Kidney Week

Abstract: FR-PO251

Dual-Energy CT Bone Findings in Kidney Transplant Recipients with Uncontrolled Gout

Session Information

• Mineral Bone Disease: Transplant and Kidney Stones
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Bone and Mineral Metabolism

• 502 Bone and Mineral Metabolism: Clinical

Authors

• Marder, Bradley Allan, Amgen, Inc., Thousand Oaks, California, United States

Bradley Allan Marder, MD

• Dalbeth, Nicola, Department of Medicine, University of Auckland, Auckland, New Zealand

Nicola Dalbeth, MD, MBChB

• Abdellatif, Abdul A., Baylor College of Medicine, Nephrology, Houston, Texas, United States

Abdul A. Abdellatif, MD, FASN

• Botson, John K., Orthopedic Physicians Alaska, Anchorage, Alaska, United States

John K. Botson, MD, RPh

• Kumar, Ada, Amgen, Inc., Thousand Oaks, California, United States

Ada Kumar, MD

• Padnick-Silver, Lissa, Amgen, Inc., Thousand Oaks, California, United States

Lissa Padnick-Silver, MS, PhD

• Vranic, Zana, Amgen, Inc., Thousand Oaks, California, United States

Zana Vranic, PhD

• Becce, Fabio, Department of Diagnostic and Interventional Radiology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland

Fabio Becce, MD

Background

CKD pts are at risk for metabolic bone disease including osteopenia and deposition disease. Monosodium urate crystal (MSU) deposits in gout also cause bone erosions/joint damage. The PROTECT study examined pegloticase safety/efficacy in immunosuppressed kidney transplant recipients (KTRs) with uncontrolled gout; a subset underwent dual-energy CT (DECT). Here we report baseline bone-related findings.

Methods

Pts (eGFR≥15,>1yr post-transplant) with baseline DECT were included. Standard protocols were used to acquire images (bilateral hands/wrists, feet/ankles, and/or knees); default post-processing for MSU detection. A central reader interpreted images (typical DECT artifacts removed) and calculated erosion scores (additive% of pre-specified bones [OMERACT RAMRIS scoring¹]).

Results

18regions of 8pts included (all male, 52.3±11.2yrs, time since transplant:18.7±6.9yrs, eGFR:45.6±12.4; SU:10.4±2.1mg/dL, 5.3±4.6 flares/6mo). DECT showed multiple bone abnormalities in all pts, including erosions and osteopenia/osteomalacia (trabecular bone loss, cortical thinning, and/or bone resorption). Erosions were common in feet/ankles and hands/wrists (both 7/8[88%]) and most severe in feet/ankles (≥10% eroded: 3/8[38%], ≥40% eroded: 2/8[25%]) and were adjacent to MSU deposits, non-MSU mineralized matrix, and/or not adjacent to any deposits (Figure).

Conclusion

These images provide new insight on bone/soft tissue abnormalities in KTRs with uncontrolled gout. Though not an intended PROTECT outcome, DECT showed overall poor bone health. Given additional erosive bone/joint damage MSU deposits can cause, findings suggest effective gout management as an opportunity to improve an aspect of bone health in KTRs with gout.

Reference
1. Dalbeth N et al. Rheumatology 2011;50:410-6

Funding

• Commercial Support – Horizon Therapeutics (now Amgen, Inc.)