Mette Rye Clausen

Historical epidemiology of hepatitis C virus (HCV) in selected countries

Chronic infection with hepatitis C virus (HCV) is a leading indicator for liver disease. New treatment options are becoming available, and there is a need to characterize the epidemiology and disease burden of HCV. Data for prevalence, viremia, genotype, diagnosis and treatment were obtained through literature searches and expert consensus for 16 countries. For some countries, data from centralized registries were used to estimate diagnosis and treatment rates. Data for the number of liver transplants and the proportion attributable to HCV were obtained from centralized databases. Viremic prevalence estimates varied widely between countries, ranging from 0.3% in Austria, England and Germany to 8.5% in Egypt. The largest viremic populations were in Egypt, with 6 358 000 cases in 2008 and Brazil with 2 106 000 cases in 2007. The age distribution of cases differed between countries. In most countries, prevalence rates were higher among males, reflecting higher rates of injection drug use. Diagnosis, treatment and transplant levels also differed considerably between countries. Reliable estimates characterizing HCV‐infected populations are critical for addressing HCV‐related morbidity and mortality. There is a need to quantify the burden of chronic HCV infection at the national level.

Strategies to manage hepatitis C virus (HCV) disease burden

The number of hepatitis C virus (HCV) infections is projected to decline while those with advanced liver disease will increase. A modeling approach was used to forecast two treatment scenarios: (i) the impact of increased treatment efficacy while keeping the number of treated patients constant and (ii) increasing efficacy and treatment rate. This analysis suggests that successful diagnosis and treatment of a small proportion of patients can contribute significantly to the reduction of disease burden in the countries studied. The largest reduction in HCV‐related morbidity and mortality occurs when increased treatment is combined with higher efficacy therapies, generally in combination with increased diagnosis. With a treatment rate of approximately 10%, this analysis suggests it is possible to achieve elimination of HCV (defined as a >90% decline in total infections by 2030). However, for most countries presented, this will require a 3–5 fold increase in diagnosis and/or treatment. Thus, building the public health and clinical provider capacity for improved diagnosis and treatment will be critical.

CD4+ and CD8+ Regulatory T Cells (Tregs) are Elevated and Display an Active Phenotype in Patients with Chronic HCV Mono‐Infection and HIV/HCV Co‐Infection

The aim of this study was to examine regulatory T cells (Tregs) in peripheral blood and liver tissue in patients with chronic hepatitis C virus (HCV) mono‐infection and in patients with HIV/HCV co‐infection. In a cross‐sectional study were included 51 patients with chronic HCV infection, 24 patients with HIV/HCV co‐infection and 24 healthy individuals. CD4+ and CD8+ Tregs were determined using flow cytometry. Fibrosis was examined by transient elastography. Inflammation, fibrosis and Tregs were determined in liver biopsies from 12 patients. Increased frequency of CD4+ and CD8+ Tregs was found in HIV/HCV co‐infected patients [median: 6.4% (IQR: 5.7–6.9) and 1.0% (0.7–1.2), respectively] compared to HCV mono‐infected patients [5.6% (4.2–6.3), P = 0.01 and 0.5% (0.3–0.7), P < 0.001, respectively]. Furthermore, HCV mono‐infected patients had increased frequencies of Tregs compared with healthy controls (P < 0.05). However, no associations between the frequency of Tregs and fibrosis were found. Furthermore, characterization of CD4+ Tregs using CD45RA demonstrated a higher frequency of activated Tregs in both HCV mono‐infected and HIV/HCV co‐infected patients compared with healthy controls. Finally, number of intrahepatic Tregs was associated with both peripheral CD8+ Tregs and intrahepatic inflammation. In conclusion, HCV mono‐infected patients and particularly HIV/HCV co‐infected patients have increased the frequency of CD4+ and CD8+ Tregs compared with healthy controls. Furthermore, CD4+ Tregs in infected patients displayed an active phenotype. Tregs were not associated with fibrosis, but a positive correlation between intrahepatic Tregs and inflammation was found. Taken together, these results suggest a role for Tregs in the pathogenesis of chronic HCV infection.

Predictors of antiviral treatment initiation in hepatitis C virus‐infected patients: a Danish cohort study

Summary.  Predictive factors for initiation of antiviral therapy in chronically infected hepatitis C virus (HCV) patients are not fully elucidated. The aim of this study was to determine predictive factors for initiation of treatment with standard or pegylated interferon either alone or combined with ribavirin. A Danish cohort of individuals chronically infected with HCV was used and observation time was calculated from the date of inclusion in the cohort to date of death, last clinical observation, 1 January 2007, or start of HCV antiviral treatment in treatment‐naïve patients. Kaplan–Meier survival analysis was used to construct time to event curves. Cox regression was used to determine the incidence rate ratios as estimates of relative risk (RR) and 95% confidence intervals (CI). A total of 1780 patients were enrolled in the study. The cumulative chance of treatment initiation over 5 years was 33.0%. We found several strong predictors of treatment initiation: elevated alanine aminotransferase [>2 times upper limit (RR = 2.17, 95% CI 1.64–2.87), >3 times upper limit (RR = 3.64, 95% CI 2.75–4.81)], genotype 2 or 3 (RR = 1.86, 95% CI 1.49–2.31) and HIV co‐infection (RR = 0.28, 95% CI 0.15–0.53). To our knowledge, this study is the first to estimate factors predicting initiation of antiviral treatment in patients with chronic HCV infection on a nationwide scale. We found that several of the factors predicting initiation of antiviral treatment correlate with factors known to predict a better response to treatment and factors known to increase the progression of liver disease.

Impaired thymic output in patients with chronic hepatitis C virus infection.

Altered T cell homeostasis in chronic hepatitis C virus (HCV) infection has been demonstrated. However, it is unknown whether fibrosis is associated with more perturbed T cell homeostasis in chronic HCV infection. The aim of this study was to examine and compare T cell subsets including recent thymic emigrants (RTE), naive, memory, senescent, apoptotic and IL‐7 receptor α (CD127) expressing CD4+ and CD8+ T cells as well as telomere length and interferon‐γ production in HCV‐infected patients with (n = 25) and without (n = 26) fibrosis as well as in healthy controls (n = 24). Decreased proportions of CD4+ and CD8+ RTE were found in HCV‐infected patients, especially in HCV‐infected patients with fibrosis (14.3% (9.7–23.0) and 28.8% (16.1–40.5), respectively) compared with healthy controls (24.2% (16.3–32.1), P = 0.004 and 39.1% (31.6–55.0), P = 0.010, respectively). Furthermore, HCV‐infected patients with fibrosis presented with a higher proportion of CD4+ T cells expressing CD127 compared with HCV‐infected patients without fibrosis [88.4% (84.5–91.0) versus 83.8% (79.9–86.8), P = 0.016]. Thus, impaired thymic output in HCV infection was found, and high proportion of CD127+ T cells may illustrate a compensatory mechanism to preserve T cell counts.

Vertical transmission of hepatitis B virus during pregnancy and delivery in Denmark

Abstract Objective: In Denmark, pregnant women have been screened for hepatitis B virus (HBV) since 2005, and children born to HBV-infected mothers offered hepatitis B immunoglobulin at birth, vaccination against HBV at birth and after 1, 2 and 12 months. The purpose of this study was to determine the risk of vertical HBV transmission in children born to mothers with chronic HBV infection, to investigate the antibody response in the children and to investigate possible maternal predictive risk factors for HBV transmission. Materials and methods: Through the Danish Database for Hepatitis B and C, we identified 589 HBV-infected women who had given birth to 686 children, of whom 370 children were born to 322 women referred to hospital. 132 (36%) children, born to 109 mothers, were included in the study; 128 children had blood samples tested for HBsAg, anti-HBc (total), anti-HBs and HBV-DNA and four children had saliva samples tested for anti-HBc. Results: We found vertical HBV transmission in Denmark to be 2.3% [95% CI: 0.5, 6.5], a high proportion of HBsAg-negative children with low levels of anti-HBs (18.4%) and a high proportion (15.2%) with resolved HBV infection. No maternal risk factor was statistically significantly associated with HBV vertical transmission. Conclusion: In a HBV low prevalence setting as Denmark, despite a national vaccination program, vertical HBV transmission occurred in 2.3% of children born to HBV-infected mothers. In addition, a high proportion of the children had insufficient anti-HBs levels and a high proportion had serological signs of resolved HBV infection.

Mortality in patients with Chronic Hepatitis C and cirrhosis compared to the general population: a Danish cohort study

Background Knowledge of mortality in patients with Chronic Hepatitis C (CHC) with cirrhosis is limited. This study aimed to estimate all-cause mortality among CHC patients with and without cirrhosis in Denmark compared to the general population. Methods Patients registered in The Danish Database for Hepatitis B and C with CHC and a liver fibrosis assessment were eligible for inclusion. Liver fibrosis was based on liver biopsy, transient elastography, and clinical cirrhosis. Up to 20 sex- and age-matched individuals per patient were identified in the general population. Data were extracted from nationwide registries. Results 3,410 CHC patients (1,014 with cirrhosis), and 67,315 matched individuals were included. Adjusted mortality rate ratios (MRR) between patients with and without cirrhosis and their comparison cohorts were 5.64 [CI95% 4.76; 6.67] and 1.94 [1.55; 2.42], respectively. Cirrhosis among patients was associated with a MRR of 4.03 [3.43; 4.72]. A cure for CHC was associated with a MRR of 0.64 [0.40; 1.01] among cirrhotic patients and 2.33 [1.47; 3.67] compared to the general population. Conclusions Mortality was high among CHC patients with and without cirrhosis compared to the general population. Curing CHC was associated with reduced mortality among cirrhotic patients but remained higher than the general population.

