Kidney transplant recipients with gout and hyperuricemia face increased risks for adverse outcomes. Results of the PROTECT study demonstrated that pegloticase lowered serum urate in 89% of kidney transplant recipients with uncontrolled gout.
During a poster session at the National Kidney Foundation Spring Clinical Meetings 2023, Nicola Dalbeth, MBChB, MD, and colleagues reported associated changes in monosodium urate deposition volume (Vmsu) as seen on dual-energy computed tomography (DECT). The poster was titled Monosodium Urate Crystal Depletion in Renal Transplant Recipients Treated With Pegloticase: PROTECT Serial Dual-Energy Computed Tomography Findings.
Inclusion criteria were uncontrolled gout (serum urate, ≥7 mg/dL; oral urate-lowering therapy refractory/intolerant; and ≥2 flares/year, ≥1 tophi, or chronic gouty arthritis), kidney transplant >1 year prior, graft estimated glomerular filtration rate (eGFR) ≥15 mL/min/1.73 m2, and stable immunosuppression. All patients received ≤24 weeks of pegloticase (8 mg biweekly; serum urate response, <6 mg/dL for ≥80% of month 6).
DECT imaging was measured with standard protocols at screening (Scr). Vmsu was measured at weeks 14 and 24 with default postprocessing settings. Joints with Scr and week 24 images and Scr Vmsu ≥0.5 cm3 were included. The Vmsu criterion reduced the effects of DECT artifact.
Eight patients underwent imaging. All eght were male, mean age was 52.3 years, mean time since kidney transplant was 18.7 years, mean eGFR was 45.6 mL/min/1.73 m2, and mean serum urate was 10.4 mg/dL. Six of the eight received 24 weeks of pegloticase and were serum urate responders (week 24 serum urate, 0.5 mg/dL). Two patients discontinued the study due to COVID-19.
Five imaged regions of four responders met inclusion criteria for the current analysis. In all joints, Vmsu rapidly and progressively decreased (≥96% reduction at week 24; mean, –98.9).
“In this kidney transplant recipient population, sustained profound serum urate lowering was associated with a rapid, marked decrease in Vmsu on DECT,” the researchers concluded.
Source: Dalbeth N, Abdellatif A, Botson J, et al. Monosodium urate crystal depletion in renal transplant recipients treated with pegloticase: PROTECT serial dual-energy computed tomography findings. Poster #430. Abstract of a poster presented at the National Kidney Foundation Spring Clinical Meetings; April 11-15, 2023; Austin, Texas.