Abstract
Objective Lymphomas are the third most common cancer after squamous cell carcinoma and salivary
gland tumors. Extranodal diffuse B cell lymphoma (DBCL) represents 30 to 58% of non-Hodgkin's
lymphoma. One of the major problems of DBCL is the high likelihood of disease relapse
following treatment. A recent trend in the treatment of diffuse large B cell lymphoma
(DLBCL) is blockage of an immune checkpoint inhibitor that targets the programmed
death of cell ligand 1 receptors (PD-L1). PD-L1 activation results in negative regulatory
signals that induce apoptosis and inhibit tumor antigen-specific T cells allowing
immune evasion of the tumor.
The aim of this aim is to measure the expression level of PD-L1 on oral tissue samples
from DLBCL patients using immunohistochemistry.
Materials and Methods This current study was performed at the Faculty of Dentistry, Tanta University, Egypt.
Ethical approval was conducted from Faculty of Dentistry, Tanta University. Tissue
samples were collected from 13 patients diagnosed with oral extranodal DLBCL) nongerminal
center B cell like subtype. Both hematoxylin and eosin and immunohistochemical staining
(The avidin-biotin-complex procedure) was performed with anti-PD-L1 antibody (clone
number: 28–8, Abcam, Cambridge, Massachusetts, United States).
Cytoplasmic and/or membranous positive intensity was graded as follows: very mild
staining, mild staining, moderate staining, and intense staining using Image J, 1.41a
(National Institutes of Health, United States) image analysis software. The mean area
fraction of the stained cells was calculated by counting immunostained cells in three
fields of each case by two pathologists. Data was entered in SPSS program for analysis.
Results PD-L1 was overexpressed on tumor cells of oral extranodal DLBCL than control cells
from lesion free areas of oral tissues of the same patient.
Keywords
oral extranodal diffuse B cell lymphoma - diffuse large B cell lymphoma - programmed
cell death ligand 1