Hemoglobin-to-Inflammation Marker Ratios Reflect Endoscopic Activity in Inflammatory Bowel Disease

To investigate the diagnostic value of hemoglobin-to-inflammation marker ratios (Hb/WBC, Hb/Neu, Hb/PLT, Hb/CRP) in assessing endoscopic activity in inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD).

A single-center retrospective cross-sectional study was conducted. We screened patients diagnosed with UC or CD between January 2017 and July 2025. Patients were excluded if they had coexisting severe gastrointestinal/infectious diseases potentially affecting endoscopic or laboratory results, iron supplements intake, incomplete data, or a significant time discrepancy (>3 days) between endoscopy and laboratory testing. Ultimately, 270 IBD patients (175 UC, 95 CD) were included for the primary cross-sectional analysis. Clinical data, laboratory indicators, and endoscopic scores (Mayo Endoscopic Score, Ulcerative Colitis Endoscopic Index of Severity [UCEIS], Simplified Endoscopic Score for Crohn's Disease [SES-CD]) were collected. Receiver operating characteristic (ROC) curve analysis, correlation analysis, multivariate logistic regression, and sensitivity analyses were employed.

The Hb/CRP ratio demonstrated the best performance in distinguishing endoscopic active phase from remission phase in IBD. In UC patients based on the Mayo Endoscopic Score, the area under the curve (AUC) of Hb/CRP was 0.924 (95% CI: 0.884-0.964); based on the UCEIS score, the AUC was 0.890 (95% CI: 0.842-0.938); in CD patients based on the SES-CD score, the AUC was 0.839 (95% CI: 0.749-0.929). Hb/CRP significantly outperformed hemoglobin alone across all subgroups (all P<0.01), while showing comparable diagnostic accuracy to CRP alone. It also served as an independent protective factor for disease remission phase in multivariate analysis (odds ratio [OR] range = 1.007 to 1.014, all P<0.01). Sensitivity analyses stratified by anemia status confirmed the robustness of Hb/CRP, particularly in UC patients. However, the absence of fecal calprotectin (FC) data is a key limitation of the study.

Hemoglobin-to-inflammation ratios, particularly Hb/CRP, show promising diagnostic performance for assessing endoscopic activity in IBD in this retrospective study. They may serve as non-invasive adjunctive tools for clinical disease activity monitoring, though their comparative value against established biomarkers like FC warrants further prospective validation.