Calcium oxalate and other crystals associated with kidney diseases and arthritis

Oxalate Decarboxylase from Collybia velutipes

“…Such vegetables when consumed in large quantities cause secondary hyperoxaluria where precipitation of oxalic acid as calcium oxalate leads to kidney stones and hypocalcemia (4,5). Lathyrus sativus, a protein rich hardy legume that grows under extreme environmental conditions, is not edible due to the presence of a neurotoxin ␤-N-oxalyl-L-␣,␤-diaminopropionic acid.…”

Non-crystalline and crystalline rheumatic disorders in chronic kidney disease

“…Therefore, diagnostic arthrocentesis and examination of synovial fl uid by compensated polarizing light microscopy is required to properly identify CaOX crystals. Two main forms of these crystals can be identifi ed in the synovial fl uid or synovium by polarized light microscopy: CaOX monohydrate (whewellite) appear as irregular birefringent squares, chunks, or rods that can be confused with CPPD crystals [ 90 ]; CaOX dihydrate (weddellite) crystals have a typical envelope-like or bipyramidal shape. Positive alizarin red S staining of CaOX on fresh synovial fl uid preparations may facilitate diagnosis.…”

Unusual and memorable

“…Soft tissue calcification in chronic renal failure may be visceral or non-visceral. Various calcium crystals may be responsible, most commonly calcium phosphates and oxalates 1. Visceral calcification, in heart, lung and muscle, is usually an amorphous compound similar to whitlockite (anhydrous calcium carbonate).…”