Abstract

Neutrophil Extracellular Traps (NETs) Measurements In a Drop of Blood

Daniel Irimia, Associate Professor/Associate Director, Massachusetts General Hospital & Harvard Medical School

The pathology of several conditions, from acute respiratory distress syndrome (ARDS) and COVID-19 complications, acute kidney injury (AKI), liver failure, and stroke, to rheumatic diseases, atherosclerosis, and cancer is mediated by the release of neutrophil extracellular traps (NETs) in the circulation. Monitoring the levels of NETs in the blood of patients with these conditions is important for monitoring to progression of disease and for evaluating the efficacy of treatments that block the release of NETs or accelerate NETs degradation. However, the assays available today for measuring NETs are imprecise because they lose NETs during separation from blood, cannot distinguish between intact and degraded NETs, and are laborious and difficult to integrate in clinical studies. To circumvent the shortcomings of current assays, we developed a class of microfluidic devices that capture and measure intact NETs directly from blood samples. These devices rely on the physical properties of NETs rather than their biochemistry, which is the basis of current assays. Moreover, our devices can measure NETs in samples as small as a drop (10 microliters), measure the degradation rate of NETs in plasma, and study the trapping of microbes on NETs, processes that are important in pathology and cannot be evaluated using current assays.