of 5 participants (40%) in the peginterferon lambda group became negative at day 14, while 0 out of 2 participants (0%) in the placebo group achieved negativity for SARS-CoV-2 by day 14 (p > 0.05). The median change in viral load (log copies per ml) was +1.72 (IQR -2.78 to 3.19) in the placebo group and -2.22 (IQR -3.24 to 0.55) in the peginterferon lambda group at day 14 (p = 0.24). Symptomatic changes did not differ between the two groups. Peginterferon lambda was well tolerated with a few treatment-related adverse effects. Conclusion: Peginterferon lambda appears to accelerate SARS-CoV-2 viral load decline and improve plasma disease progression markers in hospitalized patients with COVID-19.

Internalization of Angiotensin-(1-12) in Adult Retinal Pigment Epithelial-19 Cells.

Purpose: Angiotensin-(1-12) [Ang-(1-12)] serves as a primary substrate to generate angiotensin II (Ang II) by angiotensin-converting enzyme and/or chymase suggests it may be an unrecognized source of Ang II-mediated microvascular complication in hypertension-mediated retinopathy. We investigated Ang-(1-12) expression and internalization in adult retinal pigment epithelial-19 (ARPE-19) cultured cells. We performed the internalization of Ang-(1-12) in ARPE-19 cells in the presence of a highly specific monoclonal antibody (mAb) developed against the C-terminal end of the Ang-(1-12) sequence. Methods: All experiments were performed in confluent ARPE-19 cells (passage 28-35). We employed high-performance liquid chromatography to purify radiolabeled, 125I-Ang-(1-12) and immuno-neutralization with Ang-(1-12) mAb to demonstrate Ang-(1-12)'s internalization in ARPE-19 cells. Internalization was also demonstrated by immunofluorescence (IF) method. Results: These procedures revealed internalization of an intact 125I-Ang-(1-12) in ARPE-19 cells. A significant reduction (∼53%, P < 0.0001) in 125I-Ang-(1-12) internalization was detected in APRE-19 cells in the presence of the mAb. IF staining experiments further confirms internalization of Ang-(1-12) into the cells from the extracellular culture medium. No endogenous expression was detected in the ARPE-19 cells. An increased intensity of IF staining was detected in cells exposed to 1.0 µM Ang-(1-12) compared with 0.1 µM. Furthermore, we found hydrolysis of Ang-(1-12) into Ang II by ARPE-19 cells' plasma membranes. Conclusions: Intact Ang-(1-12) peptide is internalized from the extracellular spaces in ARPE-19 cells and metabolized into Ang II. The finding that a selective mAb blocks cellular internalization of Ang-(1-12) suggests alternate therapeutic approaches to prevent/reduce the RPE cells Ang II burden.

Early initiation of glecaprevir/pibrentasvir after transplantation of HCV-viremic kidneys into HCV-negative recipients is associated with normalization in the altered inflammatory milieu.

Our previous Multicenter Trial to Transplant HCV-infected Kidneys (MYTHIC) observed that 100% of hepatitis C virus (HCV)-uninfected patients who received a kidney from an HCV-infected deceased donor were cured of HCV with an 8-week regimen of glecaprevir and pibrentasvir (G/P) initiated 2-5 days after transplantation. Following acute and chronic infection with HCV, immune system perturbations have been reported to persist even after viral clearance. The aim of this study was to determine whether HCV viremic kidney recipients in the MYTHIC study experience sustained changes in the soluble inflammatory milieu associated with HCV infection. Among nine patients with HCV viremia at day 3 post-kidney transplant (post-KT D3), IP-10, IL-10, MIP-1ß, and IL-8 were significantly elevated from baseline. However, over the subsequent visits, there was a rapid, dramatic reduction back to baseline levels. Among seven patients who were not HCV viremic at post-KT D3, the cytokine levels did not significantly change. HCV-uninfected patients who received a kidney from an HCV-viremic deceased donor and were treated with early G/P experienced only transient alterations in the soluble inflammatory milieu. These data provide reassuring evidence that there appear to be no persistent cytokine disturbances with transient HCV viremia accompanying HCV donor positive/recipient negative kidney transplant.

Long-term clinical outcomes of patients with COVID-19 and chronic liver disease: US multicenter COLD study.

