Spotlight on hepatitis A, B, and C

The past month's gastroenterology research may not have been simple as ABC, but it did focus on the major types of hepatitis, including a hepatitis A outbreak, a comparison of hepatitis B drugs, and new data on hepatitis C complications and incidence.

Hepatitis has been in the news this month, with public health officials and researchers focusing on hepatitis A, B, and C.

First, the CDC requested assistance from clinicians in regard to hepatitis A outbreaks spread through person-to-person contact in the U.S. The outbreaks are occurring primarily among people who use drugs, people experiencing homelessness, and men who have sex with men. Although hepatitis A infection is typically self-limited, morbidity and mortality in the current outbreaks are higher than normally reported. As of Oct. 18, there have been 27,282 cases, 16,451 hospitalizations (60% of cases), and 274 deaths reported in 30 states since the outbreaks were first identified in August 2016.

Health care visits represent an ideal opportunity to vaccinate people at highest risk of hepatitis A infection, which include those previously mentioned as well as those currently or recently incarcerated and those with chronic liver disease (including cirrhosis, hepatitis B, and hepatitis C), the CDC said. One dose of single-antigen hepatitis A vaccine can help control outbreaks and provides up to 95% seroprotection in healthy individuals for up to 11 years. Prevaccination serologic testing is not required to administer the vaccine, and vaccinations should not be postponed if vaccination history cannot be obtained or records are unavailable, the agency said.

Second, a retrospective cohort study found no differences in hepatocellular carcinoma (HCC) prevention between two hepatitis B antivirals, tenofovir disoproxil fumarate and entecavir. Using an international consortium of previously treated patients with chronic hepatitis B who were then treated with either entecavir (n=4,837) or tenofovir (n=700) monotherapy, researchers assessed the association between antiviral regimen and HCC risk. Patients were observed for HCC occurrence for up to five years. Results were published online on Oct. 11 by the American Journal of Gastroenterology.

Patients who started tenofovir were significantly younger and less sick than those who started entecavir. However, while tenofovir was associated with a lower risk of HCC in the unadjusted analysis, the multivariable analysis found that the association was no longer significant. In addition, a propensity score-matched analysis of 1,040 patients found no difference in HCC incidence between the groups. Thus, the drugs may be considered similarly effective in the prevention of HCC, the study authors concluded. The study was limited by a lack of long-term follow-up in the tenofovir group, as few patients continued to be at risk and observed beyond five years.

In the third study, researchers compared survival rates of hepatitis C virus (HCV)-related HCC between patients who were untreated for HCV and those who achieved sustained virologic response with interferon-free direct-acting antivirals. They used data from two U.S. and six Asian centers from 2005 to 2017 to categorize 1,676 patients with HCV-related HCC (untreated, n=1,239; sustained virologic response, n=437). All patients received palliative or curative HCC treatment, and the mean age was 66 years. Results were published online on Oct. 14 by Hepatology.

After propensity score matching 321 pairs of patients and applying time-varying adjustment for HCV treatment initiation, patients who achieved sustained virologic response had higher five-year overall survival compared to untreated patients (87.78% vs. 66.05%; P<0.001). Sustained virologic response was independently associated with a 63% lower risk of five-year all-cause mortality (hazard ratio, 0.37; 95% CI, 0.16 to 0.83; P=0.016) and a 66% lower risk of five-year liver-related mortality (hazard ratio, 0.34; 95% CI, 0.13 to 0.88; P=0.026), with similar trends when liver-transplant patients were excluded.

Interferon-free direct-acting antiviral treatment should not be withheld from HCC patients who are eligible for HCC therapies, “since the improved survival benefit of HCV treatment may outweigh the cost of care factor,” the study authors concluded. They noted that more research is needed to understand the impact of sustained virologic response in patients with HCV-related HCC who do not receive HCC treatment, who have Child-Pugh class C or Barcelona Clinic Liver Cancer above stage A, or who are younger than age 50 years.

Finally, CDC researchers found that rates of HCV infection at delivery hospitalization among women giving birth in the U.S. was about five times higher in 2015 than it was in 2000 (4.1 vs. 0.8 per 1,000 live births), according to results published in the Oct. 4 Morbidity and Mortality Weekly Report. Increases were even higher among women with opioid use disorder. From 2000 to 2015, the rate of HCV infection among women with opioid use disorder increased from 87.4 to 216.9 per 1,000 live births, compared to 0.7 to 2.6 per 1,000 live births among women without opioid use disorder. “Treatment of opioid use disorder should include screening and referral for related conditions such as HCV infection,” the authors concluded.