Clinical Profiles of Leucine-Rich Alpha-2 Glycoprotein for Indicating Mucosal Healing in Ulcerative Colitis Patients under Administration of Molecular-Targeted Drug.

Introduction: Leucine-rich alpha-2 glycoprotein (LRG) is a useful serum biomarker for monitoring disease activity during remission in ulcerative colitis (UC). Because LRG levels differ among patients, it is necessary to assess them after profiling patients, especially in patients with refractory UC undergoing treatment with molecular-targeted drugs. This study aimed to analyze LRG levels that indicate mucosal healing according to clinical characteristics and molecular-targeted drugs.

Methods: Among 214 patients with UC treated with biologics or Janus kinase (JAK) inhibitors, this study evaluated 111 patients (174 measurements) who achieved mucosal healing based on colonoscopy performed within 2 months before and after LRG measurement and experienced no changes in disease status or treatment during the same period. We analyzed the relationship of LRG with clinical characteristics (including sex, age, body mass index, and disease type and duration) and molecular-targeted drugs.

Results: Compared with men, women had significantly higher LRG levels (9.5 μg/mL vs. 11.3 μg/mL, p < 0.001). In addition, LRG levels were significantly higher in older patients (12.0 μg/mL vs. 9.8 μg/mL, p < 0.01). LRG levels were the highest in patients treated with vedolizumab and lower in patients treated with JAK inhibitors (vedolizumab: 12.7 μg/mL; tofacitinib: 8.9 μg/mL; upadacitinib: 8.5 μg/mL; and filgotinib: 9.1 μg/mL; p < 0.0001).

Conclusion: Among the patients who achieved mucosal healing, LRG levels were significantly higher in women and older patients. LRG levels differed according to the molecular-targeted drug used and were higher with vedolizumab and lower with JAK inhibitors.