Novel Inflammatory-Nutritional Biomarkers as Predictors of Histological Activity in Crohn's Disease

Background There has increasingly been an interest in histological remission as a therapeutic endpoint in inflammatory bowel disease. The aim of this study was to evaluate the utility of a variety of inflammatory - nutritional markers for predicting histological disease activity in patients diagnosed with Crohn's disease. Methods Patients with Crohn's disease that had requisite endoscopic, pathological, and laboratory data were retrospectively enrolled in the study. Relevant clinical, laboratory, endoscopic, and pathological data were abstracted. The neutrophil:lymphocyte ratio (NLR), lymphocyte:monocyte ratio (LMR), platelet:lymphocyte ratio (PLR), red blood cell distribution width (RDW), modified Glasgow Prognostic score (mGPS), Prognostic Nutritional Index (PNI), Geriatric Nutritional Risk index (GNRI), CRP/Albumin ratio (CAR), Iron:Ferritin ratio (Fe:F) and the Systemic immune inflammation index (SII) were calculated. The cohort was stratified by presence of histological disease on colonoscopy, and groups were compared with appropriate statistical methods. Results When comparing patients without histological disease to those with disease, there was a statistically significant difference in CAR (2.9 ± 1.5 vs. 4.2 ± 2, p = 0.001), RDW (13.4 ± 1.3 vs. 14.5 ± 1.8, p = 0.008), PNI (52.4 ± 6.2 vs. 47.4 ± 9.3, p = 0.03), and mGPS (0.2 ± 0.4 vs. 0.6 ± 0.7, p = 0.01). For predicting histological activity, ROC analyses indicated an optimal cutoff of 0.3 for CAR (AUC 0.8, PPV 90.5%), 13.5 for RDW (AUC 0.7, PPV 84.1), 86.1 for PNI (AUC 0.7, PPV 86.1) and > 0 for mGPS (AUC 0.6, PPV 85.2%). The NLR, LMR, PLR, GNRI, Fe: F, and SII did not meet statistical significance (p = 0.4, 0.08, 0.2, 0.5, 0.6, and 0.3, respectively). Conclusions We report on ten biomarkers, many of them never studied in Crohn's disease, which can help in predicting the presence of active histological disease. Larger prospective studies are needed to investigate the utility of these biomarkers alone and in combination.