Comparison of line probe assay (LIPA) and sequence analysis for detection of HIV-1 drug resistance

The identification of HIV strains that are resistant to antiretroviral drug s, which emerge during a patient's therapy or are already present in infect ed individuals prior to treatment, is of increasing importance for the clin ical management of HIV-infected persons. Two different methods were compare d for the genotypic detection of resistance development in the HIV-1 revers e transcriptase (RT) gene, the commonly used sequence analysis, and the com mercially available RT-line immunoprobe assay (LIPA), which can detect muta tions at six separate codons of the RT gene, which are known to confer resi stance to certain nucleoside inhibitors. Eighty serum samples from HIV-1-in fected persons, some of whom were receiving antiretroviral therapy, were in vestigated in parallel by sequencing as well as by LIPA. LIPA results agree d with sequence data in the vast majority of the cases. However, in 40% of the samples, LIPA failed to yield evaluable results for one or more of the codon positions. In particular, LIPA detection rate was low at codon 41 (75 %), whereas at codons 69/70, 74, 184, and 215 results were obtained from 90 %-95% of the samples. A number of mutations in the vicinity of the respecti ve codons were detected by sequencing, and these may have been responsible for the LIPA hybridization failure. There remained a number of samples, how ever, where no explanation for the lack of hybridization could be derived f rom sequence data. Our results indicate that the use of the LIPA does not e liminate the need for sequence analysis for detection of drug-resistant HIV strains. J. Med. Virol. 57:283-289, 1999. (C) 1999 Wiley-Liss, Inc.