The matrix of urinary tract stones: protein composition, antigenicity, and ultrastructure.

We have extracted proteins from urinary tract stones by electrodialysis and have developed antisera to the core and the shell of a renal stone. The protein composition varies between stones but is identical in the core and the shell of the same stone. One stone antigen is present in the urine of normal individuals and stone formers, as well as in cholesterol gallstone extracts. Electron microscopy of the core of a urate-calcium oxalate stone before and after demineralization reveals a fibrillar structure associated with mineral deposits, as well as aggregates of crystals.