Background: Numerous non-invasive serologic tests are available to diagnose and monitor ulcerative colitis (UC), but their accuracy levels are limited. Thus, there is a pressing need for a serologic biomarker with higher precision for clinical practice. This study aims to evaluate the predictive capacity of monocyte/HDL ratio (MHR) and neutrophil/lymphocyte ratio (NLR) for UC disease activity.
Patients and Methods: We conducted a retrospective analysis of 81 UC patients and 77 age- and sex-matched healthy controls. UC patients were categorized into active and inactive groups based on the Mayo score. The Mayo endoscopic subscore classified them into mild-to-moderate and severe UC groups.
Results: The optimal cut-off values for diagnosing UC were 0.34 for MHR (85.7% sensitivity, 76.0% specificity, 88.9% positive predictive value, 70.4% negative predictive value) and 2.49 for NLR (66.1% sensitivity, 88.0% specificity, 92.5% positive predictive value, 53.7% negative predictive value). The optimal MHR and NLR cut-off values to differentiate between mild-to-moderate UC and severe UC were 0.38 (92.9% sensitivity, 56.6% specificity, 53.1% positive predictive value, 93.7% negative predictive value) and 3.46 (71.4% sensitivity, 88.7% specificity, 76.9% positive predictive value, 85.5% negative predictive value), respectively.
Conclusion: NLR and MHR are simple yet effective biological predictors of disease activity in UC patients.

Keywords: ulcerative colitis, monocyte/HDL ratio, neutrophil/lymphocyte ratio, disease activity