AEGiS-12IAC: Discordances between peptide serotyping and HMA genotyping in distinguishing HIV-1 subtype B from non-B.

12th International AIDS Conference


Geneva, Switzerland - June 28-July 3, 1998

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Discordances between peptide serotyping and HMA genotyping in distinguishing HIV-1 subtype B from non-B.

Int Conf AIDS 1998 Jun 28-Jul 3; 12:21 (abstract no. 11193)

Murphy G, Belda FJ, Clewely JP, Parry JV
Central Public Health Laboratory, London, UK.

BACKGROUND: Assignation of HIV-1 samples to specific subtypes is important for diagnosis, disease monitoring, treatment and vaccine development.

OBJECTIVE: To correlate subtype specific serotyping and genotyping, and investigate discordant results.

METHOD: We compared the ability of a peptide-based serotyping assay to assign HIV-1 infections to specific subtypes with that of genotypic analysis of amplified HIV-1 sequences from the same specimens. Subtype B and non-B specimens were differentiated by the heteroduplex mobility assay (HMA) using only subtype A and subtype B plasmids; the same specimens were tested with the peptide based serotyping assay. Results that were discordant were further investigated with a full HMA plasmid panel and/or by sequencing.

RESULTS: On the basis of genotyping, serotyping was 69% accurate for all subtypes. Of 68 samples that reacted monotypically as serotype B, 64 were genotype B (2 were D, 1 was A, 1 was unamplifiable). An additional 4 genotype B specimens were monotypically reactive with heterologous peptide antigens (2 were A, 2 were C). Variation in the amino acids of the immunoreactive gp 120 V3 crown recovered from the infecting HIV strain of the 7 serotypically anomalous specimens was investigated. In 5 of these specimens discordant results occurred when the peptide sequence closely resembled more than one consensus peptide antigen or the observed V3 crown motif of the strain was atypical for the genetic subtype present. Five specimens gave unclear or discordant results in the initial HMA screen and were only resolved when the full plasmid panel was employed.

CONCLUSIONS: Serotyping is generally adequate to distinguish between subtype B and non-B, but not between all non-B subtypes. For non-B specimens genotyping is required.

Keywords: AEGIS, HIV-1, Serotyping, HIV Infections, Genotype, HIV Seropositivity, Peptides, Variation (Genetics), Peptide Fragments, genetics, ICA12KWDaegis,hiv-1,serotyping,hivinfections,genotype,hivseropositivity,peptides,variation(genetics),peptidefragments,genetics,ica12
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Copyright © 1998 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.