Direct-acting antiviral treatment downregulates immune checkpoint inhibitor expression in patients with chronic hepatitis C

Natural killer cells in liver transplantation: Can we harness the power of the immune checkpoint to promote tolerance?

The roles that natural killer (NK) cells play in liver disease and transplantation remain ill‐defined. Reports on the matter are often contradictory, and the mechanisms elucidated are complex and dependent on the context of the model tested. Moreover, NK cell attributes, such as receptor protein expression and function differ among species, make study of primate or rodent transplant models challenging. Recent insights into NK function and NK‐mediated therapy in the context of cancer therapy may prove applicable to transplantation. Of specific interest are immune checkpoint molecules and the mechanisms by which they modulate NK cells in the tumor micro‐environment. In this review, we summarize NK cell populations in the peripheral blood and liver, and we explore the data regarding the expression and function of immune checkpoint molecules on NK cells. We also hypothesize about the roles they could play in liver transplantation and discuss how they might be harnessed therapeutically in transplant sciences.

Cancer in People with and without Hepatitis C Virus Infection: Comparison of Risk Before and After Introduction of Direct-Acting Antivirals

BACKGROUND

Chronic hepatitis C virus (HCV) infection is a leading cause of liver cancer. The association of HCV infection with extrahepatic cancers, and the impact of direct-acting antiviral (DAA) treatment on these cancers, is less well known.

METHODS

We conducted a cohort study in a healthcare delivery system. Using electronic health record data from 2007 to 2017, we determined cancer incidence, overall and by type, in people with HCV infection and by DAA treatment status. All analyses included comparisons with a reference population of people without HCV infection. Covariate-adjusted Poisson models were used to estimate incidence rate ratios.

RESULTS

2,451 people with HCV and 173,548 people without HCV were diagnosed with at least one type of cancer. Compared with people without HCV, those with HCV were at higher risk for liver cancer [adjusted incidence rate ratio (aIRR) = 31.4, 95% confidence interval (CI) = 28.9-34.0], hematologic cancer (aIRR = 1.3, 95% CI = 1.1-1.5), lung cancer (aIRR = 1.3, 95% CI = 1.2-1.5), pancreatic cancer (aIRR = 2.0, 95% CI = 1.6-2.5), oral/oropharynx cancer (aIRR = 1.4, 95% CI = 1.1-1.8), and anal cancer (aIRR = 1.6, 95% CI = 1.1-2.4). Compared with people without HCV, the aIRR for liver cancer was 31.9 (95% CI = 27.9-36.4) among DAA-untreated and 21.2 (95% CI = 16.8-26.6) among DAA-treated, and the aIRR for hematologic cancer was 1.5 (95% CI = 1.1-2.0) among DAA-untreated and 0.6 (95% CI = 0.3-1.2) among DAA-treated.

CONCLUSIONS

People with HCV infection were at increased risk of liver cancer, hematologic cancer, and some other extrahepatic cancers. DAA treatment was associated with reduced risk of liver cancers and hematologic cancers.

IMPACT

DAA treatment is important for reducing cancer incidence among people with HCV infection.

Diabetes Mellitus Increases the Risk of Hepatocellular Carcinoma After Direct-Acting Antiviral Therapy: Systematic Review and Meta-Analysis

Background: Hepatitis C virus (HCV)-infected patients treated with direct-acting antivirals (DAAs) are still at risk of developing hepatocellular carcinoma (HCC) after sustained virologic response (SVR). This study aimed to investigate the role of diabetes mellitus (DM) as a potential predictive risk factor in developing de novo HCC in HCV-infected patients after DAA treatment. Methods: This study was registered on PROSPERO under registration number CRD42021230457. We performed a systematic search in four medical databases from inception through November 3rd, 2020. Studies were eligible if they reported on HCV-infected patients treated with DAAs and compared the frequency of de novo HCC in patients with and without DM. We calculated pooled odds ratios, unadjusted (UHR), and adjusted hazard ratios (AHR) with 95% confidence intervals (CIs) in meta-analysis. Results: We included 30 articles in our systematic review and meta-analysis. DM proved to be a significant risk factor of HCC in DAA-treated HCV patients in unadjusted (UHR = 1.44, CI: 1.15-1.79) and adjusted analyses (AHR = 1.31, CI: 1.06-1.62). In the group of patients achieving SVR after DAA therapy, DM increased the risk of HCC in unadjusted (UHR = 1.3, CI: 1.09-1.51) analysis; however, in adjusted results, the risk was non-significant (AHR = 1.07, CI: 0.89-1.28). In patients with advanced liver fibrosis, DM was a risk factor for HCC in adjusted (AHR = 1.36, CI: 1.03-1.8), but not in unadjusted analysis (UHR = 1.11, CI: 0.8-1.42). Conclusions: DM is an independent risk factor of de novo HCC after DAA treatment in HCV-infected patients. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=230457, identifier: CRD42021230457.

