The Associations Between Polymorphisms Of T Cells Immunoglobulin Musin-3 Gene And Different Outcomes Of Persistent HBV Infection

Background HBV infection is one of the major worldwide public health issues, the relationship between CHB infection and long-term prognosis has received constant attention. The different outcomes and clinical manifestations of HBV infection are related to immune function and genetic factors of host. The possibility of HBV clearance after infection is closely tied to the strength of immune function. Among the genetic factors, Multiple single nucleotide polymorphisms (SNPs) were confirmed to have linkage with different clinical outcomes of HBV infection. Researches on susceptible genes will help clarify the pathogenesis of CHB, and may become a valid index for diagnosis, treatment and prognosis of CHB. As a multi-gene infectious disease with genetic predisposition, CHB's genetic characteristics have various levels of mutations in different races, regions and even individuals. Tim-3 gene, which is located on human chromosome 5, is an important member in Tim gene family, its encoded membrane protein is specifically expressed on the surface of activated Th1 cells instead of initial T cells, and can act as inhibitory molecule to reduce Th1 cell's response, leading to weakened immune surveillance capability. Researches have shown that the expression of Tim-3 gene had close associations with many autoimmune diseases, it was demonstrated that Tim-3 may play an important role in the course of HBV infection. This study is to investigate the associations between genotype and haplotype of Tim-3 gene's Tag SNP loci and different outcomes of HBV infection. Objective To investigate the relationship between the single nucleotide polymorphisms (SNPs) of T cells immunoglobulin musin-3 gene and the outcome of HBV infection in the Chinese Han population.Metholds The two tagSNPs of Tim-3 gene (rs11741184 and rs13170556) were genotyped by ABI SNaPshot method for 996 chronic HBV infection group and 301 acute self-limiting HBV infection group. The genotype, allele frequencies and haplotype of Tim-3 tagSNP were calculated and analyzed respectively.Results The genotype frequencies of CC, CG and GG in rs11741184 polymorphism of Tim-3 gene were 84.39%(254/301), 15.28%(46/301) and 0.33%(1/301) in the 301 acute serf-limiting HBV infection patients, and 86.04% (857/996), 13.65%(136/996) and 0.3%(3/996) in the 996 chronic HBV infection patients. P value for acute serf-limiting HBV infection subjects and chronic HBV infection controls are 0.7719, 0.4857 respectively. The genotype frequencies of AA, GA and GG in rs13170556 polymorphism of Tim-3 gene were 68.77%(207/301), 28.57%(6/301) and 2.66%(8/301)in the 301 acute serf-limiting HBV infection patients, and 68.07%(678/996), (28.41%) (283/996)and 3.51%(35/996) in the 996 chronic HBV infection patients. The three haplotypes of Tim-3 gene tagSNP were C-A,C-G,G-A in the Chinese Han population, and their haplotype frequencies were distributed similarly in the acute serf-limiting HBV infection patients (75.08%, 16.94%, 7.97%),and in the chronic HBV infection patients (75.15%, 17.72%, 7.13%). The differences weren't statistically significant (P>0.05).Conclusions The two tagSNP of Tim-3 may not be associated with the outcome of HBV infection in Chinese Han population.