Inflammatory mediators and radiographic changes in temporomandibular joints of patients with rheumatoid arthritis

The aim of this study was to investigate the relation between the inflammatory mediators tumor necrosis factor alpha (TNFalpha) and serotonin (5-HT), the inflammatory markers erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), as well as rheumatoid factor (RF) and thrombocyte particle concentration (TPC) in blood versus temporomandibular joint (TMJ) radiographic changes in patients with clinical TMJ involvement by rheumatoid arthritis (RA). Twenty patients were included. Venous blood was collected for quantification of the mediators, markers, and TPC. The radiographic signs of erosion, flattening, sclerosis, subchondral pseudocyst, and osteophyte as well as radiographic grade were investigated with computed tomography. The median (IQR) plasma levels of TNFalpha and 5-HT were 0 (13) pg/ mL and 13 (22) nmol/L, respectively, while serum level of 5-HT was 1360 (874) nmol/L. ESR, CRP, and TPC were abnormally high in 53%, 25%, and 15% of the patients, respectively. The most frequent radiographic signs were sclerosis (75%), erosion (50%), and flattening (30%). Erosion was found to be associated with high TPC and flattening with high plasma level of TNFalpha. In conclusion, patients with clinical TMJ involvement by RA show an association between high level of TPC and TNFalpha in plasma versus radiographic signs of joint bone destruction.