HBsAg/HBsAb双阳性慢性乙型肝炎患者HBV S基因免疫逃逸相关变异分析

Analysis of HBV S gene immune escape-related mutation in chronic hepatitis B patients with HBsAg/HBsAb co-existence

目的分析HBsAg/HBsAb双阳性慢性乙型肝炎患者HBV S基因主要亲水区免疫逃逸相关位点变异特点。方法收集89例HBsAg/HBsAb双阳性和148例HBsAg单阳性的慢性乙型肝炎患者血清及临床资料,提取患者血清HBV DNA,扩增患者HBV S基因并进行测序,应用DNASTAR Lasergene Meg Align软件对主要亲水区已有文献报道的46个免疫逃逸相关位点及新增N-糖基化变异进行比对分析。结果 2组患者在年龄、ALT、TBIL、HBV DNA载量和HBe Ag阳性率方面差异均无统计学意义(P均<0.05)。HBsAg/HBsAb双阳性患者HBV S基因主要亲水区变异的总检出率为31.46%,明显高于HBsAg单阳性患者的18.92%(P<0.05),其中s L110I/S、s T113N/S、s T131I/N/P和s S143L/M/T的变异检出率明显高于单阳性组;双阳性患者多位点联合变异检出率亦明显高于单阳性患者(20.22%vs.6.08%,P<0.05)。双阳性患者新增N-糖基化变异检出率高于单阳性患者(7.87%vs.2.03%),差异具有统计学意义(P<0.05)。结论 HBsAg/HBsAb双阳性患者比HBsAg单阳性患者的HBV S基因免疫逃逸相关变异种类更多,单位点和多位点联合变异检出率更高,并且新增N-糖基化变异检出率也更高,这些变异可能是引起慢性乙型肝炎患者HBsAg/HBsAb双阳性共存的驱动因素之一。

Objective To analyze the mutation characteristics of the immune escape-related sites of HBV S gene major hydrophilic regions in chronic hepatitis B patients with HBsAg and HBsAb co-existence.Methods The serum samples and clinical data of 89 patients with HBsAg/HBsAb co-existence and 148 single HBsAg positive patients with chronic hepatitis B were collected.Serum HBV DNA was extracted from the included patients,and HBV S genes were amplified from serum and then sequenced.Forty-six well-documented immune escape-related site mutation and additional N-glycosylation mutation alignments in major hydrophilic regions were analyzed using DNASTAR Lasergene MegAlign software.Results There were no statistically significant differences in age,ALT,TBIL,HBV DNA level and HBeAg positive rate between the 2 groups.The overall detection rate of immune escape-related mutations of HBV S gene major hydrophilic regions in co-existence group was 31.46%,which was significantly higher than that in HBsAg single positive group(18.92%,P<0.05).The detection rates of sL110I/S mutation,sT113N/S mutation,sT131I/N/P mutation and sS143L/M/T mutation were significantly higher than those in the single positive group,and the detection rates of multiple mutations in co-existence group were also significantly higher than those in the single positive group(20.22%vs.6.08%,P<0.05).In addition,the detection rate of additional N-glycosylation mutations in co-existence group was higher than that in single positive group(7.87%vs.2.03%),the difference was statistically significant(P<0.05).Conclusions HBV S gene in HBsAg/HBsAb co-existence patients harbours more mutational diversity,higher detection rate of single and multiple mutation,and higher detection rate of additional N-glycosylation mutations than those in HBsAg single positive patients.These mutations may be one of the driven factors of HBsAg and HBsAb co-existence in chronic hepatitis B patients.