Periodontitis may induce rheumatoid arthritis precursor
medwireNews: Periodontal disease caused by Porphyromonas gingivalis infection can induce the autoimmune response that characterizes rheumatoid arthritis (RA), a pilot study indicates.
The research shows that levels of anti-cyclic citrullinated peptide (CCP) antibodies are elevated in infected patients, which could be a response to host protein citrullination caused by P. gingivalis peptidylarginine deiminase.
“Low levels of anti-CCP antibodies are detectable several years prior to the onset of RA,” explain the study authors, writing in the Journal of Clinical Periodontology. “Thus, periodontitis may impact on RA initiation and progression.”
David Lappin (University of Glasgow, UK) and colleagues analyzed plaque and serum samples from 39 adults being treated for periodontitis, 16 of whom tested positive for P. gingivalis infection, and 36 healthy individuals.
Serum anti-CCP levels were significantly higher in patients with periodontal disease than healthy controls (1.37 vs 0.40 Assay Units [AU]), the authors report. And, among periodontitis patients, anti-CCP levels were higher in those with P. gingivalis infection than in uninfected individuals.
Interestingly, among periodontitis patients, those who smoked cigarettes had lower levels of anti-P. gingivalis antibodies than their nonsmoking counterparts (15956 vs 2512 Units/mL) but similar anti-CCP titers (1.31 and 1.41 AU, respectively).
Among healthy controls, smokers had significantly increased anti-CCP titers compared with non-smokers (0.75 vs 0.15 AU), consistent with previous evidence of increased citrullination of host proteins in smokers.
All patients underwent nonsurgical treatment of periodontitis. Six months later, anti-CCP levels had fallen significantly among patients with P. gingivalis infection and among smokers; furthermore, levels of anti-P. gingivalis antibodies had fallen significantly in all patients.
The team concludes: “These data demonstrate changes in anti-CCP associated with periodontal treatment, and further confirm that both smoking and presence of P. gingivalis may modulate anti-CCP circulating antibodies.”
They add: “Understanding such a relationship will be crucial to improving preventative and therapeutic strategies for both diseases independently and in combination.”
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Joanna Lyford, Senior medwireNews Reporter