T-cell homeostasis in chronic HCV-infected patients treated with interferon and ribavirin or an interferon-free regimen

Soluble form of CTLA-4 is a good predictor for tumor recurrence after radiofrequency ablation in hepatocellular carcinoma patients

BACKGROUND

A soluble form of cytotoxic-T-lymphocyte-antigen-4 (sCTLA-4) is a prognostic biomarker for several cancers but remains unclear in HCC patients. The aim of study is to evaluate the predictive role of serum sCTLA-4 levels for tumor recurrence of chronic hepatis C (CHC)-HCC patients receiving radiofrequency ablation (RFA).

MATERIAL AND METHOD

A prospective study recruiting 88 CHC-HCC patients was done between 2013 and 2019. Cox regression analysis was used to determine the predictors of early recurrence. All tests were two-tailed, and the level of statistical significance was set as p < 0.05.

RESULTS

During a median follow-up of 44.4 months, 53 of the 88 (60.2%) CHC-HCC patients encountered early recurrence within 2 years. The predictability of sCTLA-4 for local recurrence (LR) and intrahepatic metastasis (IHM) by 2-years using AUROC curve analysis were 0.740 and 0.715, respectively. Patients with high sCTLA-4 levels (>9 ng/ml) encountered shorter recurrence-free survival (RFS) for LR (log-rank p = 0.017) but paradoxically longer RFS for IHM (log-rank p = 0.007) compared to those with low levels (≤9 ng/ml). By multivariate Cox regression analysis, sCTLA-4 levels and antiviral therapy were independent prognostic factor of early recurrence both in LR and IHM. A combination of baseline sCTLA-4 and AFP level could improve the predictability of early LR and IHM with specificity of 80.0% and 79.7% and positive predictive value of 63.3% and 67.3%, respectively.

CONCLUSIONS

sCTLA-4 level is a good predictor for early HCC recurrence with higher levels indicating susceptibility to early LR, but protecting from early IHM.

In Chronic Hepatitis C Infection, Myeloid-Derived Suppressor Cell Accumulation and T Cell Dysfunctions Revert Partially and Late After Successful Direct-Acting Antiviral Treatment

Chronic HCV infection is characterized by several immunological alterations, such as the accumulation of suppressor cells and of hyperactivated T lymphocytes. However, it is unclear whether direct-acting antiviral (DAA)-mediated HCV clearance restores immune dysfunctions. We performed a phenotypic characterization by flow cytometry of different immune cell subsets, including monocytic myeloid-derived suppressor cells (M-MDSCs) and T lymphocytes in 168 patients with persistent HCV infection not treated, under DAA therapies and sustained virological responders. Chronic HCV infection prompted the accumulation of M-MDSCs independently of patient and clinical characteristics, and altered their metabolic properties. HCV RNA was undetectable in the majority of patients just after few weeks of DAA therapy, whereas M-MDSC levels normalized only 6 months after therapy. In addition, HCV infection deeply perturbed the T cell compartment since a re-distribution of memory CD4⁺ and CD8⁺ T cells was observed at the expenses of naïve cells, and memory T lymphocytes displayed increased activation. Notably, these features were only partially restored by DAA therapies in the CD4, but not in the CD8, compartment as high immune activation levels persisted in the terminally differentiated memory CD8⁺ T cells even more than 1 year after sustained virological response. Together, these results suggest that successful DAA therapies do not lead to full immunological reconstitution as fast as viral clearance.

Immune regulation in chronic hepatitis C virus infection

The immunological result of infection with Hepatitis C virus (HCV) depends on the delicate balance between a vigorous immune response that may clear the infection, but with a risk of unspecific inflammation and, or a less inflammatory response that leads to chronic infection. In general, exhaustion and impairment of cytotoxic function of HCV-specific T cells and NK cells are found in patients with chronic HCV infection. In contrast, an increase in immune regulatory functions is found primarily in form of increased IL-10 production possibly due to increased level and function of anti-inflammatory Tregs. Thus, the major immune players during chronic HCV infection are characterized by a decrease of cytotoxic function and increase of inhibitory functions. This may be an approach to diminish intrahepatic and systemic inflammation. Finally, there has been increasing awareness of regulatory functions of epigenetic changes in chronic HCV infection. A vast amount of studies have revealed the complexity of immune regulation in chronic HCV infection, but the interplay between immune regulation in virus and host remains incompletely understood. This review provides an overview of regulatory functions of HCV-specific T cells, NK cells, Tregs, IL-10, and TGF-β, as well as epigenetic changes in the setting of chronic HCV infection.