HCV Cure With Direct-Acting Antivirals Improves Liver and Immunological Markers in HIV/HCV-Coinfected Patients

Hepatitis C virus (HCV) cure after all-oral direct-acting antiviral (DAA) therapy greatly improves the liver and immune system. We aimed to assess the impact of this HCV clearance on immune system-related markers in plasma and the gene expression profile in human immunodeficiency virus (HIV)/HCV-coinfected patients with advanced cirrhosis. We performed a prospective study on 33 HIV/HCV-coinfected patients at baseline and 36 weeks after the sustained virological response. Gene expression was evaluated by RNA-seq analysis on peripheral blood mononuclear cells (PBMCs) and plasma biomarkers by multiplex immunoassays. We found a decrease in plasma biomarkers (PD1, PDL1, CXCL10, CXCL8, IL12p70, IL10, and TGFβ) and liver disease markers (stiffness measurement (LSM), hepatic venous pressure gradient (HVPG), and transaminases, among others). Furthermore, decreased plasma levels of CXCL8, CXCL10, IL10, and PD1 were associated with reduced LSM values. We also found two upregulated (HAS1 and IRG1) and 15 downregulated (CXCL11, CCL8, CCL7, CCL2, ADARB2, RRAD, MX1, SIGLEC1, IFI44L, IFI44, IFI27, IFI6, IFIT3, IFIT1B, and IFIT1) genes at the end of follow-up, all interferon-stimulated genes (ISGs) grouped into four pathways (“cytokine-cytokine receptor interaction”, “viral protein interaction with cytokine and cytokine receptor”, “chemokine signaling pathway”, and “hepatitis C”). Additionally, the decrease in most of these ISGs was significantly related to reduced LSM and HVPG values. In conclusion, HIV/HCV-coinfected patients with advanced-HCV-related cirrhosis who eradicated HCV following DAA therapy exhibited an improvement in liver disease markers and a significant decrease in plasma biomarkers and gene expression related to antiviral/inflammatory response, particularly in levels of several chemokines and ISGs.

Lymphocyte Landscape after Chronic Hepatitis C Virus (HCV) Cure: The New Normal

Chronic HCV (CHC) infection is the only chronic viral infection for which curative treatments have been discovered. These direct acting antiviral (DAA) agents target specific steps in the viral replication cycle with remarkable efficacy and result in sustained virologic response (SVR) or cure in high (>95%) proportions of patients. These treatments became available 6–7 years ago and it is estimated that their real impact on HCV related morbidity, including outcomes such as cirrhosis and hepatocellular carcinoma (HCC), will not be known for the next decade or so. The immune system of a chronically infected patient is severely dysregulated and questions remain regarding the immune system’s capacity in limiting liver pathology in a cured individual. Another important consequence of impaired immunity in patients cleared of HCV with DAA will be the inability to generate protective immunity against possible re-infection, necessitating retreatments or developing a prophylactic vaccine. Thus, the impact of viral clearance on restoring immune homeostasis is being investigated by many groups. Among the important questions that need to be answered are how much the immune system normalizes with cure, how long after viral clearance this recalibration occurs, what are the consequences of persisting immune defects for protection from re-infection in vulnerable populations, and does viral clearance reduce liver pathology and the risk of developing hepatocellular carcinoma in individuals cured with these agents. Here, we review the recent literature that describes the defects present in various lymphocyte populations in a CHC patient and their status after viral clearance using DAA treatments.

Different Expression Pattern of TIM-3 and Galectin-9 Molecules by Peripheral and Peritoneal Lymphocytes in Women with and without Endometriosis

Endometriosis is a gynecological condition that is associated with chronic pelvic inflammation, pain, and infertility. Although substantial evidence supports that immunological alterations contribute to its pathogenesis and we previously posed a pivotal role of Galectin-9 (Gal-9) in this disorder, the involvement of the TIM-3/Gal-9 pathway in the development of endometriosis-associated immunological abnormalities is not yet known. In the present study, multicolor flow cytometry was used to compare the immunophenotype and cell surface expression of TIM-3 and Gal-9 molecules on peripheral blood (PB) and peritoneal fluid (PF) lymphocytes of women with and without endometriosis. We found an altered distribution of different lymphocyte subpopulations, a markedly decreased TIM-3 labeling on all T and NK subsets and a significantly increased Gal-9 positivity on peripheral CD4+ T and Treg cells of the affected cohort. Furthermore, a significantly increased TIM-3 expression on CD4+T-cells and elevated Gal-9 labeling on all T and NK subsets was also revealed in the PF of the examined patients. In conclusion, our results suggest a persistent activation and disturbed TIM-3/Gal-9-dependent regulatory function in endometriosis, which may be involved in the impaired immune surveillance mechanisms, promotes the survival of ectopic lesions, and aids the evolution of reproductive failures in endometriosis.