Lack of Association of Interleukin 12 p40 Subunit Polymorphism (IL-12B +1188) and Risk of Chronic Hepatitis B Infection in Iranian Patients

Background: Hepatitis B virus is a major cause of incidence of chronic hepatitis in the world. Although the cause of chronic infection in individuals is not well known, cytokines that are of the main factors to regulate the immune reaction play an important role in determining the clinical course of infection of this virus, and host genetic background and single nucleotide polymorphisms have a decisive effect on the level and performance of cytokines. Thus, the aim of this study is to investigate the relationship between the single nucleotide polymorphisms of 3' noncoding region of IL-12 p40 subunit gene on position +1188, and susceptibility to chronic hepatitis B.
Materials and Methods: This case-control study was performed on a population including 140 patients with chronic hepatitis B and 150 healthy people. PCR-RFLP method was used to determine genotype of individuals. In order to confirm the genotyping results, sequence of 10% of samples was reviewed using direct sequencing.
Results: The frequency of AA, AC and CC genotypes of this gene at position +1188 was respectively calculated 56.4, 36.4 and 7.1% in group of patients and 59.3, 33.3 and 7.3% in the control group. No significant difference was found between both case and control groups (p = 0.487).
Conclusion: The frequency of different genotypes of this gene in the studied population is similar to the results of most studies conducted in different countries. The results of this study shows no association between IL-12B +1188 polymorphism and the risk of chronic hepatitis B is in Iranian population.