Description
Calprotectin is a calcium-binding protein secreted predominantly by neutrophils and monocytes.
The heterocomplex consists of the two proteins, S100A8 (calgranulin A) and S100A9 (calgranulin B), also designated as MRP8 and MRP14, respectively. The genes S100A8 and S100A9 are located in a gene cluster on chromosome 1q21, a region in which several rearrangements that occur during tumor development have been observed. Elevated MRP8/14 levels have been found in many sites of inflammation and in the extracellular fluid of patients with many types of inflammatory conditions. The concentration of MRP8/14 in blood is increased in patients with rheumatoid arthritis, cystic fibrosis, multiple sclerosis, and HIV infections, while elevated MRP8/14 levels have been detected in stool of patients with Crohn’s disease and colorectal cancer. Extracellular MRP8/14 has antimicrobial, antigrowth and apoptotic effects. It suppresses the growth of some fungi and bacteria. It also suppresses the proliferation of several different types of cells including macrophages, lymphocytes, hematopoietic progenitors, and tumor cell lines.