Synonym: S100A8/9 or MRP8/14
Method(s): MALDI-TOF MS.
What is measured: S100A8, S100A9, S100A9dm and S100A9tr. S100At is the total concentration of detected calprotectin isoforms.
What is calprotectin?
Calprotectin belongs to the S100 family of Ca-binding proteins and represents different hetero-complexes of S100A8, S100A9 and an isoform of truncated S100A9. The definition of the calprotectin hetero-complex is not consistent in the literature. The hetero-dimer has a molecular mass of about 24kDa. Binding of calcium and zinc determines the conformation, stability and function of the complexes. Calprotectin is highly expressed in neutrophils and other cells, and is classified as Damage Associated Molecular Pattern (DAMP). While faecal calprotectin is widely used to diagnose inflammatory bowel diseases, quantification of serum calprotectin has recently become increasingly important for investigation of various inflammatory diseases as well as different types of cancers.
Performance of the assay
Lower limit of detection (LOD): na.
Within-day CV, na; between-day CV, na.
Assessment of inflammation.
Specimen, collection and processing
Matrix: EDTA plasma and serum.
Volume: Minimum volume is 20 µL, but 100 µL is optimal and allows reanalysis.
Preparation: The blood sample must be centrifuged and the plasma/serum fraction put on ice, and frozen.
Samples may be stored at 2-8 °C for up to 30 days and are stable at -20°C for at least 6 months. Levels in serum and EDTA plasma samples can differ due calcium-dependent stability of calprotectin.
Transportation; for general instruction on transportation, click here.
Frozen, on dry ice.
Reported values, interpretation
Reported values: 0-30 µg/ml.
Intraclass correlation coefficient (ICC): na.