Hot off the presses: applying the 2017 British Society for Rheumatology guidelines in a patient with polyarticular tophaceous gout and renal impairment

Introduction: Gout is the commonest inflammatory arthritis with a prevalence of 2.49% (Kuo, Doherty et al. 2013). The treatment of gout remains sub-optimal despite recommendations from international guideline groups, which advocate the use of urate-lowering therapies (ULT) such as Allopurinol to lower uric acid levels, shrink tophi and prevent acute attacks of gout. Only 30% of patients take definitive treatment (e.g. Allopurinol) for gout in primary care (Mikuls et al 2005; Roddy et al 2007). Some important reasons for the under-prescribing of ULT include the potential for drug toxicity and treatment by non-rheumatologists (who may not be aware of up to date treatment guidelines). As the majority of the uric acid is excreted via the kidneys (70%) (Edwards 2008; Lipkowitz 2012), under-excretion due to chronic kidney disease (CKD) may be a risk factor for hyperuricaemia. Hyperuricaemia may occur as a result of reduced glomerular filtration rate and albuminuria (Chen, Wang et al. 2009). In cases of significant renal impairment, the approach may be complicated as a balance needs to be achieved between preventing gouty flares and avoiding toxicity from accumulation of the medications used. We report here recent application of the 2017 British Society of Rheumatology Guidelines (Hui, Carr et al., 2017) in an 88 year-old Asian patient who newly presented to the rheumatology clinic with polyarticular tophaceous gout on existing Allopurinol and with a new finding of severe renal impairment.

Case description: An 88 year-old Asian male patient was referred to the rheumatology clinic by his GP for management of polyarticular tophaceous gout. He reported having gout for more than 20 years. Historically, he had gouty flares 1-2 times per year managed with Indomethacin, Colchicine and Prednisolone and was maintained on Allopurinol 300 mg daily. His other medications included Thiamine, Sodium bicarbonate, Furosemide, Folic acid and Aspirin. In the preceding couple of years, flares of gout were increasing both in frequency and in severity. He had visible tophi on fingers, left extensor tendons of hand, and on his toes. Although not observed in clinic, his family reported that these lesions extruded off-white material at times, description of which was consistent with uric acid crystals. In his most recent medical history, he had a hospital admission 2 years previously with resistant E-coli septicaemia, congestive cardiac failure, severe anaemia (cause not established), vitamin D deficiency and chronic obstructive pulmonary disease. His family reported a history of alcohol excess . The most recent severe flare of gout had caused a marked decline in his mobility. Two weeks before his clinic appointment, his GP injected both knees with intra-articular steroids. His biochemistry results in clinic were abnormal with estimated glomerular filtration rate of 19 mL/min/1.73 m2 (previously in the 30s), a haemoglobin level of 69 g/L and a uric acid level of 274 micromol/L, the low level of which likely reflects a recent flare. CRP and ESR were raised at 49 mg/L and 118 mm/Hr. His Allopurinol was paused, he had an iron infusion and imaging to look for source of blood loss. The 2017 British Society for Rheumatology Guidelines for the Management of Gout was used to create a treatment strategy for our patient, his family and his GP to manage his gout. Treatment strategy The patient and his family were advised on non-pharmacological remedial activities to do in the event of a gouty flare (affected joint rested, elevated and cooled). We decided to re-introduce regular allopurinol at a dose of 50 mg every 2 days (Stamp et al 2012). In this case, consideration for use of febuxostat was excluded due to presence of concurrent cardiac failure . For single joint flares, intraarticular triamcinolone will be considered in the future. Short courses of oral prednisolone (20 mg daily for a week) and colchicine (500 microgram once to twice daily) were planned for more widespread flares. Where there is renal impairment, the use of non-steroidal anti-inflammatory agents is not recommended and dose of colchicine should be reduced (as long as eGFR >10 mL/min/1.73 m2). Advice regarding lifestyle modification was provided in the light of clear dietary associations of gout with intake of red meat, seafood, alcohol and sugar sweetened soft drinks. Consumption of dairy products, cherries and coffee had a protective effect on developing gout (Choi, Curhan 2008; Choi, Willett et al. 2007). Despite the well-recognised risk of gout associated with loop diuretics, it was not feasible to discontinue the furosemide as it was used for treatment of congestive cardiac failure Response to this treatment plan is currently being gauged but patient and his family are happy that they have been given clear guidelines on what they themselves can do to reduce the risk of further flares.

Discussion: The 2017 guidelines emphasize the benefits of early treatment for gout particularly given gout is an independent risk factor for death due to coronary heart disease and renal disease and may slow down renal progression in patients with chronic kidney disease. In patients on diuretics, urate lowering therapy in patients is believed to reduce the risk of gouty arthritis. In our experience, most cases of gout in a secondary care setting are managed within the context of renal impairment. The latest BSR guidelines for the management of gout incorporate clear advice about the starting dose of Allopurinol stratified by GFR which is unambiguous. It would be interesting to hear from the audience how comfortable they would be in reintroducing lower dose Allopurinol and to discuss some of the other recommendations of the guidelines relating to the use of uricosuric agents.

Key learning points: Use of the 2017 BSR guidelines for gout allows a comprehensive management plan to be established with patients with clear explanation for the rationale for each item in the treatment plan. Buy shares in cherry farms!