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Background: Post-acute sequelae of COVID-19, or long COVID, is a condition characterized by persistent COVID-19 symptoms. As long COVID is defined by clinical criteria after an elapsed period, an opportunity for early intervention may aid in future prophylactic approaches; however, at present, the pathobiological mechanisms are multifactorial. By analyzing early virally infected upper respiratory tract tissue prior to eventual clinical diagnosis, it may be possible to identify biomarkers of altered immune response to facilitate future studies and interventions. Methods: This is a sub-group analysis of samples collected from those with confirmed COVID-19. RNA extraction from nasopharyngeal/mid-turbinate samples, sequencing, and bioinformatic analysis were performed to analyze long COVID and non-long COVID cohorts at day 14 post infection. Differences in mean viral load at various timepoints were analyzed as well as serological data. Results: We identified 26 upregulated genes in patients experiencing long COVID. Dysregulated pathways including complement and fibrinolysis pathways and IL-7 upregulation. Additionally, genes involved in neurotransmission were dysregulated, and the long COVID group had a significantly higher viral load and slower viral clearance. Conclusions: Uncovering early gene pathway abnormalities associated with eventual long COVID diagnosis may aid in early identification. We show that, post acute infection, in situ pathogenic deviations in viral response are associated with patients destined to meet consensus long COVID diagnosis that is entirely dependent on clinical factors. These results identify an important biological temporal window in the natural history of COVID-19 infection and long COVID pathogenesis amenable to testing from standard-of-care upper respiratory tract specimens.
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BACKGROUND AIMS: Pegylated interferon-α (PegIFNα) is of limited utility during immunotolerant or immune active phases of chronic hepatitis B infection but is being explored as part of new cure regimens. Low/absent levels of IFNα found in some patients receiving treatment are associated with limited/no virological responses. The study aimed to determine if sera from participants inhibit IFNα activity and/or contain therapy-induced anti-IFNα antibodies. APPROACH RESULTS: Pre-treatment, on-treatment, and post-treatment sera from 61 immunotolerant trial participants on PegIFNα/entecavir therapy and 88 immune active trial participants on PegIFNα/tenofovir therapy were screened for anti-IFNα antibodies by indirect ELISA. The neutralization capacity of antibodies was measured by preincubation of sera±recombinant human IFNα added to Huh7 cells with the measurement of interferon-stimulated gene (ISG)-induction by qPCR. Correlations between serum-induced ISG inhibition, presence, and titer of anti-IFNα antibodies and virological responses were evaluated. Preincubation of on-treatment serum from 26 immunotolerant (43%) and 13 immune active (15%) participants with recombinant-human IFNα markedly blunted ISG-induction in Huh7 cells. The degree of ISG inhibition correlated with IFNα antibody titer ( p < 0.0001; r = 0.87). On-treatment development of anti-IFNα neutralizing antibodies (nAbs) was associated with reduced quantitative HBsAg and qHBeAg declines ( p < 0.05) and inhibited IFNα bioactivity to 240 weeks after PegIFNα cessation. Children developed anti-IFNα nAbs more frequently than adults ( p = 0.004) but nAbs in children had less impact on virological responses. CONCLUSIONS: The development of anti-IFNα nAbs during PegIFNα treatment diminishes responses to antiviral therapy. Understanding how and why anti-IFNα antibodies develop may allow for the optimization of IFN-based therapy, which is critical given its renewed use in HBV-cure strategies.
