dos Ramos Farías María Sol, Garcia María Noé, Dilernia Darío, Rabinovich Roberto Daniel, Avila María Mercedes
Centro Nacional de Referencia para el SIDA, Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos Aires, Paraguay, Buenos Aires, Argentina.
J Virol Methods. 2009 Jun;158(1-2):6-10. doi: 10.1016/j.jviromet.2009.01.010. Epub 2009 Jan 31.
Detection of HIV proteins and/or nucleic acids is necessary for the diagnosis of perinatal HIV infection. Despite its low sensitivity, detection of p24 antigen in plasma is a simple and economic method for the diagnosis of HIV in exposed children. The aim of this study was to improve the sensitivity of detection of p24 using centrifugation of plasma. Forty-seven selected stored samples from 37 children (23 infected, 14 uninfected, median age of 137 days) were examined. Plasma samples (volume 0.3-1.5 ml) were defrosted, centrifuged at 23,500 x g at 4 degrees C for 60 min and determination of p24 was carried out in the resuspended pellet (0.12 ml). In 32 plasma samples from infected children, p24 was found originally in 6 (18.7%) and resulted positive in 24 (75%) pellets. When only one sample per child was considered, sensitivity was significantly higher in pellets, 3/23 uncentrifuged plasma samples and 15/23 pellets (McNemar Test, p<0.001). Specificity was 100%. The absorbance/cut-off ratio was always higher in the pellets from positive children (p=0.028). Plasma samples with volumes of 1 ml or more achieved a higher sensitivity (91.7% vs. 36.4%, p=0.009). Centrifugation of plasma samples prior to determination of p24 in pediatric patients resulted in a significant increase in sensitivity.
检测HIV蛋白和/或核酸对于围产期HIV感染的诊断至关重要。尽管血浆中p24抗原检测的灵敏度较低，但它是诊断暴露儿童HIV感染的一种简单且经济的方法。本研究的目的是通过血浆离心来提高p24检测的灵敏度。对来自37名儿童（23名感染，14名未感染，中位年龄137天）的47份选定的储存样本进行了检测。将血浆样本（体积0.3 - 1.5 ml）解冻，在4℃下以23,500×g离心60分钟，并对重悬的沉淀（0.12 ml）进行p24检测。在32份来自感染儿童的血浆样本中，最初有6份（18.7%）检测到p24，而在沉淀中有24份（75%）呈阳性。当每个儿童仅考虑一份样本时，沉淀中的灵敏度显著更高，23份未离心血浆样本中有3份，23份沉淀中有15份（McNemar检验，p<0.001）。特异性为100%。阳性儿童沉淀中的吸光度/临界值比值始终更高（p = 0.028）。体积为1 ml或更多的血浆样本具有更高的灵敏度（91.7%对36.4%，p = 0.009）。在儿科患者中，在检测p24之前对血浆样本进行离心可显著提高灵敏度。
