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.

Memory-like HCV-specific CD8+ T cells retain a molecular scar after cure of chronic HCV infection.

In chronic hepatitis C virus (HCV) infection, exhausted HCV-specific CD8+ T cells comprise memory-like and terminally exhausted subsets. However, little is known about the molecular profile and fate of these two subsets after the elimination of chronic antigen stimulation by direct-acting antiviral (DAA) therapy. Here, we report a progenitor-progeny relationship between memory-like and terminally exhausted HCV-specific CD8+ T cells via an intermediate subset. Single-cell transcriptomics implicated that memory-like cells are maintained and terminally exhausted cells are lost after DAA-mediated cure, resulting in a memory polarization of the overall HCV-specific CD8+ T cell response. However, an exhausted core signature of memory-like CD8+ T cells was still detectable, including, to a smaller extent, in HCV-specific CD8+ T cells targeting variant epitopes. These results identify a molecular signature of T cell exhaustion that is maintained as a chronic scar in HCV-specific CD8+ T cells even after the cessation of chronic antigen stimulation.

Epigenetic scars of CD8+ T cell exhaustion persist after cure of chronic infection in humans.

T cell exhaustion is an induced state of dysfunction that arises in response to chronic infection and cancer. Exhausted CD8+ T cells acquire a distinct epigenetic state, but it is not known whether that chromatin landscape is fixed or plastic following the resolution of a chronic infection. Here we show that the epigenetic state of exhaustion is largely irreversible, even after curative therapy. Analysis of chromatin accessibility in HCV- and HIV-specific responses identifies a core epigenetic program of exhaustion in CD8+ T cells, which undergoes only limited remodeling before and after resolution of infection. Moreover, canonical features of exhaustion, including super-enhancers near the genes TOX and HIF1A, remain 'epigenetically scarred.' T cell exhaustion is therefore a conserved epigenetic state that becomes fixed and persists independent of chronic antigen stimulation and inflammation. Therapeutic efforts to reverse T cell exhaustion may require new approaches that increase the epigenetic plasticity of exhausted T cells.

Pioneering a Global Cure for Chronic Hepatitis C Virus Infection.

This year's Lasker∼Debakey Clinical Medical Research Award honors Ralf Bartenschlager, Charles Rice, and Michael Sofia, pioneers in the development of curative and safe therapies for the 170 million people with hepatitis C virus infection.

Impending HCC diagnosis in patients with cirrhosis after HCV cure features a natural killer cell signature.

BACKGROUND AND AIMS: The risk of developing HCC in chronically infected patients with AQ2 HCV with liver cirrhosis is significantly elevated. This risk remains high even after a sustained virological response with direct-acting antivirals. To date, disease-associated signatures of NK cells indicating HCC development are unclear. APPROACH AND RESULTS: This study investigated NK cell signatures and functions in 8 cohorts covering the time span of HCC development, diagnosis, and onset. In-depth analysis of NK cell profiles from patients with cirrhosis who developed HCC (HCV-HCC) after sustained virological response compared with those who remained tumor-free (HCV-noHCC) revealed increasingly dissimilar NK cell signatures over time. We identified expression patterns with persistently high frequencies of TIM-3 and CD38 on NK cells that were largely absent in healthy controls and were associated with a high probability of HCC development. Functional assays revealed that the NK cells had potent cytotoxic features. In contrast to HCV-HCC, the signature of HCV-noHCC converged with the signature found in healthy controls over time. Regarding tissue distribution, single-cell sequencing showed high frequencies of these cells in liver tissue and the invasive margin but markedly lower frequencies in tumors. CONCLUSIONS: We show that HCV-related HCC development has profound effects on the imprint of NK cells. Persistent co-expression of TIM-3hi and CD38 + on NK cells is an early indicator for HCV-related HCC development. We propose that the profiling of NK cells may be a rapid and valuable tool to assess the risk of HCC development in a timely manner in patients with cirrhosis after HCV cure.

Revaccination for Hepatitis B in Previous Nonresponders Following Hepatitis C Eradication.

