Review of Calcium Pyrophosphate Deposition Disease Save

Lancet Rheumatology has published a review of Calcium pyrophosphate deposition (CPPD) disease - a chronic inflammatory and degenerative crystal arthropathy that increases with aging.

While the inflammatory response to calcium pyrophosphate (CPP) crystals may cause an acute or chronic inflammatory arthritis, over time CPPD is associated with cartilage degradation and osteoarthritis, but its unclear which is primary or if this evolution is bidirectional. 

The following are highlight or excerpts from the review article by Pascart et al:

• CPPD disease might be the most common cause of inflammatory arthritis in older people (aged >60 years). 
• Risk factors for CPPD disease include ageing and previous joint injury. 
• There is an unclear association between CPPD and metabolic conditions (eg, hyperparathyroidism, haemochromatosis, hypomagnesaemia, and hypophosphatasia) 
• The inflammatory response involve the NLRP3 inflammasome (liek gout)
• Diagnosis rests with detection of CPP crystals in synovial fluid, but also with imaging evidence of CPPD in joints by radiography, and ultrasonography
• CT imaging may show calcification in axial joints such as in patients with crowned dens syndrome
• Prednisone might provide the best benefit–risk ratio for the treatment of acute CPP-crystal arthritis, but low-dose colchicine is also effective with a risk of mild diarrhoea. 
• Also there is limited evidence supporting treatment with colchicine, low-dose weekly methotrexate, and hydroxychloroquine, or IL-1 and IL-6 inhibitors for refractory disease
• Asymptomatic CPPD is an ambiguous aspect of the disease, defined as imaging evidence of CPP deposition without symptoms 
• CPPD disease is often mistaken for other rheumatic diseases such as gout, rheumatoid arthritis, polymyalgia rheumatica, or osteoarthritis
• CPPD disease is a polyarticular, systemic condition associated with comorbidities.
• Like gout, CPPD is often associated with comorbidities, including chronic kidney disease and cardiovascular events, myocardial infarction, acute coronary syndrome, and stroke
• Aside from having common risk factors, the association between CPPD and osteoarthritis is puzzling