Short Communication
Joseph Nkeze, Dong Liang, Heat
Abstract
Accurate quantification of HIV-1 viral load (VL) is crucial for disease monitoring and management. This study was designed to compare HIV-1 VL determination between two of the major commercial real-time PCR-based methods, i.e., the Roche’s COBAS AmpliPrep/COBAS TaqMan HIV-1 Test and the Abbott Real Time HIV-1 Assay. Out of 308 paired plasma tested, 85.1% (262/308) of test results were concordant with 173 samples were quantifiable for VL and 89 were “Not Detected” (ND). There was a strong overall correlation of the quantifiable VL between the two methods (R2=0.952). Comparison of the mean VL with differences of the two methods using the Bland Altman plot showed rough symmetric distribution of the differences, indicating neither method is better than the other for measuring VL. However, a relative high 14.9% (46/308) of discordant results was found between the two methods. ?2 test of those discordant results indicated a significant difference (?2= 96.37; p = <0.001). Of the 104 ND Roche samples, 15 (14.4%) were detected by Abbott method; of the 120 ND Abbott samples, 31 (25.8%) were detected by Roche method. Differences in gene target, test sensitivity, input volume and their abilities to detect different HIV-1 subtypes could potentially explain some of the discordance.