BACKGROUND: Patients with chronic hepatitis C virus (HCV) do not respond to hepatitis B virus (HBV) vaccination as efficiently as the general population. We assessed if revaccination after HCV treatment resulted in improved response. METHODS: Previous HBV vaccine nonresponders were prospectively recruited for revaccination after HCV eradication. Hepatitis B surface antibody (HBsAb) testing was performed 1 month after series completion. RESULTS: Follow-up HBsAb testing was performed in 31 of 34 enrolled patients with 21 (67.7%) reactive results. There were no significant differences in HBsAb reactivity based on age, sex, race, or advanced fibrosis presence. CONCLUSIONS: HBV vaccine nonresponders should be considered for revaccination following HCV cure.

Hepatitis C Treatment in People With HIV: Potential to Eliminate Disease and Disparity.

Access to direct acting antivirals (DAAs) may be associated with reductions in hepatitis C virus (HCV) viremia prevalence among people with human immunodeficiency virus (PWH). Among 3755 PWH, estimated HCV viremia prevalence decreased by 94.0% from 36% (95% confidence interval [CI], 27%-46%) in 2009 (pre-DAA era) to 2% (95% CI, 0%-4%) in 2021 (DAA era). Male sex, black race, and older age were associated with HCV viremia in 2009 but not in 2021. Injection drug use remained associated with HCV viremia in 2009 and 2021. Targeted interventions are needed to meet the HCV care needs of PWH who use drugs.

Opportunistic Treatment of Hepatitis C Infection Among Hospitalized People Who Inject Drugs (OPPORTUNI-C): A Stepped Wedge Cluster Randomized Trial.

BACKGROUND: We aimed to evaluate the efficacy of opportunistic treatment of hepatitis C virus (HCV) infection among hospitalized people who inject drugs (PWID). METHODS: We performed a pragmatic, stepped wedge cluster randomized trial recruiting HCV RNA positive individuals admitted for inpatient care in departments of internal medicine, addiction medicine, and psychiatry at three hospitals in Oslo, Norway. Seven departments were sequentially randomized to change from control conditions (standard of care referral to outpatient care) to intervention conditions (immediate treatment initiation). The primary outcome was treatment completion, defined as dispensing the final package of the prescribed treatment within six months after enrolment. RESULTS: A total of 200 HCV RNA positive individuals were enrolled between 1 October 2019 and 31 December 2021 (mean age 47.4 years, 72.5% male, 60.5% injected past 3 months, 20.4% cirrhosis). Treatment completion was accomplished by 67 of 98 (68.4% [95% confidence interval {CI}: 58.2-77.4]) during intervention conditions and by 36 of 102 (35.3% [95% CI: 26.1-45.4]) during control conditions (risk difference 33.1% [95% CI: 20.0-46.2]; risk ratio 1.9 [95% CI: 1.4-2.6]). The intervention was superior in terms of treatment completion (adjusted odds ratio [aOR] 4.8 [95% CI: 1.8-12.8]; P = .002) and time to treatment initiation (adjusted hazard ratio [aHR] 4.0 [95% CI: 2.5-6.3]; P < .001). Sustained virologic response was documented in 60 of 98 (61.2% [95% CI: 50.8-70.9]) during intervention and in 66 of 102 (64.7% [95% CI: 54.6-73.9]) during control conditions. CONCLUSIONS: An opportunistic test-and-treat approach to HCV infection was superior to standard of care among hospitalized PWID. The model of care should be considered for broader implementation. Clinical Trials Registration. NCT04220645.

Success of the US Veterans Health Administration's Hepatitis C Virus Care Continuum in the Direct-acting Antiviral Era.

BACKGROUND: Estimated hepatitis C prevalence within the Veterans Health Administration is higher than the general population and is a risk factor for advanced liver disease and subsequent complications. We describe the hepatitis C care continuum within the Veterans Health Administration 1 January 2014 to 31 December 2022. METHODS: We included individuals in Veterans Health Administration care 2021-2022 who were eligible for direct-acting antiviral treatment 1 January 2014 to 31 December 2022. We evaluated the proportion of Veterans who progressed through each step of the hepatitis C care continuum, and identified factors associated with initiating direct-acting antivirals, achieving sustained virologic response, and repeat hepatitis C viremia. RESULTS: We identified 133 732 Veterans with hepatitis C viremia. Hepatitis C treatment was initiated in 107 134 (80.1%), with sustained virologic response achieved in 98 136 (91.6%). In those who achieved sustained virologic response, 1097 (1.1%) had repeat viremia and 579 (52.8%) were retreated for hepatitis C. Veterans of younger ages were less likely to initiate treatment and achieve sustained virologic response, and more likely to have repeat viremia. Stimulant use and unstable housing were negatively associated with each step of the hepatitis C care continuum. CONCLUSIONS: The Veterans Health Administration has treated 80% of Veterans with hepatitis C in care 2021-2022 and achieved sustained virologic response in more than 90% of those treated. Repeat viremia is rare and is associated with younger age, unstable housing, opioid use, and stimulant use. Ongoing efforts are needed to reach younger Veterans, and Veterans with unstable housing or substance use disorders.

