Ultrasonographic Evaluation of the Ankle Joint in Relation to Rheumatoid Factor Status and Disease Activity in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a form of inflammatory disease whose clinical pattern is largely dependent on the presence of both anti-citrullinated protein antibodies and rheumatoid factor (RF). Although this is still debatable, seronegative RA seems to be a somewhat less serious condition. The present study aimed to evaluate ankle joint ultrasound in relation to RF status and disease activity in RA patients. A cross-sectional study involving RA patients from a single center was conducted. Laboratory test evaluations and clinical activity assessments were carried out. The ankle joint was examined using musculoskeletal ultrasound (US). The study included 100 patients with established RA in total. Eighty-two patients tested positive for RF with a mean age of 42.3, whereas only 18 tested negative with a mean age of 39.6. Patients who tested positive for RF had a longer duration of illness (9.39 ± 5.39 vs. 4.56 ± 3.24). There were no differences in clinical activity scores between the seropositive and seronegative groups. The pathological US findings of any ankle joint showed no differences between the seropositive and seronegative groups. Patients with US findings of tibialis posterior tenosynovitis in the left ankle and synovitis and erosion in the right ankle, particularly in the tibiotalar and talonavicular joints, had significantly high Disease Activity Score 28-Erythrocyte sedimentation rate-scores. The increased disease activity was accompanied by significant erosions on both ankles. In terms of disease activity, there is no clinically significant difference between seropositive and seronegative RA patients. Sonographic ankle joint abnormalities do not appear to be associated with the patients’ RF status. High RA disease activity, on the other hand, is associated with synovitis and erosions, particularly in the talonavicular and tibiotalar joints, as well as tibialis posterior tenosynovitis.