Hepatitis C virus-specific cellular immune responses in sustained virological responders with viral persistence in peripheral blood mononuclear cells

Occult Infection with Hepatitis C Virus: Looking for Clear-Cut Boundaries and Methodological Consensus

The sustained virologic response and elimination of HCV is widely viewed as a true cure of chronic hepatitis C as it associates with amelioration of histological liver damage and improved clinical outcomes. Therefore, the existence and clinical burden of occult HCV infection (OCI) has been a controversial issue for many years. In this review, we summarize recently published data that adds new information on the molecular and clinical background of OCI and its epidemiological significance. We also identify and discuss the most important methodological pitfalls, which can be a source of inconsistency between studies. Data that have accumulated so far, strongly support the existence of extrahepatic HCV replication in individuals negative for serum HCV-RNA by conventional clinical tests. OCI emerges as a condition where the immune system is unable to fully resolve infection but it is continuously stimulated by low levels of HCV antigens, leading to progression of liver pathology and extrahepatic HCV-related complications. Moreover, the development of monitoring strategies or management guidelines for OCI is still hampered by the lack of clear definition and the confusion regarding its clinical significance. Careful study design and the introduction of uniform protocols for the detection of low-level HCV-RNA are crucial for obtaining reliable data on OCI.

HCV eradication with IFN-based therapy does not completely restore gene expression in PBMCs from HIV/HCV-coinfected patients

Objective

To evaluate the impact of hepatitis C virus (HCV) elimination via interferon (IFN)-based therapy on gene expression profiles related to the immune system in HIV/HCV-coinfected patients.

Methods

We conducted a prospective study in 28 HIV/HCV-coinfected patients receiving IFN-based therapy at baseline (HIV/HCV-b) and week 24 after sustained virological response (HIV/HCV-f). Twenty-seven HIV-monoinfected patients (HIV-mono) were included as a control. RNA-seq analysis was performed on peripheral blood mononuclear cells (PBMCs). Genes with a fold-change (FC) ≥ 1.5 (in either direction) and false discovery rate (FDR) ≤ 0.05 were identified as significantly differentially expressed (SDE).

Results

HIV/HCV-b showed six SDE genes compared to HIV-mono group, but no significantly enriched pathways were observed. For HIV/HCV-f vs. HIV/HCV-b, we found 58 SDE genes, 34 upregulated and 24 downregulated in the HIV/HCV-f group. Of these, the most overexpressed were CXCL2, PDCD6IP, ATP5B, IGSF9, RAB26, and CSRNP1, and the most downregulated were IFI44 and IFI44L. These 58 SDE genes revealed two significantly enriched pathways (FDR < 0.05), one linked to Epstein-Barr virus infection and another related to p53 signaling. For HIV/HCV-f vs. HIV-mono group, we found 44 SDE genes that revealed 31 enriched pathways (FDR < 0.05) related to inflammation, cancer/cell cycle alteration, viral and bacterial infection, and comorbidities associated with HIV/HCV-coinfection. Five genes were overrepresented in most pathways (JUN, NFKBIA, PIK3R2, CDC42, and STAT3).

Conclusion

HIV/HCV-coinfected patients who eradicated hepatitis C with IFN-based therapy showed profound gene expression changes after achieving sustained virological response. The altered pathways were related to inflammation and liver-related complications, such as non-alcoholic fatty liver disease and hepatocellular carcinoma, underscoring the need for active surveillance for these patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12929-021-00718-6.

Neutrocyte-to-lymphocyte ratio predicts the presence of a replicative hepatitis C virus strand after therapy with direct-acting antivirals

