Chlamydophila pneumoniae and the etiology of late-onset Alzheimer's disease.
Sporadic, late-onset Alzheimer's disease (LOAD) is a non-familial, progressive neurodegenerative disease that is now the most common and severe form of dementia in the elderly. That dementia is a direct result of neuronal damage and loss associated with accumulations of abnormal protein deposits in the brain. Great strides have been made in the past 20 years with regard to understanding the pathological entities that arise in the AD brain, both for familial AD ( approximately 5% of all cases) and LOAD ( approximately 95% of all cases). The neuropathology observed includes: neuritic senile plaques (NSPs), neurofibrillary tangles (NFTs), neuropil threads (NPs), and often deposits of cerebrovascular amyloid. Genetic, biochemical, and immunological analyses have provided a relatively detailed knowledge of these entities, but our understanding of the "trigger" events leading to the many cascades resulting in this pathology and neurodegeneration is still quite limited. For this reason, the etiology of AD, in particular LOAD, has remained elusive. However, a number of recent and ongoing studies have implicated infection in the etiology and pathogenesis of LOAD. This review focuses specifically on infection with Chlamydophila (Chlamydia) pneumoniae in LOAD and how this infection may function as a "trigger or initiator" in the pathogenesis of this disease.
Balin
Brian J
BJ
Department of Pathology, Microbiology, Immunology and Forensic Medicine, Philadelphia PA 19131, USA. Brianba@pcom.edu
Little
C Scott
CS
Hammond
Christine J
CJ
Appelt
Denah M
DM
Whittum-Hudson
Judith A
JA
Gérard
Hervé C
HC
Hudson
Alan P
AP
D000544:Alzheimer Disease / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology; D001921:Brain / Q000382:microbiology / Q000473:pathology; D002494:Central Nervous System Infections / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology; D002690:Chlamydia Infections / Q000150:complications* / Q000188:drug therapy; D016993:Chlamydophila pneumoniae / Q000472:pathogenicity*; D006801:Humans; D009297:Nasal Mucosa / Q000382:microbiology; D009831:Olfactory Mucosa / Q000382:microbiology; D058225:Plaque, Amyloid / Q000473:pathology; D012307:Risk Factors