BACKGROUND: COVID-19 is associated with higher morbidity and mortality in patients with chronic liver diseases (CLDs). However, our understanding of the long-term outcomes of COVID-19 in patients with CLD is limited. METHODS: We conducted a multicenter, observational cohort study of adult patients with CLD who were diagnosed with COVID-19 before May 30, 2020, to determine long-term clinical outcomes. We used a control group of patients with CLD confirmed negative for COVID-19. RESULTS: We followed 666 patients with CLD (median age 58 years, 52.8% male) for a median of 384 (interquartile range: 31-462) days. The long-term mortality was 8.1%; with 3.6% experiencing delayed COVID-19-related mortality. Compared to a propensity-matched control group of patients with CLD without COVID-19 (n=1332), patients with CLD with COVID-19 had worse long-term survival [p<0.001; hazards ratio (HR): 1.69; 95% CI: 1.19-2.41] and higher rate of hospitalization (p<0.001, HR: 2.00, 1.62-2.48) over a 1-year follow-up period. Overall, 29.9% of patients reported symptoms of long-COVID-19. On multivariable analysis, female sex (p=0.05, HR: 2.45, 1.01-2.11), Hispanic ethnicity (p=0.003, HR: 1.94, 1.26-2.99), and severe COVID-19 requiring mechanical ventilation (p=0.028, HR: 1.74, 1.06-2.86) predicted long-COVID-19. In survivors, liver-related laboratory parameters showed significant improvement after COVID-19 resolution. COVID-19 vaccine status was available for 72% (n=470) of patients with CLD and history of COVID-19, of whom, 70% (n=326) had received the COVID-19 vaccine. CONCLUSIONS: Our large, longitudinal, multicenter study demonstrates a high burden of long-term mortality and morbidity in patients with CLD and COVID-19. Symptoms consistent with long-COVID-19 were present in 30% of patients with CLD. These results illustrate the prolonged implications of COVID-19 both for recovering patients and for health care systems.

One-Year Outcomes of the Multi-Center StudY to Transplant Hepatitis C-InfeCted kidneys (MYTHIC) Trial.

INTRODUCTION: Transplanting kidneys from hepatitis C virus (HCV) viremic donors into HCV-negative patients (HCV D-RNA-positive/R-negative) has evolved from experimental to "standard-of-care" at many centers. Nevertheless, most data derive from single centers and provide only short-term follow-up. METHODS: The Multicenter Study to Transplant Hepatitis C-Infected Kidneys (MYTHIC) study was a multicenter (7 sites) trial of HCV D-RNA-positive/R-negative kidney transplantation (KT) followed by 8 weeks of glecaprevir/pibrentasvir (G/P) initiated 2 to 5 days post-KT. Prespecified outcomes included probability of KT (vs. matched waitlist comparators) and 1-year safety outcomes, allograft function, and survival. RESULTS: Among 63 enrolled patients, 1-year cumulative incidence of KT was approximately 3.5-fold greater for the MYTHIC cohort versus 2055 matched United Network for Organ Sharing (UNOS) comparators who did not opt-in to receive a kidney from an HCV-viremic donor (68% vs. 19%, P < 0.0001). Of 30 HCV D-RNA-positive/R-negative KT recipients, all achieved HCV cure. None developed clinically significant liver disease or HCV-related kidney injury. Furthermore, 1-year survival was 93% and 1-year graft function was excellent (median creatinine 1.17; interquartile range [IQR]: 1.02-1.38 mg/dl). There were 4 cases of cytomegalovirus (CMV) disease among 10 CMV-negative patients transplanted with a kidney from an HCV-viremic/CMV-positive donor. CONCLUSION: The 1-year findings from this multicenter trial suggest that opting-in for HCV-viremic KT offers can increase probability of KT with excellent 1-year outcomes. Trial Registration: NCT03781726.

ADAMTSL2 protein and a soluble biomarker signature identify at-risk non-alcoholic steatohepatitis and fibrosis in adults with NAFLD.

