Treatment of HCV with direct-acting antivirals on reducing mortality related to extrahepatic manifestations: a large population-based study in British Columbia, Canada

Background

HCV infection is associated with mortality due to extrahepatic manifestations (EHM). Sustained virologic response (SVR) following direct-acting antiviral (DAA) therapy has been linked to decreased all-cause and liver-related mortality. However, evidence regarding the impact of DAA on EHM-related deaths is lacking. This study aimed to assess the impact of DAA and SVR on EHM-related mortality.

Methods

The British Columbia Hepatitis Testers Cohort comprises ∼1.7 million people tested for HCV between 1990 and 2015 and is linked with administrative health data. Among individuals diagnosed with HCV by 12/31/2020, those who received at least one DAA treatment were matched to those who never received treatment by the year of their first HCV RNA positive date. We compared three groups: treated & SVR, treated & no-SVR, and untreated; and generated EHM mortality rates and incidence curves. To account for differences in baseline characteristics, we used inverse probability of treatment weights (IPTW). IPTW-weighted multivariable cause-specific Cox regression models were adjusted for competing risk and confounders.

Findings

Study population included 12,815 treated (12,287 SVR, 528 no-SVR) and 12,815 untreated individuals (median follow-up 3.4 years, IQR 2.9). The untreated group had the highest EHM mortality rate (30.9 per 1000 person-years [PY], 95% CI 29.2-32.8), followed by the treated & no-SVR group (21.2 per 1000 PY, 95% CI 14.9-30.1), while the treated & SVR group had the lowest EHM mortality rate (7.9 per 1000 PY, 95% CI 7.1-8.7). In the multivariable model, EHM mortality in the treated & SVR group was significantly decreased (adjusted cause-specific hazard ratio [acsHR] 0.20, 95% CI 0.18-0.23). The treated & SVR group had significant reductions in mortality related to each of the EHMs (78-84%).

Interpretation

Treatment of HCV with DAA was associated with significant reductions in EHM-related mortality. These findings emphasize the critical importance of timely diagnosis and treatment of HCV to prevent deaths associated with EHM, and have important implications for clinical practice and public health.

Funding

This work was supported by the BC Centre for Disease Control and the Canadian Institutes of Health Research (CIHR) [Grant # NHC-348216, PJT-156066, and PHE-337680]. DJ has received Doctoral Research Award (#201910DF1-435705-64343) from the Canadian Institutes of Health Research (CIHR) and Doctoral fellowship from the Canadian Network on Hepatitis C (CanHepC). CanHepC is funded by a joint initiative of the Canadian Institutes of Health Research (CIHR) (NHC-142832) and the Public Health Agency of Canada (PHAC).

Chronic hepatitis C infection is associated with higher incidence of extrahepatic cancers in a Canadian population based cohort

INTRODUCTION

Chronic infection with hepatitis C virus (HCV) is an established risk factor for liver cancer. Although several epidemiologic studies have evaluated the risk of extrahepatic malignancies among people living with HCV, due to various study limitations, results have been heterogeneous.

METHODS

We used data from the British Columbia Hepatitis Testers Cohort (BC-HTC), which includes all individuals tested for HCV in the Province since 1990. We assessed hepatic and extrahepatic cancer incidence using data from BC Cancer Registry. Standardized incidence ratios (SIR) comparing to the general population of BC were calculated for each cancer site from 1990 to 2016.

RESULTS

In total, 56,823 and 1,207,357 individuals tested positive and negative for HCV, respectively. Median age at cancer diagnosis among people with and without HCV infection was 59 (interquartile range (IQR): 53-65) and 63 years (IQR: 54-74), respectively. As compared to people living without HCV, a greater proportion of people living with HCV-infection were men (66.7% vs. 44.7%, P-value <0.0001), had comorbidities (25.0% vs. 16.3%, P-value <0.0001) and were socially deprived (35.9% vs. 25.0%, P-value <0.0001). The SIRs for liver (SIR 33.09; 95% CI 29.80-36.39), anal (SIR: 2.57; 95% CI 1.52-3.63), oesophagus (SIR: 2.00; 95% CI 1.17-2.82), larynx (SIR: 3.24; 95% CI 1.21-5.27), lung (SIR: 2.20; 95% CI 1.82-2.58), and oral (SIR: 1.78; 95% CI 1.33-2.23) cancers were significantly higher among individuals living with HCV. The SIRs for bile duct and pancreatic cancers were significantly elevated among both individuals living with (SIR; 95% CI: 2.20; 1.27-3.14; 2.18; 1.57-2.79, respectively) and without HCV (SIR; 95% CI: 2.12; 1.88-2.36; 1.20; 1.11-1.28, respectively).

DISCUSSION/CONCLUSION

In this study, HCV infection was associated with increased incidence of several extrahepatic cancers. The elevated incidence of multiple cancers among negative HCV testers highlights the potential contributions of screening bias and increased cancer risks associated with factors driving acquisition of infection among this population compared to the general population. Early HCV diagnosis and treatment as well as public health prevention strategies are needed to reduce the risk of extrahepatic cancers among people living with HCV and potentially populations who are at higher risk of HCV infection.

Impact of HCV infection and ethnicity on incident type 2 diabetes: findings from a large population-based cohort in British Columbia

INTRODUCTION

Increasing evidence indicates that chronic hepatitis C virus (HCV) infection is associated with higher risk of diabetes. Previous studies showed ethnic disparities in the disease burden of diabetes, with increased risk in Asian population. We described the incidence of type 2 diabetes related to HCV infection and assessed the concurrent impact of HCV infection and ethnicity on the risk of diabetes.

