Ultrasonography and magnetic resonance imaging changes in patients with polymyalgia rheumatica treated by tocilizumab

This study assessed inflammatory changes using ultrasound (US) and magnetic resonance imaging (MRI) in patients taking tocilizumab for polymyalgia rheumatica (PMR).

Eighteen patients were included in the prospective open-label TENOR study and received three tocilizumab infusions, without corticosteroids. B-mode and power Doppler US and MRI (T1 and T2-short time inversion recuperation weighted sequences) of the hips and shoulders were performed at weeks 0, 2, and 12. Subacromial, trochanteric, and iliopsoas bursitis and intraarticular glenohumeral and coxofemoral effusions/synovitis were scored from 0 to 3. Changes over time and US-MRI correlations were evaluated.

At baseline, the proportions of shoulders and hips with bursitis were 93 and 100% by MRI and 61 and 13% by US; and the corresponding proportions for intraarticular effusions/synovitis were 100 and 100% by MRI and 57 and 53% by US. Imaging findings did not improve during the first two treatment weeks. From baseline to week 12, bursitis improved significantly at all four joints by MRI (P = 0.005) and US (P = 0.029) and intraarticular effusions/synovitis by US only (P = 0.001). The proportion of abnormalities that improved by week 12 was 42% by MRI and 37% by US. MRI detected bursitis in a larger proportion of hips (73% versus 13%) and US in a larger proportion of shoulders (57% versus 28%), whereas no difference was found for intraarticular effusions/synovitis. At baseline, agreement between US and MRI findings was poor.

US and MRI showed significant improvements in inflammatory lesions during tocilizumab treatment of PMR.