Cluster of differentiation 31 (CD31), also known as platelet/endothelial cell adhesion molecule‑1 (PECAM‑1), is a 130 kDa transmembrane glycoprotein of the immunoglobulin superfamily. It is highly expressed at endothelial intercellular junctions and on select hematopoietic cells, including platelets, monocytes, neutrophils, and subsets of lymphocytes. CD31 mediates homophilic and heterophilic adhesion, contributing to vascular integrity, leukocyte transmigration, mechanotransduction, angiogenesis, and immune cell signaling.
Biological Significance of CD31
- Endothelial marker: Robust expression at endothelial borders makes CD31 a reliable indicator of vascular endothelium in IHC.
- Cell adhesion & signaling: Regulates vascular permeability and leukocyte trafficking through adhesion and intracellular signaling.
- Hematopoietic expression: Present on megakaryocytes and lymphoid subsets, reflecting roles beyond endothelium.
- Angiogenesis: Participates in normal and tumor-associated neovascularization.
Diagnostic Utility in Hematopathology
- Endothelial lineage identification: Detects endothelial cells and vascular tumors such as angiosarcoma, aiding differential diagnosis.
- Panel marker complement: Combined with markers like CD34 and ERG to confirm endothelial origin in poorly differentiated neoplasms.
- Interpretation considerations: High sensitivity for endothelial cells, but occasional staining of hematopoietic subsets requires careful evaluation.
Key Features of Anti‑CD31 CE/IVD Antibodies
- CE/IVD validated: Designed for in vitro diagnostic use in FFPE tissue IHC.
- Specific endothelial detection: Membranous and cytoplasmic staining across arteries, arterioles, venules, veins, and capillaries.
- High sensitivity and specificity: Among the most reliable markers for endothelial differentiation in diagnostic panels.
- Tumor characterization: Enables assessment of vascular invasion and angiogenesis for research and clinical pathology.
