Drop in Spinal Fluid Protein May Be Early Alzheimer Sign
Gene linked to age and falling cerebrospinal fluid beta-amyloid 42
TUESDAY, July 11 (HealthDay News) -- Starting in their 50s, patients who carry the apolipoprotein E-e4 (APOE4) allele experience a greater decline in beta-amyloid 42 (Aβ42) concentrations in their cerebrospinal fluid, a biomarker for Alzheimer disease, than those who do not carry the APOE4 allele, researchers report in the July issue of the Archives of Neurology. The finding could be a way to determine if patients have asymptomatic disease, and thus may be candidates for early intervention.
Elaine R. Peskind, M.D., of the Veterans Administration Puget Sound Health Care System in Seattle, and colleagues studied the influence of aging and the apolipoprotein E alleles on cerebrospinal fluid in 184 adults aged 21 to 88.
The researchers found that cerebrospinal fluid concentrations of Aβ42, but not Aβ40, declined with age. Starting in their 50s, the cerebrospinal fluid concentrations of Aβ42 fell sharply in those with APOE4 allele. The decline was greater in those with APOE4 than in those without the allele.
"These cerebrospinal fluid Aβ42 findings are consistent with acceleration by the APOE4 allele of pathogenic Aβ42 brain deposition starting in later middle age in persons with normal cognition," the authors write.
In an editorial, Roger N. Rosenberg, M.D., of the University of Texas Southwestern Medical Center in Dallas, writes that the data "provide the means to identify patients who have the apolipoprotein Ee4 allele, potentially have asymptomatic Alzheimer disease...and would be ideal candidates for therapeutic intervention."