Optimal hepatitis C treatment adherence patterns and sustained virologic response among people who inject drugs: The HERO study.

BACKGROUND & AIMS: Direct-acting antivirals (DAAs) are highly effective for treating HCV infection even among people who inject drugs (PWID). Yet, little is known about patients' adherence patterns and their association with sustained virologic response (SVR) rates. We aimed to summarize various adherence patterns and determine their associations with SVR. METHODS: Electronic blister packs were used to measure daily adherence to once-a-day sofosbuvir/velpatasvir during the 12-week treatment period among active PWIDs. Blister pack data were available for 496 participants who initiated DAAs for whom SVR status was known. Adherence was summarized in multiple patterns, such as total adherent days, consecutive missed days, and early discontinuations. Thresholds for adherence patterns associated with >90% SVR rates were also determined. RESULTS: The overall SVR rate was 92.7%, with a median adherence rate of 75%. All adherence patterns indicating greater adherence were significantly associated with achieving SVR. Participant groups with ≥50% (>42/84) adherent days or <26 consecutive missed days achieved an SVR rate of >90%. Greater total adherent days during 9-12 weeks and no early discontinuation were significantly associated with higher SVR rates only in those with <50% adherence. Participants with first month discontinuation and ≥2 weeks of treatment interruption had low SVR rates, 25% and 85%, respectively. However, greater adherent days were significantly associated with SVR (adjusted odds ratio 1.10; 95% CI 1.04-1.16; p <0.001) even among participants with ≥14 consecutive missed days. CONCLUSIONS: High SVR rates can be achieved in the PWID population despite suboptimal adherence. Encouraging patients to take as much medication as possible, with <2 weeks consecutive missed days and without early discontinuation, was found to be important for achieving SVR. IMPACT AND IMPLICATIONS: People who inject drugs can be cured of HCV in >90% of cases, even with relatively low adherence to direct-acting antivirals, but early discontinuations and long treatment interruptions can significantly reduce the likelihood of achieving cure. Clinicians should encourage people who inject drugs who are living with HCV to adhere daily to direct-acting antivirals as consistently as possible, but if any days are interrupted, to continue and complete treatment. These results from the HERO study are important for patients living with HCV, clinicians, experts writing clinical guidelines, and payers. CLINICAL TRIAL NUMBER: NCT02824640.

Post-treatment LSM rather than change during treatment predicts decompensation in patients with cACLD after HCV cure.

BACKGROUND & AIMS: Baveno VII has defined a clinically significant (i.e., prognostically meaningful) decrease in liver stiffness measurement (LSM) in cACLD as a decrease of ≥20% associated with a final LSM <20 kPa or any decrease to <10 kPa. However, these rules have not yet been validated against direct clinical endpoints. METHODS: We retrospectively analysed patients with cACLD (LSM ≥10 kPa) with paired liver stiffness measurement (LSM) before (BL) and after (FU) HCV cure by interferon-free therapies from 15 European centres. The cumulative incidence of hepatic decompensation was compared according to these criteria, considering hepatocellular carcinoma and non-liver-related death as competing risks. RESULTS: A total of 2,335 patients followed for a median of 6 years were analysed. Median BL-LSM was 16.6 kPa with 37.1% having ≥20 kPa. After HCV cure, FU-LSM decreased to a median of 10.9 kPa (<10 kPa: 1,002 [42.9%], ≥20 kPa: 465 [19.9%]) translating into a median LSM change of -5.3 (-8.8 to -2.4) kPa corresponding to -33.9 (-48.0 to -15.9) %. Patients achieving a clinically significant decrease (65.4%) had a significantly lower risk of hepatic decompensation (subdistribution hazard ratio: 0.12, 95% CI 0.04-0.35, p <0.001). However, these risk differences were primarily driven by a negligible risk in patients with FU-LSM <10 kPa (5-year cumulative incidence: 0.3%) compared to a high risk in patients with FU-LSM ≥20 kPa (16.6%). Patients with FU-LSM 10-19.9 kPa (37.4%) also had a low risk of hepatic decompensation (5-year cumulative incidence: 1.7%), and importantly, the risk of hepatic decompensation did not differ between those with/without an LSM decrease of ≥20% (p = 0.550). CONCLUSIONS: FU-LSM is key for risk stratification after HCV cure and should guide clinical decision making. LSM dynamics do not hold significant prognostic information in patients with FU-LSM 10-19.9 kPa, and thus, their consideration is not of sufficient incremental value in the specific context of HCV cure. IMPACT AND IMPLICATIONS: Liver stiffness measurement (LSM) is increasingly applied as a prognostic biomarker and commonly decreases in patients with compensated advanced chronic liver disease achieving HCV cure. Although Baveno VII proposed criteria for a clinically significant decrease, little is known about the prognostic utility of LSM dynamics (changes through antiviral therapy). Interestingly, in those with a post-treatment LSM of 10-19.9 kPa, LSM dynamics did not provide incremental information, arguing against the consideration of LSM dynamics as prognostic criteria. Thus, post-treatment LSM should guide the management of patients with compensated advanced chronic liver disease achieving HCV cure.

