Hot TopicsEvolution of Quality Assurance for Clinical Immunohistochemistry in the Era of Precision Medicine. Part 3: Technical Validation of Immunohistochemistry (IHC) Assays in Clinical IHC LaboratoriesTorlakovic, Emina E. MD, PhD*†‡; Cheung, Carol C. MD, PhD, JD*§; D’Arrigo, Corrado MB, ChB, PhD, FRCPath∥¶#; Dietel, Manfred MD, PhD**; Francis, Glenn D. MBBS, FRCPA, MBA, FFSc (RCPA)††,‡‡,§§; Gilks, C. Blake MD∥∥; Hall, Jacqueline A. PhD¶¶; Hornick, Jason L. MD, PhD##; Ibrahim, Merdol PhD***; Marchetti, Antonio MD, PhD†††; Miller, Keith FIBMS***; van Krieken, J. Han MD, PhD‡‡‡; Nielsen, Soren BMS§§§,∥∥∥; Swanson, Paul E. MD¶¶¶; Vyberg, Mogens MD§§§,∥∥∥; Zhou, Xiaoge MD###,****; Taylor, Clive R. MD††††; From the International Society for Immunohistochemistry and Molecular Morphology (ISIMM) and International Quality Network for Pathology (IQN Path) Author Information *Department of Laboratory Medicine and Pathobiology, University of Toronto Departments of †Laboratory Hematology §Pathology, University Health Network, Toronto, ON ∥∥Vancouver General Hospital, University of British Columbia, Vancouver, BC ¶¶¶Department of Pathology and Laboratory Medicine, Cumming School of Medicine University of Calgary, and Calgary Laboratory Services, Calgary, AB, Canada ‡Canadian Immunohistochemistry Quality Control (CIQC), Vancouver, BC, Canada/Canadian Association of Pathologists National Standards Committee for High Complexity Testing/Immunohistochemistry ∥Poundbury Cancer Institute ¶Dorset County Hospital NHS Foundation Trust, Dorchester, UK #Cancer Diagnostic Quality Assurance Services (CADQAScic), Dorchester ***UK National External Quality Assessment Scheme (UK NEQAS), University College London, London, UK **School of Medicine, Institute of Pathology, Charité—University Hospital, Berlin, Berlin, Germany ††Griffith University, Gold Coast ‡‡RCPA Quality Assurance Program, Sydney §§Genomics For Life, Brisbane, Australia ¶¶International Quality Network for Pathology (IQN Path), Luxembourg City, Luxembourg ##Brigham and Women’s Hospital, Harvard Medical School, Boston, MA †††Center of Predictive Molecular Medicine, Center for Excellence on Ageing and Translational Medicine, University of Chieti-Pescara, Chieti, Italy ‡‡‡Department of Pathology, Radboud University Medical Centre, Nijmegen, The Netherlands §§§Institute of Pathology, and Department of Clinical Medicine, Aalborg University, Aalborg University Hospital ∥∥∥Nordic Immunohistochemistry Quality Control (NordiQC), Aalborg, Denmark ###Department of Pathology, Beijing Friendship Hospital, Capital Medical University, Beijing ****Chinese Committee for Pathologists—Immunohistochemistry Quality Control, China ††††Keck School of Medicine, University of Southern California, Los Angeles, CA The authors declare no conflict of interest. Reprints: Emina E. Torlakovic, MD, PhD, Department of Laboratory Hematology, Toronto General Hospital/UHN, 200 Elizabeth Street, Toronto, ON, Canada M5G 2C4 (e-mail: [email protected]). Applied Immunohistochemistry & Molecular Morphology 25(3):p 151-159, March 2017. | DOI: 10.1097/PAI.0000000000000470 Buy Metrics Abstract Validation of immunohistochemistry (IHC) assays is a subject that is of great importance to clinical practice as well as basic research and clinical trials. When applied to clinical practice and focused on patient safety, validation of IHC assays creates objective evidence that IHC assays used for patient care are “fit-for-purpose.” Validation of IHC assays needs to be properly informed by and modeled to assess the purpose of the IHC assay, which will further determine what sphere of validation is required, as well as the scope, type, and tier of technical validation. These concepts will be defined in this review, part 3 of the 4-part series “Evolution of Quality Assurance for Clinical Immunohistochemistry in the Era of Precision Medicine.” Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.