A team led by Haifeng Wu, an associate professor of pathology and internal medicine at Ohio State University, recently demonstrated a new rapid multiplexed genotyping method that promises to bring a personalized approach to warfarin therapy. Despite its effectiveness, the widely prescribed anti-coagulant drug has many contraindications with common medications, as well as with chemicals present in some foods, so a physician's ability to choose the correct dosage is crucial — especially as potential side effects include bleeding and clot development.
Wu's group used surface-enhanced laser desorption and ionization time-of-flight mass spec to determine three warfarin-related SNPs in less than five hours, with a high rate of accuracy.
SELDI-TOF is a flavor of mass spec that, when combined with chip technology, facilitates efficient enrichment of a DNA analyte prior to the detection process, thereby permitting investigators to more effectively identify SNPs of possible clinical significance. "In comparison to other methods for SNP analysis, SELDI-TOF provides similar — if not better — analytical performance such as test turnaround time, test precision, and cost effectiveness," Wu says. "Enabling the on-site detection of SNPs influencing warfarin therapy in the hospital setting would help clinicians to get same-day results so that they can administer initial doses to their patients correctly."
Wu's group is now working -closely with the Center for Personalized Health Care at Ohio State to apply their SELDI-TOF platform to develop protocols to pin down other medically significant SNPs that affect the efficacy of drug therapies. Areas of interest include SNPs that influence the effect of the anti-platelet drug Plavix and the breast cancer drug tamoxifen. "We have demonstrated through research a proof of principle for a plausible application of this unique method," he says. "The next step is to build a business-academic partnerships to further refine SELDI-TOF technology and eventually bring about a broader application of this approach to benefit more patients."