Level And Significance Of SOX40L In Different Stages Of Natural History Of Chronic HBV Infection

Objective:Chronic HBV infection is one of the important causes of chronic liver injury.The progress and outcome of HBV infection is directly related to the intensity and type of virus-induced immune response.As an important member of the immune system,T lymphocyte,especially hepatitis B virus-specific cytotoxic T cell(cytotoxic lymphocyte,CTL)is the central effector cell in the removal of HBV.Generally speaking,T cell could be activated by two signals:the first one is generated from the binding between MHC-antigen peptide complex,expressed by antigen presenting cells(antigen presenting cell,APC),and the T cell receptor(T cell receptor,TCR);the second one is provided by the interaction of the costimulatory molecules.OX40/OX40L is a pair of important costimulatory molecules,which involved in T cell activation,proliferation and migration.sOX40L is the soluble form of OX40L in serum.The aim of this study is to investigate the content of s OX40L in peripheral blood of patients with chronic HBV infection at different stages of natural history,liver inflammation and fibrosis.Materials and Methods:In this study,80 patients with chronic HBV infection were collected from inpatient and outpatient departments of The Third Hospital of Hebei Medical University and Baoding Infectious Diseases Hospital during May 2016 and May 2017.The studied patients include 43males and 37 females,aged from 16-69 years(mean±SD:39.3±13.3 years).The diagnosis of chronic HBV infection was according to criterias of Guidelines for Prevention and Treatment of Chronic Hepatitis B,jointly developed by the Chinese Medical Association Liver Disease Branch,the Chinese Medical Association Infectious Diseases Branch in 2015.Based on characteristics of natural history of HBV infection and liver histology,the enrolled patients were divided into 4 groups,including immune tolerance phase(n=20),immune-clearance phase(n=25),low replication phase(n=20)and immune-reactive phase(n=15).In order to observe the relationship between sOX40L and the degree of inflammatory and fibrosis in different stages of chronic HBV infection,all patients were divided into different groups based on the inflammatory activity and the degree of fibrosis,respectively.Patients with different inflammatory activity was divided into 3groups:mild group(G0-G1,n=40),moderate group(G1-G2,n=24),and severe group(G3 and above,n=16).According to different degrees of fibrosis,patients were divided into three groups:the mild group(S0-S1,n=40),the moderate group(S1-S2,n=16),and the severe group(S3 and above,n=24).In the same period,14 healthy subjects were recruited as health control group.Early morning peripheral blood were collected from the control group.The indexes of blood routine,biochemistry and virology of the subjects,including platelet count(PLT),alanine transaminase(ALT),aspartate aminotransferase(AST),and total bilirubin(TB)were detected.Detection limit:APRI=(AST/ULN x 100)/PLT(10~9/L),that laboratory normal limit(upper limit of normal for that that ULN)was the upper limit of normal reference value for the AST.FIB-4 index was calculated based on the ALT,AST,PLT and patient age.FIB-4=(age x AST)/(ALT x PLT)~2.The serum levels of s OX40L of all subjects were measured by enzyme-linked immunosorbent assay(ELISA).Data analysis were performed using SPSS17.0 statistical software package.Results:1 The age and sex ratio of each group were comparable.The ALT and AST level of the chronic HBV infected patients at immune tolerance period and low replicative period were significantly lower than those in immune clearance and reperfusion(P<0.01,Table 1).HBV-DNA results showed the highest value(8.16±0.69)in immune tolerance period and the lowest value(3.11±0.85)in low replicative period.2 The expression levels of s OX40L in the serum of chronic HBV infected patients(7.22±3.28 ng/ml,4.47±1.79 ng/ml and 6.89±3.39 ng/ml)were significantly higher than those in healthy control group(3.854±0.994,P<0.05,Fig.1).The immune tolerance period(3.72±2.26 ng/ml)was lower than that of the healthy control group(3.854±0.994 ng/ml).Among them,during the immune clearance phase,the reactivation of s OX40L increased more significantly than the other two groups,and the difference was also statistically significant(all P<0.05)3 There was a significant positive correlation between serum sOX40L level and ALT level in different stages of natural HBV infection(r=0.64,P<0.0001,Fig.2).With the increase of sOX40L level,serum ALT levels were increasing.4 The results showed positive correlation between the level of sOX40L and the APRI score(0.39±0.16 ng/ml,0.88±0.43 ng/ml,0.32±0.10 ng/ml and 0.73±0.32 ng/ml)in the immune tolerance period,immune clearance period,recurrence period and low replicative period(r=0.53,P<0.0001,Fig.3).5 There was a positive correlation between s OX40L level and FIB-4score(0.78±0.41 ng/ml,1.40±0.70 ng/ml,0.89±0.29 ng/ml and 1.06±0.52ng/ml)in immune tolerance period,immune clearance period,recurrence period and low replicative serum(r=0.031,P<0.0001,Fig.4).6 The sOX40L levels were significantly higher in patients with severe histological activity(G3 and above)than those in patients with moderate(G1-G2)or mild(G0-G1)histological activity(P<0.05)(Fig.5,Table 2).Furthermore,patients with degree of fibrosis(S3 and above)also showed increased serum levels of sOX40L compared with patients with degree of fibrosis(S1-S2)and also showed increased serum levels of sOX40L compared with degree of fibrosis(S0-S1)(P<0.05)(Fig.6,Table 3)..Conclusion:The serum levels of sOX40L in HBV infection were closely related to the inflammation and fibrosis degrees of the liver,indicating that OX40/OX40L may be involved in the development of hepatic inflammation and fibrosis after chronic HBV infection.