Residual HCV-RNA can persist in liver tissue and peripheral blood mononuclear cells (PBMCs) long after antiviral therapy of chronic hepatitis C in patients repeatedly negative for viral RNA in serum. This occult infection associates with impaired immune response and the risk of lymphoproliferative disorders or progressive liver disease. There are currently no monitoring strategies for patients after treatment. We investigated if serum inflammation markers and interferon lambda (IFNL) genotype can be predictors of the presence of HCV-RNA and the replicative HCV-RNA (−) strand in patients who reached sustained virological response after interferon-free therapy. Forty-two consecutive patients who remained HCV-RNA negative in serum 24 weeks after the end of treatment (EOT) and during the follow-up were enrolled. Total HCV-RNA and HCV-RNA (−) strand were detected using ultrasensitive RT-PCR in PBMCs collected 12–15 months after EOT. Polymorphisms within IFNL3–IFNL4 region (rs12979860 and ss469415590) were genotyped with allele-specific PCR. Viral RNA was found in PBMCs from 31 (74%) patients, and of those 29 (69%) were also positive for HCV-RNA (−). Neither normalization of alanine aminotransferase nor IFNL genotype predicted the presence of residual HCV-RNA. A significantly higher neutrocyte-to-lymphocyte ratio (NLR) 24 weeks after the start of treatment predicted elimination of replicative HCV-RNA strand (OR 0.23; 95% CI 0.10–0.86; P = 0.019). Patients with no HCV-RNA (−) in PBMCs showed a greater increase in neutrocyte count between EOT and baseline (P = 0.028). Lack of significant elevation of NLR after therapy with direct-acting antivirals could predict the presence of residual replicative HCV-RNA strand in PBMCs.

Cocaine Use and Liver Disease are Associated with All-Cause Mortality in the Miami Adult Studies in HIV (MASH) Cohort

OBJECTIVE

Liver disease is a frequent cause of morbidity and mortality in HIV infection. We examined the relationship of cocaine use, liver disease progression and mortality in an HIV-infected cohort.

METHODS

Consent was obtained from 487 HIV+ participants, a subset of the Miami Adult Studies on HIV (MASH) cohort. Participants were eligible if they were followed for at least two years, completed questionnaires on demographics and illicit drug use and had complete metabolic panels, CD4 cell counts and HIV-viral loads. FIB-4 was calculated and cut-off points were used for staging liver fibrosis. Death certificates were obtained.

RESULTS

Participants were 65% men, 69% Black and 81% were on ART at recruitment. Cocaine was used by 32% of participants and 29% were HIV/HCV co-infected. Mean age was 46.9 ± 7.7 years, mean CD4 cell count was 501.9 ± 346.7 cells/μL and mean viral load was 2.75 ± 1.3 log₁₀ copies/mL at baseline. During the follow-up, 27 patients died, with a mortality rate of 28.2/1000 person-year. Cocaine was used by 48% of those who died (specific mortality rate was 13/1000 person-year). Those who died were more likely to use cocaine (HR=3.8, P=0.006) and have more advanced liver fibrosis (HR=1.34, P<0.0001), adjusting for age, gender, CD4 cell count and HIV-viral load at baseline and over time. Among the HIV mono-infected participants, cocaine users were 5 times more likely to die (OR=5.09, P=0.006) than participants who did not use cocaine.

CONCLUSION

Cocaine use and liver fibrosis are strong and independent predictors of mortality in HIV infected and HIV/HCV co-infected adults. Effective interventions to reduce cocaine use among people living with HIV (PHLW) are needed.

Lymphomagenesis-related gene expression in B cells from sustained virological responders with occult hepatitis C virus infection

The expression of activation-induced cytidine deaminase, B-aggressive lymphoma, cyclin D1 and serine/threonine kinase 15 genes, among others, is increased in B cells from patients with chronic hepatitis C virus (HCV) infection. It is unknown whether the level of expression of these genes in B cells is increased in patients with hepatitis C who have achieved a sustained virological response (SVR) but who have persistent, detectable HCV RNA, so-called occult infection. Eighty-three patients who achieved and SVR, 27 with detectable HCV and 56 without detectable HCV RNA, 28 chronic hepatitis C patients and 32 healthy controls were studied. RNA was extracted from B cells, and gene expression levels were measured by RT-PCR. Patients with chronic HCV and those who achieved an SVR (with and without persistent low-level HCV RNA) showed a statistically significant higher expression compared to healthy controls, of activation-induced cytidine deaminase (P = 0.004, P < 0.001 and P = 0.002, respectively), B-aggressive lymphoma (P < 0.001, P = 0.001 and P = 0.006) and cyclin D1 (P = 0.026, P = 0.001; P = 0.038). For activation-induced cytidine deaminase patients with an SVR and 'occult infection' had a statistically significantly higher expression level than patients with and SVR without 'occult infection' (P = 0.014). The higher expression levels found for activation-induced cytidine deaminase, together with other genes indicates that these B lymphomagenesis-related genes are upregulated following HCV therapy and this is more marked when HCV can be detected in PBMCs.

