A New Twist to a Chronic HCV Infection: Occult Hepatitis C

Abstract

Background. The prevalence of occult hepatitis C infection (OCI) in the population of HCV-RNA negative but anti-HCV positive individuals is presently unknown. OCI may be responsible for clinically overt recurrent disease following an apparent sustained viral response (SVR) weeks to years later. Purpose. To review the available current literature regarding OCI, prevalence, pathogenic mechanisms, clinical characteristics, and future directions. Data Sources. Searching MEDLINE, article references, and national and international meeting abstracts for the diagnosis of OCI (1990–2014). Data Synthesis. The long-term followup of individuals with an OCI suggests that the infection can be transient with the loss of detectable HCV-RNA in PPBMCs after 12–18 months or alternatively exist intermittently and potentially long term. The ultimate outcome of HCV infection is decided by interplay between host immune responses, antiviral therapies, and the various well-identified viral evasion mechanisms as well as the presence of HCV infection within extrahepatic tissues. Conclusion. The currently widely held assumption of a HCV-cure in individuals having had “SVR” after 8–12 weeks of a course of DAA therapy as recently defined may not be entirely valid. Careful longitudinal followup utilizing highly sensitive assays and unique approaches to viral isolation are needed.

Effect of Hepatitis C virus proteins on the production of proinflammatory and profibrotic cytokines in Huh7.5 human hepatoma cells

“…Our findings provide further insight into the mechanisms of virus pathogenesis and may be used to design DAA-based therapeutic regimens because current treatments, including combinations of two DAAs, are still not fully successful, especially at advanced chronic stages with fibrosis [32]. Moreover, the virus can persist in liver and blood cells even in cured patients with HCV RNA undetectable in the peripheral blood and normal liver enzyme tests [33], and risk of fibrosis, cirrhosis, and liver cancer remains high [34]. A current trend in treating virus diseases is identifying cell targets for therapy and designing drugs to block virus replication.…”

Host genetic factors and clinical parameters influencing the occult hepatitis C virus infection in patients on chronic hemodialysis: Is it still a controversial infection?

“…Numerous reports indicated that the unfavorable IFNL3 and IFNL4 genotypes are associated with reduced response to pegIFN‐α/RBV therapy and augmented the frequency of HCV infection in PBMCs . The impact of IFNL3 rs12979860 genotypes on OCI is controversial.…”

“…The HCV genome is identified by liver biopsy using tissue samples or PBMCs (in 70% of cases) in patients with undetectable HCV genome in serum, representing the gold standard to identify OCI …”

Prevalence of Occult Hepatitis C Virus Infection among Blood Donors in Jiangsu, China

“…Traditionally, HCV detected in serum or plasma is clinical therapy evidence, but as more and more OCI issues are being discussed, the concern of clinical relevance and influence on the patients has become of great importance [27]. In a follow-up study of people undergoing phlebotomy therapy [28], 6 subjects with OCI were monitored, with only 2 showing detectable HCV infection in PBMCs at 11 and 13 months of follow-up, demonstrating a persistent infection.…”