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ULT Not for CPPD — SCE Rheumatology MCQ

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EasyCrystal ArthropathyULT Not for CPPDSCE Rheumatology

A 60-year-old man has synovial fluid-confirmed acute calcium pyrophosphate crystal arthritis. Polarised microscopy shows weakly positively birefringent rhomboid crystals, with no monosodium urate crystals. His acute flare is being treated appropriately. Which additional strategy should be used specifically to reduce future calcium pyrophosphate crystal deposition?

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Correct answer: E — No urate-lowering therapy, because none reduces CPP crystal deposition

No urate-lowering therapy should be started specifically for CPPD. CPPD results from deposition of calcium pyrophosphate crystals, and no currently available treatment has been shown to dissolve these crystals or reduce their articular burden. Management instead targets inflammation: acute attacks may be treated with joint aspiration and intra-articular corticosteroid, an NSAID, colchicine or a short course of systemic corticosteroid, selected according to comorbidity. Allopurinol and febuxostat inhibit uric-acid production, probenecid increases urate excretion, and pegloticase metabolises urate. These drugs target monosodium urate deposition in gout and have no disease-modifying role in isolated CPPD.

Reference: Pascart T, Filippou G, Lioté F, et al. Calcium pyrophosphate deposition disease. The Lancet Rheumatology. 2024;6:e791-e804. https://pubmed.ncbi.nlm.nih.gov/21257614/