To determine whether the presence of radiographic erosions at disease onset in patients with early rheumatoid arthritis (RA) is associated with clinical, serological, or genetic factors of poor outcome and whether patients with erosions only in the feet have a different pattern of presentation.
Sixty one patients with early RA (<6 months of evolution) were studied. Clinical evaluation and serological, radiological, and genetic studies were performed at disease onset and after one year.
Forty one (67%) patients showed erosions in their hands or in their feet, or in both. Subjects with erosive RA had a higher number of swollen joints (SJN; 9 (SD 6) v. 6 (3), p=0.008), and rheumatoid factor (RF) positivity was more common (80% v. 50%, p<0.02) than those without erosions. Seven (17%) of the 41 patients in the group with erosions had erosions only in their feet. This group had a longer duration of morning stiffness (120 (60) v. 72 (52) min, p<0.005), better patient's global assessment of general health (34 (22) v. 57 (25), p< 0.05), and lower erythrocyte sedimentation rate (32 (22) v. 60 (30) mm/1st h, p <0.05) than the rest of the subjects with erosions, and none of them was in remission after one year. Remission after one year was related to a lack of cortical damage at onset and RF negativity.
Radiological damage at disease onset is associated with a worse clinical presentation and RF positivity, which are markers of poor outcome. There is a subgroup of patients, with erosions only in their feet, whose clinical presentation is less aggressive. To identify these cases of early erosive RA, radiographs of the feet should be obtained routinely.