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.
Department of Medicine, Karolinska Hospital, Karolinska Institute, Stockholm, Sweden. annette.alaeus@inf.ds.sll.se
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Alaeus
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Lilja
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Herman
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Spadoro
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Wang
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Albert
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