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, 3 (3), 107-114

Salivary Ammonia Levels and Tannerella Forsythia Are Associated With Rheumatoid Arthritis: A Cross Sectional Study


Salivary Ammonia Levels and Tannerella Forsythia Are Associated With Rheumatoid Arthritis: A Cross Sectional Study

José-Iván Martínez-Rivera et al. Clin Exp Dent Res.


The aim of this paper is to evaluate the relationship of salivary ammonium levels and the presence of bacteria with rheumatoid arthritis (RA) clinical disease activity in a cross-sectional study of Mexican patients. From a periodontal and disease activity standpoint, 132 consecutive RA patients fulfilling clinical criteria were evaluated. Ammonia levels (including peptidyl arginine deiminase activity) were evaluated by colorimetric assay and the presence of Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia was evaluated by polymerase chain reaction (PCR) technique. After a multivariate analysis, adjusting for clinical and serological parameters, a significant association was only observed between severe periodontitis and probing depth with high RA disease activity. Additionally, in contrast to P. gingivalis, the presence of T. forsythia was significantly associated with high disease RA activity even after multivariable adjustment analysis. There was also a significant increase in ammonium levels in the high RA activity group and a significant correlation between salivary ammonia and RA disease activity but not with autoantibody titers. Similarly, we observed a significant increase in the ammonium levels derived from the cultures of P. gingivalis and T. forsythia, with respect to P. intermedia and S. gordonii cultures, or even healthy donors. These results suggest that RA activity is associated with severe periodontitis, high salivary ammonium levels and the presence of T. forsythia.

Keywords: T. forsythia; periodontitis; rheumatoid arthritis; salivary ammonia levels.


Figure 1
Figure 1
Increased levels of total ammonium were observed in salivary samples from high RA activity patients, in comparison to low RA activity. Enzymatic assay for total ammonium levels determination is described in Methods. Graphical analysis was done normalizing for experimental control (without oral samples). Statistical comparison was done employing Mann–Whitney test, considering p < .01 (**)
Figure 2
Figure 2
Total salivary ammonium levels positively correlated with RA clinical activity. Values from all RA patient subgroups were correlated (Spearman) with clinical activity (DAS28), showing ρ = 0.67 and p < .001

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