Rodés Berta, Sheldon Julie, Toro Carlos, Cuevas Laureano, Pérez-Pastrana Esperanza, Herrera Inmaculada, Soriano Vincent
Department of Infectious Diseases, Hospital Carlos III, Sinesio Delgado, 10, Madrid 28029, Spain.
J Clin Microbiol. 2007 Jan;45(1):88-92. doi: 10.1128/JCM.01613-06. Epub 2006 Nov 8.
No commercial viral load assay has yet been approved for use for measurement of human immunodeficiency virus type 2 (HIV-2) RNA levels in plasma. We assessed the performance of the NucliSens EasyQ (version 1.1) assay (EasyQ; bioMérieux, Boxtel, The Netherlands) to quantify HIV-2 viremia. A viral stock was prepared from an HIV-2 (subtype A)-infected patient. Culture supernatant was subjected to viral particle counting by electron microscopy. Serial dilutions of the viral stock were made in HIV-negative plasma and were used to test EasyQ for its sensitivity, linearity, and reproducibility. RNA was quantified by the NucliSens EasyQ (version 1.1) assay. Plasma samples from 75 HIV-2-infected patients were further tested. EasyQ was able to quantify HIV-2 RNA in a reproducible manner. Overall, estimates of the number of HIV-2 RNA copies/ml obtained with EasyQ were lower than those obtained by electron microscopy; however, the differences were always less than 0.7 log (mean, 0.55 +/- 0.19 log(10)). The assay showed good linearity (r(2) = 0.964; P < 0.0001). The agreement between both measures was assessed by use of a Bland-Altman plot; the narrow limits (0.158 to 0.952), defined as the mean difference +/- 2 standard deviations, indicated good agreement. The reproducibility was also good, since the between-run coefficients of variation were 1.49, 3.60, and 12.25% for samples containing 6.30, 4.30, and 2.30 log(10) HIV-2 RNA copies/ml, respectively. HIV-2 RNA was detected in 34 of 75 (45%) plasma specimens (mean, 2.72 log RNA copies/ml; range, 1.74 to 4.11 log RNA copies/ml); the rest of the specimens were considered to have undetectable viremia. A negative correlation was found between the number of HIV-2 RNA copies/ml and CD4 counts. In summary, EasyQ was shown to be reliable for the measurement of plasma HIV-2 subtype A RNA levels and may be a feasible tool for routine clinical monitoring of HIV-2 subtype A-infected patients.
尚无用于检测血浆中人类免疫缺陷病毒2型（HIV-2）RNA水平的商用病毒载量检测方法获得批准。我们评估了NucliSens EasyQ（1.1版）检测方法（EasyQ；法国生物梅里埃公司，荷兰博克斯泰尔）对HIV-2病毒血症进行定量的性能。从一名感染HIV-2（A亚型）的患者制备病毒储备液。通过电子显微镜对培养上清液进行病毒颗粒计数。将病毒储备液在HIV阴性血浆中进行系列稀释，并用于检测EasyQ的灵敏度、线性和重复性。通过NucliSens EasyQ（1.1版）检测方法对RNA进行定量。对75名感染HIV-2的患者的血浆样本进行了进一步检测。EasyQ能够以可重复的方式对HIV-2 RNA进行定量。总体而言，通过EasyQ获得的每毫升HIV-2 RNA拷贝数估计值低于通过电子显微镜获得的估计值；然而，差异始终小于0.7对数（平均值，0.55±0.19对数（10））。该检测方法显示出良好的线性（r² = 0.964；P < 0.0001）。通过Bland-Altman图评估两种测量方法之间的一致性；定义为平均差异±2个标准差的狭窄界限（0.158至0.952）表明一致性良好。重复性也很好，因为对于每毫升分别含有6.30、4.30和2.30对数（10）HIV-2 RNA拷贝的样本，批间变异系数分别为1.49%、3.60%和12.25%。在75份血浆标本中有34份（45%）检测到HIV-2 RNA（平均值，2.72对数RNA拷贝/毫升；范围，1.74至4.11对数RNA拷贝/毫升）；其余标本被认为病毒血症检测不到。发现每毫升HIV-2 RNA拷贝数与CD4细胞计数之间呈负相关。总之，EasyQ被证明对于检测血浆中HIV-2 A亚型RNA水平是可靠的，并且可能是对感染HIV-2 A亚型患者进行常规临床监测的一种可行工具。
