Monocyte Distribution Width Predicts Sepsis in Critically Ill Patients

Sepsis has been reported as a major cause of increased morbidity, length of stay and mortality among patients hospitalized in Intensive Care Units (ICUs) for any cause. The survival of patients developing sepsis in the ICU is strictly related to an early diagnosis, as well as a prompt start of appropriate medical interventions.

Among biomarkers of sepsis, procalcitonin (PCT) is acknowledged as the single best parameter for patients at the ICU. However, even with serial PCT measurements, the level of sensitivity and specificity achieved for the prediction of sepsis was at best equal to 75%. Recent findings suggested using Monocyte Distribution Width (MDW), a relatively simple proxy of innate monocyte response to bacterial or fungal bloodstream invasion, as a biomarker for the early recognition of sepsis.


A multidisciplinary team of medical scientists at the University of Chieti (Chieti, Italy) and the performed an observational, prospective study to estimate the analytical performance of MDW in detecting sepsis or septic shock in patients hospitalized at the ICU of the General Hospital of Pescara (Abruzzo, Italy). Sepsis and septic shock were diagnosed according to the diagnostic criteria of the Sepsis-3 classification.

Microbiology identification and sensitivity assays were performed, using the Vitek2 system (bioMérieux, Marcy l'Etoile, France), Accelerate Pheno Test (Accelerate Diagnostics, Tucson, AZ, USA), GeneXpert (Cepheid, Sunnyvale, CA, USA), as well as disc diffusion methods and agar MIC determinations by antibiotic discs and MIC test strips (Liofilchem, Roseto degli Abruzzi, Italy). Blood cell counts including MDW were determined with the UniCel DxH800 hematologic analyzer system (Beckman Coulter, Inc., Brea, CA, USA).

The investigators reported that a total of 211 patients were observed, 129 of whom were included in the final sample due to the suspect of ensuing sepsis; of these, 74 (57%) had a confirmed diagnosis of sepsis, which was best predicted with the combination of MDW > 23.0 and PCT > 0.5 ng/mL (Positive Predictive Value, PPV: 92.6, 95% CI: 82.1–97.9). The best MDW cut-off to rule out sepsis was ≤20.0 (Negative Predictive Value, NPV: 86.4, 95% CI: 65.1–97.1). Multivariate analyses using both MDW and PCT found a significant association for MDW > 23 only (OR:17.64, 95% CI: 5.53–67.91).

The authors concluded that that MDW can be used as a novel sustainable biomarker of ensuing sepsis at the ICU, alone or in combination with PCT. Values of MDW ≤ 20 can be used to rule out sepsis (sensitivity = 95.9%, NPV = 86.4%). On the other hand, MDW > 23 can be used to rule in sepsis (PPV = 90.2%), with a slight gain when used in combination with PCT > 0.5 ng/mL (PPV = 92.6%). The study was published on November 22, 2021 in the journal BMC Emergency Medicine.

Related Links:
University of Chieti
General Hospital of Pescara
bioMérieux
Cepheid
Accelerate Diagnostics
Liofilchem
Beckman Coulter