title: A gp41-based heteroduplex mobility assay provides rapid and accurate assessment of intrasubtype epidemiological linkage in HIV type 1 heterosexual transmission Pairs.
abstract: A critical step in HIV-1 transmission studies is the rapid and accurate identification of epidemiologically linked transmission pairs. To date, this has been accomplished by comparison of polymerase chain reaction (PCR)-amplified nucleotide sequences from potential transmission pairs, which can be cost-prohibitive for use in resource-limited settings. Here we describe a rapid, cost-effective approach to determine transmission linkage based on the heteroduplex mobility assay (HMA), and validate this approach by comparison to nucleotide sequencing. A total of 102 HIV-1-infected Zambian and Rwandan couples, with known linkage, were analyzed by gp41-HMA. A 400-base pair fragment within the envelope gp41 region of the HIV proviral genome was PCR amplified and HMA was applied to both partners' amplicons separately (autologous) and as a mixture (heterologous). If the diversity between gp41 sequences was low (<5%), a homoduplex was observed upon gel electrophoresis and the transmission was characterized as having occurred between partners (linked). If a new heteroduplex formed, within the heterologous migration, the transmission was determined to be unlinked. Initial blind validation of gp-41 HMA demonstrated 90% concordance between HMA and sequencing with 100% concordance in the case of linked transmissions. Following validation, 25 newly infected partners in Kigali and 12 in Lusaka were evaluated prospectively using both HMA and nucleotide sequences. Concordant results were obtained in all but one case (97.3%). The gp41-HMA technique is a reliable and feasible tool to detect linked transmissions in the field. All identified unlinked results should be confirmed by sequence analyses.
authors.affiliation: Rwanda Zambia HIV Research Group (RZHRG), Projet San Francisco (PSF), Kigali, Rwanda.
authors.forename: Olivier
authors.initials: O
authors.lastname: Manigart
authors.forename: Debrah I
authors.initials: DI
authors.lastname: Boeras
authors.forename: Etienne
authors.initials: E
authors.lastname: Karita
authors.forename: Paulina A
authors.initials: PA
authors.lastname: Hawkins
authors.forename: Cheswa
authors.initials: C
authors.lastname: Vwalika
authors.forename: Nathan
authors.initials: N
authors.lastname: Makombe
authors.forename: Joseph
authors.initials: J
authors.lastname: Mulenga
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Derdeyn
authors.forename: Susan
authors.initials: S
authors.lastname: Allen
authors.forename: Eric
authors.initials: E
authors.lastname: Hunter
mesh_terms: D004586:Electrophoresis; D005260:Female; D015700:HIV Envelope Protein gp41 / Q000235:genetics*; D015658:HIV Infections / Q000635:transmission* / Q000821:virology*; D015497:HIV-1 / Q000235:genetics / Q000302:isolation & purification*; D020180:Heteroduplex Analysis / Q000379:methods*; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology / Q000379:methods*; D008969:Molecular Sequence Data; D011446:Prospective Studies; D017422:Sequence Analysis, DNA; D014773:Virology / Q000379:methods*
chemical_list: D015700:HIV Envelope Protein gp41; C514787:gp41 protein, Human immunodeficiency virus 1