AEGiS-14IAC: HIV-1 resistance testing using a commercial kit can be performed reliably without prior sequencing experience.

14th International AIDS Conference

Barcelona, Spain - July 7-12, 2002

HIV-1 resistance testing using a commercial kit can be performed reliably without prior sequencing experience.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. B10187)

Debaisieux L, Laethem KV, Vandamme AM, Schrooten Y, Delforge ML, Liesnard C
Hopital Erasme-Universite Libre de Bruxelles, Bruxelles, Belgium

OBJECTIVE: To compare 1) sequencing results obtained with a commercial kit in a lab without experience in sequencing (Lab A) with those of an experienced lab (Lab B), 2) the drug resistance reports generated.

METHODS: 16 plasma samples already analyzed by Lab B were retrospectively tested by Lab A. Lab A used the TRUGENE HIV-1 Genotyping Kit and its interpretation algorithm (Visible Genetics). Prior the study, the operator (who had 10 years experience of nucleic acid testing but no sequencing experience) completed a 3-day training at Visible Genetics. Lab B used the ViroSeq HIV-1 Genotyping System (Applied Biosystem) or an in-house sequencing protocol and an in-house algorithm.

RESULTS: 50 individual mutations related to antiretroviral resistance (29 in the RT gene, 21 in the protease gene) were studied (800 positions for the 16 samples). For 6 samples detected mutations were different. 126 resistance related mutations were found in both labs (mixed wildtype/mutant populations were considered as mutant). 2/800 mixed populations identified in lab A were wildtype in Lab B. 8/800 mixed populations identified in lab B were wildtype in Lab A (6/8 in 1 sample). Concordance (% of identical response/position) between the 2 labs was 98.8 %. Drug resistance reports (15 drugs evaluated) were different for 14/16 samples (57 drugs/240). In only 2 samples, these discrepancies were due to difference in detected mutations (corresponding to 9 drugs). In all other cases, different resistance reports (no shifts from resistant to no evidence of resistance) were due to the use of a different algorithm.

CONCLUSION: Highly reliable sequencing results can be obtained using a commercial kit without prior experience in sequencing. Correlation of techniques in term of detected mutations was very good. Differences in term of drug resistance deduced were mainly due to interpretatiion rules of the algorithms.

Keywords: AEGIS, HIV-1, HIV-1 Reverse Transcriptase, Renin, Chymosin, Genotype, Mutation, Research Design, Oncogenes, genetics

020707
B10187