URINARY MATRIX CALCULI CONSISTING OF LOW MOLECULAR WEIGHT PROTEIN IN CHRONIC UREMIC PATIENTS WITH HEMODIALYSIS

Abstract

Seven hemodialysis patients were examined to detect urolithiasis associated with clinical observations, chemical analysis of stones, biochemical analysis of matrix protein, and histological study on the stone bearing kidneys.
All patients were males. The underlying renal disease was chronic glomerulonephritis in all patients.
Numerous small stones were found in the bilateral kidneys. In most cases the stones were radiolucent on plain X-ray films.
Although pyelonephritis was observed in three patients, none of them showed perpetual urinary infection.
Both infrared spectroscopic analysis of stones and analysis of proteins revealed that the stones from the five patients were matrix calculi and these from the two patients were Ca-oxalate stone.
The matrix calculi in hemodialysis patients, however, differed from ordinary matrix calculi related to urinary infection as indicated by their morphological appearance.
The composition of that matrix protein was homogeneous and uniform in three stones. The molecular weight of that unique protein was estimated to be 10, 000-to 20, 000 dalton.
The hitological studies on extirpated kidneys from all five patients examined revealed “intrancphronic calculi”.
It is suggested that urinary low molecular weight proteins which appear in chronic renal failure may promote the formation of renal stones consisted of matrix protein in hemodialysis patients.