Advancing the precision management of inflammatory bowel disease in the era of omics approaches and new technology

Table 1 Biomarkers of serum or feces identifying disease progression risk and activity

Sample	Biomarker	Outcome	Characteristic
Serum	CRP[17-20]	Monitor disease activity and mucosal healing	Widely used and low-cost; lack of specificity for intestinal inflammation; relatively low sensitivity
	SC[27]	Disease burden, prognosis, and relapse	More representative of systemic inflammation
	LRG[31]	Monitor disease activity and mucosal healing	More correlated to activity in UC than CRP
	Serum antibodies
	ASCA[35,36]	More aggressive fibro stenosing and internal penetrating disease behaviors	CD specificity
	pANCA[35,37]	UC disease activity	UC specificity
	Cytokines
	G-CSF, IL-1Ra, PDGF-BB[38]	Endoscopically active disease	-
	IL-6, IL-2[39]	Predict disease relapse in quiescent CD	-
	Noncoding RNAs[32]	Monitor disease activity and stricture phenotypes	-
	ECM components[32]	Intestinal fibrosis and stenosis	-
	Growth factors[32]	Intestinal fibrosis and stenosis	-
	Cathelicidin[40]	Mucosal disease activity in UC, risk of intestinal stricture in CD, and clinical prognosis in IBD	-
	Trefoil Factor 3[41]	Monitor disease activity	-
	Vitamin D[42]	Disease activity	-
	Secondary biomarkers (CRP-albumin ratio, NLR, PLR, LMR)[29,30]	IBD activity	Easy to obtain; fluctuates greatly
Feces	FC[21-26]	Monitor disease activity and mucosal healing; early prediction of relapse risk	Higher sensitivity than CRP; confounding of non-IBD gut inflammation
	FL[28]	Monitor disease activity and predict disease relapse	Higher specificity than fecal calprotectin
	MPO[44]	Endoscopic activity in IBD and predict the disease course during follow-up	-

ASCA: Anti-Saccharomyces cerevisiae antibody; CD: Crohn’s disease; CRP: C-reactive protein; ECM: Extracellular matrix; FC: Fecal calprotectin; FL: Fecal lactoferrin; G-CSF: Granulocyte colony-stimulating factor; IL-1Ra: Interleukin 1 receptor antagonist; IBD: Inflammatory bowel disease; LMR: Lymphocyte-monocyte ratio; LRG: Leucine-rich alpha-2 glycoprotein; MPO: Myeloperoxidase; NLR: Neutrophil-lymphocyte ratio; pANCA: Perinuclear anti-neutrophil cytoplasmic antibody; PDGF-BB: Platelet-derived growth factor BB; PLR: Platelet-lymphocyte ratio; SC: Serum calprotectin; UC: Ulcerative colitis.