[Comparison of commercial HIV-1 viral load tests by using proficiency test results in China, 2013- 2015]

Objective: To compare the bio-equivalence among commercial HIV-1 viral load tests, including EasyQ HIV-1 v2.0 (EasyQ) from bioMerieux NucliSens of France; VERSANT HIV-1 RNA 3.0 assay (bDNA) from Siemens Healthcare Diagnostics of USA; COBAS AmpliPrep/COBAS TaqMan HIV-1 test (Taqman) from Roche Molecular Diagnosis of USA; Abbott Real Time HIV-1 Kit (M2000) from Abbott Molecular of USA and two domestic HIV-1 viral load test kits (domestic kit) from DaAn Gene Company of Sun Yat-Sen University and Liaoning Bio-Pharmaceutical company of Northeast pharmaceutical group, by using proficiency test results in China from 2013 to 2015. Methods: A total of 2 954 proficiency test results, obtained from 22 positive samples of 6 proficiency tests in 155 laboratories conducted by China CDC were analyzed during 2013-2015. The results from each sample were first logarithmic transformed and then grouped according to the method used, the mean value of logarithmic results was calculated. Subsequently, 22 clusters of mean values were analyzed by Bland-Altman analysis for the consistency, and linear regression analysis for the interdependency. Results: The results indicated that, by taking Taqman as the reference, EasyQ, M2000, bDNA and domestic kit had good consistency (90%-100%) and interdependency. Conclusion: All the viral load tests were bio-equivalent. Moreover, according to the conversion formula derived from domestic proficiency test results, all the viral load results could be converted, which is critical for epidemiological analysis.