Impaired Platelet Aggregation and Rebalanced Hemostasis in Patients with Chronic Hepatitis C Virus Infection

Increased risk of both cardiovascular disease (CVD) and bleeding has been found in patients with chronic hepatitis C (CHC) infection, and a re-balanced hemostasis has been proposed. The aim of this study was to investigate functional whole blood coagulation and platelet function in CHC infection. The prospective study included 82 patients with CHC infection (39 with advanced liver fibrosis and 43 with no or mild liver fibrosis) and 39 healthy controls. A total of 33 patients were treated for CHC infection and achieved sustained virological response (SVR). Baseline and post-treatment blood samples were collected. Hemostasis was assessed by both standard coagulation tests and functional whole blood hemostatic assays (thromboelastograhy (TEG), and platelet aggregation (Multiplate). Patients with CHC and advanced fibrosis had impaired platelet aggregation both compared to patients with no or mild fibrosis and to healthy controls. Patients with CHC and advanced fibrosis also had lower antithrombin, platelet count, and coagulation factors II-VII-X compared to healthy controls. In contrast, TEG did not differ between groups. In treated patients achieving SVR, post-treatment platelet count was higher than pre-treatment counts (p = 0.033) and ADPtest, ASPItest, and RISTOhightest all increased post treatment (all p < 0.05). All Multiplate tests values, however, remained below those in the healthy controls. CHC-infected patients displayed evidence of rebalanced hemostasis with only partly hemostatic normalization in patients achieving SVR. The implications of rebalanced hemostasis and especially the impact on risk of CVD and bleeding warrants further studies.

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

Direct‐acting antiviral has replaced pegylated interferon‐α and ribavirin‐based treatment in the treatment of chronic hepatitis C virus (HCV) infection. While interferon‐α is immune modulating and causes lymphopenia, interferon‐free regimens seem to be well‐tolerated. This study aimed to compare T‐cell homeostasis before, during, and after HCV treatment with or without interferon‐α in patients with chronic HCV infection. A total of 20 patients with chronic HCV infection were treated with pegylated interferon‐α and ribavirin, and six patients were treated with an interferon‐free regimen. All patients were treated for a minimum of 12 weeks. Interferon‐α treatment caused an increase in the density of the receptor for IL‐7 (IL‐7Rα) during treatment, while interferon‐free regimens caused a decrease in IL‐7Rα density. After a sustained viral response, proportions of IL‐7Rα+ T cells and IL‐7Rα density decreased compared to prior treatment values. Finally, a proportion of CD8+ effector memory was lower while proportion of apoptotic T cells was higher after sustained virologic response compared to prior treatment. Despite lymphopenia during interferon, alterations in T‐cell homeostasis during treatment were relatively similar in patients receiving interferon‐based treatment and in patients receiving interferon‐free treatment, and alterations during and after treatment seem to illustrate a reduced need for high levels of T cells aimed at controlling infection.

Genetic Variants in the Apoptosis Gene BCL2L1 Improve Response to Interferon-Based Treatment of Hepatitis C Virus Genotype 3 Infection

Genetic variation upstream of the apoptosis pathway has been associated with outcome of hepatitis C virus (HCV) infection. We investigated genetic polymorphisms in the intrinsic apoptosis pathway to assess their influence on sustained virological response (SVR) to pegylated interferon-α and ribavirin (pegIFN/RBV) treatment of HCV genotypes 1 and 3 infections. We conducted a candidate gene association study in a prospective cohort of 201 chronic HCV-infected individuals undergoing treatment with pegIFN/RBV. Differences between groups were compared in logistic regression adjusted for age, HCV viral load and interleukin 28B genotypes. Four single nucleotide polymorphisms (SNPs) located in the B-cell lymphoma 2-like 1 (BCL2L1) gene were significantly associated with SVR. SVR rates were significantly higher for carriers of the beneficial rs1484994 CC genotypes. In multivariate logistic regression, the rs1484994 SNP combined CC + TC genotypes were associated with a 3.4 higher odds ratio (OR) in SVR for the HCV genotype 3 (p = 0.02). The effect estimate was similar for genotype 1, but the association did not reach statistical significance. In conclusion, anti-apoptotic SNPs in the BCL2L1 gene were predictive of SVR to pegIFN/RBV treatment in HCV genotypes 1 and 3 infected individuals. These SNPs may be used in prediction of SVR, but further studies are needed.