Hepatitis C.

Hepatitis C virus (HCV) is a hepatotropic RNA virus that can cause acute and chronic hepatitis, with progressive liver damage resulting in cirrhosis, decompensated liver disease, and hepatocellular carcinoma. In 2016, WHO called for the elimination of HCV infection as a public health threat by 2030. Despite some progress, an estimated 57 million people were living with HCV infection in 2020, and 300 000 HCV-related deaths occur per year. The development of direct-acting antiviral therapy has revolutionised clinical care and generated impetus for elimination, but simplified and broadened HCV screening, enhanced linkage to care, and higher coverage of treatment and primary prevention strategies are urgently required.

Regional Differences in Clinical Presentation and Prognosis of Patients With Post-Sustained Virologic Response Hepatocellular Carcinoma.

BACKGROUND & AIMS: Widespread use of direct-acting antivirals for hepatitis C virus infection has been paralleled with increased numbers of patients with hepatocellular carcinoma (HCC) after achieving sustained virologic response (post-SVR HCC) worldwide. Few data compare regional differences in the presentation and prognosis of patients with post-SVR HCC. METHODS: We identified patients with advanced fibrosis (F3/F4) who developed incident post-SVR HCC between March 2015 and October 2021 from 30 sites in Europe, North America, South America, the Middle East, South Asia, East Asia, and Southeast Asia. We compared patient demographics, liver dysfunction, and tumor burden by region. We compared overall survival by region using Kaplan-Meier analysis and identified factors associated with survival using multivariable Cox regression analysis. RESULTS: Among 8796 patients with advanced fibrosis or cirrhosis who achieved SVR, 583 (6.6%) developed incident HCC. There was marked regional variation in the proportion of patients detected by surveillance (range: 59.5%-100%), median maximum tumor diameter (range, 1.8-5.0 cm), and the proportion with multinodular HCC (range, 15.4%-60.8%). The prognosis of patients highly varied by region (hazard ratio range, 1.82-9.92), with the highest survival rates in East Asia, North America, and South America, and the lowest survival rates in the Middle East and South Asia. After adjusting for geographic region, HCC surveillance was associated with early stage detection (Barcelona Clinic Liver Cancer stage 0/A, 71.0% vs 21.3%; P < .0001) and lower mortality rates (adjusted hazard ratio, 0.29; 95% CI, 0.18-0.46). CONCLUSIONS: Clinical characteristics, including early stage detection, and prognosis of post-SVR HCC differed significantly across geographic regions. Surveillance utilization appears to be a high-yield intervention target to improve prognosis among patients with post-SVR HCC globally.

Hepatocellular Carcinoma Incidence Threshold for Surveillance in Virologically Cured Hepatitis C Individuals.

