Calcium Pyrophosphate Deposition Disease (CPPD): Causes and Treatment
Causes and Risk Factors
CPPD results from elevated extracellular pyrophosphate concentrations in cartilage, leading to calcium pyrophosphate crystal formation and NLRP3 inflammasome activation. 1
Primary Risk Factors
- Aging is the strongest risk factor, with CPPD being most common in people over 60 years 1
- Previous joint injury significantly increases risk 1
- Cartilage degradation and osteoarthritis are strongly associated, though causality remains unclear 1
Metabolic Causes to Screen For
Always screen for and treat associated metabolic conditions, as their correction is evidence-based management: 2
Genetic Factors
- Variants in ANKH and osteoprotegerin genes 1
- Genetic association signals at ENPP1 and RNF144B genes on chromosome 6 3
- The ENPP1 gene encodes NPP1, which produces pyrophosphate that combines with calcium to form CPP crystals 3
Treatment Approach
No treatment currently dissolves CPP crystals or modifies crystal formation; therefore, inflammation control is the sole therapeutic focus. 2, 4
Acute CPP Crystal Arthritis
For monoarticular or oligoarticular attacks, joint aspiration with intra-articular glucocorticoid injection plus ice application and temporary rest is optimal first-line therapy—these approaches alone are often sufficient. 2
First-Line Systemic Options (when intra-articular injection insufficient):
- Oral NSAIDs (with gastroprotection if indicated): effective but limited by toxicity in elderly 2
- Low-dose oral colchicine: 0.5 mg up to 3-4 times daily (with or without 1 mg loading dose) 2
Second-Line Options (when intra-articular injection not feasible or NSAIDs/colchicine contraindicated):
- Short tapering course of oral glucocorticoids 2
- Parenteral glucocorticoids (intramuscular or intravenous): betamethasone 7 mg IM or methylprednisolone 125 mg IV provide faster pain control (NNT=3 on day 1) 2
- ACTH 40-80 units (IV, IM, or subcutaneous): resolves attacks in average 4.2 days 2
Important caveat: Glucocorticoids are particularly useful in elderly patients with contraindications to NSAIDs 2
Prophylaxis for Recurrent Acute Attacks
For patients with frequent recurrent flares, use low-dose colchicine 0.5-1 mg daily or low-dose NSAIDs with gastroprotection. 2
- Colchicine prophylaxis reduces attack frequency from 3.2 to 1.0 episodes per year (p<0.001) 2
- Consider side effect profiles carefully, especially in elderly with renal impairment 2
Chronic CPP Crystal Inflammatory Arthritis
Pharmacological options in order of preference: 2
- Oral NSAIDs (plus gastroprotection) and/or colchicine 0.5-1.0 mg daily 2
- Low-dose corticosteroids 2
- Methotrexate (5-10 mg/week): showed marked improvement within 7.4 weeks in refractory cases 2
- Hydroxychloroquine 2
Refractory Disease:
- Anakinra (IL-1 receptor antagonist) for acute flares unresponsive to standard therapy 1, 5
- Tocilizumab (IL-6 inhibitor) for refractory chronic disease 5
CPPD with Osteoarthritis
Manage identically to osteoarthritis without CPPD, following standard evidence-based OA guidelines. 2
- Treatment objectives: reduce pain/stiffness, maintain mobility, limit disability, improve quality of life 2
- Avoid intra-articular high molecular weight hyaluronan as it may trigger acute attacks 2
Asymptomatic Chondrocalcinosis
No treatment is required for asymptomatic chondrocalcinosis. 2
Critical Clinical Pitfalls
- Always evaluate for metabolic causes (hyperparathyroidism, hemochromatosis, hypomagnesemia) as these are treatable 2
- Exercise extreme caution with NSAIDs and colchicine in elderly patients due to high risk of gastrointestinal bleeding, cardiovascular events, renal impairment, and drug interactions 2
- Never use intravenous colchicine due to high risk of serious toxicity and fatality 2
- Avoid traditional high-dose colchicine regimens (1 mg loading then 0.5 mg every 2 hours) as side effect incidence is 100% 2