Elevated Alpha₁-Antichymotrypsin Serum Levels in a Subset of Nondemented First-Degree Relatives of Alzheimer's Disease Patients

Abstract

A portion of Alzheimer''s disease (AD) patients have elevated serum levels of the acute phase reactant α₁-antichymotrypsin (A1ACT) compared to age-matched controls. We measured serum levels of A1ACT in AD patients, age-matched controls, Down''s Syndrome patients, and nondemented first-degree relatives of AD patients. Significantly elevated levels of A1ACT were found in both AD patients and first-degree-relatives. In AD patients, serum A1ACT concentrations decreased with increasing severity of cognitive impairment. These results may suggest that inflammatory phenomena may be an early component of AD pathophysiology.

Blood Levels of Alpha-1-Antichymotrypsin and Risk Factors for Alzheimer’s Disease: Effects of Gender and Apolipoprotein E Genotype

“…These findings excluded the presence of a systemic inflammation in AD [21]. Elevated levels of serum ACT have also been reported in a subset of first-degree relatives of AD patients [23], and it has been suggested that serological ACT may represent a useful biological marker to monitor the disease [23]. However, other studies could not confirm the above findings and reported normal levels of ACT from peripheral blood of AD patients [24][25][26].…”

Alpha-1-Antichymotrypsin Polymorphism in Schizophrenia: Frequency, Age at Onset and Cognitive Function

“…Elevated ACT concentrations have been widely but not universally reported in AD patients [22,23]. Recently, Gabriel et al [24] extended this finding and demonstrated the association between elevated ACT and cognitive impairment in a medically stable elderly population.…”

A Pilot Study of Prednisone in Alzheimer's Disease

“…Elevated scrum levels of ACT in patients with AD have been reported by some laboratories [5][6][7][8], but not others [26,27], Increased deposition of ACT in the brain in AD may be part of a 'cerebral acute phase response' contributing to neuronal loss [28,29], If serum levels of ACT reflect inflammatory activity in the brain, they may provide an accessible measure to guide anti-inflammatory therapy. But the validity of this idea will only be deter mined when the results of a full-scale therapeutic trial become available.…”

“…karger, ch serve as a peripheral marker of cerebral inflammatory activity [5][6][7][8]. All of the tissue-bound products of the clas sical pathway of complement activation arc found in the area of senile plaques, including the membrane attack complex which may lvsc neuronal membranes [3,[9][10][11].…”

“…Serum ACT and CRP levels were determined by antibody capture enzyme-linked immunosorption assay, as previously described [5]. Replicate analysis of selected sam ples indicated that the results were reproducible within 15% using the same lots of standards and antibodies.…”