P214 Plasma fatty acid binding protein 2, interleukin-10 and lipopolysaccharides as biomarkers for microscopic colitis

Vytautas, K.(1);Varkalaite, G.(2);Vaitkeviciute, E.(2);Arstikyte, J.(2);Skieceviciene, J.(2);Kupcinskas, J.(1);

(1)Lithuanian University of Health Sciences, Department of Gastroenterology, Kaunas, Lithuania;(2)Lithuanian University of Health Sciences, Institute for Digestive Research, Kaunas, Lithuania;

Background

The pathogenesis of microscopic colitis (MC) is still poorly understood and there are no non-invasive diagnostic markers to aid in disease diagnosis. Fatty acid binding protein 2 (FABP2) is expressed in enterocytes and colonocytes (although to a lesser extent) and is released after intestinal injury. Interleukin-10 (IL-10) is an anti-inflammatory cytokine that is reduced in inflammatory bowel diseases. Lipopolysaccharides (LPS) are bacterial endotoxins that promote inflammation and their presence in systemic circulation represents impaired intestinal barrier function. Our aim was to investigate these compounds as possible non-invasive diagnostic biomarkers for MC and compare their profile between MC and ulcerative colitis (UC).

Methods

63 patients with active MC, 52 healthy controls (HCs), 43 patients with active and 43 with inactive UC were recruited for the study. The presence of active disease was assessed using the Hjortswang criteria in MC and Mayo score in UC patients. Plasma concentrations of FABP2, IL-10 and LPS were measured using Human FABP2/I-FABP Quantikine ELISA Kit (DFBP20; R&D systems, MN, USA), Human IL-10 Quantikine ELISA KIT (D1000B; R&D systems, MN, USA), and Human Lipopolysaccharides (LPS) ELISA Kit (CSB-E09945h; Cusabio, China). Statistical significance of concentration differences between groups was determined using the Mann-Whitney U test.

Results

No significant difference was discovered when comparing the plasma FABP2, IL-10 and LPS concentrations between MC patients and HCs. However, FABP2 concentrations were significantly lower in the plasma of UC patients, both active (median 1272 pg/ml, p = 0,004) and inactive (median 1334 pg/ml, p = 0,001) when compared with MC patients (median 1680 pg/ml). The difference in FABP2 concentration between HCs (median 1365 mg/ml) and active or inactive UC patients did not reach statistical significance.

IL-10 concentrations were significantly lower in patients with active UC (median 2,58 pg/ml) than in MC patients (3,89 pg/ml, p = 0,006) and HCs (median 4,79 pg/ml, p = 0,005). There was no significant difference between MC patients or HCs when compared with inactive UC patients (median 3,04 pg/ml).

The plasma concentrations of LPS were similar across all the patient groups and no significant difference was observed.

Conclusion

Plasma FABP2, IL-10 and LPS did not distinguish MC patients from HCs in our study and did not show potential as biomarkers. Our results of lower plasma IL-10 concentration in patients with active UC show that it could be a useful biomarker for disease activity. It is unclear whether the lower plasma concentration of FABP2 in active UC patients compared to MC patients is important since neither group differed significantly from HCs.