The purpose of this study is to determine whether thorough analytical evaluation is useful to diagnose metabolic conditions associated to calcium pyrophosphate deposition disease.

The diagnostic usefulness of screening for hyperparathyroidism, hemochromatosis, hypothyroidism and hypophosphatasia in patients diagnosed with calcium pyrophosphate dihydrate (CPPD) deposition disease is uncertain.

Patients diagnosed with CPPD deposition disease were compared to patients with rheumatoid arthritis and psoriatic arthritis over a 9-year period. All patients were prospectively followed for at least 12 months. Serum calcium, phosphorus, alkaline phosphatase, thyroid-stimulating hormone, ferritin, iron, and total iron binding capacity were determined in all patients.

Inclusion Criteria:

• Patients diagnosed as having calcium pyrophosphate dihydrate deposition disease.

Exclusion Criteria:

• Patients mimicking a rheumatoid arthritis disease, with positive rheumatoid factor or with psoriasis.