Monocyte Distribution Width Indicates Sepsis Regardless of Sepsis Etiology

Introduction

Sepsis is a life-threatening condition without characteristic signs and symptoms, and early diagnosis of the septic state is crucial for improving patient prognosis. Standard diagnostics of infectious agents using microbiological methods or molecular techniques are time-consuming and do not allow for early case recognition. In recent years, several biomarkers and clinical criteria for early sepsis diagnosis have been evaluated.

Among the promising new methods is the assessment of monocyte distribution width (MDW) using a specialized laboratory analyzer. Monocytes, along with neutrophils, play a role in the first line of defense against infectious organisms. An increase in the so-called monocyte distribution width reflects their activity during an infectious disease and, along with other examinations, helps to detect early cases of sepsis. The study aimed to evaluate the effectiveness of this assessment in patients admitted to the intensive care unit.

Methodology and Course of the Study

The prospective observational study included adult patients admitted to the intensive care unit of a university hospital in Padua, Italy, from January to June 2020. A total of 506 patients (346 men, 160 women) aged 18–89 years (median 68 years; interquartile range [IQR] 57–76 years) were included.

Sepsis was diagnosed using the Sepsis-3 criteria along with the evaluation of acute organ dysfunction using the SOFA score. Patients were divided into three groups: the first group consisted of non-septic patients (n = 394), the second group included patients with sepsis (n = 108), and the third group comprised patients in septic shock (n = 4). A total of 2367 MDW evaluations were performed, and other tests included CRP, procalcitonin, and other laboratory parameters.

Results

Monocyte distribution width was statistically significantly higher in patients with sepsis and septic shock compared to non-septic patients (p < 0.001); no significant difference in values was observed between patients with sepsis and those in septic shock. The median MDW value for non-septic patients was 21.99 (IQR 19.86–24.36), for septic patients 26.23 (23.48–29.83), and for patients in septic shock 28.97 (21.27–37.21). In ROC analysis, the area under the curve (AUC) for sepsis prediction was determined to be 0.785 with a sensitivity of 66.88% and specificity of 77.79% at a cut-off value of 24.63.

In the comparison of diagnostic performance for sepsis prediction, the AUC for monocyte distribution width was comparable to that of procalcitonin (0.759; 95% CI 0.740–0.778) and better than for CRP (0.667; 95% CI 0.646–0.688) and leukocyte count (0.570; 95% CI 0.547–0.592). There was no significant difference in monocyte distribution width values between different infectious agents (gram-positive and gram-negative bacteria, viruses, fungi, and SARS-CoV-2).

An increased monocyte distribution width value was thus not influenced by the etiology of the septic state, even in patients with sepsis caused by COVID-19. In patients who developed sepsis during their stay in the intensive care unit, a significant increase in the median MDW value was observed during their stay from 21.33 (19.47–21.72) to 29.19 (27.46–31.47). In surviving septic patients, a decrease in the median MDW value from 29.14 (26.22–32.52) to 25.67 (22.93–30.28) was observed during their stay in the intensive care unit.

Conclusion

The study results indicated that the use of monocyte distribution width assessment in the intensive care setting increases the likelihood of correctly diagnosing sepsis, regardless of the sepsis etiology.

(holi)

Source: Piva E., Zuin J., Pelloso M. et al. Monocyte distribution width (MDW) parameter as a sepsis indicator in intensive care units. Clin Chem Lab Med 2021; 59 (7): 1307–1314, doi: 10.1515/cclm-2021-0192.