Quality control in diagnostic immunohistochemistry: integrated on-slide positive controls
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Standardization in immunohistochemistry is a priority in modern pathology and requires strict quality control. Cost containment has also become fundamental and auditing of all procedures must take into account both these principles. Positive controls must be routinely performed so that their positivity guarantees the appropriateness of the immunohistochemical procedure. The aim of this study is to develop a low cost (utilizing a punch biopsy—PB—tool) procedure to construct positive controls which can be integrated in the patient’s tissue slide. Sixteen frequently used control blocks were selected and multiple cylindrical samples were obtained using a 5-mm diameter punch biopsy tool, separately re-embedding them in single blocks. For each diagnostic immunoreaction requiring a positive control, an integrated PB-control section (cut from the appropriate PB-control block) was added to the top right corner of the diagnostic slide before immunostaining. This integrated control technique permitted a saving of 4.75% in total direct lab costs and proved to be technically feasible and reliable. Our proposal is easy to perform and within the reach of all pathology labs, requires easily available tools, its application costs is less than using external paired controls and ensures that a specific control for each slide is always available.
KeywordsQuality assurance Immunohistochemistry Positive controls Cost-saving
We wish to thank all the immunohistochemistry laboratory staff who helped with the project: Viviana Accorrà, Laura Barabino, Silvia Bonadio, Barbara Garzoglio and Laura Zito.
- Fitzgibbons PL, Bradley LA, Fatheree LA, Alsabeh R, Fulton RS, Goldsmith JD, Haas TS, Karabakhtsian RG, Loykasek PA, Marolt MJ, Shen SS, Smith AT, Swanson PE, College of American Pathologists Pathology and Laboratory Quality Center (2014) Principles of analytic validation of immunohistochemical assays: guideline from the College of American Pathologists Pathology and Laboratory Quality Center. Arch Pathol Lab Med 138:1432–1443. doi: 10.5858/arpa.2013-0610-CP CrossRefPubMedGoogle Scholar
- Hewitt SM, Robinowitz M, Bogen SA, Gown AM, Kalra KL, Otis CN, Spaulding B, Taylor CR (2011) Quality assurance for design control and implementation of immunohisotchemistry assays; approved guidelines - Second Edition. In: CLSI document I/LA28-A2. Clinical and Laboratory Standard Institute, Wayne, PAGoogle Scholar
- Hewitt SM, Baskin DG, Frevert CW, Stahl WL, Rosa-Molinar E (2014) Controls for immunohistochemistry: the Histochemical Society’s standards of practice for validation of immunohistochemical assays. J Histochem Cytochem 62:693–697. doi: 10.1369/0022155414545224 CrossRefPubMedPubMedCentralGoogle Scholar
- Torlakovic EE, Francis G, Garratt J, Gilks B, Hyjek E, Ibrahim M, Miller R, Nielsen S, Petcu EB, Swanson PE, Taylor CR, Vyberg M, International Ad Hoc Expert Panel (2014) Standardization of negative controls in diagnostic immunohistochemistry: recommendations from the international ad hoc expert panel. Appl Immunohistochem Mol Morphol 22:241–252. doi: 10.1097/PAI.0000000000000069 CrossRefPubMedPubMedCentralGoogle Scholar
- Torlakovic EE, Cheung CC, D’Arrigo C, Dietel M, Francis GD, Gilks CB, Hall JA, Hornick JL, Ibrahim M, Marchetti A, Miller K, van Krieken JH, Nielsen S, Swanson PE, Vyberg M, Zhou X, Taylor CR, From the International Society for Immunohistochemistry and Molecular Morphology (ISIMM) and International Quality Network for Pathology (IQN Path) (2017) Evolution of quality assurance for clinical immunohistochemistry in the era of precision medicine. part 3: technical validation of immunohistochemistry (IHC) assays in clinical IHC laboratories. Appl Immunohistochem Mol Morphol 25:151–159. doi: 10.1097/PAI.0000000000000470 CrossRefPubMedGoogle Scholar