四川地区供血浆人群隐匿性乙型肝炎病毒感染的研究

目的了解四川地区供血浆人群隐匿性乙型肝炎病毒感染(OBI)情况,分析现行标准下原料血浆的HBV残余风险。方法采用实时荧光PCR和ELISA法,对四川地区10个单采血浆站2007年7月～2009年7月筛查合格的56 620名次供浆者的135 542份原料血浆标本作HBV NAT和HBsAg同步筛查,对筛查阳性的标本以进口试剂复核、作中和试验及HBV DNA定量测定,并对阳性血浆的供血浆者追踪分析,确认OBI标本。结果共检出HBV DNA阳性12份(9人),四川地区原料血浆HBV DNA检出率为0.008 9%(12/135 542);HBV DNA载量均<1 000 IU/ml;采用国产ELISA试剂检测该12份标本HBsAg均为阴性,而用进口试剂检测并经中和试验确认了其中5份(3人)为HBsAg阳性,其余7份(6人)为OBI血浆,血清学模式均为HBsAg-/HBeAg-/HBcAb+;对供血浆者2～9个月的追踪分析显示ELISA和NAT检测结果无变化,与筛查结果一致。结论 HBsAg阴性供血浆人群中存在OBI感染者,四川供浆人群中OBI感染率为0.010 6%(6/56 620),低于现有报道的我国无偿献血者的OBI感染率;按照现行要求采用ELISA法检测原料血浆,灵敏度较低的国产试剂检测HBsAg的残余风险(0.0089%)高于进口试剂(0.005 2%)。增加HBV NAT能有效降低原料血浆OBI的漏检风险。

Study of occult hepatitis B virus infection among the source plasma donors in Sichuan area,China

Objective To investigate the prevalence rate of occult hepatitis B virus infection(OBI) among source plasma donors in Sichuan area,and to evaluate the residual risk of HBV in source plasma under current standards.Methods A total of 135 542 donations,collected from 56 620 donors from July 2007 to July 2009,were tested by PCR kits and ELISA kits for HBV DNA and HBsAg respectively according to the instruction of the kits.PCR positive samples were further analysed by Roche COBAS AmpliScreen,imported ELISA kits,HBsAg neutralization tests and quantitative determination of HBV DNA.Results 12 donations were detected as HBV DNA(+)/ HBsAg(-),for a rate of 0.008 9%(12/135 542).The HBV DNA loads were lower than 1 000 IU/ml.The donations of HBV DNA(+) were tested by imported ELISA reagents and by HBsAg confirmation.The test results demonstrated that 5 of them were positive for HBsAg,and the rest 7 donations(collected from 6 donors) were determined as plasma of OBI with the same serological pattern of HbsAg(-)/ HbeAg(-)/ HbcAb(+).Further trace analysis for 2~9 months showed no change in ELISA and NAT test results.Conclusion There were HBV infected donors in the populations of source plasma donors with negative HBsAg.Based on this study,the prevalence rate of OBI in the population of source plasma donors in Sichuan area was 0.010 6%(6/56 620),lower than several reported OBI rate of voluntary whole blood donors in China.The residual risk of HBV in source plasma tested by domestic HBsAg ELISA reagents was higher than using imported ELISA reagents.Application of nucleic acid technology could further enhance the safety of source plasma.