Salivary citrullinated proteins in rheumatoid arthritis and associated periodontal disease

Abstract

Periodontal disease (PD) can be an important precipitating factor in the production of citrullinated proteins. Its importance is emphasized, but it is not the only way to produce citrullinated proteins. The aim of the current study was to determine the periodontal conditions and the salivary citrullinated protein content in patients with rheumatoid arthritis (RA) compared to healthy controls. We also wished to correlate citrullinated protein levels in the saliva and serum biomarkers with the periodontal status and temporomandibular joint (TMJ) involvement of patients with RA. Twenty-three patients with RA and 17 healthy controls participated the study. Saliva samples were taken: citrulline content of saliva was measured. Blood test results for patients with RA were collected. TMJ disorders were described. Cariological and periodontal indices were registered. Periodontal conditions and periodontal staging were also registered. Comparison of measured values between groups was performed. Intragroup correlation of patients’ values was counted. The prevalence of TMJ complaints was significantly higher in the RA group (8/23) versus controls (1/17). The patients with RA had worse periodontal condition because more patients with RA had gingivitis with a significantly higher bleeding on probing (BOP) (RA: 22.4 ± 25.0%; controls: 6.36 ± 11.6%; p = 0.018). Gingival index (GI) was also significantly higher in the patients than in controls (RA: 0.68 ± 0.58; controls: 0.19 ± 0.38; p = 0.010). The citrullinated protein (relative) content of saliva did not differ significantly (p = 0.147) between patients with RA (1102.2 ± 530.8) and healthy controls (1873.1 ± 1594.9). In RA, the salivary anti-CCP levels positively correlated with PD staging (R = 0.464, p = 0.039) . Control subjects more commonly had healthy gingiva than RA patients. Moreover, in the control group more individuals had intact and reduced height periodontium than periodontitis compared to the RA group. There was no significant difference in the levels of salivary citrulline between patients with RA and controls, despite the significant differences in their periodontal status. Thus, salivary citrulline levels are not associated with RA disease severity.

Detection of salivary citrullinated cytokeratin 13 in healthy individuals and patients with rheumatoid arthritis by proteomics analysis

“…With respect to the presence of citrullinated peptides in human saliva, Tar et al developed an assay system to immobilize saliva samples on membranes and perform the semi-quantification of total citrullinated peptides using AMC antibodies, and reported that the quantities of total citrullinated peptides in saliva from patients with RA and healthy controls were comparable [ 24 ]. Because their assay system was based on a dot-blot method, the details of salivary citrullinated peptides remained unknown.…”

ReDisX, a machine learning approach, rationalizes rheumatoid arthritis and coronary artery disease patients uniquely upon identifying subpopulation differentiation markers from their genomic data

“…However, based on our study objectives, we need to choose a suitable tissue to analyze all diseases. Some potential issues such as whole blood ( 111 , 112 ) and the gut microbiome ( 113 ), are suitable for our study. The ReDisX framework could be extended and improved in the future using multimodal data besides mRNA expressions such as methylation and miRNA interference.…”

ReDisX: a Continuous Max Flow-based framework to redefine the diagnosis of diseases based on identified patterns of genomic signatures

“…However, based on our study objectives, we need to choose a suitable tissue to analyze all diseases. There are a few potential issues such as whole blood (Anaparti et al, 2017), saliva (Tar et al, 2021), and the gut microbiome (Shreiner et al, 2015) those are suitable for our study. In the future, the ReDisX framework could be extended and improved using multimodal data besides mRNA expressions such as methylation, and miRNA interference.…”