Table of Contents
Definition / general | Diagrams / tables | Pathophysiology | Clinical features | Uses by pathologists | Microscopic (histologic) images | Positive staining - normal | Positive staining - disease | Negative stainingCite this page: Pernick N. CD14. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cdmarkerscd14.html. Accessed March 6th, 2021.
Definition / general
- Pattern recognition receptor that detects antigenic molecules on the surface of various microorganisms
- Also called lipopolysaccharide (LPS) receptor, monocyte differentiation antigen
- Mutations can prevent adequate inflammatory response to infection, leading to systemic infections
- References: OMIM #158120
Diagrams / tables
Pathophysiology
- GPI linked pattern recognition receptor that detects antigenic molecules on the surface of bacteria (lipoteichoic acid on gram positive, lipopolysaccharides on gram negative), myobacteria (glycolipids) and fungi (mannans), as part of the innate (non-adaptive) immune system (adaptive immune system refers to lymphocytes recognizing microorganism proteins via T cell receptors and antibodies)
- Soluble form of CD14 is secreted by liver and monocytes; in low concentrations it confers LPS responsiveness to cells which are otherwise CD14 negative
- Macrophages with a multiprotein complex of CD14, MD2 and TLR4 bind to LPS, causing macrophage activation and release of cytokines (Mol Immunol 2014;57:210); overstimulation may cause toxic shock syndrome (Nature 1998;392:505)
- Detection of lipopolysaccharide induces IL12 production (mediated by CD14), producing interferon gamma, which steers immune system away from allergy driven Th2 phenotype, associated with IgE production
- Important for clearance of apoptotic cells (Nature 1998;392:505, PLoS One 2013;8:e70691)
- Early promonocytes express MY4 epitope; mature monocytes express MO2 epitope; neoplastic monocytes also often express MY4 but not MO2 (Am J Clin Pathol 2005;124:930)
Clinical features
- May regulate gastric cancer cell epithelial-mesenchymal transition and invasion (Oncol Rep 2013;30:2725)
- CD14-159C/T polymorphism:
- Contributes to TB susceptibility, particularly in Asians (Int J Tuberc Lung Dis 2013;17:1472)
- May be risk factor for chronic lung disease in India (Indian J Hum Genet 2013;19:188)
Uses by pathologists
- Identify mature monocytes / macrophages
Microscopic (histologic) images
Positive staining - normal
- Macrophages / monocytes (90%), Langerhans cells, dendritic cells, B cells and granulocytes-weak (30%)
Positive staining - disease
- AML-M4 / M5 (50 - 90%, Am J Clin Pathol 2011;135:720), chronic myelomonocytic leukemia and histiocytic sarcoma
Negative staining
- Myeloid progenitors, AML M0-M2 (usually), M3, M6 and M7
- Sinusoidal histiocytes with phagocytic properties (erythrophagocytosis, anthracosis, tingible body macrophages, Hum Pathol 2006;37:68), Gaucher macrophages (Hum Pathol 1992;23:1410)
- Most epithelial and endothelial cells