Table 2.

Expression of PD-L1 in primary lymphoma tissue specimens

PD-L1 detection methodLymphoma subtypeNumber of casesNumber of PD-L1+% PD-L1+
A. Immunohistochemistry: frozen specimensHLa9889
B. Flow cytometry: cryopreserved specimensFL1600
Small lymphocytic lymphoma/chronic lymphocytic leukemia200
Marginal zone lymphoma300
Mantle cell lymphoma100
Burkitt lymphoma100
C. Immunohistochemistry: paraffin specimensALCL5480
D. Immunohistochemistry
 Frozen (MIH1 antibody)   331 (5%)18 (95%)8 (57%)6 (42%)0.0004
 Paraffin (5H1 antibody)   300 (0%)11 (100%)6 (32%)13 (68%)0.0613

NOTE: Immunohistochemistry of frozen sections (A) and flow cytometry (B) of cryopreserved specimens were conducted with the anti-PD-L1 antibody clone MIH1. Paraffin sections (C) were stained with clone 5H1. Frozen and paraffin sections of DLBCL were classified as germinal center origin or nongerminal center origin (D). PD-L1 expression in DLBCL occurs almost exclusively in tumors of nongerminal center origin.

  • aStaining in Hodgkin and Reed–Sternberg cells.