RT Journal Article
SR Electronic
T1 Validation of multiplex immunofluorescence and digital image analysis for programmed death-ligand 1 expression and immune cell assessment in non-small cell lung cancer: comparison with conventional immunohistochemistry
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 452
OP 458
DO 10.1136/jclinpath-2021-207448
VO 75
IS 7
A1 Jianghua Wu
A1 Luning Mao
A1 Wei Sun
A1 Xin Yang
A1 Haiyue Wang
A1 Xinying Liu
A1 Kaiwen Chi
A1 Xiaozheng Huang
A1 Dongmei Lin
YR 2022
UL http://jcp.bmj.com/content/75/7/452.abstract
AB Aims This study aimed to validate the application of combined multiplex immunofluorescence (mIF) and digital image analysis (DIA) in formalin-fixed and paraffin-embedded tissues for the quantitative assessment of programmed death-ligand 1(PD-L1) and immune cells (ICs) in non-small cell lung cancer (NSCLC).Methods Fifty resected samples of NSCLC were sequentially stained with a DNA-tagged mIF (panel including PD-L1, CKpan, CD8, CD68 and 4′,6-diamidino-2-phenylindole (DAPI)) and conventional immunohistochemistry (cIHC). The assessment of cell density and consistency of tumour proportion score (TPS) via DIA were compared with those by pathologists.Results A strong correlation in the cell population of immune markers was obtained between mIF and cIHC (for PD-L1: R=0.9304, CKpan: R=0.8231, CD8: R=0.9314 and CD68: R=0.8366) within 95% limits of agreement. The continuous TPS calculated using mIF was highly consistent with the IHC staining results which were evaluated by pathologists (R=0.9362). However, in the comparison of TPS using interval variables, a poor agreement was obtained at a cut-off of 1% (κ=0.197), whereas excellent agreement was achieved at cut-offs of 50% (κ=0.908) and 5% (κ=0.823). DIA on mIF showed that PD-L1 commonly colocalised with CD68+ macrophages and CD8+ cytotoxic cells were closer to PD-L1-/CK+ tumour cells (TCs) than to PD-L1+/CK+ TCs in spatial distribution.Conclusions A combination of mIF and DIA is useful for the quantification of PD-L1 expression and IC populations in NSCLC. Further validation of TPS at a cut-off of 1% and assay harmonisation is essential for translating this method in a diagnostic setting.Data are available on reasonable request. The data that support the findings of this study are available from the corresponding author on reasonable request.