Biomarker im Blut
摘要
The development of ultrasensitive laboratory methods has allowed the measurement of the Alzheimer-specific biomarkers amyloid Aβ42 and tau in different states of pathological phosphorylation in the blood. Specifically, various phospho-tau epitopes have proven especially helpful for clinical diagnosis. They reflect the progression of the tauopathy specific for Alzheimer disease in the brain. Different blood biomarkers have selected indications: risk stratification, early diagnosis, staging of disease, and monitoring therapeutic effects. The diagnostic performance of many of these markers equals or is even superior to diagnosis by cerebral spinal fluid (CSF) analysis or positron emission tomography (PET). Combined measurements of selected biomarkers allows determination of the molecular signature of Alzheimer disease in vivo, which is a requirement for the use of disease-modifying therapies. Renowned memory clinics in the US already treat patients with amyloid antibodies based on a diagnosis supported by blood biomarkers. In the EU, the test for p‑tau181 on the Elecsys platform has recently been approved for clinical use. Due to the lack of invasive procedures, their broad availability and moderate costs, these markers will improve the diagnosis of dementia disorders in the near future and will be the basis of personalized diagnoses. However, prerequisite will be a targeted indication and interpretation of the results by well-qualified healthcare personnel and—as for today—the avoidance of tests applied to asymptomatic individuals in order to avoid uncertainty and unreliable predictions.