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A new
biochemical approach to understanding periodontal disease
The American
Academy of Periodontology notes that intensive oral hygiene care
and regular professional cleaning is the only way to control
periodontal disease, inflammation of the gingiva (gingivitis)
with loss of the periodontal attachment (periodontitis). A few
adults (<0.5% of the population) are especially difficult to
treat. If young adults with no periodontal disease stop tooth
cleaning, most exhibit an increase in the indigenous microbiota
(actinomyces, streptococci, Eikenella corrodens and
capnocytophaga) at the gingival sulcus. A few days later, a
‘fuso-spirochetal’ microbiota appears and within 3 – 4 weeks,
clinical signs of gingivitis. One possibility is that lysine
decarboxylase from E. corrodens and capnocytophaga in the
indigenous microbiota induces the GCF by depleting lysine to
cadaverine, a non-metabolizable product. The depletion of lysine
would inhibit the proliferation of dentally attached basal
keratinocytes that make up the dental-epithelial attachment at
the base of a gingival sulcus. Starved of the lysine from
interstitial fluid, the DAT cells would release IL1, which
induces the GCF and replenishes the lysine. However, the GCF
provides proteins that enable the ‘fuso-spirochetal’ microbiota
to grow in the sulcus and maintain the inflammation unless
prevented by adequate oral hygiene. Recent studies supported by
NIH-NIDCR and utilizing patients from Dr. Sig. Socransky’s
periodontal clinic at the Forsyth Center, Boston, have confirmed
that mild gingivitis, common in healthy and a few successfully
treated periodontitis patients, is proportional to lysine
decarboxylase activity, as measured from the cadaverine to
lysine ratio in whole mouth biofilm samples. By contrast, many
successfully treated periodontitis patients had moderate
gingivitis unrelated to lysine decarboxylase activity. The
findings suggest that lysine decarboxylase may initiate mild
gingivitis but that differences in the host response or in the
amount of residual ‘fuso-spirochetal’ microbiota explain the
persistence of moderate gingivitis when periodontitis is easily
controlled. By contrast, the change in the periodontal
attachment level of ‘difficult-to-treat’ patients after therapy
associated with the lysine decarboxylase activity of their
biofilm. Whether this relationship was caused by or resulted
from their ‘difficult-to-treat’ condition may be determined by
treating such patients with lysine decarboxylase inhibitors (US
Patents 6,103,220 and 6,187,296).
Relevant Publications:
Levine, M., LaPolla, S., Owen, W.L. and Socransky, S.S.
(2002)
Antibody-based Diagnostic for ‘Refractory’ Periodontitis. J.
Clinical Periodontol. 29: 935-943.
Levine, M. Progulske-Fox, A, Denslow, N.D., Farmerie, W.G.,
Smith, D.M., Swearingen, W.T., Miller, F.C., Liang, Z. Roe,
B.A. and Pan, H.-Q. (2001) Identification of lysine
decarboxylase as a mammalian cell growth inhibitor in
Eikenella corrodens: Possible role in periodontal disease.
Microbial Pathogenesis 30: 179-192.
McAnally, J.R. and Levine, M. (1993). Bacteria reactive
to plaque-toxin neutralizing monoclonal antibodies are
related to the severity of gingivitis at the sampled site.
Oral Microbiol. Immunol. 8:69-74.
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