IL28B (Immunogenetics)

Hepatitis C

Hepatitis C is an infectious disease caused by the hepatitis C virus (HCV). It is transmitted through contact with infected blood and can lead to chronic liver disease, including cirrhosis and hepatocellular carcinoma.

Following an acute phase of infection, HCV persists in the blood in 85-90% of infected individuals. 50-70% of these patients develop chronic hepatitis C, which can be complicated by cirrhosis and hepatocellular carcinoma.

The assay for identifying polymorphisms associated with IL28B function has considerable clinical relevance in the context of HCV therapy. Interleukin IL28B plays a key role in the body's antiviral defense, influencing the immune response in HCV infection.

The most studied IL28B gene polymorphisms associated with response to HCV therapy are the single nucleotide polymorphisms (SNPs) rs12979860 and rs8099917. These genetic variations affect the efficacy of antiviral therapy.

rs12979860

The rs12979860 polymorphism is adjacent to the IL28B gene. CC, CT and TT genotypes are associated with varying degrees of treatment resistance. Studies have shown that CC genotype carriers have higher probability of a sustained virologic response to interferon and ribavirin therapy compared to CT and TT genotype carriers.

rs8099917

The rs8099917 polymorphism located in the regulatory region of the IL28B gene also correlates with response to antiviral therapy. Carriers of TT genotype have a more favorable prognosis in treatment of HCV infection compared to those with GT and GG genotypes.

Identification of IL28B polymorphisms enables a personalized approach to HCV treatment. Standard interferon and ribavirin therapy usually proves successful for patients with favorable genotypes (e.g. CC for rs12979860 and TT for rs8099917), while patients with less favorable genotypes may require other treatment protocols. In addition, knowing the IL28B genotype is important for predicting potential side effects of treatment.