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J Clin Microbiol. 2013 Jul;51(7):2063-71. doi: 10.1128/JCM.00510-13. Epub 2013 Apr 17.

Results of external quality assessment for proviral DNA testing of HIV tropism in the Maraviroc Switch collaborative study.

Collaborators (153)

Salomon H, Mazzini S, Rubio AE, Kelleher A, Marks K, Suzuki K, Rismanto N, Birch C, Chibo D, Harrigan R, Swenson L, Chan D, Acevedo W, Manque P, Polanco V, Berg T, Obermeier M, Kaiser R, Luebke N, Coughlan S, Dean J, Mor O, Wax M, Sugiura W, Iwatani Y, Teran GR, Avila S, Pumarola T, Ruxrungtham K, Sirivichayakul S, Naphassanant M, Ubolyam S, Kaye S, Land S, Vincini J, Best S, Losso M, Viloria G, Parlante A, Sanchez M, De Paz Sierra M, Bissio E, Luchetti P, Lupo S, Peroni L, Warley E, Ines Vieni L, Porteiro N, Vilas C, Kelly M, Gibson A, Bloch M, Franic T, Donohue W, Thompson J, Elliot J, Hamill P, Boglis M, Sowden D, Murray S, Hehir J, Johnston C, Pett SL, Cooper D, MacRae K, Sinclair B, Dwyer D, Assam D, Woolley I, Gillies A, Orth D, Youds D, LeBlanc R, Lanteigne F, Walmsley S, Chan W, Gill J, Beckthold B, Smith G, Halpenny R, Robinette Hills J, Wolff M, Allende G, Prazuck T, de-dieuleveult B, Stephan C, Ebeling F, Wengenroth C, Jensen B, Feind C, Meyer-Olson D, Hoeper K, Beider R, Faetkenheuer G, Rund E, Ingiliz P, Wienbreyer A, Rockstroh J, Engelhardt A, Boesecke C, Spaeth B, Jessen H, Zedlack C, Stellbrink HJ, Mallon P, Simelane S, Sugiura W, Imahashi M, Losso M, Belloso W, Guelman D, Valdovinos M, Andrade-Villanueva J, Montes K, Madero JS, Hernandez ES, Ballesteros ER, Mosqueda L, Lopez-Segura M, Gatell J, González A, Paredes R, Puig J, Clotet B, Delgado M, Arribas J, Castro JM, Arnaiz A, Beleta H, Pich J, Ruxrungtham K, Intasan J, Maek-a-nantawat W, Winston A, Mullaney S, Fisher M, Clarke A, Richardson C, Perry N, Cooper D, Emery S, Pett L, Berthon-Jones N, Silk D, Tu E, Courtney-Vega K, Absar N, Amin J, Haskelberg H, Kelleher A, Merlin K, Yeung J, Fsadni B.

Author information

1
The Kirby Institute, University of New South Wales, Sydney, NSW, Australia. etu@kirby.unsw.edu.au

Abstract

The Maraviroc Switch collaborative study (MARCH) is a study in aviremic patients on stable antiretroviral therapy and utilizes population-based sequencing of proviral DNA to determine HIV tropism and susceptibility to maraviroc. An external quality assessment (EQA) program was implemented to ensure competency in assessing the tropism of clinical samples conducted by MARCH laboratories (n = 14). The MARCH EQA has three prestudy phases assessing V3 loop sequencing and tropism determination using the bioinformatic algorithm geno2pheno, which generates a false-positive rate (FPR). DNA sequences with low FPRs are more likely to be from CXCR4-using (X4) viruses. Phase 1 of the EQA involved chromatogram interpretation. Phases 2, 2/3, and 3 involved patient and clonal samples. Clinical samples used in these phases were from treatment-experienced HIV-infected volunteers; 18/20 had viral loads of <50 copies/ml, and 10/15 were CXCR4-tropic on prior phenotyping. All samples were tested in triplicate, and any replicate with a geno2pheno FPR of <10% was designated X4. Performance was deemed adequate if ≤2 R5 and ≤1 X4 specimens were miscalled. For several clinical samples in the EQA, triplicate testing revealed marked DNA variability (FPR range, 0 to 96.7%). Therefore, a consensus-based approach was employed for each sample, i.e., a median FPR across laboratories was used to define sample tropism. Further sequencing analysis showed mixed viral populations in the clinical samples, explaining the differences in tropism predictions. All laboratories passed the EQA after achieving predefined competence thresholds in either of the phase 2 rounds. The use of clinical samples from patients resembling those who were likely to be screened in the MARCH, coupled with triplicate testing, revealed inherent DNA variability that might have been missed if single or duplicate testing and/or clonal samples alone were used. These data highlight the importance of intensive EQA of tropism laboratories before embarking on clinical studies. (This study has been registered at ClinicalTrials.gov under registration no. NCT01384682 [http://www.clinicaltrials.gov/ct2/show/study/NCT01384682?term=NCT01384682&rank=1].).

PMID:
23596247
PMCID:
PMC3697703
DOI:
10.1128/JCM.00510-13
[Indexed for MEDLINE]
Free PMC Article

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