Researchers have identified a new protein marker that leaks into the bloodstream when central nervous system barriers are breached. The marker could be used to detect disease and to determine when the body may be more or less receptive to medications.

"This finding may have significant implications in the development of simple diagnostic tools for conditions affecting the central nervous system," said Damir Janigro, director of Cerebrovascular Research at The Cleveland Clinic's Lerner Research Institute. "Additionally, discovery of this marker may help us manage or diagnose disorders such as stroke, brain tumors, inflammations of the nervous system, and other cerebrovascular disorders."

Dr. Janigro lead the team that studied blood samples from patients undergoing induced therapeutic blood-brain barrier disruption for the treatment of brain cancer. The blood-brain barrier, as well as the blood-to-cerebrospinal fluid barrier (CSF barrier), protects the brain from foreign substances. Failure of either defense mechanism could signal the presence of disease. But selective opening of either barrier could provide the window needed to deliver potentially life-saving medications to the central nervous system, Dr. Janigro said.

Cleveland Clinic scientist Nicola Marchi, who works with Dr. Janigro, identified the new protein marker, called transthyretin monomer (TTR). TTR leaks into the bloodstream when central nervous system barriers are breached. Because TTR is found primarily in cerebrospinal fluid, researchers concluded that it might be a tracer of the blood-to-cerebrospinal fluid barrier.

Home to 130 principal investigators, Lerner Research Institute is the research division of The Cleveland Clinic Foundation. Throughout its eight departments - Biomedical Engineering, Cancer Biology, Cell Biology, Immunology, Molecular Biology, Molecular Cardiology, Neurosciences and Virology - Lerner Research Institute investigators conduct direct investigations in basic, developmental and clinical research.