title: A systematic review of definitions of extreme phenotypes of HIV control and progression.
abstract: The study of individuals at opposite ends of the HIV clinical spectrum can provide invaluable insights into HIV biology. Heterogeneity in criteria used to define these individuals can introduce inconsistencies in results from research and make it difficult to identify biological mechanisms underlying these phenotypes. In this systematic review, we formally quantified the heterogeneity in definitions used for terms referring to extreme phenotypes in the literature, and identified common definitions and components used to describe these phenotypes. We assessed 714 definitions of HIV extreme phenotypes in 501 eligible studies published between 1 January 2000 and 15 March 2012, and identified substantial variation among these. This heterogeneity in definitions may represent important differences in biological endophenotypes and clinical progression profiles of individuals selected by these, suggesting the need for harmonized definitions. In this context, we were able to identify common components in existing definitions that may provide a framework for developing consensus definitions for these phenotypes in HIV infection.
authors.affiliation: aWellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton bStrangeways Research Laboratory, Department of Public Health and Primary Care, University of Cambridge, Wort's Causeway, Cambridge cMedical Research Council, Clinical Trials Unit, Aviation House, London, UK dCentre for the AIDS Programme of Research in South Africa (CAPRISA), Doris Duke Medical Research Institute, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa eWellcome Trust Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford fImperial College Healthcare NHS Trust, London gCambridge University Hospitals NHS Foundation Trust, Department of Infectious Diseases, Addenbrooke's Hospital, Cambridge hKing's College London, Weston Education Centre iDivision of Infection and Immunity, University College London, London, UK.
authors.forename: Deepti
authors.initials: D
authors.lastname: Gurdasani
authors.forename: Louise
authors.initials: L
authors.lastname: Iles
authors.forename: David G
authors.initials: DG
authors.lastname: Dillon
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Young
authors.forename: Ashley D
authors.initials: AD
authors.lastname: Olson
authors.forename: Vivek
authors.initials: V
authors.lastname: Naranbhai
authors.forename: Sarah
authors.initials: S
authors.lastname: Fidler
authors.forename: Effrossyni
authors.initials: E
authors.lastname: Gkrania-Klotsas
authors.forename: Frank A
authors.initials: FA
authors.lastname: Post
authors.forename: Paul
authors.initials: P
authors.lastname: Kellam
authors.forename: Kholoud
authors.initials: K
authors.lastname: Porter
authors.forename: Manjinder S
authors.initials: MS
authors.lastname: Sandhu
mesh_terms: D018450:Disease Progression; D015658:HIV Infections / Q000175:diagnosis* / Q000473:pathology*; D020276:HIV Long-Term Survivors; D006801:Humans; D010641:Phenotype; D009626:Terminology as Topic