Leucine-rich Alpha-2 glycoprotein could be clinically useful in active and postoperative Crohn’s disease

The clinical usefulness of serum leucine-rich alpha-2 glycoprotein (LRG) levels as a surrogate marker of endoscopic activity including postoperative recurrence in patients with Crohn's disease (CD) remains unclear, and LRG production in the small intestinal mucosa has not been explored. The present study investigated the usefulness of serum LRG to ascertain endoscopic activity, the secretion of LRG from the small intestinal mucosa, and the significance of LRG as a predictor of postoperative disease course. We included 364 patients who underwent transanal endoscopy at Osaka University Hospital. Serum LRG correlated highly with endoscopic severity (LRG, r = 0.65; CRP, r = 0.37) and reflected strictly moderate endoscopic activity better than serum CRP. Especially, serum LRG reflected mucosal healing even in patients whose inflammation was confined to the small intestine. In multivariate analyses, serum LRG was an independent factor influencing mucosal healing. LRG was more strongly expressed in the inflamed mucosa of the small intestine compared with that in uninflamed mucosa, and serum LRG was more strongly correlated with postoperative small intestinal recurrence severity than CRP (LRG, r = 0.62; CRP, r = 0.32). In conclusion, serum LRG is a useful surrogate marker of endoscopic CD severity and activity, with increased LRG expression in the small bowel predicting postoperative recurrence.