Current application of proteomics in biomarker discovery for inflammatory bowel disease

Table 2 Proteomic studies for discovering diagnostic inflammatory bowel disease biomarkers

Ref.	Bio-sample	Sample size	Proteomic technique	Results
Meuwis et al[22]	Serum	CD: 30	SELDI-TOF	4 candidate proteins selected for high diagnostic value; PF4, MRP8, FIBA, Hpα 2. PF4 and Hpα 2 were also confirmed and correlated using ELISA and immunoblotting
		UC: 30
		Inflammatory control: 30
		Healthy controls: 30
Kanmura et al[23]	Blood	CD: 22	SELDI-TOF	Plasma concentrations of HNP1, 2 and 3 were significantly higher in active UC compared to inactive UC, CD and control patients
		UC: 48
		Colorectal Cancer: 5
		Infectious colitis: 6
		Healthy controls: 13
Hatsugai et al[24]	Blood	CD: 13	2-DE	Multivariate analysis of peripheral blood mononuclear cells protein profile 58 protein) allowed for accurate discrimination between UC and CD
		UC: 17	MALDI-TOF
		Healthy controls: 17
Nanni et al[25]	Blood	Healthy controls: 48	Liquid chromatography quadrupole-TOF	Exopeptidase activity may distinguish CD from UC. Label free method developed could accurately distinguish synthetic spiked samples of serum
		CD: 15	SELDI-TOF
Sumramanian et al[26]	Serum	CD: 48		Protein signature of 12 mass: Charge peaks could classify CD with approximately equal 95% sensitivity/specificity
		UC: 62		4 proteins identified as clinically useful
Nanni et al[27]	Serum	Healthy controls: 48	Solid-phase extraction MALDI-TOF	20 protein signals could be used to accurately classify IBD patients
		CD: 15
		UC: 26
Vaiopoulou et al[28]	Serum	CD: 24 (12 adults, 12 children)	2-DE	Clusterin was found to be overexpressed in adult CD. Ceruloplasmin and apolipoprotein B-100 was over-expressed in children
			MALDI-TOF
Han et al[34]	Intestinal biopsy	CD: 3	Liquid chromatography quadrupole-TOF	Increased in UC: TTBK2, SYNE2, SUCLG2, POSTN
		UC: 4		Up-regulated in CD: ANXA2, EPX, LAP3, RDX
		Inflammatory polyps: 2		Up-regulated in IBD: S100A8, MPO, DEFA1B
				Up-regulated in CD (P < 0.05 AND > 2x increase): PRG2, LCP1, PSME1
		Normal colon: 3
M’koma et al[35]	Colon samples	CD: 27	Histology directed MALDI-TOF	5 m:z peaks were identified and cross-validated for the differentiation of UC and CD
		UC: 24
Seeley et al[36]	Colon samples	CD: 26	Histology directed MALDI-TOF	Using a support vector machine and 25 m:z peaks, UC and CD cases were predicted in 93.3% and 60.4% respectively. A lower spectral accuracy cut-off increased sensitivity
		UC: 36
Wasinger et al[39]	Serum	UC: 27	MRM	SPP24 differentiated IBD patients from healthy controls
		CD: 56		α-1-microglobulin distinguished patients with UC in remission from healthy controls
		Controls: 14
		RA controls: 12

CD: Crohn’s disease; UC: Ulcerative colitis; IBD: Inflammatory bowel disease; MRM: Multiple reaction monitoring; PF4: Platelet factor 4; MRP8: Myeloid related protein 8; FIBA: Fibrinopeptide A; Hpα2: Haptoglobin α2.