Correlation of Omentin-1 with Disease Extent and Therapeutic Response to Infliximab in Ulcerative Colitis

Ulcerative colitis (UC) is classified by both activity and extent. Accumulating evidence suggests that disease extent is an independent factor in determining poor prognosis. However, there is a significant lack of blood biomarkers that mirror lesion reach, clinicians still rely on repeated endoscopy to determine disease activity and mucosal healing. Omentin-1 is an adipokine secreted mainly by visceral adipose tissue and intestinal goblet cells that has been reported to exert anti-inflammatory and epithelial-barrier-enhancing effects. Therefore, we hypothesized that serum omentin-1 correlates with disease extent and predicts primary response to infliximab (IFX).

Consecutive UC patients (n = 126) were enrolled and stratified by Montreal classification into distal (E1/E2, n = 84) or extensive (E3, n = 42) disease. Serum omentin-1 was quantified by ELISA. Clinical activity (partial Mayo) and endoscopic activity (MES) were recorded. Among 36 subjects who received standard IFX induction, response was assessed at week 14.

Among the 126 UC patients, serum omentin-1 levels were significantly lower in extensive than distal colitis [median: 48.60 (38.28-67.35) ng/mL vs 62.70 (58.48-73.88) ng/mL, p < 0.01]. By controlling for clinical and endoscopic activity scores between groups, we found that serum omentin-1 levels differed between patients with different UC disease extents at the same level of disease activity, suggesting that serum omentin-1 can effectively predict the disease extent of UC independently of disease activity. In the IFX cohort (n = 36), responders (n = 23) exhibited higher baseline serum omentin-1 than non-responders. Extent-stratified analysis revealed that the discriminative capacity was confined to extensive colitis, with no significant predictive value in distal disease.

Serum omentin-1 quantifies UC extent independently of activity and predicts IFX response specifically in extensive colitis, offering a blood-based tool to map disease extent and guide biologic therapy. This finding may reduce the reliance on repeated colonoscopy and support therapeutic stratification in extensive disease.