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OBJECTIVES: International infectious disease/obstetrical societies have recently recommended universal hepatitis C virus (HCV) prenatal screening and these same recommendations are forthcoming in Canada. At present, there is no formal analysis of universal HCV screening or linkage to care of pregnant people in Ontario. The objectives of our study were to determine the seroprevalence of HCV using 2 different methods to evaluate universal screening, as well as identify opportunities that may improve linkage to care. METHODS: To assess seroprevalence in a large urban area, we aimed to test 12 000 de-identified samples submitted for prenatal HIV testing in the catchment area of Toronto Public Health for HCV antibodies. Then, to assess the seroprevalence as well as the operational impact and follow-up in a real-world setting, we completed a Quality Improvement Project (QIP) for 1 year at a large tertiary care obstetrical centre in London, Ontario. RESULTS: From 2019 to 2021, 11 999 de-identified samples were screened from Toronto with a seroprevalence of 0.40 (95% CI 0.29-0.53). In London, 5771 people were screened in 2021 with a seroprevalence of 0.55% (95% CI 0.38-0.78). Taken together, those aged 26-35 years had the highest positivity; in the QIP, 9% had no documented risk factor, and 59% of individuals were not linked to the next step in HCV care. CONCLUSIONS: HCV prenatal seroprevalence in Ontario is comparable to hepatitis B virus, and â¼15-30-fold higher than HIV. Diagnosis in pregnancy is critical to facilitate referrals for treatment between pregnancies and could increase screening among children born to positive women.
Subject(s)
Hepatitis C , Mass Screening , Pregnancy Complications, Infectious , Humans , Female , Ontario/epidemiology , Hepatitis C/epidemiology , Hepatitis C/diagnosis , Pregnancy , Seroepidemiologic Studies , Pregnancy Complications, Infectious/epidemiology , Pregnancy Complications, Infectious/diagnosis , Adult , Mass Screening/methods , Prevalence , Prenatal Diagnosis/methods , Prenatal CareABSTRACT
BACKGROUND AND AIMS: Despite the availability of highly effective direct-acting antiviral therapy, chronic hepatitis C (CHC) continues to cause a major public health burden. In many high-income countries, treatment rates have been declining, which was exacerbated by the impact of the COVID-19 pandemic, threatening the ability to meet the World Health Organization (WHO)'s targets for eliminating HCV as a public health threat by 2030. We sought to model the impact of CHC in Canada, a resource-rich country with ongoing immigration from HCV-endemic regions; which relies exclusively on risk-based screening for case identification. APPROACH AND RESULTS: We developed an agent-based model to characterize the HCV epidemic in a high-income country with ongoing immigration. Combinations of prevention such as harm reduction, screening, and treatment strategies were considered. Model parameters were estimated from the literature and calibrated against historical HCV data. Sensitivity analyses were performed to assess uncertainty. Under the current status quo of risk-based screening, we predict the incidence of CHC-induced decompensated cirrhosis, HCC, and liver-related deaths would decrease by 79.4%, 76.1%, and 62.1%, respectively, between 2015 and 2030, but CHC incidence would only decrease by 11.1%. The results were sensitive to HCV transmission rate and an annual number of people initiating treatment. CONCLUSIONS: Current risk-based screening, and subsequent treatment, will be inadequate to achieve WHO goals. With extensive scale-up in screening, and treatment, the mortality target may be achievable, but the target for preventing new CHC cases is unlikely reachable, highlighting the importance of developing enhanced harm-reduction strategies for HCV elimination.
Subject(s)
Antiviral Agents , Feasibility Studies , Hepatitis C, Chronic , Mass Screening , Humans , Mass Screening/methods , Antiviral Agents/therapeutic use , Canada/epidemiology , Hepatitis C, Chronic/diagnosis , Hepatitis C, Chronic/epidemiology , Hepatitis C, Chronic/drug therapy , Hepatitis C, Chronic/prevention & control , COVID-19/epidemiology , COVID-19/prevention & control , Developed Countries/statistics & numerical data , Disease Eradication/methods , Female , Male , Incidence , SARS-CoV-2 , Middle Aged , AdultABSTRACT
Background: Migrants from hepatitis B virus (HBV) endemic regions are at high risk of having chronic infection. Despite this, HBV knowledge and awareness programming, and low-barrier screening methods such as point of care (POC) testing, among this group have yet to become routine. Methods: We conducted a mass HBV POC screening and knowledge and awareness campaign for individuals of Chinese descent in Toronto, Canada. POC screening was administered, then participants completed a knowledge questionnaire. Logistic regression identified associations between demographic factors and participants' level of HBV knowledge. Results: From 2015 to 2018, 33 outreach events resulted in 891 individuals completing testing and the knowledge questionnaire. Individuals averaged 64.4 years old. Most, 62% (N = 552), were female, and 73.6% (N = 656) have been in Canada for <30 years. The average questionnaire score was 70.7% correct, with 65.2% (N = 581) demonstrating a high level of HBV knowledge. Post-secondary education (OR: 2.19, 95% CI: 1.41, 3.39), income of $50,000 to <$75,000 (OR: 2.74, 95% CI: 1.39, 5.43), and having familial history of HBV (OR: 1.72, 95% CI: 1.06, 2.78) were associated with high knowledge. The observed prevalence of HBV was 1.5%, with 13 individuals testing positive on the POC test and confirmatory laboratory testing. Conclusions: Improving knowledge and awareness of HBV is critical to empowering people, especially migrants who experience barriers to care, to pursue vaccination, testing, and treatment. Combining knowledge outreach and POC test campaigns, enabled discussion and screening for HBV with large numbers of people, and can be tailored for optimal effectiveness for specific groups.
