[Specific brain antigens as the indicators of the blood-brain barrier permeability in Alzheimer's disease].

A study was made of the hypothesis of blood-brain barrier dysfunction in Alzheimer's disease (AD) and of the role it plays in the disease pathogenesis. Use was made of the enzyme immunoassay test systems to detect neurospecific proteins in the blood serum within the following sensitivity range: gliofibrillar acid protein 10 ng/ml, alpha 2-glycoprotein of the brain 0.9 ng/ml, alpha 1- and alpha 2-specific brain globulins 50 pg/ml. Gliofibrillar acid protein and alpha 2-glycoprotein of the brain appeared the most sensitive markers of the process. Demonstration of these antigens in the blood serum in a concentration exceeding donor's ones suggests the impairment of the blood-brain integrity in active passage of brain proteins to the blood. A direct relationship is shown between the level of gliofibrillar acid protein in the blood serum and the severity of the clinical picture of AD.