Hepatitis C virus (HCV) is one of the more common causes of chronic liver disease in world with a variety of extrahepatic complications such as essential mixed cryoglobulinemia, membranoproliferative glomerulonep hritis, autoimmune thyroiditis, sialadenitis, and cardiomyopathy. IPF is present in patients with chronic HCV infection. However, there is little or no information on the yearly cumulative incidence and risk factors on the development rate of IPF in patients with HCV.
A research team led by Yasuji Arase from Toranomon Hospital of Japan addresses this question and this will be published on October 14, 2008 in the World Journal of Gastroenterology. In this study, they studied 6150 HCV infected patients who were between 40-70 years old (HCV-group). Another 2050 patients with hepatitis B virus (HBV) were selected as control (HBV-group). The mean observation period was 8.0 ± 5.9 years in HCV-group and 6.3 ± 5.5 years in HBV-group.
They found that fifteen patients in HCV-group developed IPF. On the other hand, none of the patients developed IPF in HBV-group. In HCV-group, the cumulative rates of IPF development were 0.3% at 10th year and 0.9% at 20th year. The IPF development rate in HCV-group was higher than that in HBV-group (P = 0.021). The IPF development rate in patients with HCV or HBV was high with statistical significance in the following cases: (1) patients ≥ 55 years (P < 0.001); (2) patients who had smoking index (package per day × year) of ≥ 20 (P = 0.002); (3) patients with liver cirrhosis (P = 0.042). This result indicated that age, liver cirrhosis and smoking enhance the development of IPF in patients with chronic hepatitis C infection.