Serum antibodies to periodontal pathogens are a risk factor for Alzheimer's disease.
Alzheimers Dement.
2012
May;8(3):196-203.
Source
Department of Oral Health
Science,
College of Dentistry, University of Kentucky, Lexington, KY,
USA.
Abstract
BACKGROUND:
Chronic inflammation in periodontal disease has been suggested
as
a potential risk factor in Alzheimer's disease (AD). The purpose of this
study
was to examine serum antibody levels to bacteria of periodontal disease in
participants who eventually converted to AD compared with the antibody
levels in
control subjects.
METHODS:
Serum samples from 158 participants in the Biologically
Resilient
Adults in Neurological Studies research program at the University of
Kentucky
were analyzed for immunoglobulin G antibody levels to seven oral bacteria
associated with periodontitis, including Aggregatibacter
actinomycetemcomitans,
Porphyromonas gingivalis, Campylobacter rectus, Treponema denticola,
Fusobacterium nucleatum, Tannerella forsythia, and Prevotella intermedia.
All
158 participants were cognitively intact at baseline venous blood draw. In
all,
81 of the participants developed either mild cognitive impairment (MCI) or
AD or
both, and 77 controls remained cognitively intact in the years of follow-up.
Antibody levels were compared between controls and subjects with AD at
baseline
draw and after conversion and controls and subjects with MCI at baseline
draw
and after conversion using the Wilcoxon rank-sum test. AD and MCI
participants
were not directly compared. Linear regression models were used to adjust for
potential confounding.
RESULTS:
Antibody levels to F nucleatum and P intermedia were
significantly
increased (α = 0.05) at baseline serum draw in the patients with AD compared
with controls. These results remained significant when controlling for
baseline
age, Mini-Mental State Examination score, and apolipoprotein epsilon 4
status.
CONCLUSIONS:
This study provides initial data
that
demonstrate elevated antibodies to periodontal disease bacteria in subjects
years before cognitive impairment and suggests that periodontal disease
could
potentially contribute to the risk of AD onset/progression.
Additional cohort studies profiling oral clinical presentation with systemic
response and AD and prospective studies to evaluate any cause-and-effect
association are warranted
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