Abstract
BACKGROUND
Tophi develop in untreated or uncontrolled gout. Their presence can lead to severe and potentially fatal complications. To date there have been no systematic reviews focused on the management of tophi in gout.
OBJECTIVES
To assess the benefits and harms of non-surgical and surgical treatments for the management of tophi in gout.
SEARCH METHODS
We searched three databases: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE. We handsearched American College of Rheumatology (ACR) and European League against Rheumatism (EULAR) abstracts from 2010 to 2011, references from included studies and trial registries. We completed the most recent search on 20 May 2013.
SELECTION CRITERIA
All published randomised controlled trials (RCTs) or controlled clinical trials with quasi-randomised methods of allocating participants to treatment examining interventions for tophi in gout in adults. Possible interventions included urate-lowering pharmacological treatment (e.g. benzbromarone, probenecid, allopurinol, febuxostat, pegloticase), surgical removal or other interventions such as haemodialysis.
DATA COLLECTION AND ANALYSIS
Two review authors extracted data from titles, abstracts and selected studies for detailed review, and extracted data and risk of bias independently. Major outcomes were number of participants with complete resolution of tophi, number of study participant withdrawals due to adverse events, joint pain reduction, function, quality of life, serum urate normalisation and total adverse events.
MAIN RESULTS
Only one study, at low risk of all biases, met the inclusion criteria. This was the pooled results from two RCTs (225 participants, 145 with tophi at baseline) randomised to one of three arms; pegloticase infusion every two weeks (biweekly), monthly pegloticase infusion (pegloticase infusion alternating with placebo infusion every two weeks) and placebo. Moderate-quality evidence from one study indicated that biweekly pegloticase 8 mg infusion reduced tophi in the subset of participants with tophi, but increased withdrawals due to adverse events in all participants, and monthly infusion appeared to result in less benefit.Biweekly pegloticase treatment resulted in resolution of tophi in 21/52 participants compared with 2/27 who received placebo (risk ratio (RR) 5.45, 95% confidence intervals (CI) 1.38 to 21.54; number needed to treat for an additional beneficial outcome (NNTB) 3 (95% CI 2 to 6).Eleven of 52 participants with monthly pegloticase treatment had complete resolution of one or more tophi compared with 2/27 who received placebo (RR 2.86, 95% CI 0.68 to 11.97).Participant-reported pain relief of 30% or greater, function, quality of life, serum urate normalisation, were reported for all participants but not separately for those with tophi; therefore, we did not include the results.Pegloticase administered biweekly resulted in more withdrawals due to adverse events compared with placebo (15/85 participants with pegloticase versus 1/43 participants with placebo; RR 7.59, 95% CI 1.04 to 55.55; number needed to treat for an additional harmful outcome (NNTH) 7, 95% CI 4 to 17). Pegloticase administered monthly also resulted in more withdrawals due to adverse events than placebo (16/84 participants with pegloticase versus 1/43 participants with placebo; RR 8.19, 95% CI 1.12 to 59.71; NNTH 6, 95% CI 4 to 14). Most withdrawals were due to infusion reactions.Total adverse events were high in all treatment groups: 80/85 participants administered pegloticase biweekly reported an adverse event compared with 41/43 from the placebo group (RR 0.99, 95% CI 0.91 to 1.07); 84/84 participants administered pegloticase monthly reported an adverse event versus 41/43 in the placebo group (RR 1.05, 95% CI 0.98 to 1.14). As 80% of adverse events were due to flares of gout, probably unrelated to the drug treatment per se, this may explain the high rate of adverse events in the placebo group - who were essentially untreated.
AUTHORS' CONCLUSIONS
This study showed pegloticase is probably beneficial in the management of tophi in gout, in terms of resolution of tophi, but with a high risk of adverse infusion reactions. However, there is a need for more RCT data considering other interventions, including surgical removal of tophi.
Collapse