title: Evaluation of the RealTime HIV-1, Xpert HIV-1, and Aptima HIV-1 Quant Dx Assays in Comparison to the NucliSens EasyQ HIV-1 v2.0 Assay for Quantification of HIV-1 Viral Load.
abstract: HIV-1 RNA monitoring, both before and during antiretroviral therapy, is an integral part of HIV management worldwide. Measurements of HIV-1 viral loads are expected to assess the copy numbers of all common HIV-1 subtypes accurately and to be equally sensitive at different viral loads. In this study, we compared for the first time the performance of the NucliSens v2.0, RealTime HIV-1, Aptima HIV-1 Quant Dx, and Xpert HIV-1 viral load assays. Plasma samples (n = 404) were selected on the basis of their NucliSens v2.0 viral load results and HIV-1 subtypes. Concordance, linear regression, and Bland-Altman plots were assessed, and mixed-model analysis was utilized to compare the analytical performance of the assays for different HIV-1 subtypes and for low and high HIV-1 copy numbers. Overall, high concordance (>83.89%), high correlation values (Pearson r values of >0.89), and good agreement were observed among all assays, although the Xpert and Aptima assays, which provided the most similar outputs (estimated mean viral loads of 2.67 log copies/ml [95% confidence interval [CI], 2.50 to 2.84 log copies/ml] and 2.68 log copies/ml [95% CI, 2.49 to 2.86 log copies/ml], respectively), correlated best with the RealTime assay (89.8% concordance, with Pearson r values of 0.97 to 0.98). These three assays exhibited greater precision than the NucliSens v2.0 assay. All assays were equally sensitive for subtype B and AG/G samples and for samples with viral loads of 1.60 to 3.00 log copies/ml. The NucliSens v2.0 assay underestimated A1 samples and those with viral loads of >3.00 log copies/ml. The RealTime assay tended to underquantify subtype C (compared to the Xpert and Aptima assays) and subtype A1 samples. The Xpert and Aptima assays were equally efficient for detection of all subtypes and viral loads, which renders these new assays most suitable for clinical HIV laboratories.
authors: National HIV Reference Laboratory, Central Virology Laboratory, Ministry of Health, Sheba Medical Center, Ramat-Gan, Israel orna.mor@sheba.health.gov.il.
authors: Orna
authors: O
authors: Mor
authors: National HIV Reference Laboratory, Central Virology Laboratory, Ministry of Health, Sheba Medical Center, Ramat-Gan, Israel.
authors: Yael
authors: Y
authors: Gozlan
authors: National HIV Reference Laboratory, Central Virology Laboratory, Ministry of Health, Sheba Medical Center, Ramat-Gan, Israel.
authors: Marina
authors: M
authors: Wax
authors: National HIV Reference Laboratory, Central Virology Laboratory, Ministry of Health, Sheba Medical Center, Ramat-Gan, Israel.
authors: Fernando
authors: F
authors: Mileguir
authors: National HIV Reference Laboratory, Central Virology Laboratory, Ministry of Health, Sheba Medical Center, Ramat-Gan, Israel.
authors: Avia
authors: A
authors: Rakovsky
authors: Ilex Medical, Petach Tikva, Israel.
authors: Bina
authors: B
authors: Noy
authors: National HIV Reference Laboratory, Central Virology Laboratory, Ministry of Health, Sheba Medical Center, Ramat-Gan, Israel School of Public Health, Tel Aviv University, Tel Aviv, Israel.
authors: Ella
authors: E
authors: Mendelson
authors: Infectious Diseases Unit, Sheba Medical Center, Ramat-Gan, Israel.
authors: Itzchak
authors: I
authors: Levy
mesh_terms: D001681:Biological Assay / Q000379:methods*; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000821:virology; D015497:HIV-1 / Q000235:genetics; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D012367:RNA, Viral / Q000097:blood* / Q000235:genetics; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D019562:Viral Load / Q000379:methods*
chemical_list: D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic