Multiplexed Single-Cell Leukocyte Enzymatic Secretion Profiling from Whole Blood Reveals Patient-Specific Immune Signature

Enzymatic secretion of immune cells (leukocytes) plays a dominant role in host responses to myriad biological triggers, including infections, cancers, and cardiovascular diseases. Current tools probe these leukocytes inadequately profile vital biomarkers; the need for sample preprocessing steps cell lysis, labeling, washing, pipetting inevitably triggers cells, changes its basal state, dilutes individual bulk assays. Using fully integrated system multiplexed profiling native single-cell enzyme from 50 μL undiluted blood, we eliminate handling. With total analysis time 60 min, platform performs six tasks leukocyte extraction, fluorescent substrate mixing, droplet making, incubation, real-time readout neutrophil elastase, granzyme B, metalloproteinase. We calibrated device, optimized protocols, tested acute heart failure (AHF) patients at admission predischarge. This paper highlights presence enzymatic phenotypes independent CD marker which could potentially elucidate innate response states. found that recovering AHF showed corresponding reduction immune-cell levels donor-specific signatures were observed, suggests patient-to-patient heterogeneous response. presents opportunities complexities single drop blood bridge current technological, biological, medical gap understanding triggers.