Acute-phase proteins in Alzheimer's disease

Area of Science:

• Neuroimmunology
• Biochemistry
• Gerontology

Background:

• Alzheimer's disease (AD) is a neurodegenerative disorder with complex pathophysiology.
• Altered immune responses and inflammation are increasingly recognized in AD pathogenesis.
• Acute-phase proteins (APPs) are markers of inflammation and cellular stress.

Purpose of the Study:

• To investigate serum levels of acute-phase proteins and complement factors in presenile Alzheimer's disease (AD).
• To compare these levels between AD patients and age-matched healthy controls.
• To explore the potential role of these markers in AD-associated immunoregulation and inflammation.

Main Methods:

• Serum samples from 20 presenile AD patients and 18 healthy controls were analyzed.
• Levels of specific acute-phase proteins (alpha-1-antitrypsin, haptoglobin, transferrin, acidic alpha-1-glycoprotein, ceruloplasmin, alpha-2-macroglobulin, C-reactive protein, albumin) were measured.
• Levels of immunoglobulins (IgG, IgM, IgA) and complement factors (C3, C4, properdin factor B) were quantified.

Main Results:

• Statistically significant increases in alpha-1-antitrypsin (p<0.001), ceruloplasmin (p<0.001), and all studied complement factors (p<0.005) were observed in AD patients.
• Levels of other APPs and immunoglobulins did not differ significantly between AD patients and controls.
• Elevated alpha-1-antitrypsin may correlate with reduced interleukin-1 production in AD.

Conclusions:

• Elevated levels of specific acute-phase proteins and complement factors in presenile AD suggest altered immunoregulation.
• These findings support the hypothesis of chronic inflammation and/or cell damage in AD.
• The results indicate potential derangement in macrophage function and suggest these proteins as potential AD biomarkers.