Paneth

Paneth may refer to a surname or to Paneth cells, a type of specialized epithelial cell in the small intestine. Paneth cells are named after the scientist who first described them and are most numerous at the base of the crypts of Lieberkühn in the ileum, though they occur throughout the small intestine.

Histology: Paneth cells contain large eosinophilic secretory granules that store antimicrobial proteins and enzymes, including alpha-defensins (HD5 and HD6), lysozyme, secretory phospholipase A2, and ribonucleases. They release these products into the intestinal lumen and into the stem cell niche.

Function: They play a key role in innate immunity by limiting microbial invasion and shaping the gut microbiota. Through signaling to intestinal stem cells (via Wnt and other pathways) they help maintain the stem cell niche and epithelial renewal. They respond to bacterial products through pattern recognition receptors such as Toll-like receptors.

Clinical relevance: Paneth cell abnormalities have been observed in Crohn's disease and other inflammatory bowel diseases. Reduced Paneth cell antimicrobial peptides have been reported in neonatal necrotizing enterocolitis, and changes in Paneth cell number or function can reflect intestinal inflammation.

Etymology: The name Paneth is used as an eponym for the cell type and also as a surname in German-speaking regions.