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INTRODUCTION: Complete viral suppression with nucleos(t)ide analogs (NAs) has led to a profound reduction in hepatocellular carcinoma and mortality among patients with chronic hepatitis B. Finite therapy yields higher rates of functional cure; however, initial hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) elevations are almost certain after treatment interruption. We aimed to analyze off-treatment outcomes beyond 12 months after NA cessation. METHODS: Patients with well-suppressed chronic hepatitis B who were hepatitis B e antigen-negative at NA cessation and remained off treatment without hepatitis B surface antigen (HBsAg) loss at 12 months were included (n = 945). HBV DNA and ALT fluctuations were allowed within the first 12 months. We used Kaplan-Meier methods to analyze outcomes beyond 12 months. Sustained remission was defined as HBV DNA <2,000 IU/mL and ALT <2× upper limit of normal (ULN) and an ALT flare as ALT ≥5× ULN. RESULTS: Cumulative probability of sustained remission was 29.7%, virological relapse was 65.2% with a mean peak HBV DNA of 5.0 ± 1.5 log 10 IU/mL, an ALT flare was 15.6% with a median peak ALT × ULN of 8.3 (5.7-11.3), HBsAg loss was 9.9% and retreatment was 34.9% at 48 months after NA cessation. A single occurrence of virological relapse or an ALT flare within the first 12 months off-treatment were associated with significantly lower rates of sustained remission beyond 12 months. DISCUSSION: Despite allowing for HBV DNA and ALT fluctuations within the first 12 months off-treatment, most patients without HBsAg loss did not maintain a sustained response thereafter. The best candidates for NA withdrawal are patients with low HBsAg levels at NA cessation, and those without profound or recurrent virological and biochemical relapses in the first off-treatment year.
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OBJECTIVES: Health administrative data can be used to improve the health of people who inject drugs by informing public health surveillance and program planning, monitoring, and evaluation. However, methodological gaps in the use of these data persist due to challenges in accurately identifying injection drug use (IDU) at the population level. In this study, we validated case-ascertainment algorithms for identifying people who inject drugs using health administrative data in Ontario, Canada. STUDY DESIGN AND SETTING: Data from cohorts of people with recent (past 12 months) IDU, including those participating in community-based research studies or seeking drug treatment, were linked to health administrative data in Ontario from 1992 to 2020. We assessed the validity of algorithms to identify IDU over varying look-back periods (ie, all years of data [1992 onwards] or within the past 1-5 years), including inpatient and outpatient physician billing claims for drug use, emergency department (ED) visits or hospitalizations for drug use or injection-related infections, and opioid agonist treatment (OAT). RESULTS: Algorithms were validated using data from 15,241 people with recent IDU (918 in community cohorts and 14,323 seeking drug treatment). An algorithm consisting of ≥1 physician visit, ED visit, or hospitalization for drug use, or OAT record could effectively identify IDU history (91.6% sensitivity and 94.2% specificity) and recent IDU (using 3-year look back: 80.4% sensitivity, 99% specificity) among community cohorts. Algorithms were generally more sensitive among people who inject drugs seeking drug treatment. CONCLUSION: Validated algorithms using health administrative data performed well in identifying people who inject drugs. Despite their high sensitivity and specificity, the positive predictive value of these algorithms will vary depending on the underlying prevalence of IDU in the population in which they are applied.
