Serological alpha 1-antichymotrypsin in patients with probable senile dementia of Alzheimer type: a short-term longitudinal study.

: Serum levels of alpha 1-antichymotrypsin (alpha 1-ACT), macroglobulin, alpha 1-antitrypsin, ceruloplasmin, acid glycoprotein, transferrin, and C-reactive protein were measured in patients with probable late onset dementia of Alzheimer type (I-AD), patients with vascular dementia (VD), healthy elderly (HC), and patients with chronic or acute inflammation. Three blood samples were taken at 10-15 day intervals. Serum alpha 1-ACT levels from first and second serum samples were elevated in one out of 11 I-AD patients. Serpin serum levels from the third sample were increased in four out of 11 I-AD patients. None of these patients showed increased levels of other acute phase proteins measured in the three serum samples. VD patients did not show abnormal serum levels of alpha 1-ACT. Serum levels of alpha 1-ACT along with those of other acute phase proteins were altered in patients with inflammation. This investigation showed that in I-AD patients with increased alpha 1-ACT and no concomitant elevation of other acute phase proteins, serum levels of alpha 1-ACT varied with time. Based on our results, serum alpha 1-ACT does not appear to be a useful biomarker for clinical diagnosis of probable I-AD, but it might be associated with the clinical history of the disease.