Rapid single-molecule digital detection of protein biomarkers for continuous monitoring of systemic immune disorders

Digital protein assays have great potential to advance immunodiagnostics because of their single-molecule sensitivity, high precision, and robust measurements. However, translating digital protein assays to acute clinical care has been challenging because it requires deployment of these assays with a rapid turnaround. Herein, we present a technology platform for ultrafast digital protein biomarker detection by using single-molecule counting of immune-complex formation events at an early, pre-equilibrium state. This method, which we term pre-equilibrium digital enzyme-linked immunosorbent assay (PEdELISA), can quantify a multiplexed panel of protein biomarkers in 10 mu L of serum within an unprecedented assay incubation time of 15 to 300 seconds over a 10(4) dynamic range. PEdELISA allowed us to perform rapid monitoring of protein biomarkers in patients manifesting post-chimeric antigen receptor T-cell therapy cytokine release syndrome, with similar to 30-minute sample-to-answer time and a sub-picograms per mL limit of detection. The rapid, sensitive, and low-input volume biomarker quantification enabled by PEdELISA is broadly applicable to timely monitoring of acute disease, potentially enabling more personalized treatment.

Automated summary

Digital protein assays show potential for advancing immunodiagnostics, but face challenges in translating to acute clinical care. The PEdELISA technology platform enables rapid and sensitive monitoring of protein biomarkers, allowing for timely surveillance of acute diseases and potentially facilitating more personalized treatment.