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Algorithms , Substance Abuse, Intravenous , Humans , Ontario/epidemiology , Substance Abuse, Intravenous/epidemiology , Male , Female , Adult , Middle AgedABSTRACT
Non-invasive methods have largely replaced biopsy to identify advanced fibrosis in hepatitis C virus (HCV). Guidelines vary regarding testing strategy to balance accuracy, costs and loss to follow-up. Although individual test characteristics are well-described, data comparing the accuracy of using two tests together are limited. We calculated combined test characteristics to determine the utility of combined strategies. This study synthesizes empirical data from fibrosis staging trials and the literature to estimate test characteristics for Fibrosis-4 (FIB4), APRI or a commercial serum panel (FibroSure®), followed by transient elastography (TE) or FibroSure®. We simulated two testing strategies: (1) second test only for those with intermediate first test results (staged approach), and (2) second test for all. We summarized empiric data with multinomial distributions and used this to estimate test characteristics of each strategy on a simulated population of 10,000 individuals with 4.2% cirrhosis prevalence. Negative predictive value (NPV) for cirrhosis from a single test ranged from 98.2% (95% CB 97.6-98.8%) for FIB-4 to 99.4% (95% CB 99.0-99.8%) for TE. Using a staged approach with TE second, sensitivity for cirrhosis rose to 93.3-96.9%, NPV to 99.7-99.8%, while PPV dropped to <32%. Using TE as a second test for all minimally changed estimated test characteristics compared with the staged approach. Combining two non-invasive fibrosis tests barely improves NPV and decreases or does not change PPV compared with a single test, challenging the utility of serial testing modalities. These calculated combined test characteristics can inform best methods to identify advanced fibrosis in various populations.
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Elasticity Imaging Techniques , Liver Cirrhosis , Humans , Liver Cirrhosis/diagnosis , Liver Cirrhosis/pathology , Liver Cirrhosis/virology , Elasticity Imaging Techniques/methods , Sensitivity and Specificity , Hepatitis C, Chronic/complications , Hepatitis C, Chronic/pathology , Predictive Value of Tests , Severity of Illness Index , Male , Female , Hepatitis C/diagnosis , Hepatitis C/complications , Middle AgedABSTRACT
BACKGROUND: Current guidelines recommend HCV screening by 18 months of age for those exposed to HCV in utero; yet, screening occurs in the minority of children. OBJECTIVES: To evaluate the association between maternal neighbourhood-level social determinants of health (SDOH) and paediatric HCV screening in the general population in a publicly funded healthcare system in Canada. METHODS: Retrospective cohort study using administrative healthcare data held at ICES. Children born to individuals positive for HCV RNA in pregnancy from 2000 to 2016 were identified and followed for 2 years. Major SDOH were identified, and the primary outcome was HCV screening in exposed children (HCV antibody and/or RNA). Associations between SDOH and HCV screening were determined using multivariate Poisson regression models adjusting for confounding. RESULTS: A total of 1780 children born to persons with +HCV RNA were identified, and 29% (n = 516) were screened for HCV by age two. Most mothers resided in the lowest income quintile (42%), and most vulnerable quintiles for material deprivation (41%), housing instability (38%) and ethnic diversity (26%) with 11% living in rural locations. After adjustment for confounding, maternal rural residence (risk ratio [RR] 0.82, 95% confidence interval [CI] 0.62, 1.07) and living in the highest dependency quintile (RR 0.83, 95% CI 0.65, 1.07) were the SDOH most associated with paediatric HCV screening. Younger maternal age (RR 0.98 per 1-year increase, 95% CI 0.97, 0.99), HIV co-infection (RR 1.69, 95% CI 1.16, 2.48) and GI specialist involvement (RR 1.18, 95% CI 1.00, 1.39) were associated with higher probabilities of screening. CONCLUSIONS: Among children exposed to HCV during pregnancy, rural residences and living in highly dependent neighbourhoods showed a potential association with a lower probability of HCV screening by the age of 2. Future work evaluating barriers to paediatric HCV screening among rural residing and dependent residents is needed to enhance the screening.
