Comparison Between Occult HCV Infection and Chronic Hepatitis C

By Liz Highleyman

Occult or "hidden" hepatitis C virus (HCV) infection is a term used to describe individuals who have HCV RNA in their livers, but no detectable HCV RNA or anti-HCV antibodies in their blood.

Spanish researchers previously determined that occult HCV was sometimes present in patients with persistently abnormal liver function of unknown cause. In the present study, described in the January 2007 Journal of Viral Hepatitis, the investigators sought to compare the characteristics of 68 patients with occult HCV infection and 69 untreated patients with typical chronic hepatitis C (detectable HCV RNA and anti-HCV antibodies in the blood), matched for sex, age, body mass index, and duration of abnormal liver function tests.

Results

• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were higher in patients with chronic HCV than in those with occult HCV (P < 0.001).

• Chronic HCV patients also had higher levels of gamma-globulin (P = 0.005), iron (P < 0.001), and alpha-fetoprotein, a marker associated with hepatocellular carcinoma (P < 0.001).

• In contrast, cholesterol and triglyceride levels were significantly higher in patients with occult HCV infection (P < 0.001 and 0.002).

• The rate of necro-inflammatory activity and fibrosis was higher among chronic HCV patients (P < 0.001).

• The mean percentage of infected hepatocytes (liver cells) was higher in chronic HCV patients than in those with occult HCV (10.1% vs 5.3%; P = 0.001).

Conclusion

In conclusion, the authors wrote, "[O]ccult HCV infection is a milder disease than chronic HCV, and this could be related to the significantly lower number of infected hepatocytes observed in occult HCV."

02/02/07

Reference
M Pardo, J M Lopez-Alcorocho, E Rodriguez-Inigo, and others. Comparative study between occult hepatitis C virus infection and chronic hepatitis C. Journal of Viral Hepatitis 14(1): 36-40. January 2007.