RESEARCH DESIGN AND METHODS

In British Columbia Hepatitis Testers Cohort, individuals were followed from HCV diagnosis to the earliest of (1) incident type 2 diabetes, (2) death or (3) end of the study (December 31, 2015). Study population included 847 021 people. Diabetes incidence rates in people with and without HCV were computed. Propensity scores (PS) analysis was used to assess the impact of HCV infection on newly acquired diabetes. PS-matched dataset included 117 184 people. We used Fine and Gray multivariable subdistributional hazards models to assess the effect of HCV and ethnicity on diabetes while adjusting for confounders and competing risks.

RESULTS

Diabetes incidence rates were higher among people with HCV infection than those without. The highest diabetes incidence rate was in South Asians with HCV (14.7/1000 person-years, 95% CI 12.87 to 16.78). Compared with Others, South Asians with and without HCV and East Asians with HCV had a greater risk of diabetes. In the multivariable stratified analysis, HCV infection was associated with increased diabetes risk in all subgroups: East Asians, adjusted HR (aHR) 3.07 (95% CI 2.43 to 3.88); South Asians, aHR 2.62 (95% CI 2.10 to 3.26); and Others, aHR 2.28 (95% CI 2.15 to 2.42).

CONCLUSIONS

In a large population-based linked administrative health data, HCV infection was associated with higher diabetes risk, with a greater relative impact in East Asians. South Asians had the highest risk of diabetes. These findings highlight the need for care and screening for HCV-related chronic diseases such as type 2 diabetes among people affected by HCV.

Sustained virological response from interferon-based hepatitis C regimens is associated with reduced risk of extrahepatic manifestations

BACKGROUND & AIMS

HCV infection is associated with several extrahepatic manifestations (EHMs). We evaluated the impact of sustained virological response (SVR) on the risk of 7 EHMs that contribute to the burden of extrahepatic disease: type 2 diabetes mellitus, chronic kidney disease or end-stage renal disease, stroke, ischemic heart disease, major adverse cardiac events, mood and anxiety disorders, and rheumatoid arthritis.

METHODS

A longitudinal cohort study was conducted using data from the British Columbia Hepatitis Testers Cohort, which included ~1.3 million individuals screened for HCV. We identified all HCV-infected individuals who were treated with interferon-based therapies between 1999 and 2014. SVR was defined as a negative HCV RNA test ≥24 weeks post-treatment or after end-of-treatment, if unavailable. We computed adjusted subdistribution hazard ratios (asHR) for the effect of SVR on each EHM using competing risk proportional hazard models. Subgroup analyses by birth cohort, sex, injection drug exposure and genotype were also performed.

RESULTS

Overall, 10,264 HCV-infected individuals were treated with interferon, of whom 6,023 (59%) achieved SVR. Compared to those that failed treatment, EHM risk was significantly reduced among patients with SVR for type 2 diabetes mellitus (asHR 0.65; 95%CI 0.55-0.77), chronic kidney disease or end-stage renal disease (asHR 0.53; 95% CI 0.43-0.65), ischemic or hemorrhagic stroke (asHR 0.73; 95%CI 0.49-1.09), and mood and anxiety disorders (asHR 0.82; 95%CI 0.71-0.95), but not for ischemic heart disease (asHR 1.23; 95%CI 1.03-1.47), major adverse cardiac events (asHR 0.93; 95%CI 0.79-1.11) or rheumatoid arthritis (asHR 1.09; 95% CI 0.73-1.64).

CONCLUSIONS

SVR was associated with a reduction in the risk of several EHMs. Increased uptake of antiviral therapy may reduce the growing burden of EHMs in this population.

LAY SUMMARY

We estimated the rates of chronic comorbidities other than liver disease between those who were cured and those who failed treatment for hepatitis C virus (HCV) infection. Our findings showed that the rates of these non-liver diseases were largely reduced for those who were cured with interferon-based treatments. Early HCV treatments could provide many benefits in the prevention of various HCV complications beyond liver disease.

Occupational tuberculosis in South Africa: are health care workers adequately protected?

Setting: A provincial tertiary hospital in Gauteng province, South Africa, with a high burden of tuberculosis (TB) patients and high risk of TB exposure among health care workers (HCWs). Objective: To determine HCWs' adherence to recommended TB infection prevention and control practices, TB training and access to health services and HCW TB rates. Design: Interviews with 285 HCWs using a structured questionnaire as part of a large, international mixed-methods study. Results: Despite 10 HCWs (including seven support HCWs) acquiring clinical TB during their period of employment, 62.8% of interviewees were unaware of the hospital's TB management protocol. Receipt of training was low (34.5% of all HCWs and <5% of support HCWs trained on TB transmission; 27.5% of nurses trained on respirator use), as was use of respiratory protection (44.5% of HCWs trained on managing TB patients). Support HCWs were over 36 times more likely to use respiratory protection if trained; nurses who were trained were approximately 40 times more likely to use respirators if they were readily available. Conclusion: Improved coordination and uptake of TB infection prevention training is urgently needed, especially for non-clinical HCWs in settings of regular exposure to TB patients. Adequate supplies of appropriate respiratory protection must be made available.