Leucine-rich alpha-2 glycoprotein is useful in predicting clinical relapse in patients with Crohn's disease during biological remission

Background/Aims: Serum leucine-rich alpha-2 glycoprotein (LRG) is a potential biomarker of Crohn's disease (CD). This study aimed to evaluate the usefulness of LRG in predicting clinical relapse in patients in remission with CD. Methods: This retrospective observational study assessed the relationships among patient-reported outcome (PRO2), LRG, and other blood markers. The influence of LRG on clinical relapse was assessed in patients in remission with CD. Results: Data of 94 patients tested for LRG between January 2021 and May 2023 were collected. LRG level did not correlate with PRO2 score ( rho = 0.06); however, it strongly correlated with C-reactive protein (CRP) level ( r = 0.79) and serum albumin level ( r = -0.70). Among 69 patients in clinical remission, relapse occurred in 22 patients (31.9%). In the context of predicting relapse, LRG showed the highest area under the curve, followed by CRP level, platelet count, and albumin level. Multivariate analysis revealed that only LRG ( P = 0.02) was an independent factor for predicting clinical remission. The cumulative non-relapse rate was significantly higher in patients with LRG < 13.8 p.g/mL than in patients in remission with LRG >_ 13.8 p.g/mL and normal CRP level ( P = 0.002) or normal albumin level ( P = 0.001). Cumulative non-relapse rate was also higher in patients with LRG < 13.8 p.g/mL compared to those with LRG >_ 13.8 p.g/mL in patients with L3 or B2+B3 of Montreal calcification. Conclusions: LRG is useful in predicting clinical relapse in patients with CD during biological remission. LRG is a useful biomarker for predicting prognosis, even in patients with intestinal stenosis, or previous/present fistulas. (Intest Res, Published online )