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Updated: Jan 5, 2026
Using 22C3 Anti-PD-L1 Antibody Concentrate on Biopsy and Cytology Samples from Non-small Cell Lung Cancer Patients
Published on: September 25, 2018
Effects of Decalcifying Agents of Variable Duration on PD-L1 Immunohistochemistry
Amanda L Strickland1, Sara Blacketer2, Kyle Molberg1,2
1Department of Pathology, University of Texas Southwestern Medical Center, Dallas.
Objectives:
To evaluate the effects of decalcifying agents on programmed cell death ligand 1 (PD-L1) immunohistochemistry (IHC).
Methods:
Fragments of 10 placentas (high PD-L1 expressor) and 10 lungs (lower PD-L1 expressor) were formalin-fixed and subjected to four decalcifying solutions (EDTA, formic acid/MasterCal IM Plus [FA/MC], 12% HCl, and Decal STAT/23% HCl) for 1, 2, 6, or 24 hours. H&E staining and PD-L1 using IHC 22C3 pharmDx were performed, and PD-L1 staining was assessed.
Results:
Minimal to no change in staining intensity or proportion of stained cells was seen with EDTA or FA/MC at all decalcifying durations. Both HCl-based decalcifiers demonstrated a progressive decrease in percentage of positive cells and staining intensity with longer decalcifying duration, particularly with Decal STAT.
Conclusions:
EDTA and FA/MC have little effect on PD-L1 expression. 12% HCl causes a progressive decline in staining. Decal STAT dramatically reduced staining with all treatment durations, especially at 24 hours.
