Gout is more severe and difficult to treat in patients with a history of kidney transplantation (KT) than in those without a KT history, a new study suggests.
The study included 312 patients with gout. Of these, 25 (8%) had a KT history and 287 did not. Compared with the no-KT group, the KT group had a significantly higher prevalence of severe uncontrolled gout (27% vs 8%) and tophi (36% vs 17%) and higher rates of allopurinol discontinuation or physician perceived contraindication to allopurinol (44% vs 23%), Mark D. Brigham, PhD, of Trinity Partners in Waltham, Massachusetts, and colleagues reported in Transplantation Proceedings. The most common reason for allopurinol discontinuation was lack of efficacy (patients inadequately controlled) in both cohorts, followed by hepatic impairment in the KT group and renal impairment in the no-KT group.
“In the present study, the increased presence of tophi among patients with gout and a history of KT highlights higher gout disease burden in these patients,” the authors wrote. “The high prevalence of gout among patients with KT and increased health risks associated with severe gout compound the potential importance of these findings and underscores the need for further investigations in this area.”
The KT group was significantly younger than the no-KT group (mean 55.1 vs 62 years). The groups had similar proportions of male patients: 72% and 75%, respectively.
For the study, a panel of 104 board-certified US nephrologists provided Dr Brigham and his team with de-identified chart data for their 3 most recent patients with gout. The investigators defined severe uncontrolled gout as a serum uric acid level of 7 mg/dL or higher, 1 or more tophi, and 2 or more flares in the previous 12 months as well as a history of xanthine oxidase inhibitor treatment.
The study’s retrospective design and small sample size limits interpretations of the findings. In addition, the authors pointed out, they lacked information about certain factors that might influence gout severity, such as immunosuppressant use, timing and persistence of urate-lowering therapy, and duration of disease and onset relative to transplantation.
Brigham MD, Radeck LP, Mendonca CM, et al. Gout severity in recipients of kidney transplant. Transplant Proc. 2019. Published online ahead of print.