Quantitative assessment of multiple pathogen exposure and immune dynamics at scale

Abstract

ABSTRACT Serological responses reveal recent and historical exposure to pathogens, as well as the state of autoimmune and other chronic conditions, including cancer. Serological tests either assess one or a few antigens in many people, or multiple antigens for modest sample sizes. Here, we describe a multiplexed serology method that evaluates samples at the scale of thousands. This molecular epidemiology tool operates at a population scale sufficient to evaluate broadly how various infectious exposures or autoimmune responses affect health. The method employs full-length folded proteins, is quantitative over a wide dynamic range, and performs favorably compared with commercial clinical assays [severe acute respiratory syndrome coronavirus 2 chemiluminescent IgG II assay (Beckman) and Platelia SARS-CoV-2 total Ab enzyme-linked immunosorbent assay (Bio-Rad, California, USA)]. Responses to 39 bacteria species/strains and 99 viruses in 2,400 people were evaluated. Subjects with longitudinal data showed quantitative stability of response to all antigens over the 6-month time window, enabling the detection of intervening clinical events. We expect this highly adaptable method will find broad application in immune profile tracking. IMPORTANCE Serology reveals exposure to pathogens, as well as the state of autoimmune and other clinical conditions. It is used to evaluate individuals and their histories and as a public health tool to track epidemics. Employing a variety of formats, studies nearly always perform serology by testing response to only one or a few antigens. However, clinical outcomes of new infections also depend on which previous infections may have occurred. We developed a high-throughput serology method that evaluates responses to hundreds of antigens simultaneously. It can be used to evaluate thousands of samples at a time and provide a quantitative readout. This tool will enable doctors to monitor which pathogens an individual has been exposed to and how that changes in the future. Moreover, public health officials could track populations and look for infectious trends among large populations. Testing many potential antigens at a time may also aid in vaccine development.