Pseudogout: pathogenesis and clinical findings - Idiopathic (vast majority of cases) -> Mechanism unknown - Familial chondrocalcinosis -> Overactivity of the NTPPPH enzyme and mutations in the ANKH gene, Incr pyrophosphate production - Hyperparathyroidism -> Incr levels of parathyroid hormone produced, incr gut Ca2+ absorption - Hemochromatosis -> Clearance of calcium pyrophosphate dihydrate (CPPD) crystals from joints is inhibited by iron - Hypomagnesia -> The relative absence of magnesium impairs pyrophosphatase activity, reduces pyrophosphate breakdown - Hypophosphatasia -> Defective mineralization of calcium and phosphorous in bones - Chondrocalcinosis, seen on high-resolution ultrasound and/or x-ray - CPPD Crystals - Positively birefringent (crystals appear blue parallel to axis of polarizer) - PAINFUL, warm, swollen joint (sudden onset) - Incr C-reactive protein (CRP); erythrocyte sedimentation rate (ESR) - Subchondral sclerosis & cysts, joint space narrowing, and osteophytes seen on x-ray #Chondrocalcinosis #Pseudogout #CPPD #Disease #Signs #Symptoms #Pathophysiology #Diagnosis
