Trace elements and urinary stone formation: new aspects of the pathological mechanism of urinary stone formation.

The urinary stone, serum and 24-hour urine concentrations of 14 trace elements were determined in urinary stone patients by inductively coupled plasma atomic-emission spectroscopy. The data obtained for 25 active stone patients and 32 whose last stone episode had occurred at least 12 months previously were compared with those of 25 healthy individuals. Urinary nickel, manganese and lithium excretion, and serum nickel, manganese and cadmium concentrations were statistically significantly lower for active stone patients compared to those with previous stone episodes and healthy individuals. No difference in the concentrations of trace elements could be found, however, for patients with previous stone episodes and healthy individuals. Nickel, manganese, lithium and cadmium could be of significance in the pathological mechanism of stone formation, not from mineralogical or crystallographic viewpoints but for the smooth flow of enzymatic reactions in biological systems.