Toward a Field Test
In urine samples from Africans with active onchocerciasis infections, Globisch found that levels of the biomarker were on average four to six times higher than in samples from Africans with non-active infections. In a separate test, the team determined that a full course of doxycycline treatment, which sterilizes or kills infecting worms by destroying their symbiotic bacteria, also reduced levels of the biomarker to near-normal. "This biomarker appears to be specific for an active infection," Globisch said. The wide gap between biomarker levels in active and non-active infections suggests that a field test based on the biomarker would be robustly useful.
Such a diagnostic, said Janda, might ultimately be a simple urine dipstick test, much like a home pregnancy test, which would indicate the amount of the O. volvulus biomarker present in the sample. "Ultimately for this to be of value in Third World countries we will need to morph this biomarker into something that's inexpensive, simple to use, tolerant of extreme temperatures and portable—basically distilling our finding to a test that can be carted around in a backpack," Janda said.
Importantly, he adds that Globisch's metabolome-mining approach in theory should be applicable to the development of diagnostic tests for other worm diseases.Other contributors to the study, "Onchocerca volvulus Neurotransmitter Tyramine is a Biomarker for River Blindness," were Amira Y. Moreno, Mark S. Hixon, Ashlee A. K. Nunes and Judith R. Denery of TSRI; and Sabine Specht and Achim Hoerauf of the University Hospital Bonn, Germany. The study was funded by WIRM, which was established at TSRI through a generous donation by John J. Moores. About The Scripps Research Institute The Scripps Research Institute (TSRI) is one of the world's largest independent, not-for-profit organizations focusing on research in the biomedical sciences. Over the past decades, TSRI has developed a lengthy track record of major contributions to science and health, including laying the foundation for new treatments for cancer, rheumatoid arthritis, hemophilia, and other diseases. The institute employs about 3,000 people on its campuses in La Jolla, CA, and Jupiter, FL, where its renowned scientists—including three Nobel laureates—work toward their next discoveries. The institute's graduate program, which awards PhD degrees in biology and chemistry, ranks among the top ten of its kind in the nation. For more information, see www.scripps.edu. SOURCE The Scripps Research Institute