Blood Test to Diagnose Alzheimer’s Disease

by Cleveland Clinic:A blood test to diagnose Alzheimer's disease may be moving closer to reality following a recent clinical trial at Cleveland Clinic Lou Ruvo Center for Brain Health.Kate Zhong, MD, Senior Director of Clinical Research and Development, and her team are working with a French company (ExonHit) to develop a new diagnostic blood test for Alzheimer’s disease. Currently, Alzheimer’s diagnostic tests aren’t performed until the patients exhibit symptoms of the disease. If the test is validated after this study and other tests, primary care physicians will be able to order a simple blood test to identify patients at high risk for the disease.They recently completed the first U.S. study of the test, a five-month, clinical trial involving 160 participants at three Cleveland Clinic locations. In the test the participants, who have been referred to the Lou Ruvo Center for Brain Health for memory impairment, had their blood drawn and underwent a MiniMental State Exam and evaluation by the Center. The results were compared to data from patients who don’t have Alzheimer’s disease.“We are very excited about the possibility of contributing to the development of this critically needed new test,” says Dr. Zhong.Currently, 5.5 million Americans have been diagnosed with Alzheimer’s disease. “One to 2 percent of Americans have Alzheimer’s disease by the time they are 65,” says Dr. Zhong. “By the time they are 85, nearly half will have Alzheimer’s disease if we do not find a more effective treatment.”Why clinical trials are neededClinical trials are the only way that new diagnostic tests and treatments can receive approval from the Food and Drug Administration. All new tests and treatments must first be studied in a laboratory to determine any potential toxicity before human testing begins.Safe and promising treatments then move into three phases of clinical trials:Phase 1 trials involve a small number (20 to 100) of healthy volunteers participate to examine the safety and drug profile of the candidate treatment in human beings.Phase 2 trials include a larger number of participants (100 to 300) with the condition to be treated (such as Alzheimer’s disease) who are entered into a trial to determine the safety and preliminary efficacy of the promising treatment. Phase 2 trials also determine the dose to be advanced to Phase 3.Phase 3 trials involve large numbers of patients (600 – 2000) with the disease who are given the drug or a placebo to confirm the efficacy of the drug.  If Phase 3 succeeds, the drug is advanced for FDA approval after which it can be made widely available.“Clinical trials are the bridge between bench side (basic research) and bedside (patient use),” Dr. Zhong says.Source: http://bit.ly/UTYlLS