Calcium pyrophosphate deposition (CPPD) disease is associated with several metabolic conditions. Which metabolic disorder should be PRIMARILY screened when a 50-year-old man presents with acute CPPD arthritis of the knee?
- A Type 2 diabetes mellitus
- B Haemochromatosis and hyperparathyroidism (most important secondary causes) ✓
- C Hypothyroidism exclusively
- D Hyperuricaemia and gout
Explanation
CPPD disease in a patient under 60 years warrants a search for metabolic causes. The most important secondary associations are hyperparathyroidism (elevated PTH increases inorganic pyrophosphate in cartilage), haemochromatosis (iron deposition in chondrocytes inhibits pyrophosphatase), hypomagnesaemia, hypophosphatasia, and hypothyroidism. Haemochromatosis and hyperparathyroidism are the most clinically significant and commonly tested. Serum calcium, PTH, ferritin, transferrin saturation, and thyroid function should be checked. Gout and CPPD can coexist but gout does not cause CPPD.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.