乙型肝炎血清学标志物单项抗-HBc-IgG阳性结果的解释及临床意义

Clinical significance of anti-HBc-IgG only positivity of HBV markers in serum

目的探讨HBV标志物单项抗-HBc-IgG（抗-HBc）阳性结果的临床意义。方法对微粒子酶免分析（MEIA）检测5213例、ELISA检测594例住院患者HBV标志物总抗-HBc阳性率和单项抗-HBc阳性率进行回顾性统计；对MEIA检测的124例单项抗-HBc阳性和167例HBV标志物全阴性住院患者的抗-HBs水平进行分析；对ELISA筛选的97例流行病学意义的单项抗-HBc阳性血清标本采用含10％小牛血清PBS进行稀释后分别采用ELlSA和MEIA检测抗-HBc并进行比较。结果ELISA检测抗-HBc“流行病学意义”和“临床意义”的总抗-HBc阳性率及单项抗-HBc阳性率分别为72．1％、16．3％和62．6％、7．6％。MEIA检测抗-HBc的总抗-HBc阳性率及单项抗-HBc阳性率分别为78．1％、13．2％；MEIA检测HBV标志物单项抗-HBc阳性组和HBV标志物全阴性组的抗-HBs结果。差异有统计学意义（χ^2=86．9，P〈0．001），ELISA筛选的97例单项抗-HBc阳性标本不同倍数稀释后ELISA和MEIA检测抗-HBc结果提示，未稀释或低倍稀释存在较高的非特异性反应，高倍稀释则存在较高的漏检率。结论不同方法单项抗-HBc阳性率存在一定的差异，单项抗-HBc阳性可作为乙肝病毒感染的证据，但存在一定比例的非特异性反应和假阴性，日常工作中ELISA检测抗-HBc以5～10倍稀释为宜。

Objective To discuss the clinical significance of anti HBc-IgG（anti-HBc） only posi tivity of HBV markers in serum. Methods The total and the isolated anti-HBc positive rate were calculated retrospectively from 5 213 and 594 inpatients＇ serum samples determined for five HBV markers including HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc by microparticle enzyme immunoassay （ MEIA）, enzyme-linked immunosorbent assay（ELISA）, respectively. The levels of anti-HBs were analysed in 167 five-HBV-marker negative and 124 anti-HBc-only positive subjects determined for five HBV markers by MEIA. Making a dilution with range from 2 to 30-fold with the phosphate buffer system containing 10% bovine calf serum to 97 serum samples with epidemiological anti-HBc only pos itivity screened from 594 inpatients determined for five HBV markers by ELISA,and anti-HBc of the dilute serum samples were determined by ELISA and MEIA, respectively. Results The total and the isolated anti-HBc positive rate with epidemiological and clinical significance by ELISA were 72. 1% ,16.3% and 62. 6%, 7. 6%, respectively. The total and the isolated anti-HBc positive rate by MEIA were 78. 1% and 13. 2%, respectively. The difference of anti-HBs levels between five-HBV-marker negative and anti HBc only positive subjects determined for anti-HBs by MEIA was significant（χ^2= 86.9,P〈0. 001）. There were higher nonspecific reactivity rate in low fold dilution and higher false negative rate in high-fold dilution to anti-HBc only seropositive samples by ELISA and MEIA. Conclusion The differences of anti-HBc positive rate exist among methods for determing HBV markers in serum. The anti-HBc only seropositivity by EILSA and MEIA is a evidence for HBV infection,and for the purpose of avoiding nonspecific reactivity and false negativity,a 5 or 10 fold dilution is feasible to determine anti-HBc by ELISA.