title: Quantification of PD-L1 and PD-1 expression on tumor and immune cells in non-small cell lung cancer (NSCLC) using non-enzymatic tissue dissociation and flow cytometry.
abstract: We report a truly quantitative technology for PD-L1 expression in non-small cell lung cancer (NSCLC). In addition, we present a non-enzymatic technology that creates a cell suspension from fresh tumor tissue so that either fine-needle aspiration (FNA) or fresh tissue can be used in this assay.
  
  
  
  Non-enzymatic tissue homogenization (IncellPREP; IncellDx, Menlo Park, California) was performed on 4-mm punch biopsies. An FNA was taken from the same tumor to create matched sample sets. Cells were labeled with antibodies directed against CD45, PD-1, and PD-L1 and then stained with DAPI to identify intact, single cells, and to analyze cell cycle.
  
  
  
  Comparing the IncellPREP homogenization and FNA demonstrated a strong correlation (r2- 0.8) for expression of PD-L1. We compared PD-L1 expression by flow cytometry using a 1 % cutoff for positivity in the tumor cell population and a 1 % cutoff of cells with at least 1+ intensity in immunohistochemically stained tissue sections as positive. Ten of 12 lung tumor samples were concordant while 2 were discordant. PD-L1 expression by flow cytometry varied widely (1.2-89.4 %) even in the positive concordant cases. In addition, PD-L1 expression in the aneuploid tumor population did not necessarily agree with the expression in the diploid tumor population. Fine, unequivocal quantification of PD-L1 on tumor and immune cells in NSCLC may allow for better prediction of response to therapies. The present study also offers a technology that can create a universal sample type from either FNA or fresh tissue.
authors: IncellDx, Inc., 1700 El Camino Real, Menlo Park, CA, 94027, USA.
authors: Amanda
authors: A
authors: Chargin
authors: IncellDx, Inc., 1700 El Camino Real, Menlo Park, CA, 94027, USA.
authors: Rian
authors: R
authors: Morgan
authors: Department of Anatomic Pathology, William Beaumont Hospital, Royal Oak, MI, 48073, USA.
authors: Uma
authors: U
authors: Sundram
authors: IncellDx, Inc., 1700 El Camino Real, Menlo Park, CA, 94027, USA.
authors: Keith
authors: K
authors: Shults
authors: IncellDx, Inc., 1700 El Camino Real, Menlo Park, CA, 94027, USA.
authors: Ellen L
authors: EL
authors: Tsay
authors: Tissue Diagnostics Inc., 2829 Depot Road, Suite 4B, Hayward, CA, 94545, USA.
authors: Navneet
authors: N
authors: Ratti
authors: IncellDx, Inc., 1700 El Camino Real, Menlo Park, CA, 94027, USA. brucep@incelldx.com.
authors: Bruce K
authors: BK
authors: Patterson
mesh_terms: D060890:B7-H1 Antigen / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D044963:Biopsy, Fine-Needle; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D002469:Cell Separation / Q000379:methods; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D061026:Programmed Cell Death 1 Receptor / Q000378:metabolism*
chemical_list: D060890:B7-H1 Antigen; D014408:Biomarkers, Tumor; C423236:CD274 protein, human; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor
keywords: Cell cycle; Immune cells; Non-small cell lung cancer; PD-1; PD-L1