Table 1.

The most important currently used markers for nonspecific inflammatory bowel diseases (IBD).

Marker	Name	Expression	Comments	References
Tests evaluating neutrophil activation
ENA-78	Epithelial neutrophil activating peptide	Bowel epithelial cells; intestinal epithelial cells	Stimulates the chemotaxis of neutrophils, possesses angiogenic properties	[10, 21]
HLE	Human leucocytic elastase	Activated neutrophils	Plays a role in degenerative and inflammatory diseases through proteolysis of collagen-IV and elastin	[6]
MRP-8/MRP-14 or S100A8/A9	Calprotectin	Cytoplasm of neutrophils and monocytes	Antibacterial, antifungal, immunomodulatory, and antiproliferative action; a chemotactic factor for neutrophils; the fecal level is proportional to neutrophilic influx into the intestinal tract	[1, 77]
L	Lactoferrin	Neutrophils	Takes part in acute inflammatory response; exhibits high affinity to iron making iron inaccessible to bacteria; fecal L increases significantly with bowel infiltration by neutrophils	[10, 58]
N	Neopterine	Monocytes and macrophages	Inflammatory marker; may help predict the progress of the disease; useful to assess clinical activity of IBD	[9]
Serological markers
ANCAs	Antineutrophil cytoplasmic antibodies		High p-ANCA levels and antibodies to CBir1 have been associated with increased risk of pouchitis after colectomy in UC	[70]
cANCA	Cytoplasmic	Antibodies against granules of neutrophil cytoplasm	Increase in UC
sANCA	Speckled		Patients with CD and positive p-ANCA were less likely to respond to therapy with infliximab
pANCA	Peripheral-antinuclear cytoplasmic antibody		Increase significantly in UC	[74]
ASCAs	Anti-Saccharomyces cerevisiae antibodies		The utility in diagnosing difficult cases of indeterminate colitis (IC)	[74]
Anti-OmpC	Antiouter membrane protein C antibody		OmpC pANCA, ASCA, and I2 altogether can be found in 80% of patients with CD	[10]
Hup-B	Mycobacterial histone H1 homologue		May represent the target antigen for pANCA	[10]
Anti-CBir1 flagellin	Antibodies to bacterial flagellin		May be a marker of Crohn's disease complicated by fistulas, perforations, or other serious problems	[10]
PAB	Pancreatic antibody (an antibody to a trypsin-sensitive protein in pancreatic secretions)		PAB is positive in 20%–40% of CD cases and 5% of UC cases; PAB expression may exhibit racial differences	[6]
Anti-I2	Antibodies to Pseudomonas fluorescens-associated sequence I2		IgA anti-I2 is positive in 55% of CD cases, 10% of UC cases, and 20% of non-IBD colitis cases; anti-I2 has also been found in patients with other inflammatory enteritis	[10]
Platelet abnormalities
	β-Tromboglobulin	Platelets	Increased during active IBD	[20]
	P selectin	Endothelial cells	Serum level of soluble platelet selectin (sP-selectin) is increased during progression of IBD; in inactive CD, serum levels of sP-selectin are lower than in controls; in patients with ulcerative colitis, serum concentrations of sP-selectin and IL-6 are significantly higher compared to healthy subjects	[34, 49]
PAF	Platelet activation factor	Platelets	Increased in patients with IBD	[36]
TF(+) MPs	Procoagulant microparticles	Microparticles circulating into the blood	Indicates for hypercoagulability of blood in IBD patients, which is associated with the appearance of thrombin in the vasculature of the intestine and extraintestinal tissues	[33]