title: The in vivo Pig-a assay: A report of the International Workshop On Genotoxicity Testing (IWGT) Workgroup.
abstract: The in vivo Pig-a assay uses flow cytometry to measure phenotypic variants for antibody binding to cell surface glycosylphosphatidylinositol (GPI)-anchored proteins. There is good evidence suggesting that the absence of antibody binding is the result of a mutation in the endogenous X-linked Pig-a gene, which forms the rationale for the assay. Although the assay has been performed with several types of hematopoietic cells and in a variety of mammalian species, including humans, currently it is optimized only for measuring CD59-deficient (presumed Pig-a mutant) erythrocytes in the peripheral blood of rats. An expert workgroup formed by the International Workshop on Genotoxicity Testing considered the state of assay development and the potential of the assay for regulatory use. Consensus was reached on what is known about the Pig-a assay and how it should be conducted, and recommendations were made on additional data and refinements that would help to further enhance the assay for use in hazard identification and risk assessment.
authors.affiliation: E(x)ponent , Midland, MI, USA.
authors.forename: B Bhaskar
authors.initials: BB
authors.lastname: Gollapudi
authors.affiliation: GlaxoSmithKline, Hertfordshire, UK.
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Lynch
authors.affiliation: US Food and Drug Administration, National Center for Toxicological Research, Jefferson, AR, USA. Electronic address: robert.heflich@fda.hhs.gov.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Heflich
authors.affiliation: Litron Laboratories, Rochester, NY, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Dertinger
authors.affiliation: US Food and Drug Administration, National Center for Toxicological Research, Jefferson, AR, USA.
authors.forename: Vasily N
authors.initials: VN
authors.lastname: Dobrovolsky
authors.affiliation: Federal Institute for Drugs and Medical Devices, Bonn, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Froetschl
authors.affiliation: National Institute of Health Sciences, Tokyo, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Horibata
authors.affiliation: Pfizer Global Research and Development, Groton, CT, USA.
authors.forename: Michelle O
authors.initials: MO
authors.lastname: Kenyon
authors.affiliation: Teijin Pharma, Tokyo, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Kimoto
authors.affiliation: St. George's, University of London, UK.
authors.forename: David P
authors.initials: DP
authors.lastname: Lovell
authors.affiliation: BioReliance, Rockville, MD, USA.
authors.forename: Leon F
authors.initials: LF
authors.lastname: Stankowski
authors.affiliation: Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada.
authors.forename: Paul A
authors.initials: PA
authors.lastname: White
authors.affiliation: National Institutes of Health, National Institute of Environmental Health Sciences, Division of the National Toxicology Program, Research Triangle Park, NC, USA.
authors.forename: Kristine L
authors.initials: KL
authors.lastname: Witt
authors.affiliation: Health and Environmental Sciences Institute, Washington, DC, USA.
authors.forename: Jennifer Y
authors.initials: JY
authors.lastname: Tanir
mesh_terms: D000743:Anemia, Hemolytic / Q000378:metabolism / Q000473:pathology; D000818:Animals; D000906:Antibodies / Q000737:chemistry; D004493:Education; D004912:Erythrocytes / Q000378:metabolism / Q000473:pathology; D005434:Flow Cytometry / Q000379:methods / Q000592:standards; D006456:Hemoglobinuria / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D051381:Rats
chemical_list: D000906:Antibodies; D008565:Membrane Proteins; C080086:phosphatidylinositol glycan-class A protein
keywords: CD59; Flow cytometry; Glycosylphosphatidylinositol; Mutation; Red blood cells; Reticulocytes