Indicator Explainer
Calprotectin
A heterodimeric or heterotetrameric protein complex comprised of protein S100A8 and protein S100A9. This complex is expressed in the cytosol of neutrophils and macrophages and plays a role in multiple host defense related processes including immunomodulation, neutrophil chemotaxis and both antibacterial and antifungal responses.
This page explains what the indicator is and how results are interpreted in general terms. Reference ranges depend on the laboratory, the method, and your own situation — no single “normal value” applies to everyone. This page is health information, not a diagnosis. For symptoms, treatment, or urgent concerns, contact a healthcare professional.
When it is tested
Source: National Cancer Institute, NCI Thesaurus 26.09d, C105971. NCI definition, reproduced without modification under CC BY 4.0. Source identity and definition checked automatically on 2026-10-20. No individual clinical interpretation or human reviewer is asserted.
Reading results
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.
Also Known As
References
- NCI Thesaurus 26.09d — Calprotectin (C105971)
- Source: National Cancer Institute, NCI Thesaurus 26.09d, C105971. NCI definition, reproduced without modification under CC BY 4.0.
- Plasma calprotectin as infection biomarker in hip fracture patients: a prospective cohort study. — Acta Orthop, 2026-10-19 (PMID 42894498; literature)
- Building a Better Model for Fecal Calprotectin Monitoring in IBD: Room for Some Home Improvement. — Gastroenterology, 2026-10-16 (PMID 42887790; literature)
- Circulating calprotectin levels are associated with lung damage and disease outcome in patients with COVID-19. — Biomark Med, 2026-10-22 (PMID 42910722; literature)
- Clinical and sonographic enthesitis in psoriatic arthritis patients and its relation to serum calprotectin level. — Clin Rheumatol, 2026-10-14 (PMID 42873410; literature)
- TASTY AND HEALTHY DIET REDUCES FECAL CALPROTECTIN IN HIGH-RISK FIRST-DEGREE RELATIVES OF PATIENTS WITH CROHN'S DISEASE: PIONIR RANDOMIZED CROSSOVER TRIAL. — Gastroenterology, 2026-10-26 (PMID 42933673; literature)
- Calprotectin as a Prognostic Marker for Sepsis Independent of Renal Dysfunction. — Ann Lab Med, 2026-10-13 (PMID 42865138; literature)