Abstract / Summary
Leucine-rich alpha-2 glycoprotein (LRG) has recently emerged as a serum indicator of intestinal inflammation in ulcerative colitis (UC). Although it has been linked to endoscopic activity, its usefulness in patients receiving biologics or Janus kinase (JAK) inhibitors remains unclear. This study examined the relationship between serum LRG and mucosal healing in UC across different treatment histories. This prospective observational cohort study included 372 patients with UC who underwent both colonoscopy and serum biomarker assessment at Kindai University Hospital. Patients were categorized as biologic/JAK inhibitor-naïve or previously treated with biologics/JAK inhibitors. Serum LRG, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), prostaglandin E-major urinary metabolite, age, sex, disease duration, UC extent, 5-aminosalicylic acid use, prednisolone use, thiopurin use, and histologic activity by Geboes score were evaluated against endoscopic findings. Mucosal healing was defined by the Mayo endoscopic subscore. Associated factors were examined using univariate and multivariate analyses, with receiver operating characteristic analyses used to estimate discriminatory performance and cutoff values. Of the 372 patients, 251 (67%) achieved mucosal healing. In biologic/JAK inhibitor-naïve patients, LRG, ESR, and the Geboes score were associated with mucosal healing in univariate analysis, whereas LRG and the Geboes score were independently associated factors in multivariate analysis. In patients previously treated with biologics or JAK inhibitors, LRG, CRP, ESR, the Geboes score were significant in univariate analysis; however, LRG was not independently associated with mucosal healing in multivariate analysis. In the overall cohort, multivariate analysis similarly demonstrated independent associations for LRG and the Geboes score. For complete endoscopic remission (Mayo endoscopic subscore [MES] 0), LRG was not independently associated with MES 0 in any group. For endoscopic healing (MES 0–1), optimal LRG cutoffs were 13.5 µg/mL in biologic-naïve patients and 15.6 µg/mL in the overall cohort. Serum LRG was associated with endoscopic mucosal healing in UC, although its independent association varied by treatment history and was not observed for complete endoscopic remission (MES 0). LRG may serve as a practical, minimally invasive biomarker for assessing intestinal inflammatory activity, but its ability to discriminate deeper endoscopic remission may be limited. Not applicable.