REACTIVITY AND AMPLIFICATION EFFICIENCY OF THE NASBA HIV-1 RNA AMPLIFICATION SYSTEM WITH REGARD TO DIFFERENT HIV-1 SUBTYPES

In view of the genetic diversity of the human immunodeficiency virus T ype 1, we assessed the sensitivity and quantification efficiency of th e HIV-1 RNA NASBA amplification system with respect to different HIV-1 subtypes and recombinants. Twenty cell culture supernatants represent ing 17 HIV-1 group M and 3 group O strains were tested, and NASBA RNA loads were compared with results obtained with a RT-PCR based HIV-1 RN A quantitation method, with p24-antigen concentrations and with the in fective dose. The current HIV-1 RNA NASBA seemed suitable to quantitat e representatives of different HIV-1 M subtypes. Differences between N ASBA and RT-PCR loads were observed for certain HIV-1 M strains. Signi ficantly lower RT-PCR loads were measured for most gag A, gag B and ga g F strains, whereas NASBA detected lower copy numbers in 1 gag H stra in and 1 gag H/env G recombinant. NASBA was not able to quantify 1 HIV -1 group M recombinant. Some of these differences could be explained b y the presence and position of mismatches with primers. HIV-I group O strains were not detectable by both RNA amplification methods. A firm correlation was not observed between the measured RNA loads and either the p24-antigen concentration or the infective dose. (C) 1997 Elsevie r Science B.V.