BACKGROUND & AIMS: Identifying fibrosis in non-alcoholic fatty liver disease (NAFLD) is essential to predict liver-related outcomes and guide treatment decisions. A protein-based signature of fibrosis could serve as a valuable, non-invasive diagnostic tool. This study sought to identify circulating proteins associated with fibrosis in NAFLD. METHODS: We used aptamer-based proteomics to measure 4,783 proteins in 2 cohorts (Cohort A and B). Targeted, quantitative assays coupling aptamer-based protein pull down and mass spectrometry (SPMS) validated the profiling results in a bariatric and NAFLD cohort (Cohort C and D, respectively). Generalized linear modeling-logistic regression assessed the ability of candidate proteins to classify fibrosis. RESULTS: From the multiplex profiling, 16 proteins differed significantly by fibrosis in cohorts A (n = 62) and B (n = 98). Quantitative and robust SPMS assays were developed for 8 proteins and validated in Cohorts C (n = 71) and D (n = 84). The A disintegrin and metalloproteinase with thrombospondin motifs like 2 (ADAMTSL2) protein accurately distinguished non-alcoholic fatty liver (NAFL)/non-alcoholic steatohepatitis (NASH) with fibrosis stage 0-1 (F0-1) from at-risk NASH with fibrosis stage 2-4, with AUROCs of 0.83 and 0.86 in Cohorts C and D, respectively, and from NASH with significant fibrosis (F2-3), with AUROCs of 0.80 and 0.83 in Cohorts C and D, respectively. An 8-protein panel distinguished NAFL/NASH F0-1 from at-risk NASH (AUROCs 0.90 and 0.87 in Cohort C and D, respectively) and NASH F2-3 (AUROCs 0.89 and 0.83 in Cohorts C and D, respectively). The 8-protein panel and ADAMTSL2 protein had superior performance to the NAFLD fibrosis score and fibrosis-4 score. CONCLUSION: The ADAMTSL2 protein and an 8-protein soluble biomarker panel are highly associated with at-risk NASH and significant fibrosis; they exhibited superior diagnostic performance compared to standard of care fibrosis scores. LAY SUMMARY: Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of liver disease worldwide. Diagnosing NAFLD and identifying fibrosis (scarring of the liver) currently requires a liver biopsy. Our study identified novel proteins found in the blood which may identify fibrosis without the need for a liver biopsy.

Distinct Hepatic Gene-Expression Patterns of NAFLD in Patients With Obesity.

Approaches to manage nonalcoholic fatty liver disease (NAFLD) are limited by an incomplete understanding of disease pathogenesis. The aim of this study was to identify hepatic gene-expression patterns associated with different patterns of liver injury in a high-risk cohort of adults with obesity. Using the NanoString Technologies (Seattle, WA) nCounter assay, we quantified expression of 795 genes, hypothesized to be involved in hepatic fibrosis, inflammation, and steatosis, in liver tissue from 318 adults with obesity. Liver specimens were categorized into four distinct NAFLD phenotypes: normal liver histology (NLH), steatosis only (steatosis), nonalcoholic steatohepatitis without fibrosis (NASH F0), and NASH with fibrosis stage 1-4 (NASH F1-F4). One hundred twenty-five genes were significantly increasing or decreasing as NAFLD pathology progressed. Compared with NLH, NASH F0 was characterized by increased inflammatory gene expression, such as gamma-interferon-inducible lysosomal thiol reductase (IFI30) and chemokine (C-X-C motif) ligand 9 (CXCL9), while complement and coagulation related genes, such as C9 and complement component 4 binding protein beta (C4BPB), were reduced. In the presence of NASH F1-F4, extracellular matrix degrading proteinases and profibrotic/scar deposition genes, such as collagens and transforming growth factor beta 1 (TGFB1), were simultaneously increased, suggesting a dynamic state of tissue remodeling. Conclusion: In adults with obesity, distinct states of NAFLD are associated with intrahepatic perturbations in genes related to inflammation, complement and coagulation pathways, and tissue remodeling. These data provide insights into the dynamic pathogenesis of NAFLD in high-risk individuals.

Interleukin-6 promotes microtubule stability in axons via Stat3 protein-protein interactions.

The interleukin-6 (IL-6) family of cytokines and its downstream effector, STAT3, are important mediators of neuronal health, repair, and disease throughout the CNS, including the visual system. Here, we elucidate a transcription-independent mechanism for the neuropoietic activities of IL-6 related to axon development, regeneration, and repair. We examined the outcome of IL-6 deficiency on structure and function of retinal ganglion cell (RGC) axons, which form the optic projection. We found that IL-6 deficiency substantially delays anterograde axon transport in vivo. The reduced rate of axon transport is accompanied by changes in morphology, structure, and post-translational modification of microtubules. In vivo and in vitro studies in mice and swine revealed that IL-6-dependent microtubule phenotypes arise from protein-protein interactions between STAT3 and stathmin. As in tumor cells and T cells, this STAT3-stathmin interaction stabilizes microtubules in RGCs. Thus, this IL-6-STAT3-dependent mechanism for axon architecture is likely a fundamental mechanism for microtubule stability systemically.

BCLXL gene therapy moderates neuropathology in the DBA/2J mouse model of inherited glaucoma.

