USEFULLNESS OF SERUM LEUCINE-RICH ALPHA2-GLYCOPROTEIN AND FECAL CALPROTECTIN ASSURROGATE MARKERS IN ULCERATIVE COLITIS

Abstract

Abstract BACKGROUND AND AIM Serum Leucine-rich alpha-2 glycoprotein (LRG) was identified as a novel biomarker for rheumatoid arthritis and IBD by using a proteomics approach. Several studies have suggested that serum LRG levels and fecal calprotectin (fCal) were correlated with clinical activities in patients with ulcerative colitis (UC). We compared utility of these biomarkers for monitoring disease activity in UC. METHODS A single-center observational study was conducted at Kyushu University Hospital. A total of 101 patients who underwent colonoscopy during the period from February to December 2021 were enrolled. The associations between endoscopic and histological activity and biomarkers were investigated. Endoscopic activity was defined as Mayo endoscopic score (MES) of 1 or less for mucosal healing and 0 for complete mucosal healing. For histological activity (n=90), Geboes score of 2 or less was defined as histological remission. RESULTS Subjects ranged in age from 16 to 80 years (35 males and 66 females). There were 63 cases of total colitistype, 32 cases of left-sided colitis type, and 6 cases of proctitis type. The MES at enrollment were as follows: MES 0 in 41 cases, MES 1 in 33 cases, MES 2 in 19 cases, and MES 3 in 8 cases. In comparison between the mucosal healing and non-mucosal healing groups, LRG was significantly lower in the mucosal healing group (p<0.0001). The correlation coefficient of LRG with MES was r=0.614 (p<0.0001), which was higher than that of fCal, r=0.414 (p<0.0001). In ROC analysis with mucosal healing as the outcome, the AUC and cut-off value of LRG were 0.781 and 17.9 μg/ml, respectively, and for fCal were 0.850 and 396 μg/g, respectively. In the ROC analysis with complete mucosal healing as the outcome, the AUC for LRG was 0.690, which was lower than the AUC of 0.846 for fCal . When compared by histological remission, LRG was lower in the histological remission group (p<0.001). In the ROC analysis with histological remission as the outcome, the AUC for LRG was 0.722 (cutoff value 14.2 μg/ml) and for fCal was 0.837 (cutoff value 119 μg/g). CONCLUSION Both LRG and fCal are valuable biomarkers reflecting disease activity in UC.