To investigate if serial clinical and ultrasound evaluations differ between early rheumatoid arthritis patients who do or do not develop erosive disease and to identify predictors of erosions.
Methods: Patients with at least 7 consecutive 2-monthly clinical and 3 consecutive 6-monthly ultrasound evaluations were included. Ultrasound (gray scale and power Doppler) assessed synovitis, power Doppler-positive synovitis (PD+) and power Doppler-negative synovitis (PD-) in each of 14 joints of the dominant hand. After 1 and 2 years, erosive disease was defined according to digitized radiography. Areas under the curve (AUCs) for serial assessments were calculated. Multivariate logistic regression analysis was performed.
Results: Seventy-one and 38 patients completed 1- and 2-year consecutive assessments. After 2 years (21.5 +/- 6.2 months), 13 patients developed erosions. At baseline, nonerosive patients had shorter duration of symptoms to RA diagnosis, lower number of the American College of Rheumatology (ACR) classification criteria, lesser synovitis and PD+ synovitis than erosive patients. At follow-up, erosive and nonerosive patients showed similar AUC for clinical, serological, and treatment parameters; erosive patients had higher AUCs for synovitis and PD+ synovitis than nonerosive patients. In the multivariate model, the amount of PD+ synovitis (odds ratio, 1.3; 95% confidence interval, 1.11-1.51; P = 0.001) and more ACR classification criteria (odds ratio, 2.3; 95% confidence interval, 1.05-5.02; P = 0.04), both at baseline, predicted erosive disease.
Conclusions: Serial Power Doppler ultrasonography-assessed synovitis was greater in patients who developed erosions than in those who did not. More power Doppler positive (hypervascular) synovitis and more ACR classification criteria, both at baseline, were the only predictors of erosions.