Axonal degeneration of retinal ganglion cells (RGCs) causes blindness in glaucoma. Currently, there are no therapies that target axons to prevent them from degenerating. Activation of the BAX protein has been shown to be the determining step in the intrinsic apoptotic pathway that causes RGCs to die in glaucoma. A putative role for BAX in axonal degeneration is less well elucidated. BCLXL (BCL2L1) is the primary antagonist of BAX in RGCs. We developed a mCherry-BCLXL fusion protein, which prevented BAX recruitment and activation to the mitochondria in tissue culture cells exposed to staurosporine. This fusion protein was then packaged into adeno-associated virus serotype 2, which was used to transduce RGCs after intravitreal injection and force its overexpression. Transduced RGCs express mCherry-BCLXL throughout their somas and axons along the entire optic tract. In a model of acute optic nerve crush, the transgene prevented the recruitment of a GFP-BAX fusion protein to mitochondria and provided long-term somal protection up to 12 weeks post injury. To test the efficacy in glaucoma, DBA/2J mice were transduced at 5 months of age, just prior to the time they begin to exhibit ocular hypertension. Gene therapy with mCherry-BCLXL did not affect the longitudinal history of intraocular pressure elevation compared to naive mice but did robustly attenuate both RGC soma pathology and axonal degeneration in the optic nerve at both 10.5 and 12 months of age. BCLXL gene therapy is a promising candidate for glaucoma therapy.

Differentiation of exhausted CD8+ T cells after termination of chronic antigen stimulation stops short of achieving functional T cell memory.

T cell exhaustion is associated with failure to clear chronic infections and malignant cells. Defining the molecular mechanisms of T cell exhaustion and reinvigoration is essential to improving immunotherapeutic modalities. Here we confirmed pervasive phenotypic, functional and transcriptional differences between memory and exhausted antigen-specific CD8+ T cells in human hepatitis C virus (HCV) infection before and after treatment. After viral cure, phenotypic changes in clonally stable exhausted T cell populations suggested differentiation toward a memory-like profile. However, functionally, the cells showed little improvement, and critical transcriptional regulators remained in the exhaustion state. Notably, T cells from chronic HCV infection that were exposed to antigen for less time because of viral escape mutations were functionally and transcriptionally more similar to memory T cells from spontaneously resolved HCV infection. Thus, the duration of T cell stimulation impacts exhaustion recovery, with antigen removal after long-term exhaustion being insufficient for the development of functional T cell memory.

Liver Biochemistries in Hospitalized Patients With COVID-19.

BACKGROUND AND AIMS: Coronavirus disease 2019 (COVID-19) leads to elevated liver biochemistries in approximately half of patients on presentation. To date, data are limited regarding the trend of liver biochemistries over the course of illness. We aimed to evaluate the trend, etiology, and outcomes associated with liver biochemistries in COVID-19. APPROACH AND RESULTS: A total of 60 patients with COVID-19 were admitted between March 21 and March 28, 2020. The mean age was 57 years, 65% were male, and 28% were Hispanic. At the study conclusion, 6 patients were deceased, 28 were discharged, and 26 remained admitted. Patients who remained admitted were followed for a median of 12 days. Of 60 patients, 41 (69%) had at least one abnormal liver biochemistry on admission. Median aspartate aminotransferase (AST) was higher than alanine aminotransferase (ALT) at admission (46 vs. 30 U/L) and during the hospital course. Aminotransferases rose above normal in 54 (93%) patients, whereas alkaline phosphatase and total bilirubin elevations were rare. Ten (17%) patients developed aminotransferases more than 5 times the upper limit of normal. AST highly correlated with ALT throughout the illness course (r = 0.97; P < 0.0001), whereas correlations with markers of muscle injury and inflammation were weak. Statin use was common before (40%) and during admission (80%) at our center, with no difference in peak liver biochemistries between users and nonusers. No demographic or comorbid illness was associated with liver injury. Admission AST (69 vs. 49; P < 0.05), peak AST (364 vs. 77; P = 0.003), and peak ALT (220 vs. 52; P = 0.002) were higher in intubated patients. CONCLUSIONS: AST-dominant aminotransferase elevation is common in COVID-19, mirrors disease severity, and appears to reflect true hepatic injury.

Multicenter Study to Transplant Hepatitis C-Infected Kidneys (MYTHIC): An Open-Label Study of Combined Glecaprevir and Pibrentasvir to Treat Recipients of Transplanted Kidneys from Deceased Donors with Hepatitis C Virus Infection.

