Complement activation in very early Alzheimer's disease.

H. Zanjani (1, 2) , C. E. Finch (2) , C. Kemper (3) , J. Atkinson (3) , D. Mckeel (4) , J. C. Morris (4, 5) , J. L. Price (6)

1 NPA - Neurobiologie des processus adaptatifs
2 Andrus gerontology center and department of biological sciences
3 Department of medicine, Division of rheumatology
4 Department of pathology and immunology
5 Department of neurology
6 Department of anatomy and neurobiology

The activation of the classical complement (C)-system in early-stage Alzheimer disease (AD) and nondemented aging was examined with immunohistochemistry in subjects assessed by the Clinical Dementia Rating (CDR). Activation (staining for C3 and C4 fragments) was found in all brains with amyloid deposits, including all nondemented (CDR 0) cases, with either small numbers of diffuse plaques or with sufficient plaques and tangles to indicate preclinical AD. Staining for C3 and C4 increased in parallel with plaque density in very mild to severe clinical AD. A subset of very mild AD (CDR 0.5) cases also showed C1q (on plaques) and C5b-9 (on neuritic plaques and tangles), whereas these C-fragments were consistently found in severe AD (CDR 3). Mirror section (split-face) analysis showed that C1q, C3, and apoJ (clusterin) occurred on the same plaques. However, C-system regulators CD59, CR1, DAF, and MCP were not detected on plaques or tangles at any stage, indicating that C-activation related to AD is incompletely controlled.

Mots clés: Alzheimer

Domaines: Sciences cognitives

H. Zanjani, C. E. Finch, C. Kemper, J. Atkinson, D. Mckeel, et al.. Complement activation in very early Alzheimer's disease.. Alzheimer Disease and Associated Disorders, 2005, 19, pp.55-66. ⟨hal-00077828⟩