Background/aims: The aim of this study was to evaluate the impact of the host immune status and of virological and environmental parameters on the development of cirrhosis during chronic hepatitis C virus infection.
Methods: Liver histology (cirrhosis or not, Knodell score) was evaluated according to age, sex, route and age of contamination, alcohol consumption and immune status in a large series of 553 HBsAg-negative patients (whose duration of hepatitis C virus infection could be precisely evaluated) divided into three groups: group 1 consisted of 462 immunocompetent subjects (46.1% intravenous drug users, 53.9% transfused), infected for a mean of 12.5+/-6.7 years, including 16.6% of alcohol abusers (>80 g/day); groups 2a and 2b consisted of 91 immunocompromised patients, 52 human immunodeficiency virus-coinfected patients corresponding to group 2a and 39 kidney recipients undergoing immunosuppressive therapy for group 2b, having been infected by hepatitis C virus for a mean of 12.6+/-5.3 and 11.5+/-5.3 years, respectively.
Results: Group 1: cirrhosis was present in 11.0% of group 1 patients and in 23.6% of immunocompetent patients with a duration of hepatitis C virus infection of 20 years or more. Forty-three percent of patients with cirrhosis and with hepatitis C virus infection for more than 20 years were alcohol abusers. The time taken to develop cirrhosis was 14+/-7 years in patients infected before the age of 40 years as compared to 8+/-5 years in those infected after 40 years (p<0.001). Groups 2a and 2b: cirrhosis was present in 19.8% of immunocompromised patients, a significantly higher rate than in immunocompetent patients (p<0.01). Alcohol abuse did not increase the risk of cirrhosis in this group. All patients but one were infected by hepatitis C virus before the age of 40 and the calculated time elapsed until the occurrence of cirrhosis was 12.4+/-5.5 years. In groups 1, 2a and 2b, there was no relation between histological severity, hepatitis C virus genotype and viral load. Four variables were independently associated with the occurrence of cirrhosis in the multivariate analysis: age over 40 at time of contamination (RR=9.3 in age range 40 to 59 and 91.2 in > or =60 years); long duration (> or =20 years) of hepatitis C virus infection (RR=15.4); alcohol consumption over 80 g/d (RR=2.9); and human immunodeficiency virus-coinfection (RR=2.6).
Conclusions: Our study on a large series of well-characterized patients provides an accurate evaluation of the risk of cirrhosis in parenterally-contaminated immunocompetent hepatitis C virus-infected patients, with an overall figure of 11%. It also demonstrates the impact of the host immune status on the risk of severe histological lesions during chronic hepatitis C virus infection. It finally establishes the importance of age at the time of viral infection in the occurrence of cirrhosis, as well as the importance of alcohol consumption. Thus, at least following parenteral infection, both host-related and environmental cofactors play a major role in the severity of the liver lesions associated with hepatitis C virus infection.