HCV-specific T-cell responses in HIV/hepatitis C virus-coinfected patients on highly active antiretroviral therapy are comparable to those observed in hepatitis C virus-monoinfected individuals

Both Hepatitis C Virus-Specific T Cell Responses and IL28B rs12979860 Single-Nucleotide Polymorphism Genotype Influence Antihepatitis C Virus Treatment Outcome in Patients with Chronic Hepatitis C

Despite new treatments for hepatitis C virus (HCV) infection, IFNα-based regimens still have clinical relevance in special populations of patients and remain the only therapeutic option for many patients. We sought to elucidate the interplay between two relevant factors (IL28B polymorphism and T cell immune responses) involved in the outcome of this therapy in HCV-infected patients. We evaluated 38 patients infected with HCV genotype 1-17 coinfected with HIV-who were undergoing a full course of pegIFNα/RBV therapy. The interdependence and roles of T cell-mediated immune responses and IL28B rs12979860 single-nucleotide polymorphism genotype as predictors of virological response to anti-HCV treatment in patients with chronic hepatitis C were evaluated using nonparametric tests. Factors associated with rapid virological response (RVR) in univariate analysis were presence of CD4 T cell response against NS3 HCV protein, low baseline HCV-RNA, and IL28B CC genotype. Factors associated with sustained virological response (SVR) in univariate analysis were IL28B CC genotype, low baseline HCV-RNA, and presence of CD4 response against NS2. In the multivariate analysis, low baseline HCV-RNA and NS3-specific CD4 response showed a clear trend toward association with RVR (P = 0.09 and P = 0.07, respectively). Regarding SVR, IL28B CC genotype was the strongest predictor (P = 0.02), with presence of NS2-specific CD4 response showing a clear trend (P = 0.09). HCV-specific T cell response influences the outcome of pegIFNα/RBV therapy regardless of IL28B genotype. HCV-specific T cell responses (adaptive immunity) seem to influence viral clearance both in the short and long term during therapy (RVR and SVR), whereas the influence of the IL28B genotype (innate immunity) may be more relevant to the long-lasting therapeutic effect (SVR).

The dynamics of HCV-specific antibody responses in HIV/HCV patients on long-term antiretroviral therapy

Antibody responses have not been fully characterised in chronically HIV/HCV patients receiving antiretroviral therapy (ART). Seventeen HIV/HCV patients receiving ART were followed for a median (range) interval of 597 (186-766) weeks. Prior to ART, HIV/HCV patients had lower levels of antibodies reactive with HCV core and JFH-1, and lower genotype cross-reactive neutralising antibodies (nAb) titres, than HCV patients. Levels of JFH-1 reactive antibody increased on ART, irrespective of CD4⁺ T-cell counts or changes in serum ALT levels. The appearance of nAb coincided with control of HCV viral replication in five HIV/HCV patients. In other patients, HCV viral loads remained elevated despite nAb responses. Sustained virological responses following HCV therapy were associated with reduced antibody responses to JFH-1 and core but elevated responses to non-structural proteins. We conclude that nAb responses alone may fail to clear HCV, but contribute to control of viral replication in some HIV/HCV patients responding to ART.

Virologic and immunologic aspects of HIV-hepatitis C virus coinfection

HIV/hepatitis C virus (HCV) coinfection is estimated to affect 2 million individuals globally. The acceleration of HCV-associated complications, particularly hepatic fibrosis, because of HIV coinfection has been well established, whereas the impact of HCV on HIV progression remains unclear. In this review, we summarize the current evidence on the impact of coinfection on the transmission and clinical progression of each infection. We focus on the virological and immunological alterations that contribute to HIV and HCV pathogenesis in coinfection and also review the disease-modifying effects of antiretroviral therapy as they pertain to HCV.

T Cell Distribution in Relation to HIV/HBV/HCV Coinfections and Intravenous Drug Use

Intravenous drug use (IDU) is one of the most important transmission routes for blood borne viruses, including human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). These infections alter the subset distributions of T cells; however, knowledge of such effects during HIV, HBV, and or HCV coinfection is limited. Therefore, we aimed to evaluate any associations between T cell distribution and the presence of HIV, HBV, and HCV coinfections among persons who inject drugs (PWID). Blood samples from 88 Caucasian PWID (mean age 30; 82% male) and 47 age-matched subjects negative for all three infections (mean age of 29; 83% male) were analyzed. The T cell markers CD3, CD4, CD8, CD45RA, CCR7, HLA-DR, and CCR5 were assessed using flow cytometry. Of the PWID, 40% were HIV+HBV+HCV+, 20% HBV+HCV+, 19% HCV+, and 13% negative for all three infections. The HIV+HBV+HCV+ PWID had lower percentages of CD4⁺ and higher percentages of CD8⁺ cells compared to triple negative PWID (p < 0.001 in all cases). The only difference between HBV+HCV+ with triple negative PWID was the lower CD4⁺ cell percentages among the former (52.1% and 58.6%, p = 0.021). Triple negative PWID had higher immune activation and number of CCR5⁺ cells compared to the controls. We suggest that the altered T cell subset distribution among PWID is mainly triggered by HIV infection and or IDU, while HBV and or HCV seropositivity has minimal additional effects on CD4⁺ cell distribution.

Hepatitis C virus infection in patients with HIV-1: epidemiology, natural history and management

Hepatitis C virus (HCV)-related liver diseases have contributed to increased morbidity and mortality in HIV-1-infected individuals in the era of effective antiretroviral therapy. HCV transmission patterns have changed among the HIV co-infected population during the last decade, with acute HCV infection emerging worldwide. HIV infection accelerates the progression of HCV-related liver diseases and consequently cirrhosis, liver failure, and hepatocellular carcinoma. However, the current standard treatment of HCV infection with pegylated interferon plus ribavirin results in only a limited viral response. Furthermore, cumbersome pill regimens, antiretroviral related hepatotoxicity, and drug interactions of HCV and HIV regimens complicate therapy strategies. Fortunately, in the near future, new direct-acting anti-HCV agents will widen therapeutic options for HCV/HIV co-infection. Liver transplantation is also gradually accepted as a therapeutic option for end stage liver disease of HCV/HIV co-infected patients.

Characterization of CD4⁺ T-cell immune activation and interleukin 10 levels among HIV, hepatitis C virus, and HIV/HCV-coinfected patients

BACKGROUND

HIV/hepatitis C virus (HCV)-coinfected patients have accelerated liver disease compared with HCV monoinfection. In HIV-positive patients with viral suppression, data comparing inflammatory cytokines and immune activation between HIV/HCV coinfection with chronic hepatitis C (CHC) to HIV/HCV-seropositive patients with cleared HCV are limited.

METHODS

Fifty-nine age- and sex-matched patients were stratified: (1) HIV monoinfection (n = 15); (2) HCV monoinfection with CHC (n = 15); (3) HIV/HCV coinfection with CHC (n = 14); and (4) HIV/HCV seropositive with cleared HCV (n = 15). All HIV-positive patients had undetectable HIV viremia, and median CD4 was 420 cells per microliter. Liver fibrosis was assessed in each subject using transient elastography. Cells were collected for CD4 and CD8 immune activation (CD38/HLA-DR) markers via flow cytometry and plasma for luminex-multiplex cytokine assays.