BACKGROUND & AIMS: Guidelines recommend biannual surveillance for hepatocellular carcinoma (HCC) in hepatitis C individuals with cirrhosis if the HCC incidence rate is above 1.5 per 100 person-years (PY). However, the incidence threshold for surveillance in individuals who achieve a virologic cure is unknown. We estimated the HCC incidence rate above which routine HCC surveillance is cost-effective in this growing population of virologically cured hepatitis C individuals with cirrhosis or advanced fibrosis. METHODS: We developed a Markov-based microsimulation model of the natural history of HCC in individuals with hepatitis C who achieved virologic cure with oral direct-acting antivirals. We used published data on the natural history of hepatitis C, competing risk post virologic cure, HCC tumor progression, real-world HCC surveillance adherence, contemporary HCC treatment options and associated costs, and utilities of different health states. We estimated the HCC incidence above which biannual HCC surveillance using ultrasound and alpha-fetoprotein would be cost-effective. RESULTS: In virologically cured hepatitis C individuals with cirrhosis or advanced fibrosis, HCC surveillance is cost-effective if HCC incidence exceeds 0.7 per 100 PY using $100,000 per quality-adjusted life year willingness-to-pay. At this HCC incidence, routine HCC surveillance would result in 2650 and 5700 additional life years per 100,000 cirrhosis and advanced fibrosis persons, respectively, compared with no surveillance. At $150,000 willingness-to-pay, surveillance is cost-effective if HCC incidence exceeds 0.4 per 100 PY. Sensitivity analysis showed that the threshold mostly remained below 1.5 per 100 PY. CONCLUSIONS: The contemporary HCC incidence threshold is much lower than the previous 1.5% incidence value used to guide HCC surveillance decisions. Updating clinical guidelines could improve the early diagnosis of HCC.

Liver Stiffness Measurement and Risk Prediction of Hepatocellular Carcinoma After HCV Eradication in Veterans With Cirrhosis.

BACKGROUND & AIMS: Patients with cirrhosis secondary to chronic hepatitis C virus (HCV) are at risk for hepatocellular carcinoma (HCC) despite a sustained virological response (SVR). We examined whether post-SVR liver stiffness measurement (LSM) could be used to stratify HCC risk. METHODS: This was a retrospective cohort study of 1850 participants identified from the Veterans Health Administration, with HCV cirrhosis and SVR, followed up over 5099 person-years, from the time of post-SVR elastography until death, HCC, or the end of the study. RESULTS: The risk of HCC increased by 3% with every 1-kPa increase in LSM (adjusted hazard ratio [aHR], 1.03, 95% confidence interval [CI], 1.01-1.04; P < .001) and decreased with the number of years from SVR (aHR, 0.79; 95% CI, 0.70-0.90; P = .0003). The adjusted annual risk of HCC was 2.03% among participants with post-SVR LSM <10 kPa, 2.48% in LSM 10-14.9 kPa (aHR, 1.71; 95% CI, 1.01-2.88; P = .046), 3.22% for LSM 15-19.9 kPa (aHR, 1.59; 95% CI, 0.78-3.20; P = .20), 5.07% among LSM 20-24.9 kPa (aHR, 2.55; 95% CI, 1.30-5.01; P = .01), and 5.44% in LSM ≥25 kPa (aHR, 3.03; 95% CI, 1.74-5.26; P < .0001). The adjusted annual risk of HCC was < 0.4% in participants with LSM <5 kPa and without diabetes mellitus. CONCLUSIONS: LSM predicts rates of HCC in patients with HCV cirrhosis after SVR at multiple cutoff levels and offers a single test to predict portal hypertension-related complications and HCC. Patients with LSM <5 kPa in the absence of diabetes mellitus had a low risk of HCC in which surveillance could be discontinued.

Proteomics reveals a global phenotypic shift of NK cells in HCV patients treated with direct-acting antivirals.

Chronic hepatitis C virus (HCV) infections compromise natural killer (NK)-cell immunity. Direct-acting antivirals (DAA) effectively eliminate HCV, but the long-term effects on NK cells in cured patients are debated. We conducted a proteomic study on CD56+ NK cells of chronic HCV-infected patients before and 1 year after DAA therapy. Donor-variation was observed in NK-cell proteomes of HCV-infected patients, with 46 dysregulated proteins restored after DAA therapy. However, 30% of the CD56+ NK-cell proteome remained altered 1 year post-therapy, indicating a phenotypic shift with low donor-variation. NK cells from virus-negative cured patients exhibited global regulation of RNA-processing and pathways related to "stimuli response", "chemokine signaling", and "cytotoxicity regulation". Proteomics identified downregulation of vesicle transport components (CD107a, COPI/II complexes) and altered receptor expression profiles, indicating an inhibited NK-cell phenotype. Yet, activated NK cells from HCV patients before and after therapy effectively upregulated IFN-γ and recruited CD107a. Conversely, reduced surface expression levels of Tim-3 and 2B4 were observed before and after therapy. In conclusion, this study reveals long-term effects on the CD56+ NK-cell compartment in convalescent HCV patients 1 year after therapy, with limited abundance of vesicle transport complexes and surface receptors, associated with a responsive NK-cell phenotype.

