Rasburicase for tophaceous gout not treatable with allopurinol: an exploratory study.

OBJECTIVE: To evaluate the short-term safety and outcome of 2 different experimental applications of rasburicase 0.2 mg/kg (monthly vs daily) in patients with tophaceous gout not treatable by allopurinol. Rasburicase could be useful for patients with gout that is unresponsive to allopurinol or who cannot tolerate the therapy. METHODS: Five patients received 6 monthly infusions of rasburicase (Group 1) and 5 received 5 daily infusions (Group 2). RESULTS: In Group 1, serum uric acid (SUA) level decreased significantly, from 612.6 +/- 162.4 micromol/l at baseline to 341.2 +/- 91.8 micromol/l after 6 infusions (p = 0.001). Changes in tophus area were observed in 2 patients. In Group 2, daily infusions produced a rapid, marked decrease in SUA level during treatment. Yet SUA levels measured at 1 month (511.5 +/- 128.4 micromol/l) and 2 months (572 +/- 96.2 micromol/l) after treatment were not significantly lower than at baseline (573.6 +/- 48.2 micromol/l). No patient from Group 2 showed reduced tophus size. Eight of 10 patients experienced an adverse event, the most common being gout flare despite prophylactic treatment with colchicine. CONCLUSION: Monthly infusions of rasburicase appear to be a possible therapy for severe gout not treatable by other means. Tolerance of rasburicase in gout appears to be diminished by frequent triggering of gout attacks, and hypersensitivity reactions might be an important limitation to longterm therapy.

Inflammatory and structural evaluation in spondyloarthritis: magnetic resonance imaging analysis of axial and peripheral involvement.

OBJECTIVE: To determine the magnetic resonance imaging (MRI) criteria of most value in the assessment of patients with spondyloarthropathy (SpA) with axial or peripheral involvement. METHODS: Fat suppressed (FS)-T2 and pre- and postinjection FS-T1 images were obtained in the most symptomatic region (axial or peripheral) of patients requiring tumor necrosis factor-a blockers. Thirty-eight MRI (21 axial and 17 peripheral) were blindly scored at synovial (S) and entheseal (E) sites by 2 experienced observers screening for 7 inflammatory and 7 structural predefined criteria, which were evaluated for frequency (N) and intra- and interobserver reproducibility. RESULTS: In peripheral regions, synovitis (S; N = 69.4%), ligament inflammation (E; N = 39.7%), bone marrow edema (S; N = 22.1%; E; N = 15%), and tenosynovitis (S; N = 21%) were recorded with good to excellent intraobserver reproducibility [intraclass correlation coefficient (ICC) 0.49-0.93] and moderate to good interobserver reproducibility (ICC 0.49-0.66). With regard to structural criteria, erosions (S; N = 17.1%) and enthesophytes (E; N = 13.9%) exhibited good to excellent intraobserver (ICC 0.71-0.85) and moderate interobserver reproducibility (ICC 0.54-0.49); the reproducibility of fat inflation (N = 1.4%) was good (ICC 0.76-0.78). In axial regions, no inflammatory criteria achieved good interobserver reproducibility. However, fat inflation (S; N = 86%), chondral lesions (S; N = 85.8%), enthesophytes (E; N = 76.7%), fusion (S; N = 41.2%), and erosions (S; N = 25.1%) showed excellent intraobserver reproducibility (ICC 0.81-0.98), and moderate to excellent interobserver reproducibility (ICC 0.50-0.96). CONCLUSION: In terms of intra- and interobserver reproducibility, MRI is a reliable tool with which to assess synovitis, bone edema, ligament inflammation, tenosynovitis, erosion, enthesophytes, and fat inflation in patients with peripheral involvement. In those with axial involvement, inflammatory criteria lack interobserver reproducibility, but chondral lesions, erosion, fat inflation, fusion, and enthesophytes are relevant.