Dried blood spots,valid screening for viral hepatitis and human immunodeficiency virus in real-life

AIM To detect chronic hepatitis B(CHB),chronic hepatitis C(CHC) and human immunodeficiency virus(HIV) infections in dried blood spot(DBS) and compare these samples to venous blood sampling in real-life.METHODS We included prospective patients with known viral infections from drug treatment centers,a prison and outpatient clinics and included blood donors as negative controls. Five drops of finger capillary blood were spotted on filter paper,and a venous blood sample was obtained. The samples were analyzed for HBs Ag,antiHBc,anti-HBs,anti-HCV,and anti-HIV levels as well as subjected to a combined nucleic acid test(NAT) for HBV DNA,HCV RNA and HIV RNA.RESULTS Samples from 404 subjects were screened(85 CHB,116 CHC,114 HIV and 99 blood donors). DBS had a sensitivity of > 96% and a specificity of > 98% for the detection of all three infections. NAT testing did not improve sensitivity,but correctly classified 95% of the anti-HCV-positive patients with chronic and past infections. Anti-HBc and anti-HBS showed low sensitivity in DBS(68% and 42%).CONCLUSION DBS sampling,combined with an automated analysis system,is a feasible screening method to diagnose chronic viral hepatitis and HIV infections outside of the health care system.

采用干血斑进行丙肝病毒RNA检测的研究

目的用干血斑（dried blood spot，DBS）取代静脉血作为检测HCV RNA的样品来源的可行性。方法评价该方法的检测限、批间和批内变异。用HCV RNA阴性的血液将第二代HCV RNA国际标准（WHO，HPAUK）稀释后浓度分别为1000，500，250和150IU／ml的样品检测。批间变异是通过反复检查单个1000IU／mlDBS对照超过20次PCR反应。批内变异则是通过一次PCR反应，在20个反应孔检测1000IU／ml对照DBS。从单个已知血液样品HCV阳性的标本制备成DBS后在不同温度和时间进行评估检测HCVRNA的影响，如室温下，4℃，-20℃和-80℃。另外在不同时间点检测，如1，2，4，6，9和12个月。结果DBS样品检测HCVRNA的检测限为250IU／ml。1000IU／ml样本的批间和批内变异系数（CV）分别为2．5％和2．2％。灵敏度和特异度分别为100％和95．8％。在不同温度保存超一年的DBS样品中HCVRNA是稳定的。结论笔者建立了一种灵敏和稳定的采用DBS检测HCVRNA的方法。用干血斑作为一种样品有利于对高危人群HCVRNA的检测。