Monocyte Distribution Width as a Diagnostic and Prognostic Biomarker of Sepsis

Sepsis is a major cause of morbidity and mortality among hospitalized patients, particularly in intensive care settings, where early diagnosis and risk stratification are critical for improving outcomes. Conventional diagnostic tools such as blood cultures and biomarkers like C-reactive protein and procalcitonin have limitations related to sensitivity, specificity, cost, and availability. Monocyte Distribution Width (MDW) is a novel parameter derived from routine complete blood count that reflects monocyte morphological changes during systemic inflammation and infection. It is rapid, cost-effective, and does not require additional testing. Given that MDW is available as part of routine hematological analysis without additional cost or testing, it may serve as a practical alternative or adjunct biomarker in resource-limited settings. This prospective cross-sectional observational study aims to evaluate the diagnostic accuracy of MDW in identifying sepsis and to assess its prognostic value in predicting disease severity and patient outcomes. The study will also examine the correlation of MDW with established inflammatory markers such as CRP, NLR, RDW, and procalcitonin. MDW will be measured at admission and serially during hospitalization, and its performance will be analyzed in comparison to standard biomarkers. The findings of this study may support the use of MDW as an accessible and reliable biomarker for early diagnosis and prognostication of sepsis.