Improvement of large-joint ultrasonographic synovitis is delayed in patients with newly diagnosed rheumatoid arthritis: results of a 12-month clinical and ultrasonographic follow-up study of a local cohort.

We analyzed the longitudinal changes in gray-scale ultrasonography (GSUS) and power Doppler ultrasonography (PDUS) parameters and correlated them with clinical, functional, and radiologic outcomes in patients with newly diagnosed rheumatoid arthritis (RA). GSUS and PDUS examinations, 44-joint disease activity score (DAS44) calculations, measurements of erythrocyte sedimentation rate, and C-reactive protein levels were performed in 68 RA patients at baseline and after 1, 3, 6, 9, and 12 months. Metacarpophalangeal joints, wrist, elbow, knee, ankle, metatarsophalangeal joints, and wrist and ankle tendons were examined by GSUS and PDUS. The laboratory and clinical findings began to decrease significantly at 1 month (P < 0.05). Improvement of the ultrasonography (US) variables began at 3 months. After 6 months, all of the joint synovitis scores, except those of the knee, elbow, and ankle joints, showed a statistically significant reduction compared to baseline scores (P < 0.001). DAS44 scores were lower in the very early RA group at 12 months compared to those whose symptom duration was greater than 3 months of RA (respectively, 1.53 ± 0.34; 1.80 ± 0.38; z = -2501, P = 0.012). The total modified Sharp scores at 12 months correlated with total PDUS synovitis scores at 12 months (r = 0.354, P = 0.003). Regression of US synovitis at large joints such as the knee, elbow, and ankle tended to be delayed compared to that at small joints. PD synovitis that is persistent despite disease-modifying anti-rheumatic drug therapy may cause radiographic bone erosions.