Fran Lowry

March 02, 2016

ORLANDO, Florida — Monocyte distribution width is a better marker of sepsis than white blood cell count in the emergency department, according to new research.

"In our feasibility study, the new measure, monocyte distribution width, outperformed white blood cell count for discriminating systemic inflammatory response syndrome — or SIRS — from sepsis," said Elliott Crouser, MD, from The Ohio State University Wexner School of Medicine in Columbus.

"People with SIRS look sick but do not have sepsis; this is the difficult problem clinicians face," Dr Crouser said here at the Society of Critical Care Medicine's 45th Critical Care Congress.

"It is hard to distinguish those with sepsis, who are acutely sick with infection, from those who are acutely sick because of something other than infection, such as pancreatitis, pulmonary embolism, or tissue damage related to trauma or surgery," he told Medscape Medical News.

Dr Elliott Crouser

People are 2.4 times more likely to present with SIRS than with sepsis, "so it is important to find a biomarker that works well for this purpose or you will miss a lot of cases of sepsis," he said.

Dr Crouser and his team hypothesized that changes in circulating immune cell volume parameters would facilitate the early detection of sepsis.

They evaluated 1320 patients 18 to 90 years of age who presented to two different emergency departments and who had complete blood counts.

Patients were categorized on the basis of blood analysis, conducted using a Beckman Coulter DxH 800, version 2.0, system. Ninety-eight of the patients were classified as having sepsis (including severe sepsis and septic shock), 140 as having infection without SIRS, and 203 as having SIRS. The other 879 patients made up the control group.

Monocyte distribution width was better than any of the other volumetric cell parameters assessed — such as mean neutrophil volume, neutrophil distribution width, and percentage of white blood cells or neutrophils — at differentiating sepsis from all other conditions.

The area under the curve (AUC) for monocyte distribution width was 0.79 (95% confidence interval [CI], 0.74 - 0.84); its sensitivity was 77% and its specificity was 73%.

Monocyte distribution width was also better than any of the other volumetric cell parameters assessed at distinguishing sepsis from SIRS (AUC, 0.74; 95% CI, 0.67 - 0.84), and at distinguishing severe sepsis or septic shock from uninfected patients (AUC, 0.88; 95% CI, 0.75 - 0.99; nonpredictive value, 99%).

For sepsis, the negative predictive value of normal monocyte distribution width was 98%.

Elevated monocyte distribution width "performed best as a biomarker of sepsis in this study," Dr Crouser reported. "It is printed out as a routine measure and one that doctors can easily look at instead of the usual white blood cell count to determine who is really septic. The study, however, requires validation in a larger multisite study."

Dr Greg Martin

"This is a novel diagnostic biomarker for early sepsis," said Greg Martin, MD, professor of medicine at Emory University in Atlanta.

"Having such a test would be invaluable for more rapidly identifying patients with sepsis in need of medical care and intervention," Dr Martin told Medscape Medical News.

The study was sponsored by Beckman Coulter. Dr Crouser reports having a financial relationship with Beckman Coulter. Dr Martin has disclosed no relevant financial relationships.

Society of Critical Care Medicine's (SCCM) 45th Critical Care Congress: Abstract 58. Presented February 21, 2016.


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