Assay of plasma samples representing different HIV-1 genetic subtypes: an evaluation of new versions of the amplicor HIV-1 monitor assay.
Quantification of plasma HIV-1 RNA levels has rapidly become the main tool for monitoring disease progression and treatment. However, some first-generation assays do not accurately quantify all HIV-1 subtypes. This study compares the first-generation and two newer prototype Amplicor HIV-1 Monitor assays (Roche Diagnostic Systems) in terms of their performance in quantifying HIV-1 RNA in stored plasma samples from 101 individuals infected with various genetic subtypes of HIV-1 (28 subtype A, 18 B, 26 C, 20 D, 2 E, 3 G, 2 H, and 2 J). The HIV-1 subtype had previously been determined by direct sequencing of the V3 domain of the env gene. The results from the three assays agreed for subtypes B and C, as well as for most subtype D samples. In contrast, the first-generation assay reported significantly lower plasma HIV-1 RNA levels than did the two newer versions of the assay for most subtype A, E, G, and H samples. There were no differences in mean plasma HIV-1 RNA levels between individuals infected with subtypes A, B, C, and D if the results from the two newer test versions were used, and if an adjustment was made between subtypes for differences in CD4 count. Thus, this study confirms that the first-generation assay does not accurately quantify HIV-1 RNA levels in many individuals infected with subtype A, E, G, and H. These problems appeared to have been greatly reduced in the two new prototype versions.
Alaeus
A
A
Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, Sweden. annette.alaeus@inf.ds.sll.se
Lilja
E
E
Herman
S
S
Spadoro
J
J
Wang
J
J
Albert
J
J
D005069:Evaluation Studies as Topic; D014644:Genetic Variation; D005838:Genotype; D015699:HIV Envelope Protein gp120 / Q000235:genetics*; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy / Q000821:virology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D006801:Humans; D010446:Peptide Fragments / Q000235:genetics*; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood*; D011933:Reagent Kits, Diagnostic; D019562:Viral Load
D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic