Crystal arthropathies

Crystal arthropathies

Crystalinduced arthropathy may result in various disease patterns:

·        Monosodium urate crystals cause acute gout and chronic tophaceous gout.

·        Calcium pyrophosphate causes pseudogout.

·        Crystallised injected corticosteroids may result in iatrogenic acute synovitis.

·        Calcium hydroxyapatite crystals are involved in the pathogenesis of osteoarthritis.

The crystals deposited in the joint are phagocytosed by neutrophils. Typically pyrosphosphate crystals are seen within a phagolysosomal sac, whereas urate crystals are not confined. Phagolysosomal lysis results in the release of enzymes into the cell cytoplasm. Phagocytosis induces cytokine release leading to chemotaxis and further inflammation.