Interleukin 10 (IL-10) Cytokine Polymorphism in Patients with Chronic Hepatitis B and in Asymptomatic Hepatitis B Carriers

About one-third of the world's population is infected with the hepatitis B virus (HBV); 400 million of them are considered to have chronic hepatitis B infection. Chronic hepatitis B may lead to cirrhosis and hepatocellular carcinoma, whereas most hepatitis B carriers (inactive hepatitis B infection) present no symptoms and are healthy individuals. While 5-10% adult cases with HBV become chronic, this rate is higher in newborns and early childhood periods. Chronic hepatitis B infection leads to certain immune responses by activating the immunesystem of the patient. These responses vary with respect to individuals' genetic structures. The aim of the present study was to determine whether interleukin-10 (IL-10), which improves the immune response, affected the course of hepatitis B infection, such as chronic or asymptomatic, because of high or low levels of IL-10 due to different genetic structures ofHBVcarriers. In the present study, IL-10 cytokine polymorphisms at - 1082, - 819 and - 592 positions were investigated in 18 chronic hepatitis B patients, 17 HBV carriers and 34 healthy controls. Amplification refractory mutation system - polymerase chain reaction (ARMS-PCR) wasperformed. The AA and AG genotypes at position - 1082 was significantly different (p= 0.009 and 0.003, respectively) between chronic hepatitis B patients and HBV carriers. Haplotype analysis revealed that the ATA haplotype was more prevalent in healthy controls and HBV carriers, whereas ACC was more prevalent in chronic hepatitis B patients. In conclusion, the present study concluded that the genetic differences in IL-10 cytokines might be associated with the course of HBV infection.