BACKGROUND: Single-center trials and retrospective case series have reported promising outcomes using kidneys from donors with hepatitis C virus (HCV) infection. However, multicenter trials are needed to determine if those findings are generalizable. METHODS: We conducted a prospective trial at seven centers to transplant 30 kidneys from deceased donors with HCV viremia into HCV-uninfected recipients, followed by 8 weeks of once-daily coformulated glecaprevir and pibrentasvir, targeted to start 3 days posttransplant. Key outcomes included sustained virologic response (undetectable HCV RNA 12 weeks after completing treatment with glecaprevir and pibrentasvir), adverse events, and allograft function. RESULTS: We screened 76 patients and enrolled 63 patients, of whom 30 underwent kidney transplantation from an HCV-viremic deceased donor (median kidney donor profile index, 53%) in May 2019 through October 2019. The median time between consent and transplantation of a kidney from an HCV-viremic donor was 6.3 weeks. All 30 recipients achieved a sustained virologic response. One recipient died of complications of sepsis 4 months after achieving a sustained virologic response. No severe adverse events in any patient were deemed likely related to HCV infection or treatment with glecaprevir and pibrentasvir. Three recipients developed acute cellular rejection, which was borderline in one case. Three recipients developed polyomavirus (BK) viremia near or >10,000 copies/ml that resolved after reduction of immunosuppression. All recipients had good allograft function, with a median creatinine of 1.2 mg/dl and median eGFR of 57 ml/min per 1.73 m2 at 6 months. CONCLUSIONS: Our multicenter trial demonstrated safety and efficacy of transplantation of 30 HCV-viremic kidneys into HCV-negative recipients, followed by early initiation of an 8-week regimen of glecaprevir and pibrentasvir.

Preemptive Treatment With Elbasvir and Grazoprevir for Hepatitis C-Viremic Donor to Uninfected Recipient Kidney Transplantation.

INTRODUCTION: Long wait times for kidney transplants have prompted investigation into strategies to decrease the discarding of potentially viable organs. Recent reports suggest that kidneys from hepatitis C virus (HCV)-infected donors may be transplanted into HCV-naive donors followed by direct-acting antiviral therapy. METHODS: This was a pilot clinical trial to transplant kidneys from HCV-infected donors into HCV-naive recipients with preemptive use of elbasvir and grazoprevir for 12 weeks. The primary outcome was sustained virologic response 12 weeks after completion of therapy. Secondary outcomes were safety, quality of life, and early viral kinetics. RESULTS: A total of 33 patients were screened, and 8 underwent kidney transplantation from a HCV-viremic donors from August 2017 to March 2019. The median donor kidney donor profile index was 31% (range, 29%-65%), and patients who underwent transplantation waited a median of 6.5 months (range, 1-19 months). None had detectable HCV viremia beyond 2 weeks post-transplantation, and all achieved sustained virologic response 12 weeks after therapy (SVR12). There were no study-related severe adverse events. One patient experienced early graft loss due to venous thrombosis, whereas the remaining 7 patients had excellent allograft function at 6 months. CONCLUSION: Preemptive elbasvir and grazoprevir eliminated HCV infection in HCV-naive patients who received a kidney transplant from an HCV-infected donor.

Immediate administration of antiviral therapy after transplantation of hepatitis C-infected livers into uninfected recipients: Implications for therapeutic planning.

The practice of transplanting hepatitis C (HCV)-infected livers into HCV-uninfected recipients has not previously been recommended in transplant guidelines, in part because of concerns over uncontrolled HCV infection of the allograft. Direct-acting antivirals (DAAs) provide an opportunity to treat donor-derived HCV-infection and should be administered early in the posttransplant period. However, evidence on the safety and efficacy of an immediate DAA treatment approach, including how to manage logistical barriers surrounding timely DAA procurement, are required prior to broader use of HCV-positive donor organs. We report the results of a trial in which 14 HCV-negative patients underwent successful liver transplantation from HCV-positive donors. Nine patients received viremic (nucleic acid testing [NAT]-positive) livers and started a 12-week course of oral glecaprevir-pibrentasvir within 5 days of transplant. Five patients received livers from HCV antibody-positive nonviremic donors and were followed using a reactive approach. Survival in NAT-positive recipients is 100% at a median follow-up of 46 weeks. An immediate treatment approach for HCV NAT-positive liver transplantation into uninfected recipients is safe and efficacious. Securing payer approval for DAAs early in the posttransplant course could enable need-based allocation of HCV-positive donor organs irrespective of candidate HCV status, while averting chronic HCV allograft infection.

