ANTI-TNF-ALPHA TREATMENT IN RHEUMATOID ARTHRITIS (RA) REDUCES TENOSYNOVITIS EVALUATED BY MRI

Background: Tenosynovitis is a common problem in RA, and can lead to impaired function due to scarring, adhesions and ultimately tendon rupture. Jain et al have shown that cytokine blockade can reduce collagenase concentrations in tenosynovial tissue, suggesting cytokine inhibitors could be effective in reduction of tendon damage. Although treatment based on inhibition of TNF-alpha has proved effective in RA joint disease, Kaiser et al did not find reduction of tenosynovitis in RA patients. MRI provides the opportunity for accurate assessment of joint damage and soft tissue changes in patients with RA, and in this study a novel MRI scoring procedure is applied to evaluate tenosynovitis.Objectives: To assess the effect of anti-TNF-alpha therapy on tenosynovitis evaluated by magnetic resonance imaging of the wrist in patients with RA.Methods: 17 RA patients (median age 51.1 (range 30-73), median disease duration 9.5 years, 76.5% females, 82.4% rheumatoid factor positive) were evaluated by MRI at initiation of treatment with anti-TNF agents (etanercept 5.9%, infliximab 58.8%, adalimumab 35.3%) and after 6 months. The MRI scans were performed on a 1,5 T scanner using a circumferential wrist coil on the dominant hand, and the sequences included axial T1 scans before and after i.v. injection of contrast agent (Gd-DTPA).Tenosynovitis is visualized on MRI as tendon sheath fluid, sheath thickening and enhancement after i.v. contrast injection. The tendons were evaluated at the level of the distal radioulnar joint.On the dorsal side of the wrist the extensor tendons passes through six discrete compartments, which were scored individually. On the volar side the tendons were evaluated in four regions: The ulnar bursa, the radial bursa, the flexor carpi ulnaris and the flexor carpi radialis. The tendon sheath alterations were graded according to a scoring system suggested by Valeri et al., based on peritendinous effusion or synovial proliferation/enhancement: Grade 0 (normal); grade 1: <2mm; grade 2: >2 and <5 mm, and grade 3: >5 mm. Thus the tenosynovitis score ranges from 0 to 30.The chronological sequence of the images was unknown to the reader.Results: At baseline all patients had clinically active RA (median DAS28 score 5.76, range 2.93-7.30). Of the 17 patients 13 had both axial scans before and after iv. gadolinium at baseline and after 6 months (4 patients excluded due to previous allergy to contrast agents). At baseline 8 patients had tenosynovitis on the dorsal side, of these 5 had changes also on the volar side. None of the patients had changes only on the volar side. Compartment 6 (the extensor carpi radialis) was the most frequently affected single scoring site (61.5% of patients who had tenosynovitis). The median tenosynovitis score was 3.0 (mean 3.5, range 0-11), which decreased to 1.5 (mean 1.7, range 0-7) after 6 months of treatment. Of the 13 patients, 7 had a decrease in total tenosynovitis score, 1 increased and 5 remained unchanged. Wilcoxon Signed Ranks test was applied, and there was a statistically significant change in total tenosynovitis score from baseline to 6 months (asymp. sig. (2-tailed) 0,04).Conclusion: This is the first study to demonstrate reduced tenosynovitis in RA patients after anti-TNF-alpha treatment. These findings need to be confirmed in larger studies, including validation of the tenosynovitis scoring procedure using MRI.References: 1. Jain A, Brennan F, Nanchahal J. Treatment of rheumatoid tenosynovitis with cytokine inhibitors. Lancet 2002; 360:1565-66.2. Kaiser MJ, Bozonnat MC, Jorgensen C, Daures JP, Sany J. Effect of etanercept on tenosynovitis and nodules in rheumatoid arthritis. Arthritis Rheum 2002; 46:559-60.3. Valeri G, Ferrara C, Ercolani P, De Nigris E, Giovagnoni A. Tendon involvement in rheumatoid arthritis of the wrist: MRI findings. Skeletal Radiol 2001; 30:138-143).Citation: , volume , supplement , year 2004, page Session: Diagnostics and imaging procedures