低于血清乙型肝炎病毒DNA检测下限实测值的临床价值

Actual numerical values below the minimum detection limit for detecting hepatitis B virus DNA

目的探讨血清乙型肝炎病毒（hepatitisBvirus，HBV）DNA检验中低于检测下限（500u／mL）实测值的临床价值。方法180例6个月内首次血清HBVDNA〉0-500u／mL慢性乙型肝炎患者，采用实时荧光定量PCR法检测其血清HBVDNA水平，3个月1次，共1a；56例监测期间血清HBVDNA最高拷贝为0u／mL为减少组，57例HBVDNA〉O-10^3u／mL为维持组，36例HBVDNA〉10^3-10^4u／mL为升高1组，31例HBVDNA〉10^4u／mL为升高2组；观察各组首次HBVDNA检测载量值，并比较随访期间血清乙型肝炎e抗原（hepatitisBviruseantigen，HBeAg）和谷丙转氨酶（glutamic—pyruvictransaminase，GPT）的变化。结果血清HBVDNA升高1组和升高2组首次血清HBVDNA载量（2．32±0．27、2．37±0．24）高于减少组（1．92±0．24）和维持组（2．12±0．29），减少组HBVDNA载量低于维持组，差异均有统计学意义（P〈O．05）；随访1a中，HBVDNA升高1组、升高2组血清GPT升高至正常参考值2倍以上比率（25．00％、38．71％）高于维持组（7．02％），差异有统计学意义（P〈0．01），各组HBeAg阳性率比较差异均无统计学意义（P〉O．05）。结论持续病毒抑制的慢性乙型肝炎患者，血清HBVDNA升高早于其他血清学指标，血清HBVDNA低于检测下限实测值越接近检测下限（500u／mL），1a内疾病复发及肝损伤可能性越大。

Objective To explore the clinical significance of actual numerical values below the minimum detection limit （500 u/mL） in the detection of hepatitis B virus （HBV） DNA. Methods Totally 180 patients with chronic hepatitis B （CHB）, initially detecting HBV DNA value 〉0 to 500 u/mL within 6 months, were detected HBV DNA by real-time fluorescent quantitative-PCR once every three months for one year. The initial loading values of HBV DNA were detected in four groups： reduction group （the maximum HBV DNA value： 0, n = 56）, maintenance group （the HBV DNA value： 0x10^3 u/mL, n=57）, elevated group 1 （HBV DNA value： 〉10^3-10^4 u/mL, n= 36）, and elevated group 2 （HBV DNAvalue： 〉10^4 u/mL, n= 31）. The changes of hepatitis B virus e antigen （HBeAg） and glutamic-pyruvic transaminase （GPT） were recorded and compared during 1-year follow-up survey. Results The initial loading values of HBV DNA in elevated group 1 and 2 （2.32±0.27, 2.37±0.24） were significantly higher than those in reduction group and maintenance group （1.92±0.24, 2.12±0.29） （P〈0.01）, and the value was lower in reduction group than that in maintenance group （P〈0.05）. In 1-year follow-up survey, the percentage of patients with GPT exceeding by 2 times or more was significantly higher in elevated group 1 （25.00%） and elevated group 2 （38. 71%） than that in maintenance group （7. 02%） （P〈0.01）. The levels of serum HBeAg showed no differences among four groups （P〉 0.05）. Conclusion HBV DNA actual numerical values elevates earlier than other serum markers in CHB patients with effectively suppressed virus DNA copy. When the HBV DNA actual value is more close to the minimum detection limit （500 u/mL）, the risk for recurrence of virus or liver damage becomes higher.