A Digital Protein Microarray for COVID-19 Cytokine Storm Monitoring

Abstract

Despite widespread concern for cytokine storms leading to severe morbidity in COVID-19, rapid cytokine assays are not routinely available for monitoring critically ill patients. We report the clinical application of a machine learning-based digital protein microarray platform for rapid multiplex quantification of cytokines from critically ill COVID-19 patients admitted to the intensive care unit (ICU) at the University of Michigan Hospital. The platform comprises two low-cost modules: (i) a semi-automated fluidic dispensing/mixing module that can be operated inside a biosafety cabinet to minimize the exposure of technician to the virus infection and (ii) a 12-12-15 inch compact fluorescence optical scanner for the potential near-bedside readout. The platform enabled daily cytokine analysis in clinical practice with high sensitivity (<0.4pg/mL), inter-assay repeatability (~10% CV), and near-real-time operation with a 10 min assay incubation. A cytokine profiling test with the platform allowed us to observe clear interleukin-6 (IL-6) elevations after receiving tocilizumab (IL-6 inhibitor) while significant cytokine profile variability exists across all critically ill COVID-19 patients and to discover a weak correlation between IL-6 to clinical biomarkers, such as Ferritin and CRP. Our data revealed large subject-to-subject variability in a patient's response to anti-inflammatory treatment for COVID-19, reaffirming the need for a personalized strategy guided by rapid cytokine assays.

Microfluidic systems for the analysis of blood‐derived molecular biomarkers

“…For example, epoxy‐ and carboxy‐linked beads have been used to covalently immobilize capture antibodies to perform the multiplexed detection of cytokines from serum samples in a microfluidic device. The coupling of bead‐based immunoassay and microfluidics has allowed the 4‐plexed detection of proinflammatory cytokines (TNF‐α, IL‐1β, interleukin 10, and IL‐6, with LOD ranging from 0.2 to 3 pg/ml) to monitor cytokine storms in COVID‐19 patients [256]. The versatility of both technologies has allowed increasing the multiplexed detection capabilities, enabling the quantification of 12 different cytokines from the same sample, which has been proven useful to assess cytokine release syndrome in leukemia patients after CAR‐T cell therapy [257].…”