Performance of an in-house genotypic antiretroviral resistance assay in patients pretreated with multiple human immunodeficiency virus type 1 protease and reverse transcriptase inhibitors.
An in-house genotypic antiretroviral resistance assay was evaluated by testing 32 plasma samples obtained from heavily pretreated human immunodeficiency virus type 1 (HIV-1)-infected patients failing multiple antiretroviral regimens. The same samples were also sent to Virco Laboratories for genotypic (VircoGEN) and phenotypic (Antivirogram) resistance analysis. Sequencing results obtained by in-house (HG) and VircoGEN (VG) genotyping were concordant for 387 of 400 (96.75%) drug resistance mutations. Genotype-based prediction of drug susceptibility for 13 currently licensed antiretroviral compounds were in agreement in 336 (80.78%) cases, partially concordant in 73 (17.54%) cases and discordant in only seven (1.68%) cases. VG indicated 'possible resistance' twice as much as HG. When genotype interpretation was compared with the Antivirogram phenotypic data, there were 27 (6.49%) and 23 (5.52%) wrong calls by HG and by VG, respectively. Both assays were more sensitive in detecting drug resistance than drug susceptibility (94.61 vs. 65.19% for HG, 80.84 vs. 56.91% for VG) and more specific in detecting drug susceptibility than drug resistance (93.62 vs. 73.49% for HG, 93.62 vs. 80.32% for VG). Rule-based algorithms can reliably interpret genotypic data obtained from most heavily pretreated patients. However, occasional genotypic patterns may be erroneously interpreted without resistance phenotyping.
U. O. Malattie Infettive, Ospedale S.M. Annunziata, Firenze, Italy.
C
C
Peduzzi
P
P
Pierotti
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G
Venturi
L
L
Romano
F
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Mazzotta
M
M
Zazzi
D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D024882:Drug Resistance, Viral / Q000235:genetics*; D005838:Genotype; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy / Q000821:virology*; D016333:HIV Protease / Q000235:genetics*; D017320:HIV Protease Inhibitors / Q000627:therapeutic use*; D054303:HIV Reverse Transcriptase / Q000235:genetics*; D015497:HIV-1 / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D011933:Reagent Kits, Diagnostic; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*
D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D011933:Reagent Kits, Diagnostic; D018894:Reverse Transcriptase Inhibitors; D054303:HIV Reverse Transcriptase; D016333:HIV Protease