The diagnosis of rheumatoid arthritis (RA) often precedes the diagnosis of calcium pyrophosphate deposition disease (CPDD), according to a recent study. This asynchronous presentation supports the hypothesis that CPDD develops in RA patients through similar processes as those that cause the idiopathic forms of this disease. Medical records of patients with both RA and CPDD identified at a single academic practice site were reviewed for age, gender, age of CPDD and RA onset, disease duration, joint involvement, and lab values including rheumatoid factor (RF), cyclic citrullinated peptide antibody (CCP), iron studies, and parathyroid hormone and calcium levels. Researchers found:

• The mean age of CPDD onset was 69.5 ± 11.4 years, with a mean RA age onset of 53.9 ± 16 years, demonstrating a mean lag of 13.4 ± 10.9 years between diagnoses.
• The majority of RA patients were diagnosed with CPDD based on the presence of radiographic chondrocalcinosis (15/21).
• The most commonly involved joint was the knee, followed by the wrist, hip, and shoulder.