Background Patients with systemic lupus erythematosus (SLE) often suffer from cardiovascular comorbidity such as hypertension, dyslipidemia or coronary heart disease. However, the association with gout – an independent cardiovascular risk factor – is considered unusual - it is not reported in the EULAR textbook (1)-, and might not be taken into account when acute arthritis occurs in SLE patients, also due to the predominance of women in this disease.
Objectives To review our experience regarding SLE patients who developed gout, and to perform a literature review of reported cases to date.
Methods Retrospective review of patients with SLE and crystal-proven gout in our Rheumatology Unit, a tertiary care center. We recorded clinical and laboratory variables related to both diseases. Then, we performed a bibliographical review in Pubmed (1965 – 2016) to identify reported cases of coexistence of both diseases.
Results Out 189 SLE patients seen in our Unit, we have identified two cases with crystal-proven gout: 1) A 68 years-old woman with SLE and nephritis diagnosed 30 years ago, who developed polyarthritis affecting her hands. 2) A 47 years-old man with lupus for 22 years with nephritis and renal failure, who developed acute arthritis involving right knee and ankle. In both cases, urate crystals were demonstrated at synovial fluid. The table shows the results of the literature review together with our two cases. To date, 36 cases with coexistent SLE and gout have been reported. Median age at time of gout diagnosis was 43.5 years (p25–75 32.5–52.0), being 26 females (72%). SUA levels were found notably high (median 13.5mg/dL), and tophi, a marker of gout severity, were demonstrated in almost half of cases (44.4%). The majority of patients (91%) were on glucocorticoids at time of gout diagnosis. According to common factors leading to hyperuricemia, lupus-related renal damage (86%) and use of diuretics (83%) predominated in the series.
Conclusions Data supports including gout into the differential diagnosis of episodes of acute arthritis in SLE patients. This makes crucial the routine analysis of all synovial fluid samples, but especially in patients with long-term disease, renal impairment, and diuretic use.
EULAR Textbook on Rheumatic Diseases. BMJ, 2015.
Disclosure of Interest None declared