Abstract

Calprotectin is a protein derived from leukocytes that appears in the intestinal mucosa when there is inflammation. It belongs to the family of low molecular weight proteins S100 and is found in large quantities in the granules of neutrophils where it forms 60% of cytoplasmic proteins. It is a polypeptide formed of one light chain and two heavy chains with a molecular weight of 36.5kDa [1,2]. This protein has antimicrobial and bacteriostatic functions and is attributed an active role in the body’s defenses.S100A8 (calgranulin A) and its binding partner S100A9 (calgranulin B) exhibit increased levels in several inflammatory states. Calgranulin A and calgranulin B form the heterocomplex S200A8/9, more commonly known as calprotectin. The effects of calprotectin are mediated by calcium flux after activation of the receptor for advanced glycation end products (RAGE). Calprotectin is released from damaged cells through an atypical pathway that requires protein kinase C and RAGE, thus making calprotectin a damage-associated molecular pattern (DAMP) molecule [3].

Abbreviations: RAGE: Receptor for Advanced Glycation End Products; IBD: Inflammatory Bowel Disease; IBS: Irritable Bowel Syndrome; DAMP: Damage-Associated Molecular Pattern