Promises and challenges of populational proteomics in health and disease.

Advances in proteomic assay technologies has significantly increased coverage and throughput, enabling recent increases in the number of large-scale population-based proteomic studies of human plasma and serum. Improvement in multiplexed protein assays have facilitated quantification of thousands of proteins over a large dynamic range, a key requirement for detecting the lowest ranging, and potentially the most disease relevant, blood circulating proteins. In this perspective, we examine how populational proteomic datasets in conjunction with other concurrent omic measures can be leveraged to better understand the genomic and non-genomic correlates of the soluble proteome, constructing biomarker panels for disease prediction, among others. Mass spectrometry workflows are discussed as they are becoming increasingly competitive with the affinity-based array platforms in terms of speed, cost and proteome coverage due to advances in both instrumentation and workflows. Despite much success, there remains considerable challenges such as orthogonal validation and absolute quantification. We also highlight emergent challenges associated with study design, analytical considerations and data integration as population scale studies are run in batches and may involve longitudinal samples collated over many years. Lastly, we take a look at the future of what the nascent next-generation proteomic technologies might provide to the analysis of large sets of blood samples, as well as the difficulties in designing large-scale studies that will likely require participation from multiple and complex funding sources and where data sharing, study designs and financing must be solved.