Subject(s)
Hepatitis C , Social Determinants of Health , Child , Female , Humans , Pregnancy , Hepatitis C/diagnosis , Hepatitis C/epidemiology , HIV Infections/epidemiology , Retrospective Studies , RNA , Pregnancy Outcome , Pregnancy Complications, Infectious/epidemiologyABSTRACT
Immune-mediated liver damage is the driver of disease progression in patients with chronic hepatitis B virus (HBV) infection. Liver damage is an Ag-independent process caused by bystander activation of CD8 T cells and NK cells. How bystander lymphocyte activation is initiated in chronic hepatitis B patients remains unclear. Periods of liver damage, called hepatic flares, occur unpredictably, making early events difficult to capture. To address this obstacle, we longitudinally sampled the liver of chronic hepatitis B patients stopping antiviral therapy and analyzed immune composition and activation using flow cytometry and single-cell RNA sequencing. At 4 wk after stopping therapy, HBV replication rebounded but no liver damage was detectable. There were no changes in cell frequencies at viral rebound. Single-cell RNA sequencing revealed upregulation of IFN-stimulated genes (ISGs) and proinflammatory cytokine migration inhibitory factor (MIF) at viral rebound in patients that go on to develop hepatic flares 6-18 wk after stopping therapy. The type I IFN signature was only detectable within the liver, and neither IFN-α/ß or ISG induction could be detected in the peripheral blood. In vitro experiments confirmed the type I IFN-dependent ISG profile whereas MIF was induced primarily by IL-12. MIF exposure further amplified inflammatory cytokine production by myeloid cells. Our data show that innate immune activation is detectable in the liver before clinically significant liver damage is evident. The combination of type I IFN and enhanced cytokine production upon MIF exposure represent the earliest immunological triggers of lymphocyte bystander activation observed in hepatic flares associated with chronic HBV infection.
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Hepatitis B, Chronic , Hepatitis B , Humans , Hepatitis B virus , Liver , Cytokines/metabolism , Antiviral Agents/therapeutic use , Antiviral Agents/metabolismABSTRACT
INTRODUCTION: Progress toward hepatitis C virus (HCV) elimination is impeded by low testing and treatment due to the current diagnostic pathway requiring multiple visits leading to loss to follow-up. Point-of-care testing technologies capable of detecting current HCV infection in one hour are a 'game-changer.' These tests enable diagnosis and treatment in a single visit, overcoming the barrier of multiple visits that frequently leads to loss to follow-up. Combining point-of-care HCV antibody and RNA tests should improve cost-effectiveness, patient/provider acceptability, and testing efficiency. However, implementing HCV point-of-care testing programs at scale requires multiple considerations. AREAS COVERED: This commentary explores the need for point-of-care HCV tests, diagnostic strategies to improve HCV testing, key considerations for implementing point-of-care HCV testing programs, and remaining challenges for point-of-care testing (including operator training, quality management, connectivity and reporting systems, regulatory approval processes, and the need for more efficient tests). EXPERT OPINION: It is exciting that single-visit testing, diagnosis, and treatment for HCV infection have been achieved. Innovations afforded through COVID-19 should facilitate the accelerated development of low-cost, rapid, and accurate tests to improve HCV testing. The next challenge will be to address barriers and facilitators for implementing point-of-care testing to deliver them at scale.
