Session Type: Poster Session B
Session Time: 9:00AM-11:00AM
Background/Purpose: The coexistence of calcium pyrophosphate (CPP) and monosodium urate crystals is rarely reported in gouty tophi. We investigated CPP crystal deposits in a series of gouty tophi removed by surgery and associated factors.
Methods: 25 tophi from 22 patients were analyzed by light microscopy, field-emission-scanning electron microscopy (FE-SEM) and µ Fourier transform infrared (FTIR) spectroscopy
Tophi consisted of multiple lobules separated by fibrous septa and surrounded by a foreign-body giant cell reaction. CPP crystal aggregates were identified in 8 of 25 tophi from 5 patients. CPP crystals were dispersed or highly compacted, localized at the edge or inside the tophus lobules or filled some of them. Both monoclinic and triclinic CPP crystal phases were identified by FE-SEM and µ FTIR. As compared with patients without CPP, those with CPP-containing tophi were older (mean 61.2 vs 47.8 years, p=0.009), and had long-term gout (mean 19.0 vs 9.0 years, p=0.007) and tophus (mean 11.4 vs 4.7 years, p< 0.0001). None had radiological chondrocalcinosis of the knee or wrist
Conclusion: CPP crystal formation seems to be a late and frequent event of tophus maturation and could contribute to the apparent persistence of tophus sometimes observed even after long-lasting and efficient urate-lowering therapy.
To cite this abstract in AMA style:Ea H, Gauffenic A, Nguyen Q, Pham N, Olivier O, Frochot V, Bazin D, Le N, Marty C, Ostertag A, Cohen-Solal M, Laredo J, Richette P, Bardin T. Calcium Pyrophosphate Crystal Deposition in Gouty Tophi [abstract]. Arthritis Rheumatol. 2020; 72 (suppl 10). https://acrabstracts.org/abstract/calcium-pyrophosphate-crystal-deposition-in-gouty-tophi/. Accessed May 16, 2022.
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