ACUTE-PHASE REACTANT ALPHA(1)-ANTICHYMOTRYPSIN IS INCREASED IN CEREBROSPINAL-FLUID AND SERUM OF PATIENTS WITH PROBABLE ALZHEIMER-DISEASE

Levels of alpha(1)-antichymotrypsin (alpha(1)-ACT) in cerebrospinal fluid (CSF) and serum from patients with probable Alzheimer disease (AD) of both early (e-AD) and late (1-AD) onset assessed by a competitive enzyme-linked immunosorbent assay were higher than those found in controls or in patients with vascular dementia (VD). A negative correlation between CSF levels of alpha(1)-ACT and the stage of the disease was present in patients with both e-AD and 1-AD. No difference in alpha(2)-macroglobulin levels in CSF and serum from patients with e-AD, 1-AD, VD, and nondemented controls was found. Serum concentrations of alpha(1)-antitrypsin from 1-AD subjects were within the normal range. Thus, increased levels of alpha(1)-ACT in CSF and serum were specifically associated with AD, and the detection of this serpin in CSF may be useful in monitoring the progression of the disease.