Performance of the automated COBAS AmpliPrep/COBAS TaqMan HIV-1 test on a genetically diverse panel of specimens from China: comparison to the COBAS amplicor HIV-1 monitor test, v1.5.

OBJECTIVES To investigate the impact of genetically diverse HIV samples from China on the performance of the automated COBAS(R) AmpliPrep/COBAS TaqMan(R) HIV-1 Test (CAP/CTM). METHODS 185 samples from untreated HIV-1-infected patients were used to assess the performance of the CAP/CTM Test and COBAS Amplicor HIV-1 Monitor Test, v1.5 (Cobas). RESULTS A comparison of the qualitative results of both assays showed concordance for 1 negative and 184 positive samples (100%, kappa = 1.000). A significant correlation (R = 0.862, p < 0.001) and high agreement (95.53%) was observed for 179 samples with viral loads within the dynamic ranges of both assays. For samples of clades predominant in China, the fitted regression line differed significantly from the line of equality, although significant correlations (R = 0.694-0.899, p < 0.05) and high agreements (91.30-95.35%) were found for the two assays. The mean differences for samples from clades B' and BC were significant (p < 0.001) whilst no great difference (7.19-10.88%) between the quantitative values for both assays was found by plotting the regression line. CONCLUSION The viral loads of different HIV genotypes in China measured by the CAP/CTM and Cobas assays were comparable.