A Comprehensive Analysis of the Impact of HIV on HCV Immune Responses and Its Association with Liver Disease Progression in a Unique Plasma Donor Cohort

Objective

Human Immunodeficiency Virus (HIV) and Hepatitis C virus (HCV) co-infection is recognized as a major cause of morbidity and mortality among HIV-1 infected patients. Our understanding of the impact of HIV infection on HCV specific immune responses and liver disease outcome is limited by the heterogeneous study populations with genetically diverse infecting viruses, varying duration of infection and anti-viral treatment.

Methods

Viral-specific immune responses in a cohort of 151 HCV mono- and HIV co-infected former plasma donors infected with a narrow source of virus were studied. HCV and HIV specific T cell responses were correlated with clinical data.

Results

HIV-1 accelerated liver disease progression and decreased HCV specific T cell immunity. The magnitude of HCV specific T cell responses inversely correlated with lower HCV RNA load and reduced liver injury as assessed by non-invasive markers of liver fibrosis. HIV co-infection reduced the frequency of HCV specific CD4⁺ T cells with no detectable effect on CD8⁺ T cells or neutralizing antibody levels.

Conclusion

Our study highlights the impact of HIV co-infection on HCV specific CD4+ T cell responses in a unique cohort of patients for both HCV and HIV and suggests a crucial role for these cells in controlling chronic HCV replication and liver disease progression.

Significance of CD4+CD25+CD127low/- regulatory T cells in hepatitis C

AIM: To investigate the diagnostic and therapeutic significance of CD4⁺CD25⁺CD127^low/- regulatory T (Treg) cell ratio in peripheral blood of patients with chronic hepatitis C.

METHODS: Ninety-six chronic hepatitis C patients undergoing polyethylene glycol interferon (PEG-IFN) and ribavirin (RBV) therapy at Yucheng People's Hospital were assigned to an observation group, and 65 healthy volunteers were included in a control group. CD4⁺CD25⁺CD127^low/-Treg ratio was detected at baseline and 24 wk after treatment. The changes of CD4⁺CD25⁺CD127^low/- Treg ratio with different viral levels and liver injury were analyzed. According to whether the patients achieved a virologic response in 24 wk after withdrawal, they were divided into a sustained virologic response (SVR) group or a non-SVR group. The differences between the two groups in CD4⁺CD25⁺CD127^low/-Treg ratios were analyzed at baseline and 24 wk after treatment.

RESULTS: The proportion of CD4⁺CD25⁺CD127^low/- Treg cells at baseline in the observation group was significantly higher than that at baseline in the control group and that at the end of treatment in the observation group (P < 0.05). CD4⁺CD25⁺CD127^low/- Treg cell ratios of patients with different load of HCV RNA were different. With the increase in HCV RNA load, CD4⁺CD25⁺CD127^low/- Treg cell proportion continued to rise significantly (P < 0.05). At 24 wk after withdrawal, the rate of SVR in the observation group was 78.3%. The proportion of CD4⁺CD25⁺CD127^low/- Treg cells in SVR patients was significantly lower than that of patients without SVR (P < 0.05) no matter whether at baseline or at 24 wk after treatment. Correlation analysis showed that the baseline CD4⁺CD25⁺CD127^low/- Treg cell proportion was positively correlated with the liver function index AST/ALT (P < 0.05).

CONCLUSION: CD4⁺CD25⁺CD127^low/- Treg cells may be involved in the pathogenesis of chronic hepatitis, and clinical detection of CD4⁺CD25⁺CD127^low/- Treg cell ratio may be helpful for disease diagnosis and prognosis evaluation.

Hepatitis C virus: A time for decisions. Who should be treated and when?

Cirrhosis is the most important risk factor for hepatocellular carcinoma (HCC) regardless of the etiology of cirrhosis. Compared to individuals who are anti-hepatitis C virus (HCV) seronegative, anti-HCV seropositive individuals have a greater mortality from both hepatic as well as nonhepatic disease processes. The aim of this paper is do describe the burden of HCV infection and consider treatment strategies to reduce HCV-related morbidity and mortality. The newly developed direct acting antiviral (DAA) therapies are associated with greater rates of drug compliance, fewer adverse effects, and appear not to be limited by the presence of a variety of factors that adversely affect the outcome of interferon-based therapies. Because of the cost of the current DAA, their use has been severely rationed by insurers as well as state and federal agencies to those with advanced fibrotic liver disease (Metavir fibrosis stage F3-F4). The rationale for such rationing is that many of those recognized as having the disease progress slowly over many years and will not develop advanced liver disease manifested as chronic hepatitis C, cirrhosis, and experience any of the multiple complications of liver disease to include HCC. This mitigation has a short sided view of the cost of treatment of hepatitis C related disease processes and ignores the long-term expenses of hepatitis C treatment consisting of the cost of treatment of hepatitis C, the management of cirrhosis with or without decompensation as well as the cost of treatment of HCC and liver transplantation. We believe that treatment should include all HCV infected patients including those with stage F0-F2 fibrosis with or without evidence of coexisting liver disease. Specifically, interferon (IFN)-free regimens with the current effective DAAs without liver staging requirements and including those without evidence of hepatic diseases but having recognized extrahepatic manifestations of HCV infection is projected to be the most cost-effective approach for treating HCV in all of its varied presentations. Early rather than later therapy of HCV infected individuals would be even more efficacious than waiting particularly if it includes all cases from F0-F4 hepatic disease. Timely therapy will reduce the number of individuals developing advanced liver disease, reduce the cost of treating these cases and more importantly, reduce the lifetime cost of treatment of those with any form of HCV related disease as well as HCV associated all - cause mortality. Importantly, HCV treatment regimens without any restrictions would result in a substantial reduction in health care expenditure and simultaneously reduce the number of infected individuals who are infecting others.

Occult HCV Infection: The Current State of Knowledge

Context

Occult HCV infection (OCI) is defined as the presence of HCV-RNA in hepatocytes and the absence of HCV in the serum according to usual tests. We aimed to define OCI and provide information about the currently available diagnostic methods. Then we focus on specific groups that are at high risk of OCI and finally investigate immune responses to OCI and the available treatment approaches.

Evidence Acquisition

PubMed, Scopus and Google Scholar were comprehensively searched with combination of following keywords: “occult”, “hepatitis C virus” and “occult HCV infection”. The definition of OCI, diagnostic methods, specific groups that are at high risk and available treatment approaches were extract from literature. An analysis of available articles on OCI also was done based on Scopus search results.

Results

OCI has been reported in several high-risk groups, especially in hemodialysis patients and subjects with cryptogenic liver disease. Furthermore, some studies have proposed a specific immune response for OCI in comparison with chronic hepatitis C (CHC).

Conclusions

With a clinical history of approximately 11 years, occult HCV infection can be considered an occult type of CHC. Evidences suggest that considering OCI in these high-risk groups seems to be necessary. We suggest that alternative diagnostic tests should be applied and that there is a need for the participation of all countries to determine the epidemiology of this type of HCV infection. Additionally, evaluating OCI in blood transfusion centers and in patients who receive large amounts of blood and clotting factors, such as patients with hemophilia, should be performed in future projects.

A New Twist to a Chronic HCV Infection: Occult Hepatitis C

Background. The prevalence of occult hepatitis C infection (OCI) in the population of HCV-RNA negative but anti-HCV positive individuals is presently unknown. OCI may be responsible for clinically overt recurrent disease following an apparent sustained viral response (SVR) weeks to years later. Purpose. To review the available current literature regarding OCI, prevalence, pathogenic mechanisms, clinical characteristics, and future directions. Data Sources. Searching MEDLINE, article references, and national and international meeting abstracts for the diagnosis of OCI (1990-2014). Data Synthesis. The long-term followup of individuals with an OCI suggests that the infection can be transient with the loss of detectable HCV-RNA in PPBMCs after 12-18 months or alternatively exist intermittently and potentially long term. The ultimate outcome of HCV infection is decided by interplay between host immune responses, antiviral therapies, and the various well-identified viral evasion mechanisms as well as the presence of HCV infection within extrahepatic tissues. Conclusion. The currently widely held assumption of a HCV-cure in individuals having had "SVR" after 8-12 weeks of a course of DAA therapy as recently defined may not be entirely valid. Careful longitudinal followup utilizing highly sensitive assays and unique approaches to viral isolation are needed.