TNF-α and antibodies to periodontal bacteria discriminate between Alzheimer's disease patients and normal subjects

The associations of inflammation/immune responses with clinical presentations of Alzheimer's disease (AD) remain unclear. We hypothesized that TNF-α and elevated antibodies to periodontal bacteria would be greater in AD compared to normal controls (NL) and their combination would aid clinical diagnosis of AD. Plasma TNF-α and antibodies against periodontal bacteria were elevated in AD patients compared with NL and independently associated with AD. The number of positive IgG to periodontal bacteria incremented the TNF-α classification of clinical AD and NL. This study shows that TNF-α and elevated numbers of antibodies against periodontal bacteria associate with AD and contribute to the AD diagnosis.