POS0134 INCREASED PREVALENCE OF LUMBAR SPINE MONOSODIUM URATE DEPOSITION AMONG GOUT PATIENTS ON DUAL-ENERGY CT

Background: Gout affecting the spine is reported as a rare event presenting with neuropathy, spinal compression and acute back pain (1). Cases are often diagnosed by tissue confirmation of monosodium urate (MSU) deposition. The frequency of gout involving the spine asymptomatically or with milder, non-specific symptoms is likely higher than reported. Objectives: Using dual-energy CT (DECT), we are determining prevalence/extent of MSU deposition in the lumbosacral spines of patients with gout and tophaceous gout, compared to non-gout controls. Methods: We are recruiting 25 controls, 25 non-tophaceous and 25 tophaceous gout patients, 45-80 years old. Exclusion criteria include CPPD disease, RA, spondyloarthropathy or spinal malignancy. All gout subjects meet ACR gout classification criteria with entry serum urate (sU) of >6.8 mg/dL, or sU >6.0 mg/dL on ULT for Results: 63 subjects are enrolled and analyzed to date (25 control, 23 non-tophaceous and 15 tophaceous gout). Control, non-tophaceous gout, and tophaceous gout subjects have similar mean age in years (controls 61.8±3.8, non-tophaceous 64.0±6.2, tophaceous 63.5±9.2, p=0.45), but differ in BMI (controls 28.3±6.5 kg/m2, non-tophaceous 32.1±6.7 kg/m2, tophaceous 29.1±4.3 kg/m2, p=0.01) and creatinine (controls 1.0±0.2 mg/dL, non-tophaceous 1.4±0.6 mg/dL, tophaceous 1.7±0.9 mg/dL, p=0.048). Mean sU and ESR are higher in gout subjects (sU-controls 5.3±1 mg/dL, non-tophaceous 8.3±1.4 mg/dL, tophaceous 8.4±2.0 mg/dL, p Conclusion: Based on preliminary results, gout patients have higher inflammatory markers and greater spinal MSU deposition than controls. Preliminary analyes with more stringent DECT threshold settings suggests these differences are not artifact, but analysis is ongoing. These data suggest that MSU deposition in the spine occurs in a subset of gout patients. References: [1]Toprover M, Krasnokutsky S, Pillinger MH. Gout in the Spine: Imaging, Diagnosis, and Outcomes. Curr Rheumatol Rep. 2015;17(12):70. Acknowledgements: Supported by an investigator-initiated grant from Horizon Therapeutics Disclosure of Interests: Michael Toprover Consultant of: Horizon Pharmaceuticals, Michael Mechlin: None declared, Anastasia Slobodnick: None declared, Virginia C. Pike: None declared, Cheongeun Oh: None declared, Claudine Davis: None declared, Theodore Fields Consultant of: Horizon Pharmaceuticals, Avion Pharmaceuticals, Fabio Becce Consultant of: Horizon Therapeutics, Michael H. Pillinger Consultant of: Horizon Pharmaceuticals, Grant/research support from: Horizon Pharmaceuticals