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Hepatitis C , Substance Abuse, Intravenous , Humans , Hepatitis C/diagnosis , Hepatitis C/therapy , Hepacivirus/genetics , Point-of-Care Testing , RNA, ViralABSTRACT
We studied whether 48 weeks of PEG-IFN alfa-2a add-on increases HBsAg-decline and clearance in HBeAg-negative patients on long-term nucleo(s)tide analogue (NA) therapy. In this investigator-initiated, randomized, controlled trial conducted in Europe and Canada, HBeAg-negative patients treated with NA > 12 months, with HBVDNA < 200 IU/mL, were enrolled. Patients were randomized 2:1 to 48 weeks of PEG-IFN alfa-2a add-on (180 µg per week) or continued NA-monotherapy with subsequent follow-up to Week 72. Endpoints were HBsAg decline (≥1 log10 IU/mL) and HBsAg clearance at Week 48. Of the 86 patients in the modified-intention-to-treat analysis, 58 patients received PEG-IFN add-on, and 28 continued NA monotherapy. At Week 48, 16(28%) patients achieved HBsAg decline ≥1 log10 in the add-on arm versus none on NA-monotherapy (p < .001), and HBsAg clearance was observed in 6 (10%) PEG-IFN add-on patients versus 0% NA-monotherapy (p = .01). HBVRNA was only detected in 2% after PEG-IFN treatment versus 19% in NA-monotherapy (p = .002) at Week 48. PEG-IFN add-on therapy was well tolerated in majority of patients. Low baseline HBsAg levels (<10 IU/mL) identified patients most likely to achieve HBsAg loss with PEG-IFN add-on, whereas an HBsAg level > 200 IU/mL at on-treatment Week 12 was highly predictive of non-response (NPV = 100%). Addition of PEG-IFN to long-term NA enhanced HBsAg decline and increased the chance of HBsAg clearance in HBeAg-negative patients on long-term NA. On-treatment HBsAg levels >200 IU/mL identify patients unlikely to benefit from PEG-IFN add-on and could be used as a potential stopping-rule for PEG-IFN therapy. Our findings support further exploration of immune modulation add-on to antiviral therapy, preferably using response-guided strategies, to increase functional cure rates in patients with CHB.
Subject(s)
Antiviral Agents , Hepatitis B, Chronic , Humans , Antiviral Agents/therapeutic use , Hepatitis B Surface Antigens , Hepatitis B e Antigens , Hepatitis B, Chronic/drug therapy , Drug Therapy, Combination , Polyethylene Glycols/therapeutic use , Recombinant Proteins/therapeutic use , Treatment Outcome , DNA, ViralABSTRACT
Social determinants of health are important in designing effective interventions for hepatitis B virus (HBV) infection. This systematic review characterises equity-oriented, social determinants of health-focused HBV interventions, and describes their effectiveness in terms of the prevention, care, or treatment of HBV in high-income countries. We searched electronic databases for central concepts of 'HBV', 'equity', 'social determinants of health', 'intervention', and 'Organization for Economic Co-operation and Development (OECD) countries'. Screening and data abstraction were conducted independently by two reviewers. Data were abstracted from 66 studies; articles with a comparative study design (n=36) were included in the narrative synthesis, highlighting social determinants of health domains of interventions, HBV-relevant health outcomes, and extra-health social determinants of health effects (ie, those effects that extend beyond health outcomes). Synthesis aligned with six emergent themes corresponding to HBV prevention and care: knowledge and education, diagnosis and screening, immunisation, care initiation, engagement with clinical care and treatment, and upstream prevention. Studies presented a heterogeneous array of HBV-relevant health outcomes. Most interventions were tailored for social determinants of health domains of race, ethnicity, culture, and language; drug use; and socioeconomic status. Across the themes, at least two-thirds of interventions showed comparative effectiveness for addressing HBV. Extra-health social determinants of health outcomes were observed for two studies. Considerable diversity in population-level approaches was observed regarding intervention goals and effectiveness; most interventions were effective at enhancing the prevention, care, or treatment of HBV.
