Validation and Implementation of OptiView and EnVision FLEX Detection Systems for Immunocytochemical Staining Protocols of the Ten Most Commonly Used Diagnostic Markers in Routine Cytopathological Practice

Abstract

The withdrawal of the iView detection system (iV) forced many cytopathology laboratories, including ours, to substitute immunocytochemical (ICC) staining protocols for routine practice with other detection systems. Our objective was to optimize, validate, and implement ICC protocols using OptiView (OV) and EnVision FLEX (EnV) detection systems, comparing the results with those obtained using iV. Residual cytologic samples with known diagnoses were used, testing antibodies for the ten most common markers in routine cytopathology diagnostics (calretinin, Ber-EP4, MOC-31, CKAE1/AE3, CK5/6, CD68, LCA, desmin, HBME-1, and WT1). Different staining parameters were tested using OV on BenchMark ULTRA and EnV on Dako Omnis immunostainer, respectively. Optimal staining protocols were then selected and validated on 10 positive and 10 negative cases. The staining results were compared with iV protocols through evaluation of UK NEQAS and internal scores. The optimal staining protocols with OV and EnV demonstrated similar or superior results compared to the existing iV protocols, with slightly stronger intensity regarding positive cells. We have successfully established and validated optimal ICC staining protocols for commonly used markers in routine cytopathology practice. These protocols may benefit other laboratories using similar staining platforms. However, the challenge regarding standardizing ICC protocols across different cytopathology laboratories remains unresolved.