Leucine-rich alpha-2 glycoprotein is an accurate serum marker for endoscopic and histological remission in ulcerative colitis

Background/Aim: Achieving both endoscopic and histological remission in ulcerative colitis (UC) is associated with improved clinical outcomes. There is a growing need for non-invasive methods to assess both remission states. This study investigates the utility of serum leucine-rich alpha-2 glycoprotein (LRG) as a biomarker for monitoring endoscopic and histological remission in patients with UC. Methods: Patients with UC who underwent colonoscopy from July 2020 to September 2021 at multiple centers in Japan were included to compare the accuracy of CRP and LRG in detecting endoscopic and histological remission. ROC curve analyses were performed and AUC values compared. Results: 412 patients were identified. The median values of CRP and LRG were 0.07 mg/dL and 12.2 μg/mL, respectively. Endoscopic remission, as defined as Mayo endoscopic sub-score of 0 or 1, was observed in 188 patients, and histological remission, as defined as Geboes score <3.1, was observed in 156 patients. The AUC values for CRP and LRG for detecting endoscopic remission were 0.68 and 0.76, respectively, and the AUC values for CRP and LRG for detecting histological remission were 0.70 and 0.76, respectively. In both cases, the AUC for LRG was significantly higher than that of CRP (P<0.0001). The optimal cutoff value of LRG for detecting histological remission was 13.4 μg/mL, with a sensitivity of 82% and a specificity of 58%. Conclusion: LRG is superior to CRP in detecting both endoscopic and histological remission in patients with UC.