Cerebrospinal fluid biomarkers for Alzheimer's disease

Research progress has provided detailed understanding of the molecular pathogenesis of Alzheimer disease (AD). This knowledge has been translated into new drug candidates with putative disease-modifying effects, which are now being tested in clinical trials. The promise of effective therapy has created a great need for biomarkers able to detect AD in the predementia phase, because drugs will probably be effective only if neurodegeneration is not too advanced. In this chapter, cerebrospinal fluid (CSF) and plasma biomarkers are reviewed. The core CSF biomarkers total tau (T-tau), phosphorylated tau (P-tau) and the 42 amino acid form of b-amyloid (Ab42) reflect AD pathology, and have high diagnostic accu-racy to diagnose AD with dementia and prodromal AD in mild cognitive impairment cases. The rationale for the use of CSF biomarkers to identify and monitor the mechanism of action of new drug candidates is also outlined in this chapter. In 1906, Alois Alzheimer presented the firstcase of the disease that was to bear his name, Alzheimer disease (AD). Alzheimer described the “miliary bodies ” (plaques) and “dense bun-dles of fibrils ” (tangles) which we today kno