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Hepatitis B , Social Determinants of Health , Humans , Hepatitis B/prevention & control , Hepatitis B virusABSTRACT
Curative hepatitis C virus (HCV) therapy has increased transplantation from HCV-infected nucleic acid test-positive donors to HCV-uninfected recipients (D+/R-). We evaluated outcomes of early and late HCV treatment among D+/R- nonliver organ transplants. Patients received HCV regimens per local standard (n = 10 sites). Outcomes were compared between early and late treatments. Early treatment regimens (ETR) (n = 56) were initiated pretransplantation to day 7 posttransplant. Late treatment regimens (LTRs) (n = 102) began median 31 (range, 8-114) days posttransplant. There were 79 kidney, 50 lung, 23 heart, and 6 mixed transplants, similar between groups. HCV RNA was quantifiable in 98% of LTR versus 44.6% of ETR recipients (P < .001). Mean (range) days on treatment were 28 (7-93) ETR and 81 (51-111) LTR (P < .0001). There were no virological failures with ETR, but relapse (n = 3) and nonresponse (n = 2) in LTR (P = .16), including fibrosing cholestatic hepatitis postrelapse (n = 1). Sustained virological response was 100% (95% confidence interval, 93.4-100.0) in ETR (n = 54) and 94.9% (95% confidence interval, 88.5-98.3) in LTR (n = 98). Acute rejection occurred in 11 (19.6%) ETR and 25 (24.5%) LTR. In total, 11 HCV-unrelated deaths occurred: 8 ETR and 3 LTR. Organ transplantation from HCV-infected nucleic acid test-positive donors to HCV-uninfected recipients was safe. ETR led to fewer virological failures with shorter treatment duration, supporting recommendations to initiate treatment promptly posttransplant.
Subject(s)
Hepatitis C , Nucleic Acids , Organ Transplantation , Humans , Hepacivirus/genetics , Antiviral Agents/therapeutic use , Hepatitis C/drug therapyABSTRACT
BACKGROUND: There are no immunological biomarkers that predict control of chronic hepatitis B (CHB). The lack of immune biomarkers raises concerns for therapies targeting PD-1/PD-L1 because they have the potential for immune-related adverse events. Defining specific immune functions associated with control of HBV replication could identify patients likely to respond to anti-PD-1/PD-L1 therapies and achieve a durable functional cure. METHODS: We enrolled immunotolerant, HBeAg+ immune-active (IA+), HBeAg- immune-active (IA-), inactive carriers, and functionally cured patients to test ex vivo PD-1 blockade on HBV-specific T cell functionality. Peripheral blood mononuclear cells were stimulated with overlapping peptides covering HBV proteins +/-α-PD-1 blockade. Functional T cells were measured using a 2-color FluoroSpot assay for interferon-γ and IL-2. Ex vivo functional restoration was compared to the interferon response capacity assay, which predicts overall survival in cancer patients receiving checkpoint inhibitors. RESULTS: Ex vivo interferon-γ+ responses did not differ across clinical phases. IL-2+ responses were significantly higher in patients with better viral control and preferentially restored with PD-1 blockade. Inactive carrier patients displayed the greatest increase in IL-2 production, which was dominated by CD4 T cell and response to the HBcAg. The interferon response capacity assay significantly correlated with the degree of HBV-specific T cell restoration. CONCLUSIONS: IL-2 production was associated with better HBV control and superior to interferon-γ as a marker of T cell restoration following ex vivo PD-1 blockade. Our study suggests that responsiveness to ex vivo PD-1 blockade, or the interferon response capacity assay, may support stratification for α-PD-1 therapies.
Subject(s)
Hepatitis B, Chronic , Humans , T-Lymphocytes/metabolism , Hepatitis B virus , Interleukin-2 , Interferon-gamma , B7-H1 Antigen , Hepatitis B e Antigens , Programmed Cell Death 1 Receptor , Leukocytes, Mononuclear/metabolism , BiomarkersABSTRACT
Despite remarkable therapeutic advanced, hepatitis C virus (HCV) infection continues to be a major global problem. While the development of highly effective direct-acting antivirals (DAAs) has ensured that almost all those who are treated achieve viral cure, progress toward HCV elimination globally has stalled due to challenges upstream of treatment in the cascade of care, namely diagnosis and linkage to care. The major challenge continues to be the relative complexity of HCV diagnosis with the current requirement for a confirmatory HCV RNA test after an initial antibody-positive result. in this review, challenges with the current paradigm are highlighted with a focus on new technologies, as well as simple strategies using existing tools, that may simplify diagnosis and improve linkage to care and treatment. To achieve HCV elimination, improvements in the HCV diagnostics field to allow for a simple single-step diagnosis are required.