• inflammatory bowel disease
• defensin 5
• Paneth cells

We read with interest the article by Cunliffe et al (Gut 2001;48:176–85) on defensin 5 stored in normal Paneth cells and in metaplastic Paneth cells in inflammatory bowel disease (IBD).

In recent years a great deal of interest has centred around Paneth cells as carriers of innate host defence, effective through their content of antimicrobial peptides and proteins.¹ In humans, that mechanism seems to be conveyed by a complex system of proteins present in the granules of the Paneth cells: lysozyme, secretory phospholipase A, and probably α defensins (that is, cyptidins, so far recorded in mice).

The lysozyme rich granules in Paneth cells appears to be one of the main sources of antimicrobial peptide in the normal small bowel …