Araújo Fernando, Henriques Isabel, Monteiro Fátima, Meireles Elsa, Cruz Aldina, Tavares Gilberto, Mota-Miranda A
Molecular Biology Centre, Department of Transfusion Medicine and Blood Bank, Serviço de Imuno-hemoterapia, Hospital S. João and Medicine Faculty of Porto University, Portugal.
Transfus Clin Biol. 2005 Oct;12(4):331-5. doi: 10.1016/j.tracli.2005.08.004. Epub 2005 Sep 21.
Albeit, the NucliSens Extractor combined with the Ampliscreen was validated for application in NAT minipool screening, a study to evaluate the reliability of the procedure in relation to subtypes G of human immunodeficiency virus (HIV)-1 RNA and 4c/4d of hepatitis C virus (HCV) RNA should be performed, due to their genetic differences and the high frequency in our country.
Samples from patients infected with subtypes G of HIV-1 RNA and 4c/4d of HCV RNA were diluted with negative plasma and tested eight times for each concentration. For nucleic acid extraction we used an automated silica-based extraction method (NucliSens Extractor) and for amplification and detection the AmpliScreen HIV-1 version 1.5 and AmpliScreen HCV version 2.0 (Roche Diagnostic Systems) were applied.
The sensitivity for HIV-1 RNA genotype G using the NucliSens-AmpliScreen method-95% detection limit (95% CI) of 25 (18-50) copies per ml-is comparable with those described for genotypes B and E and to that obtained by the Multiprep procedure. In the case of HCV, the sensitivity of the method was also similar, when we compared the detection limits obtained for genotype 4c/4d-95% detection limit (95% CI) of 34 (24-71) IU/ml-with the genotype 1 published.
The data presented here suggest that these infections will not be missed because of genetic variation, as the platform exhibited similar limits of detection for the subtypes evaluated, meeting the sensitivity requirements set by the regulatory bodies.
尽管NucliSens Extractor与AmpliScreen联用已被验证可用于核酸扩增检测(NAT)混合样本筛查,但鉴于人类免疫缺陷病毒1型(HIV-1)RNA的G亚型和丙型肝炎病毒(HCV)RNA的4c/4d亚型在我国的高流行率及其基因差异,仍需开展一项研究以评估该检测方法针对这些亚型的可靠性。
将感染HIV-1 RNA G亚型和HCV RNA 4c/4d亚型患者的样本用阴性血浆稀释,并对每个浓度进行8次检测。核酸提取采用基于硅胶的自动化提取方法(NucliSens Extractor),扩增和检测则应用AmpliScreen HIV-1 1.5版本和AmpliScreen HCV 2.0版本(罗氏诊断系统公司)。
使用NucliSens-AmpliScreen方法检测HIV-1 RNA G基因型的灵敏度——每毫升25(18 - 50)拷贝的95%检测限(95%置信区间)——与针对B和E基因型所描述的以及通过Multiprep方法获得的灵敏度相当。对于HCV,当我们将4c/4d基因型的检测限——每毫升34(24 - 71)国际单位(IU)的95%检测限(95%置信区间)——与已发表的1型基因型检测限进行比较时,该方法的灵敏度也相似。
此处呈现的数据表明,由于所评估的亚型在该检测平台上具有相似的检测限,能够满足监管机构设定的灵敏度要求,因此不会因基因变异而漏检这些感染。