Identifying Low-Abundance Biomarkers

Article, see p 270 Biomarkers are clinical, molecular, or image-based measurable parameters that can characterize an individual’s specific biological state, whether normal, pathological, or in response to treatment. A biomarker is considered of clinically valuable if (1) it can be measured repeatedly with accuracy and relatively rapid clinical turnaround, (2) it provides unique, superior information on patient status, and (3) it aids in clinical decisionmaking with high precision.1 High-quality biomarkers can critically inform clinical diagnosis (eg, high-sensitivity troponin for acute myocardial infarction) and guide therapy (eg, CYP2C19 status for clopidogrel therapy). The ideal biomarkers can further reveal underlying biological processes, inform therapeutic deployment, and pave the way for true personalized precision medicine. In this issue of Circulation , Ngo et al2demonstrate the use of a developing proteomics technology to rapidly screen for protein biomarkers in patients with planned and spontaneous myocardial infarcts.How valuable are new, additional biomarkers in cardiovascular medicine? The current medical literature is replete with publications on biomarkers in cardiovascular medicine. A search of the PubMed database revealed 6421 articles on biomarkers and cardiovascular disease in 2015 alone. Unfortunately, despite the wealth of publications, truly high-value biomarkers that are etiologically specific, reproducibly validated in multiple populations, andinformative in decisionmaking, and that can be implemented in clinical care are very few indeed. As highlighted in the most recent guidance on personalized medicine for cardiovascular disease from the Food and Drug Administration, the need for high-value, validated biomarkers to guide treatment development is now more urgent than ever.3Advances in systems biology over the past decade have provided more opportunities for innovative discovery of biomarkers than ever before. These advances range from identifying disease-causing genes using deep genome sequencing, the characterization of mRNA, microRNA, and noncoding RNAs through RNA-Seq, and profiling the expressed proteins and …