Study: Protein Levels in Spinal Fluid Can Aid in Diagnosis of Alzheimer's

Measuring the levels of two proteins in a person's spinal fluid can help clinicians diagnose Alzheimer's disease, according to a study reported in the April 23 issue of the Journal of the American Medical Association.

The proteins are beta-amyloid and tau, which are both linked to the development of Alzheimer's disease. Beta-amyloid clumps together to form brain-damaging plaques, while tau strangles neurons in tangled filaments.

Researchers found that beta-amyloid levels in spinal fluid drops, while tau levels rise in Alzheimer's. The researchers made this finding after comparing the protein levels in the spinal fluid of 136 Alzheimer's patients and 72 healthy participants.

"Perhaps the most important future use for such biomarkers is in the prospective study of people at risk for developing Alzheimer's disease," said lead researcher Dr. Trey Sunderland, chief of geriatric psychiatry at the National Institute of Mental Health.

By tracking levels of the protein in a person's spinal fluid over time, Sunderland said gradual changes could be interpreted over time to be a sign that a person is developing Alzheimer's disease. However, he noted that more tests are needed before this would be possible.

Other sources: National Institute of Mental Health, JAMA 2003;289:2094-2103