Recent data published in the Journal of Hepatology showed spontaneous clearance of hepatitis C virus infection is rare; however, it was more common in women and individuals who had low level viremia.
“This is the largest cohort of patients with evidence of spontaneous clearance of chronic HCV infection studied to date,” Naomi Bulteel, MD, clinical research fellow, Medical Research Council, University of Glasgow Centre for Virus Research, U.K., and colleagues wrote. “We have demonstrated that spontaneous clearance of [chronic HCV] is rare. … A proportion of cases occurred in the context of significant intercurrent illness and hepatic decompensation.”
The researchers conducted a retrospective case-control study using data obtained from patients enrolled in a large Scottish cohort between 1994 and 2013 in the west of Scotland. Case patients were defined as untreated patients with more than two sequential samples positive for HCV RNA more than 6 months apart followed by more than one negative test, and deemed to have spontaneously cleared chronic HCV. These patients were then compared with controls who had more than two positive samples more than 6 months apart with no subsequent negative samples.
Researchers were able to identify 50 cases of late spontaneous clearance HCV, contributing 241 person-years follow-up. Two hundred chronically HCV infected patients were included for the control group.
The overall incidence density rate for spontaneous clearance in the untreated group was 0.36 per 100 person-years follow-up. The incidence rate was 0.19 per 100 person-years follow-up when analysis was restricted to only patients with spontaneous clearance.
Spontaneous clearance of HCV occurred after a median infection time of 50 months. Patients who spontaneously cleared were more likely to be female (P = .001) and diagnosed at a younger age (28.5 vs. 33 years; P = .022).
HCV RNA levels were lower in patients who had cleared compared with controls (P < .001). However, clearance was found in seven patients who had viremia more than 100,000 IU/mL.
Spontaneous clearance of HCV was found to be associated with female sex, younger age at infection, lower HCV RNA load and coinfection with hepatitis B virus infection. Spontaneous clearance of HCV was not associated with current IV drug use.
“Given that such clearance may occur after a prolonged duration of infection, more regular serum HCV RNA monitoring may be warranted, particularly in females, patients coinfected with HBV, patients with low level viremia and those with decompensated liver disease,” the researchers concluded. – by Melinda Stevens
Disclosure: The researchers report no relevant financial disclosures.