PD-L1 and PD-L2 Are Differentially Expressed by Macrophages or Tumor Cells in Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type

Am J Surg Pathol. 2018 Mar;42(3):326-334. doi: 10.1097/PAS.0000000000000983.

Abstract

As checkpoint molecules' inhibition may represent a therapeutic option in relapsing cases, we assessed programmed death ligands' (PD-L1/PD-L2) expression in a series of 29 primary cutaneous diffuse large B-cell lymphoma, leg-type (PCDLBCL-LT) cases. Double immunostaining for either PD-L1 or PD-L2 was associated either with PAX5 staining to evaluate tumor cells or with CD68 or CD163 staining for macrophages. The microenvironment of PCDLBCL-LT was characterized by immunostainings for CD3 (tumor-infiltrating lymphocytes), FOXP3 (regulatory T cells), programmed cell death-1, and CD33 (myeloid-derived suppressor cells). The 9p24.1 locus encoding for PD-L1/PD-L2 was evaluated by fluorescence in situ hybridization. A PD-L1 expression was observed in all cases. However, double staining with PD-L1/PAX5 identified only 1 case harboring PD-L1 expression by tumor cells. All cases displayed PD-L1 expression by numerous immune cells, characterized as CD68 CD163 M2 macrophages. A normal fluorescence in situ hybridization pattern was observed in 21 of 26 cases. Three cases (11.5%) harbored a low polysomy status including the case with PD-L1 expression by tumor cells. Interestingly, 2 cases (7.7%) exhibited a PD-L1/PD-L2 locus break-apart pattern, and PD-L2 expression by tumor cells was observed. PD-L2 expression by tumor cells was not observed in the 24 cases without 9p24.1 rearrangement. Treating patients with relapsing PCDLBCL-LT by using immune checkpoint inhibitors may have an indirect effect through immune cells, except in rare cases with 9p24.1 rearrangement leading to PD-L2 expression by tumor cells. Reprogramming tumor-associated macrophages with anticancer therapies is appealing in such lymphoma subtypes wherein M2 macrophages represent the majority of immune cells.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antigens, CD / analysis
  • Antigens, Differentiation, Myelomonocytic / analysis
  • B7-H1 Antigen / analysis*
  • B7-H1 Antigen / genetics
  • Biomarkers, Tumor / analysis*
  • Biomarkers, Tumor / genetics
  • CD163 Antigen
  • Female
  • Gene Rearrangement
  • Genetic Loci
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Leg
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Lymphocytes, Tumor-Infiltrating / pathology
  • Lymphoma, Large B-Cell, Diffuse / genetics
  • Lymphoma, Large B-Cell, Diffuse / immunology*
  • Lymphoma, Large B-Cell, Diffuse / pathology
  • Macrophages / immunology*
  • Macrophages / pathology
  • Male
  • Middle Aged
  • PAX5 Transcription Factor / analysis
  • Programmed Cell Death 1 Ligand 2 Protein / analysis*
  • Programmed Cell Death 1 Ligand 2 Protein / genetics
  • Receptors, Cell Surface / analysis
  • Skin Neoplasms / genetics
  • Skin Neoplasms / immunology*
  • Skin Neoplasms / pathology
  • Tumor Microenvironment

Substances

  • Antigens, CD
  • Antigens, Differentiation, Myelomonocytic
  • B7-H1 Antigen
  • Biomarkers, Tumor
  • CD163 Antigen
  • CD274 protein, human
  • CD68 antigen, human
  • PAX5 Transcription Factor
  • PAX5 protein, human
  • PDCD1LG2 protein, human
  • Programmed Cell Death 1 Ligand 2 Protein
  • Receptors, Cell Surface