RESULTS

CD38⁺HLA-DR⁺ expression on CD4⁺ T cells was significantly increased in HIV/HCV coinfection with CHC (7%) versus HCV monoinfection (4%) (P = 0.012). CD4⁺ total HLA-DR⁺ expression was significantly increased in HIV/HCV coinfection with CHC (43%) versus HIV monoinfection (31%) (P = 0.010) and HIV/HCV seropositive with cleared HCV (38%) (P = 0.046). Total CD4⁺CD38⁺ and CD4⁺CD38⁺HLA-DR⁻ expression was significantly higher in HIV monoinfection (23% and 18%) than HCV moninfection (13%, P = 0.002% and 9%, P = 0.001, respectively). Interleukin 10 levels were significantly lower in HIV monoinfection versus HIV/HCV coinfection with CHC (P = 0.0002). In multivariate analysis, severe fibrosis was associated with lower expression of CD4⁺CD38⁺HLA-DR⁺ and CD4⁺ total CD38⁺ than mild-moderate fibrosis (P = 0.03 and 0.03, respectively).

CONCLUSIONS

CD4 immune activation with HLA-DR⁺ expression in HIV/HCV coinfection with well-controlled HIV may arise from chronic HCV viremia. Conversely, CD4⁺CD38⁺ expression may be driven by underlying HIV infection. CD4 immune activation was unexpectedly found to be associated with decreased liver fibrosis.

Determinants of immunological and virological responses to antiretroviral therapy amongst HIV-infected adults in central Argentina: negative influence of hepatitis C infection

BACKGROUND

The purpose of this study was to update the epidemiological data on the prevalence of coinfection with hepatitis C virus (HCV) and HIV, and to identify whether specific clinical and epidemiological factors influenced the response of HIV-positive adults to highly active antiretroviral therapy (HAART).

METHODS

This retrospective observational cohort study of 238 HIV-infected patients evaluated the effect of different epidemiological and clinical parameters (including HCV coinfection) on therapy response among HIV-infected adults initiating HAART. Multiple logistic regression models were used to identify factors associated with therapy response and estimated risk coefficients.

RESULTS

Seroprevalence of HCV infection in this population was 26% (62/238). We did not observe a significant association between immunological or virological response relating to patient gender or HAART regimen. However, this analysis showed that HCV serological status, age at HIV diagnosis, duration of treatment and WHO clinical stage of AIDS (<200 CD4 cells/ml independently of viral load either < or > to 100,000 copies/ml), were significantly associated with immunological and virological responses to HAART.

CONCLUSIONS

These results show further evidence that hepatitis C serostatus is associated with a reduced response to HAART.

Complementary role of HCV and HIV in T-cell activation and exhaustion in HIV/HCV coinfection

Objectives

To investigate whether T-cell activation and exhaustion is linked to HCV- and HIV disease parameters in HIV/HCV infected individuals, we studied T-cell characteristics in HIV/HCV coinfected patients and controls.

Methods

14 HIV/HCV coinfected, 19 HCV monoinfected, 10 HIV monoinfected patients and 15 healthy controls were included in this cross-sectional study. Differences in expression of activation and exhaustion markers (HLA-DR, CD38, PD-1, Tim-3 and Fas) and phenotypic markers on CD4⁺ and CD8⁺ T-cells were analysed by flow cytometry and were related to HCV disease parameters (HCV-viremia, ALT and liver fibrosis).

Results

Frequencies of activated CD4⁺ and CD8⁺ T-cells were higher in HIV/HCV-coinfected compared to healthy controls and HCV or HIV mono-infected individuals. Coinfected patients also showed high expression of the exhaustion marker PD-1 and death receptor Fas. In contrast, the exhaustion marker Tim-3 was only elevated in HIV-monoinfected patients. T-cell activation and exhaustion were correlated with HCV-RNA, suggesting that viral antigen influences T-cell activation and exhaustion. Interestingly, increased percentages of effector CD8⁺ T-cells were found in patients with severe (F3–F4) liver fibrosis compared to those with no to minimal fibrosis (F0–F2).

Conclusions

HIV/HCV coinfected patients display a high level of T-cell activation and exhaustion in the peripheral blood. Our data suggest that T-cell activation and exhaustion are influenced by the level of HCV viremia. Furthermore, high percentages of cytotoxic/effector CD8⁺ T-cells are associated with liver fibrosis in both HCV monoinfected and HIV/HCV coinfected patients.