Age, sex, and race predict spontaneous hepatitis C virus clearance

Liz Highleyman
Published:
24 October 2014

African-Americans, men, and older people were less likely to experience natural hepatitis C virus (HCV) clearance without treatment, according to findings presented at IDWeek 2014 last week in Philadelphia, United States. Overall, out of more than 1000 people with newly reported HCV infection, 15% spontaneously cleared the virus.

Danica Kuncio and colleagues from the Philadelphia Department of Public Health used clinical and risk factor data from an enhanced surveillance project to assess differences between people with HCV who spontaneously clear their infection and those who are chronically infected (usually considered infection lasting longer than 6 months).

It is generally estimated that 25 to 30% of people with acute HCV infection will spontaneously clear the virus, but this process is not fully understood. Factors previously associated with spontaneous resolution include various genetic factors, non-black race, and female sex, the researchers noted as background.

In this study, surveillance data collected between January 1, 2013 and September 30, 2014, were used to identify a random sample of people with newly reported hepatitis C. Out of a total of 1064 people investigated, 808 received HCV RNA tests; within the latter group, 232 (29%) were treated for hepatitis C and 576 remained untreated. People with chronic hepatitis C, as indicated by positive HCV antibody and positive HCV RNA tests, were compared to those who spontaneously cleared infection, as indicated by having a previous positive HCV antibody or HCV RNA test but current negative HCV RNA test in the absence of treatment.

The researchers compared demographics and risk factors including injecting drugs, needle-stick injuries, receiving a blood transfusion or organ donation, undergoing kidney dialysis, having tattoos, history of incarceration, high number of lifetime sexual partners, being a man who has sex with men, living outside the US for more than six months, serving in the military, having an HCV-positive mother, or having known risky contact with someone who is HCV positive.

Results

Out of 576 untreated people with reported hepatitis C, 89 (15%) had resolved infection with negative HCV RNA, while the remaining 487 developed chronic infection.

People who developed chronic infection were significantly more likely to be male, more likely to be black (versus white or Asian), and were younger than those who spontaneously cleared HCV.

People with chronic infection were more likely than those who cleared HCV to have risk factors including injection drug use, sexual risk, and incarceration, but healthcare-related risk factors did not differ.

People with spontaneous HCV clearance and chronic infection were equally likely to be in care and to have insurance.

"Study findings are consistent with previous studies showing that African-Americans and males are less likely to spontaneously clear HCV infection," the researchers concluded. "The association between high-risk behaviours and reduced HCV clearance may be explained by reinfection from recurrent exposure to different viral strains among groups with elevated rates of HCV disease," they suggested.

"By defining the mechanisms underlying viral control, it may be possible to utilize robust surveillance data to target individuals for treatment and/or care using risk and demographic indicators," they added. "Ensuring that [HCV] RNA+ individuals are linked to care for monitoring and treatment evaluation is essential to prevent the long term effects of HCV infection, especially now that effective medications exist."

Reference

Kuncio D, Hueber A, Viner K, and Newbern C Factors associated with spontaneous resolution of HCV infection in untreated individuals. ID Week 2014, Philadelphia, 8-12 October, Abstract 1147.