Accumulation of methylglyoxal in the gingival crevicular fluid of chronic periodontitis patients.

Abstract

Methylglyoxal (MG), a toxic product of cellular metabolism, is elevated in tissues and fluids in a number of human diseases. A cross-sectional study was undertaken to determine whether MG accumulates in the gingival crevicular fluid (GCF) of chronic periodontitis patients. GCF samples were collected for 30 s each from three teeth with pocket depths greater than 3 mm (DD sites), from 14 chronic periodontitis patients. Control samples were taken from three healthy sites (DH sites) in the same patients, as well as from seven subjects who were periodontally healthy (HH sites). Fluid volumes were determined and the strips were placed in 0.5 N perchloric acid. Subsequently, samples were derivatized with o-phenylenediamine and the resulting methylquinoxaline was assayed by high-performance liquid chromatography on Lichrospher(R)-100 RP-18, with UV detection. Mean pocket depths were 5.7+/-0.7, 2.7+/-0.6 and 2.7+/-0.5 mm (mean+/-SD) for the DD, DH and HH sites, respectively. Mean MG levels were found to be 208.7+/-241.7 and 142.9+/-235.7 pmol/site in the GCF from DD and DH sites, respectively (p=0.0023), but only 11.5+/-4.4 pmol/site for the HH sites. Bacteroides forsythus has been found to accumulate high levels of MG in culture (unpublished data) and, consistent with this, the sampled diseased sites contained higher levels of B. forsythus than the corresponding healthy sites (2.7+/-4.2 x 10(5) versus 0.7+/-1.1 x 10(5), respectively; p=0.022). Total "red complex" microorganisms were significantly elevated in the DD sites. In view of the known protein- and DNA-modifying effects of MG, the finding of elevated levels of MG in the GCF from chronic periodontitis patients supports the hypothesis that MG may contribute to destructive tissue damage in this disease.