1. Measurement of LAG-3 Expression Across Multiple Staining Platforms With the 17B4 Antibody Clone
- Author
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Wojcik, John B., Desai, Keyur, Avraam, Konstantinos, Vandebroek, Arno, Dillon, Lloye M., Giacomazzi, Giorgia, Rypens, Charlotte, and Benci, Joseph L.
- Subjects
Immunohistochemistry -- Measurement ,Viral antibodies -- Measurement ,Antibodies -- Measurement ,Cloning -- Measurement ,Melanoma -- Measurement ,Algorithms -- Measurement ,Algorithm ,Health - Abstract
* Context.--An immunohistochemistry (IHC) assay developed to detect lymphocyte-activation gene 3 (LAG-3), a novel immune checkpoint inhibitor target, has demonstrated high analytic precision and interlaboratory reproducibility using a Leica staining platform, but it has not been investigated on other IHC staining platforms. Objective.--To evaluate the performance of LAG-3 IHC assays using the 17B4 antibody clone across widely used IHC staining platforms: Agilent/Dako Autostainer Link 48 and VENTANA BenchMark ULTRA compared to Leica BOND-RX (BOND-RX). Design.--Eighty formalin-fixed, paraffin-embedded melanoma tissue blocks were cut into consecutive sections and evaluated using staining platform-specific IHC assays with the 17B4 antibody clone. Duplicate testing was performed on the BOND-RX platform to assess intraplatform agreement. LAG-3 expression using a numeric score was evaluated by a pathologist and with a digital scoring algorithm. LAG-3 positivity was determined from manual scores using a 1% or greater cutoff. Results.--LAG-3 IHC staining patterns and intensities were visually similar across all 3 staining platforms. Spearman and Pearson correlations were 0.75 or greater for interplatform and BOND-RX intraplatform concordance when LAG-3 expression was evaluated with a numeric score determined by a pathologist. Correlation increased with a numeric score determined with a digital scoring algorithm (Spearman and Pearson correlations [greater than or equal to] 0.88 for all comparisons). Overall percentage agreement was 77.5% or greater for interplatform and BOND-RX intraplatform comparisons when LAG-3 positivity was determined using a 1 % or greater cutoff. Conclusions.--Data presented here demonstrate that LAG-3 expression can be robustly and reproducibly assessed across 3 major commercial IHC staining platforms using the 17B4 antibody clone. doi: 10.5858/arpa.2022-0082-OA, Lymphocyte-activation gene 3 (LAG-3) is a cell-surface immune checkpoint molecule expressed on immune cells (ICs) initiating an inhibitory signal that can impair T-cell activity and attenuate proinflammatory cytokine responses. (1-3) [...]
- Published
- 2023
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