Hepatitis C and Risk of Progression
If you have been exposed to hepatitis C (HCV), the risk for developing a chronic HCV infection is high. In studies examining disease progression, most people (about 80%) who became infected with HCV remained positive for the virus and developed chronic HCV. Among those who developed a persistent HCV infection, 30% developed stable chronic hepatitis, 40% had variable progression, and the remaining 30% had severe disease progression.1
Several factors, including genetic variations found in individuals, may be associated with increased likelihood that a person will spontaneously clear the HCV virus before it progresses to the chronic infection. One example of a genetic variation that can decrease the chances of progression to chronic disease is a variation in the interleukin-28B (IL28B) gene called the C/C type allele. 1
Factors that may predict HCV disease progression
There are several factors that may predict how quickly HCV will progress in an individual, including ethnic or racial background, age, gender, immune system response, substance use (alcohol, marijuana), whether a person is co-infected with another virus (such as HIV), and other individual and environmental factors. 1
Age. Becoming infected with HCV between the ages of 40 to 55 may be associated with increased severity of liver damage. Children who become infected with HCV appear to have decreased risk of disease progression.
Gender. Men with chronic HCV infection appear to experience more rapid progression of fibrosis than women. After age 50, women progress at about the same rate as men do.
Ethnic and racial differences. Complications of HCV (particularly liver cancer) appear to be more common among people in Japan compared with those in the US. Whether this has to do with differences in HCV genotype, environmental differences, or differences in ethnicity is not clear. African American and Black individuals tend to experience slower progression of HCV and less severe disease compared with Caucasians.
Viral co-infection. Chronic HCV progression is more rapid in individuals co-infected with HIV. In individuals with hepatitis B virus and HCV co-infection, liver disease may progress more quickly than in individuals with HCV alone.
High body-mass index. Individuals with a high body-mass index (≥25) are at increased risk of developing fibrosis. Additionally, having fatty liver disease (hepatic steatosis), a condition more common among people who are overweight, also increases risk for developing fibrosis.
Coffee consumption. Multiple studies have found that consumption of caffeinated coffee on a regular basis is associated with reduced formation of fibrosis and decreased risk of liver cancer.
Alcohol intake and HCV progression. Results from many studies have shown that alcohol intake promotes chronic HCV progression. Alcohol has been shown to increase HCV replication and to speed-up damage to the liver and increase the likelihood of developing cirrhosis. Even moderate amounts of alcohol intake may increase risk for development of fibrosis. Alcohol consumption should be avoided entirely if you have HCV.
Does HCV genotype or subtype increase risk for progression?
The evidence for how HCV genotype or subtype affects risk of progression is not conclusive. Some evidence suggests that HCV genotype 1b may be associated with increased risk for cirrhosis and liver cancer.1 A recent study found that HCV genotype 3 is associated with an increased risk of cirrhosis and hepatocellular cancer. Further studies are needed to confirm these findings. 2