How is Rheumatoid Arthritis different from CPPD?
Yes, up to 5% of patients with CPPD arthritis have involvement of multiple joints, particularly the knees, wrists, and elbows, with chronic low-grade inflammation persisting for weeks or months (chronic CPP crystal arthritis, pseudo-RA ). Joint involvement may be symmetric, and systemic symptoms such as fatigue or morning stiffness are present. Physical exam reveals synovial thickening, loss of joint motion, and flexion contractures. Inflammatory markers can be elevated. Up to 10% of CPPD patients will test positive for rheumatoid factor (RF) because of their age. If present, is usually a low titer. Higher RF titers, antibodies against cyclic citrullinated peptide, more widespread synovitis, involvement of the hands and feet, and characteristic erosions distinguish RA from pseudo-RA.