Precision Medicine Will Rely on Proteins, Not Just DNA
Like an oasis in the desert, the splendor of precision medicine seems perpetually on the horizon. Even as technological advances bring genome sequencing into routine clinical use, it’s becoming clearer than ever that genomics reveals only part of the clinical picture.
“Genes are static,” said Vinit Mahajan, MD, PhD, an associate professor of ophthalmology at Stanford University. “They don’t tell us when the disease is active, when it’s going to start, when it’s going to stop.” For real-time analysis of a patient’s disease state, he said, “You need to look at proteins.”
Proteomics is a lot harder than genomics, because of the complex chemistry, but it can be richly informative. A new generation of multiplexed antibody arrays is helping cut through some of that complexity. Quantitative, customizable multiplex ELISA arrays allow researchers to cast a net into a pool of potential biomarkers. That net can be small and focused or large and diverse, for a variety of research applications.
"Genes are static,” said Vinit Mahajan, MD, PhD, an associate professor of ophthalmology at Stanford University. “They don’t tell us when the disease is active, when it’s going to start, when it’s going to stop. For real-time analysis of a patient’s disease state, he said, “You need to look at proteins.
For Mahajan, a vitreoretinal surgeon, protein testing reveals much that’s not apparent from visual imaging. For example, similar eye symptoms arise from four very different conditions: metastatic lymphoma, or infections with bacteria, fungus, or virus. Each of those requires a different treatment plan. “Despite our amazing clinical imaging, those four diseases have overlapping phenotypes,” he said. Time spent testing for each possibility is wasted treatment time. A protein assay could cut down diagnosis time and speed up treatment. “What we’ve found is that even though, clinically, they look similar, the fluid in the eye has very obvious proteomic signatures for each of those conditions,” said Mahajan.
Inflammatory eye disease presents a similar diagnostic challenge, because the symptoms are nonspecific. Broad spectrum anti-inflammatory drugs carry nasty side effects, so it’s better to pick a targeted drug. But often, the process comes down to trial and error.