We have developed a novel, easily implementable methodology using magnetic levitation to quantify circulating leukocyte size, morphology, and magnetic properties, which may help in rapid, bed side screening for sepsis.Objective:
Our objectives were 1) to describe our methodological approach to leukocyte assessment; and 2) to perform a pilot investigation to test the ability of magnetic levitation to identify and quantify changes in leukocyte size, shape, density and/or paramagnetic properties in healthy controls and septic patients.Methods:
This prospective, observational cohort study was performed in a 56,000/year visit emergency department and affiliated out-patient phlebotomy lab. Inclusion criteria were admittance to the hospital with suspected or confirmed infection for the septic group and we enrolled the controls from ED/outpatient patients without infection or acute illness. The bench-top experiments were performed using magnetic levitation to visualize the leukocytes. We primary sought to compare septic patients with non-infected controls and secondary to assess the association with sepsis severity. Our covariates were area, length, width, roundness and standard deviation(SD) of levitation height. We used unpaired t-test and area under the curve(AUC) for assessment of accuracy in distinguishing between septic and control patients.Results:
We enrolled 39 non-infected controls and 22 septic patients. Our analyses of septic patients compared to controls showed: mean cell area in pixels(px) 562 ± 111 vs 410 ± 45, p < 0.0001, AUC=0.89(0.80–0.98); length(px), 29 ± 2.5 vs 25 ± 1.9, p < 0.0001, AUC = 0.90(0.83–0.98); and width(px), 27 ± 2.4 vs 23 ± 1.5, p < 0.0001, AUC = 0.92(0.84–0.99). Cell roundness: 2.1 ± 1.0 vs 2.2 ± 1.2, p = 0.8, AUC = 0.51. SD of the levitation height(px) was 72 ± 25 vs 47 ± 16, p < 0.001, AUC = 0.80(0.67–0.93).Conclusion:
Septic patients had circulating leukocytes with especially increased size parameters, which distinguished sepsis from non-infected patients with promising high accuracy. This portal-device compatible technology, shows promise as a potential bedside diagnostic.