COMPARISON OF THE QUANTIPLEX HIV-1 RNA-2.0 ASSAY WITH THE AMPLICOR HIV-1 MONITOR-1.0 ASSAY FOR QUANTITATION OF LEVELS OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 RNA IN PLASMA OF PATIENTS RECEIVING STAVUDINE-DIDANOSINE COMBINATION THERAPY

We compared the QUANTIPLEX HIV-1 RNA 2.0 assay with the AMPLICOR HIV-1 MONITOR 1.0 assay for quantitation of human immunodeficiency virus ty pe 1 (HIV-1) RNA in plasma in the Stadi trail, which evaluated a stavu dine plus didanosine combination therapy in 52 patients. HIV-1 RNA bas eline values measured with AMPLICOR HIV-1 MONITOR 1.0 were significant ly higher than those measured with QUANTIPLEX HIV-1 RNA 2.0, and decre ases in HIV-1 RNA levels from baseline were also found to be significa ntly higher when measured with the AMPLICOR HIV-1 MONITOR 1.0 assay. T he frequency of HIV-1 RNA levels below the lower limit of quantitation was significantly higher with QUANTIPLEX HIV-1 RNA 2.0 than with AMPL ICOR HIV-I MONITOR 1.0. Reanalysis of these results by an ultrasensiti ve procedure of AMPLICOR HIV-1 MONITOR 1.0 or by a modified version of the test that included additional primers adapted for non-B HIV-1 cla des yielded greater differences between the QUANTIPLEX HIV-1 RNA 2.0 a ssay and the AMPLICOR HIV-1 MONITOR 1.0 assay. Our results indicate th at a valid comparison of the virological efficacies obtained with diff erent antiretroviral drug regimens requires the use of the same viral load quantitation procedure; further standardization between the diffe rent HIV-1 RNA quantitation kits is therefore needed.