Label‐Free Biophysical Markers from Whole Blood Microfluidic Immune Profiling Reveal Severe Immune Response Signatures

Abstract

advances in disease diagnostics, the main culprit for disease manifestation, severity, and death is the hyper-aggressive host immune response in most instances. [1-3] In the example of severe COVID-19 infection, the leading cause of death is sepsis (dysregulated immune response) while existing risk stratification methods based on age and co-morbidity remain challenging and imprecise. [4,5] The status of the patients' immune response can quickly change in a matter of minutes, therefore assays that are able to rapidly inform on the state of the immune system are vital in early triage among patients with acute infection, as well as prediction of downstream deterioration of disease. [6,7] This enables delivery of appropriate medical response, particularly in the emergency department (ED), for timely intervention before immune dysregulation becomes clinically evident and requiring admission to the intensive care unit (ICU). Unlike patients in the ICU who almost always have clear clinical manifestations of disease severity and organ dysfunction (e.g., low blood pressure, decreased oxygenation, jaundice, low urine output), those in the ED frequently show non-specific symptoms and signs, which pose a challenge for physicians to assess the presence of infection and possibility of deterioration into organ dysfunction. Disease manifestation and severity from acute infections are often due to hyper-aggressive host immune responses which change within minutes. Current methods for early diagnosis of infections focus on detecting low abundance pathogens, which are time-consuming, of low sensitivity, and do not reflect the severity of the pathophysiology appropriately. The approach here focuses on profiling the rapidly changing host inflammatory response, which in its over-exuberant state, leads to sepsis and death. A 15-min labelfree immune profiling assay from 20 µL of unprocessed blood using unconventional L and Inverse-L shaped pillars of deterministic lateral displacement microfluidic technology is developed. The hydrodynamic interactions of deformable immune cells enable simultaneous sorting and immune response profiling in whole blood. Preliminary clinical study of 85 donors in emergency department with a spectrum of immune response states from healthy to severe inflammatory response shows correlation with biophysical markers of immune cell size, deformability, distribution, and cell counts. The speed of patient stratification demonstrated here has promising impact in deployable point-of-care systems for acute infections triage, risk management, and resource allocation at emergency departments, where clinical manifestation of infection severity may not be clinically evident as compared to inpatients in the wards or intensive care units.

Targeted Therapeutics Delivery by Exploiting Biophysical Properties of Senescent Cells

“…[104,149,150] Particularly, microfluidic technologies are appealing due to the ability for single-cell biophysical characterization of cells, which have thus seen much developments in this area. [151,152]…”

Assessment of a Cellular Host Response Test as a Sepsis Diagnostic for Those With Suspected Infection in the Emergency Department

“…Infection by a pathogen and activation of the host innate immunity are fundamental processes of sepsis pathogenesis. During activation, the cells of innate immunity—monocytes and neutrophils—undergo biochemical and biophysical changes that allow them to fulfill their function ( 9 , 10 ). Although progress has been made in the rapid identification of pathogens ( 11 ), there are limited options available for the quantification of the biophysical changes characteristic of the host response ( 12 ).…”

Understanding Microbeads Stacking in Deformable Nano-Sieve for Efficient Plasma Separation and Blood Cell Retrieval

“…We show that RBCs can be retrieved by simply increasing the flow rate and the deformation of the nanosieve, which is more superior than microstructure-based separation as the clogged RBCs cannot easily be removed from the functional structure [37][38][39]. The study of RBCs in patient sample can be used to understand and treat many bloodborne diseases such as sepsis [8,9], sickle cell anemia [10,11], and COVID-19 [40,41]. In the future, the geometry of each nano-sieve can be modulated to process a larger volume of blood sample for low concentration pathogen detection.…”

“…The cells suspension consists of white blood cells, red blood cell (RBCs), and platelets. The analysis of physical properties of cell components in blood can be used for the diagnosis of several cell-based diseases, such as cancer [6,7], sepsis [8,9], sickle-cell anemia [10,11], and malaria [12,13]. On the other hand, human plasma that is clear and straw-colored liquid (54.3% by volume of whole blood) comprises various proteins (e.g., fibrinogen, globulin, and albumin) and several inorganic compounds [14].…”