Viral Hepatitis Laboratory, Oswaldo Cruz Institute, FIOCRUZ, RJ, Brazil.
J Med Virol. 2011 Sep;83(9):1522-9. doi: 10.1002/jmv.22138.
Detection of hepatitis B virus (HBV) serological markers in dried blood spot (DBS) samples by enzyme immunoassay (ELISA) has not yet been fully optimized. In this study, the ability to detect three HBV markers (HBsAg, anti-HBc, and anti-HBs) was evaluated in DBS samples using a modified commercial ELISA. Matched serum and DBS samples were obtained from individuals with or without a past history of HBV infection. Sera samples were tested according to the manufacturer's instructions, but for DBS testing, paper diameters, elution buffer, volume of input sample, and cut-off values were evaluated to optimize the assay. Stability studies were done on DBS stored at for up to 180 days at different temperatures. The absorbance values that yielded the maximum sensitivity and specificity were determined based on the area under the ROC curve (AUROC) and chosen as the cut-off value. Using this parameter, sensitivity was 90.5%, 97.6%, and 78% for anti-HBc, HBsAg, anti-HBs assays, respectively. Specificity was 92.6%, 96.7%, and 97.3% for anti-HBc, HBsAg, and anti-HBs assays, respectively. HBV markers could be detected in DBS samples until 63 days after sample collection at most temperatures, but storage at -20°C yielded more consistent results. These results indicate that modified ELISA can be used to detect HBV markers in DBS samples, particularly if the samples are stored appropriately.
酶联免疫吸附试验（ELISA）检测干血斑（DBS）样本中的乙型肝炎病毒（HBV）血清学标志物尚未得到充分优化。在这项研究中，使用改良的商业 ELISA 评估了 DBS 样本中检测三种 HBV 标志物（HBsAg、抗-HBc 和抗-HBs）的能力。收集了有或无 HBV 感染史个体的匹配血清和 DBS 样本。血清样本按照制造商的说明进行测试，但对于 DBS 测试，评估了纸张直径、洗脱缓冲液、输入样本量和截止值，以优化检测。在不同温度下，对 DBS 进行了长达 180 天的稳定性研究。根据 ROC 曲线下面积（AUROC）确定产生最大灵敏度和特异性的吸光度值，并将其选为截止值。使用该参数，抗-HBc、HBsAg 和抗-HBs 检测的灵敏度分别为 90.5%、97.6%和 78%。抗-HBc、HBsAg 和抗-HBs 检测的特异性分别为 92.6%、96.7%和 97.3%。在大多数温度下，HBV 标志物可在采集样本后 63 天内从 DBS 样本中检测到，但在-20°C 下储存可获得更一致的结果。这些结果表明，改良的 ELISA 可用于检测 DBS 样本中的 HBV 标志物，特别是如果样本储存得当。
