title: Biological and genetic markers of sporadic Alzheimer's disease.
abstract: With the development of new treatments, there is an increasing need for early diagnosis of sporadic Alzheimer's disease. Therefore, biological markers allowing positive diagnosis early in the course of the disease are highly desirable. Cerebrospinal fluid levels of protein tau were shown to be significantly increased in patients with Alzheimer's disease. Although sensitivity is high, poor specificity limits the diagnostic value of this marker. The same is true for the 42 amino acid isoform of beta-amyloid protein that is significantly decreased in cerebrospinal fluid of Alzheimer's disease patients. However, combining both markers could improve specificity at least allowing differentiation between Alzheimer's disease, normal ageing and depressive pseudodementia. Other biological markers such as cerebrospinal fluid levels of neurotransmitters, cytokines or superoxide dismutase were shown to have even less diagnostic value. The apolipoprotein epsilon 4 allele is a risk factor for Alzheimer's disease but not a diagnostic marker as many individuals who inherit epsilon 4 do not develop the disease. Till now, a single diagnostic marker allowing discrimination between Alzheimer's disease and other dementias does not exist. Combined cerebrospinal fluid levels of beta-amyloid protein and tau protein might be used as a marker that helps discriminating Alzheimer's disease from normal ageing and depression.
authors.affiliation: Department of Neurology and Memory Clinic, Middelheim General Hospital, Antwerp, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Engelborghs
authors.forename: P P
authors.initials: PP
authors.lastname: De Deyn
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D000596:Amino Acids / Q000134:cerebrospinal fluid; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D053327:Apolipoprotein E4; D001057:Apolipoproteins E / Q000134:cerebrospinal fluid / Q000235:genetics; D015415:Biomarkers / Q000032:analysis*; D016207:Cytokines / Q000134:cerebrospinal fluid; D005819:Genetic Markers; D006801:Humans; D009479:Neuropeptides / Q000134:cerebrospinal fluid; D018377:Neurotransmitter Agents / Q000134:cerebrospinal fluid / Q000378:metabolism; D010446:Peptide Fragments / Q000134:cerebrospinal fluid; D013482:Superoxide Dismutase / Q000134:cerebrospinal fluid; D016875:tau Proteins / Q000134:cerebrospinal fluid
chemical_list: D000596:Amino Acids; D016229:Amyloid beta-Peptides; D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D015415:Biomarkers; D016207:Cytokines; D005819:Genetic Markers; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins; D013482:Superoxide Dismutase