Peptide Biomarkers - An Emerging Diagnostic Tool and Current Applicable Assay.

In the past few decades, impressive progress achieved in technology development and improvement has accelerated the application of peptides as diagnostic biomarkers for various diseases. We outline the advantages of peptides as good diagnostic targets, since they serve as molecular surrogates of enzyme activities, much more specific biomarkers than proteins, and also play vital roles in many biological processes. On the basis of an extensive literature survey, peptide markers with high specificity and sensitivity that are currently applied in clinical tests, as well as recently identified, are summarized for the following four major categories of diseases: neurodegenerative disease, heart failure, infectious disease, and cancer. In addition, we summarize a few prevalent techniques used in peptide biomarker discovery and analysis, such as immunoassays, nanopore-based and nanoparticle-based peptide detection, and also MS-based peptide analysis techniques, and their pros and cons. Currently, there are plenty of analytical technologies available to achieve fast, sensitive and reliable peptide analyses, benefiting from the developments of hardware and instrumentation, as well as data analysis software and databases. Thus, with peptides emerging as sensitive, specific and reliable biomarkers for early detection of diseases, therapeutic monitoring, clinical treatment decisions and disease prognosis, the medical need for peptide biomarkers will increase strongly in the future.