COMPARISON OF THE AMPLICOR HIV-1 MONITOR TEST AND THE NUCLEIC-ACID SEQUENCE-BASED AMPLIFICATION ASSAY FOR QUANTITATION OF HUMAN-IMMUNODEFICIENCY-VIRUS RNA IN PLASMA, SERUM, AND PLASMA SUBJECTED TO FREEZE-THAW CYCLES

The Amplicor HIV-1 Monitor test was compared to the nucleic acid seque nce based amplification (Nasba) assay system for the quantitation of h uman immunodeficiency virus (HIV) RNA in three different types of clin ical samples: plasma, serum, and plasma subjected to freeze-and-thaw c ycles, Each assay detected HIV RNA in the same 73 (90%) of 81 samples tested, and the quantitative results obtained with the two assays were significantly correlated, Both assays detected higher RNA levels in p atients with CD4(+) cell counts lower than 200 cells/mm(3) than in pat ients with CD4(+) cell counts higher than 200 cells/mm(3), In addition , RNA levels in plasma higher than 5 logs predicted higher numbers of clinical events than did RNA levels in plasma lower than 5 logs, Quant itation of HIV RNA in paired plasma and serum samples showed lower HIV RNA content in serum than in the paired plasma sample, with mean diff erences between HIV RNA contents of plasma and serum of 0.54 and 0.28 log RNA copy/ml by the Nasba assay and the Amplicor HIV-1 Monitor assa y, respectively, No significant loss of HIV RNA was detected with eith er assay in plasma samples subjected to multiple freeze-and-thaw cycle s, These studies demonstrate that the Nasba and Amplicor assays perfor m similarly with plasma and serum samples, Further, the results indica te that freeze-and-thaw cycles do not result in significant loss of de tectable HIV RNA.