Pre-emptive pangenotypic direct acting antiviral therapy in donor HCV-positive to recipient HCV-negative heart transplantation: an open-label study.

BACKGROUND: Low donor heart availability underscores the need to identify all potentially transplantable organs. We sought to determine whether pre-emptive administration of pangenotypic direct-acting antiviral therapy can safely prevent the development of chronic hepatitis C virus (HCV) infection in uninfected recipients of HCV-infected donor hearts. METHODS: Patients were recruited for this an open-label, single-centre, proof-of-concept study from Nov 1, 2017, to Nov 30, 2018. Following enrolment, the recipient's status on the heart transplantation waiting list was updated to reflect a willingness to accept either an HCV-positive or HCV-negative heart donor. Patients who underwent transplantation with a viraemic donor heart, as determined by nucleic acid testing (NAT), received pre-emptive oral glecaprevir-pibrentasvir before transport to the operating room followed by an 8-week course of glecaprevir-pibrentasvir after transplantation. Patients receiving HCV antibody-positive donor hearts without detectable circulating HCV RNA were followed using a reactive approach and started glecaprevir-pibrentasvir only if they developed viraemia. The primary outcome was achievement of sustained virological response 12 weeks after completion of glecaprevir-pibrentasvir therapy (SVR12). Patients were followed from study enrolment to 1 year after transplantation. This is an interim analysis, initiated after all enrolled patients reached the primary outcome. Results reflect data from Nov 1, 2017, to May 30, 2019. This trial is registered with ClinicalTrials.gov, number NCT03208244. FINDINGS: 55 patients were assessed for eligibility and 52 consented to enrolment. 25 patients underwent heart transplantation with HCV-positive donor hearts (20 NAT-positive, five NAT-negative), three of whom underwent simultaneous heart-kidney transplantation. All 20 recipients of NAT-positive hearts tolerated glecaprevir-pibrentasvir and showed rapid viral suppression (median time to clearance 3·5 days, IQR 0·0-8·3), with the subsequent achievement of SVR12 by all 20. The five recipients of NAT-negative grafts did not become viraemic. Median pre-transplant waiting time for patients following enrolment in the HCV protocol was 20 days (IQR 8-57). Patient and allograft survival were 100% at a median follow-up of 10·7 months (range 6·5-18·0). INTERPRETATION: Pre-emptive administration of glecaprevir-pibrentasvir therapy results in expedited organ transplantation, rapid HCV suppression, prevention of chronic HCV infection, and excellent early allograft function in patients receiving HCV-infected donor hearts. Long-term outcomes are not yet known. FUNDING: American Association for the Study of Liver Diseases, National Institutes of Health, and the Massachusetts General Hospital.

Balancing the risk and rewards of utilizing organs from hepatitis C viremic donors.

PURPOSE OF REVIEW: Owing to long waitlist times and high waitlist morbidity and mortality, strategies to increase utilization of hepatitis C viremic-deceased donor organs are under investigation in kidney, liver, heart, and lung transplantation. RECENT FINDINGS: Direct-acting antiviral medications for hepatitis C virus infection have high cure rates and are well tolerated. Small, single-center trials in kidney and heart transplant recipients have demonstrated that with early posttransplant direct-acting antiviral therapy, 100% of uninfected recipients of hepatitis C viremic organs have been cured of infection after transplantation. SUMMARY: In this manuscript, we review the risks and rewards of utilizing hepatitis C viremic organs for transplantation.

Intelligent Selection of Metal-Organic Framework Arrays for Methane Sensing via Genetic Algorithms.

Gas sensor arrays, also called electronic noses, use many chemically diverse materials to adsorb and subsequently identify gas species in complex mixture environments. Ideally these materials should have maximally complementary adsorption profiles to achieve the best sensing performance, but in practice they are selected by trial-and-error. Thus current electronic noses do not achieve optimal detection. In this work, we employ metal-organic frameworks (MOFs) as sensing materials and leverage a genetic algorithm to identify optimal combinations of them for detecting methane leaks in air. We build on our previously reported computational design methodology, which ranked MOF arrays by their Kullback-Liebler divergence (KLD) values for probabilistically describing the concentrations of each gas species in an unknown mixture. We ran the genetic algorithm to find optimal MOF arrays of various sizes when selecting from a library of 50 different MOF materials. The genetic algorithm was able to accurately predict the best arrays of any desired size when compared to brute-force screening. Thus, this search optimization can be integrated into the efficient design of MOF-based electronic noses.