Spacek L A, Lutwama F, Shihab H M, Summerton J, Kamya M R, Ronald A, Laeyendecker O, Quinn T C, Mayanja-Kizza H
Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.
Int J STD AIDS. 2011 Jun;22(6):310-4. doi: 10.1258/ijsa.2009.009363.
We evaluated the accuracy of heat-denatured, amplification-boosted ultrasensitive p24 assay (Up24) compared with reverse transcriptase polymerase chain reaction (RT-PCR). We tested 394 samples from Ugandans infected with HIV-1 non-B subtypes. We compared Up24 levels (HIV-1 p24 Core Profile enzyme-linked immunosorbent assay (ELISA), NEN Life Science Products) to RNA viral loads (Amplicor HIV-1 Monitor 1.5, Roche) by linear regression, and calculated sensitivity, specificity, positive and negative predictive values. Median viral load was 4.9 log10 copies/mL (interquartile range [IQR], 2.6-5.5); 114 samples (29%) were undetectable (<400 copies/mL). Sensitivity of the Up24 assay to detect viral load ≥400 copies/mL was 69%, specificity was 67%, and positive and negative predictive values were 84% and 47%, respectively. Sensitivity of Up24 was 90%, 80%, 68%, 62% and 45% to detect viral loads of >500,000, 250,000-500,000, 100,000-250,000, 50,000-100,000 and 400-50,000 copies/mL, respectively. In conclusion, when compared with RT-PCR for patients infected with non-B subtypes, the Up24 demonstrated limited sensitivity especially at low viral loads. Moreover, the Up24 was positive in 33% of samples deemed undetectable by RT-PCR, which may limit the use of the Up24 to detect viral suppression.
我们评估了热变性、扩增增强超敏p24检测法（Up24）与逆转录聚合酶链反应（RT-PCR）相比的准确性。我们检测了394份来自感染HIV-1非B亚型的乌干达人的样本。我们通过线性回归比较了Up24水平（HIV-1 p24核心轮廓酶联免疫吸附测定（ELISA），NEN生命科学产品）与RNA病毒载量（Amplicor HIV-1监测仪1.5，罗氏公司），并计算了灵敏度、特异性、阳性和阴性预测值。病毒载量中位数为4.9 log10拷贝/毫升（四分位间距[IQR]，2.6 - 5.5）；114份样本（29%）检测不到（<400拷贝/毫升）。Up24检测法检测病毒载量≥400拷贝/毫升的灵敏度为69%，特异性为67%，阳性和阴性预测值分别为84%和47%。Up24检测病毒载量>500,000、250,000 - 500,000、100,000 - 250,000、50,000 - 100,000和400 - 50,000拷贝/毫升的灵敏度分别为90%、80%、68%、62%和45%。总之，与RT-PCR相比，对于感染非B亚型的患者，Up24的灵敏度有限，尤其是在低病毒载量时。此外，在RT-PCR检测不到的样本中，33%的样本Up24呈阳性，这可能会限制Up24用于检测病毒抑制的用途。
