Sample-Sparing Multiplexed Antibody Fc Biomarker Discovery Using a Reconfigurable Integrated Microfluidic Platform

Abstract

Control of endemic infectious diseases is often impeded by the lack of sensitive and specific yet easy-to-obtain biomarkers. Antibody fragment crystallizable (Fc) region, such as Fc glycosylation, which are modulated in a pathogen-specific and disease-state specific manner have emerged as potential such biomarkers. However current methods to perform large scale antigen-specific antibody Fc feature screening for biomarker discovery often require too much sample volume, cost and expertise to be realistically doable in many disease contexts. Here we present a simple, flexible and reconfigurable, microfluidic device, made using rapid prototyping techniques, that can perform highly multiplexed and high-throughput biomarker discovery targeting both antibody fragment antigen-binding (Fab) and Fc features including antigen-specificity, antibody isotypes, subclasses, N-glycosylation and Fc receptor binding. Using integration of an antigen microarray and reconfigurable microfluidics for sample and probe distribution, the device can perform a total of 1400 assays measuring 100 antibody Fab and Fc features per sample from a low sample volume (15µl). The device demonstrates cleanroom-free simple fabrication and ease of use comparable to standard immunoassay platforms. Performance comparable to existing methods was validated and a biomarker screening for schistosomiasis, a helminth-mediated infection, was performed using clinical samples where antibody subclass-based biomarkers were successfully identified distinguishing current infection from former infection and endemic controls.