Characteristics Of HBeAg-specific T Cell Immune Response In Chronic Hepatitis B Patients Accepting Antiviral Therapy

Background：Hepatitis B is one of the major infectious diseases caused by hepatitis Bvirus (HBV) infection, and is a serious threat to human health. In clinical, 90to 95 percent of acute hepatitis B can clear HBV spontaneously, while a few(around 5 to 10 percent) patients lead to chronic hepatitis B because ofpersistent HBV replication, liver pathological changes and functional disorderof anti-HBV immune, and eventually lead to cirrhosis and liver cancer. Moreand more evidence indicates that the damage of hepatocyte is not caused byHBV itself but mediated by immune system. Recent studies had shown thatcelluar immunity plays an important role in the pathogenesis of chronichepatitis B, and antiviral therapy can affect the reactivity of T cells to specificantigens. HBV DNA level often below the detection limits or even less, andalanine aminotransferase (ALT) also dropped to normal, and the liver tissueinflammation subsided after HBeAg seroconversion in patients with chronicHBV infection, which prompted the immune response to HBeAg may play akey role in HBV clearing. But what role does the HBeAg-specific celluarimmunity play in patients with chronic hepatitis B accepting antiviral therapy?Is it different of the HBeAg-specific T cell response before and aftertreatment? Is there any relationship between the HBeAg-specific T cellresponse and HBV DNA level and dynamic change of serum HBeAg COI?Objective：（1）Detect the serum target ofALT、HBsAg、HBsAb and HBV DNAin patients with chronic hepatitis B to evaluate the healing efficacy;（2）To observe the characteristics of T cell immune responses toHBeAg protein;（3）To analysis the relationship of HBeAg-specfic T cell responses andserum HBV DNA level;（4）To investigate the relationship of HBeAg-specfic T cell responsesand serum HBeAg tilter .Methods：（1）Sera from patients with chronic hepatitis B accepting antiviraltherapy were collected to detect serum ALT before treatment and threemonths, six months and twelve months after treatment, respectively.（2）Serum HBsAg, anti-HBs, HBeAg, anti-HBe, anti-HBc and HBVDNA were detected before treatment and three months, six months and twelvemonths after treatment, respectively, in patients with chronic hepatitis Baccepting antiviral therapy.（3）The peripheral blood monocular cells (PBMCs) were separatedfrom the whole blood collected before treatment and three months, six monthsand twelve months after treatment, respectively. ELISPOT assay was used todetect the frequency and strength of secreting IFN-γcells of PBMCsstimulated by HBeAg protein.Results：（1）The HBV DNA level of all patients was more than 104copies/ml ,and ALT was greater than the upper limits of normal before treatment. Thepatients with HBV DNA level below the limits of detection and ALT back tonormal were 50%、61.1%、83.3% and 61.1%、83.3%、100% among three months, six months and twelve months after treatment, respectively..（2）The frequency of T cell responses to HBV specific proteins were27.8%（5/18）、44.4% (8/18)、83.3% (15/18) and 88.9% (16/18) at the time ofbefore treatment and three months, six months and twelve months afterantiviral therapy, respectively. The frequency of HBeAg specific T cellresponses in patients at six months and twelve months after treatment weresignificantly higher than those of before treatment and three months aftertreatment, P<0.05.（3）The strength of HBeAg specific T cell responses was expressed asspot forming cells (SFCs) per 2×105input cells. The SFCs of T cellresponses in patients twelve months after treatment are significant higher thanthose of patients before treatment and three months and six months aftertreatment, vs before treatment，Z=-3.479, P=0.001, P<0.05; vs three monthsafter treatment，Z=-3.243, P=0.001, P<0.05; vs six months after treatment,Z=-2.817, P=0.005, P<0.05. The SFCs of T cell responses in patients sixmonths after treatment are significant higher than those of patients beforetreatment and three months after treatment, Z=-2.327, P=0.02, P<0.05.（4）The SFCs of T cell responses to HBeAg have a negative correlationwith serum HBV DNA levels, rs= -0.241<0, P=0.042，P<0.05.（5）There was no significant correlation between SFCs of T cellresponses to HBeAg with titer of HBeAg in serum, P>0.05.Conclusion：（1）All results tested in CHB patients after antiviral therapy are betterthan those before treatment, which illustrated the antiviral therapy waseffective. （2）The HBeAg specific T cell responses in patients after treatment aregreater than those before treatment, and as the treatment time to extend, thefrenquence and strength of HBeAg specific T cell responses are greater thanthose before treatment.（3）The SFCs of T cell responses to HBeAg have a negative correlationwith serum HBV DNA levels.（4）The SFCs of T cell responses to HBeAg have no significantrelationship with serum HBeAg COI.