Multiplexed, quantitative serological profiling of COVID-19 from blood by a point-of-care test

Highly sensitive, specific, and point-of-care (POC) serological assays are an essential tool to manage coronavirus disease 2019 (COVID-19). Here, we report on a microfluidic POC test that can profile the antibody response against multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens-spike S1 (S1), nucleocapsid (N), and the receptor binding domain (RBD)-simultaneously from 60.l of blood, plasma, or serum. We assessed the levels of antibodies in plasma samples from 31 individuals (with longitudinal sampling) with severe COVID-19, 41 healthy individuals, and 18 individuals with seasonal coronavirus infections. This POC assay achieved high sensitivity and specificity, tracked seroconversion, and showed good concordance with a live virus microneutralization assay. We can also detect a prognostic biomarker of severity, IP-10 (interferon-gamma-induced protein 10), on the same chip. Because our test requires minimal user intervention and is read by a handheld detector, it can be globally deployed to combat COVID-19.

Automated summary

The microfluidic point-of-care test can profile antibody responses against multiple SARS-CoV-2 antigens and detect the prognostic biomarker IP-10, making it essential for COVID-19 management. Its high sensitivity, specificity, and diagnostic and tracking capabilities for severe patients, along with the ability to be globally deployed, make it a valuable tool in combating COVID-19.