Diagnostic accuracy and severity prediction of monocyte distribution width in sepsis: a retrospective study from the United Arab Emirates.

INTRODUCTION

Monocyte distribution width (MDW) is an early sepsis biomarker derived from the routine complete blood count. Existing evidence is overwhelmingly from European, North American, and East Asian cohorts, with no published Middle Eastern data. We evaluated the diagnostic value of MDW for sepsis identification in a United Arab Emirates (UAE) tertiary care population, comparing it with procalcitonin (PCT), C-reactive protein (CRP), and quick Sequential Organ Failure Assessment (qSOFA).

METHODS

We retrospectively reviewed 140 adults admitted to Rashid Hospital, Dubai, with confirmed infections in 2024, classified by Sepsis-3 criteria as sepsis (n = 53), septic shock (n = 21), or other infections (n = 66). MDW was measured on a UniCel DxH 900 analyzer. Receiver operating characteristic curves were compared for MDW, CRP, PCT, WBC, and the MDW + qSOFA and CRP + qSOFA composites; logistic regression identified independent predictors of sepsis.

RESULTS

Median MDW differed across groups: 27.6 (IQR 22.6-34.6) in sepsis, 28.2 (25.4-33.0) in septic shock, and 24.0 (19.9-27.6) in other infections (p = 0.001). MDW's AUC was 0.678 (95% CI 0.589-0.764), behind PCT (0.778) and ahead of CRP (0.652) and WBC (0.590). MDW + qSOFA achieved the highest AUC (0.763, 95% CI 0.683-0.840), indistinguishable from CRP + qSOFA (p = 0.550). At the FDA-cleared cutoff ≥ 20, MDW had 90.5% sensitivity and 25.8% specificity, supporting a rule-out role. After adjustment for CRP, PCT, age, and sex, only MDW (aOR 1.08; 95% CI 1.00-1.15; p = 0.037) and qSOFA (aOR 2.30; 95% CI 1.32-4.00; p = 0.003) remained independent predictors. MDW was also higher in blood culture-positive patients (median 29.5 vs. 25.0; p = 0.028), though this attenuated to borderline significance (p = 0.051) after excluding the 12 patients without cultures.

DISCUSSION: In this first UAE cohort, MDW behaved consistently with international evidence. Standalone discrimination was moderate, but MDW + qSOFA matched a CRP-based composite at no additional sample/reagent cost. As the comparator group comprised only infected patients, these AUCs reflect an infection-enriched design and are expected to be lower than in unselected emergency-department populations. Region-specific cutoffs and prospective multicenter Gulf evaluations are required for further evaluation.