DAA-mediated HCV cure reduces HIV DNA levels in HCV/HIV coinfected people.

IMPORTANCE: Antiretroviral therapy (ART) for human immunodeficiency virus (HIV) can control virus replication and prolong the life of people living with HIV (PLWH). However, the virus remains dormant within immune cells in what is called the HIV reservoir. Furthermore, 2.3 million PLWH are also coinfected with hepatitis C virus (HCV) and are at risk of developing chronic liver disease and cancer. HCV treatment with direct acting antivirals (DAA) can completely cure the infection in more than 95% of treated individuals and improve their long-term health outcomes. In this study, we investigated how HCV treatment and cure affect the HIV reservoir. We demonstrate the beneficial impact of DAA treatment as it reduces the HIV reservoirs in particular in people infected with HCV before HIV. These results support the need for early ART and DAA treatment in HIV/HCV coinfections.

Imprinted immune abnormalities in liver transplant patients cured of hepatitis C with antiviral drugs.

Chronic HCV infection induces interferon and dysregulates immune responses through inflammation and chronic antigenic stimulation. Antiviral drugs can cure HCV, providing a unique opportunity to examine the immunological restoration that does and does not occur when a chronic viral infection is eradicated. We quantified blood cytokines levels and used mass cytometry to immunophenotype peripheral blood mononuclear cells before and after HCV cure in 2 groups of patients and controls. At baseline, serum interferon α and soluble CD163 (a macrophage product) were elevated in both liver transplant and nonliver transplant patients compared to controls; the frequencies of several peripheral blood mononuclear cell populations differed from controls; and programmed death protein 1-positivity was increased in nearly all T cell subsets. Many abnormalities persisted after HCV cure, including elevated programmed death protein 1 expression on CD4 naïve and central memory T cells, elevated soluble CD163, and expansion of the plasmablast/plasma cell compartment. Several myeloid-lineage subsets, including Ag-presenting dendritic cells, remained dysregulated. In mechanistic studies, interferon α treatment increased programmed death protein 1 on human T cells and increased T cell receptor signaling. The data identify immunological abnormalities that persist after curative HCV treatment. Before cure, high levels of interferon α may stimulate programmed death protein 1 expression on human T cells, causing persistent functional changes.

CD4+ T-cell recovery in HIV/hepatitis C co-infected patients following successful hepatitis C treatment.

INTRODUCTION: Hepatitis C virus (HCV)/HIV co-infection has been identified as a risk for impaired CD4+ T-cell recovery, possibly mediated by HCV-induced liver fibrosis and/or immune activation. As HCV direct-acting antivirals (DAAs) may partially reverse liver fibrosis and immune activation, sustained HCV virological response (SVR) may lead to improved CD4 recovery. We explored the effect of HCV DAA-induced SVR on CD4 recovery among patients living with both HCV and HIV, including those with poor CD4 recovery on antiretroviral therapy (immunological non-responders [INRs]). METHODS: Subjects aged ≥18 years living with both HIV and HCV who achieved SVR with DAA were included. Pre-DAA CD4 counts were included only after sustained HIV viral suppression and HIV viral suppression was maintained for the duration of the study. Segmented regression of interrupted time series analysis was used to evaluate changes in median CD4 count in the pre-DAA period (-36 months) versus the post-DAA period (+36 months). RESULTS: In total, 156 patients were included. In the full cohort, median CD4 counts increased by 15% (p = 0.002) in the 6-month period following DAA initiation, whereafter CD4 counts decreased by 2.7% per 6-month period (p = 0.004). Among the 13 INRs, there was no immediate effect on median CD4 in the first 6 months after DAA initiation, whereafter there was a sustained CD4 increase (4.1% per 6-month time interval [p = 0.02]). In total, 54% of INRs recorded a post-DAA CD4 count of >350 cells/mm3. CONCLUSIONS: Successful DAA therapy induced a modest immediate CD4 immunological reconstitution among this cohort of patients living with both HIV and HCV, although this effect waned with time. By contrast, among INRs, achieving HCV SVR led to slower but sustained CD4 count recovery.