Diagnosis of sepsis from a drop of blood by measurement of spontaneous neutrophil motility in a microfluidic assay

Abstract

Current methods for the diagnosis of sepsis have insufficient precision, causing regular misdiagnoses. Microbiological tests can help diagnose sepsis but are usually too slow to have an impact on timely clinical-decision making. Neutrophils have high sensitivity to infections, yet measurements of neutrophil surface markers, genomic changes, and phenotype alterations have had only a marginal effect on sepsis diagnosis. Here, we report a microfluidic assay that measures the spontaneous motility of neutrophils in the context of plasma, in one droplet of blood. We measured the performance of the assay in two independent cohorts of critically ill patients suspected of sepsis. In the first cohort, we developed a machine-learning-based scoring system (sepsis score) that segregated patients with sepsis from those without sepsis. In the second cohort, we validated the sepsis score in a double-blinded, prospective case-control study. For the 42 patients across the two cohorts, the assay identified sepsis patients with 97% sensitivity and 98% specificity. The neutrophil assay could potentially be used to accurately diagnose and monitor sepsis in larger populations of at-risk patients.

Leukocyte function assessed via serial microlitre sampling of peripheral blood from sepsis patients correlates with disease severity

“…In a large cohort of patients, using a point-of-care microfluidic device, CD64 surface receptor expression on neutrophils was found to be predictive of patient diagnosis but was of limited use in sepsis severity assessment 9 . A recent study demonstrated that the measurement of patterns of neutrophil spontaneous motility in microfluidic chambers enabled the accurate diagnosis of sepsis, which suggests that the measurement of leukocyte function (rather than number) may represent a potential approach for the development of sepsis severity biomarkers 15 . Here we modified and demonstrated a closed-loop microfluidics platform to isolate leukocytes using microlitre quantities of peripheral blood volumes to provide an innovative biomedical engineering approach to both the label-free sample preparation of leukocytes and the study of leukocyte activation and function in a clinical context.…”

“…Since leukocytes (white blood cells) are sensors for multiple environmental cues and pathogens 4 , their activation and function could prove useful as cellular biomarkers of illness. To this end, polymorphonuclear neutrophil (PMN) dysmotility in microfluidic chambers correlates with sepsis diagnosis 15 . Importantly, repeated measurement of the complete blood count (CBC) can contribute to anaemia, which is often present in hospitalized critically ill patients 16 .…”

Analysis of Leukocyte Behaviors on Microfluidic Chips

“…Immunodiagnosis is a kind of diseases diagnosis which relies on the detection of immunological variations caused by disease development . The occurrence and development of diseases often bring about obvious changes in leukocyte population and certain protein expression levels in the peripheral blood . Detection of those variations as well as the intruding pathogens gives rise to a more convenient disease diagnosis.…”

Elongation Index as a Sensitive Measure of Cell Deformation in High-Throughput Microfluidic Systems

“…Malignancy and hereditary blood disorders such as sickle cell disease cause reorganization of the intracellular structure that alters the ability of the cell to deform under applied stress (1)(2)(3)(4)(5). Various techniques have been developed to measure deformability of living cells, which can be classified into 1) single-cell methods such as micropipette aspiration and atomic force microscopy (6)(7)(8)(9)(10)(11)(12)(13) and 2) microfluidics-based deformability cytometry (14)(15)(16)(17)(18)(19).…”