The effect of chelation therapy on the amino aciduria and peptiduria of Wilson's disease.

1. There is an excess urinary output of free amino acids and of urinary peptides in most cases of untreated Wilson's disease. Studies of 11 patients have shown that both these abnormalities are greatly improved by two years of standard chelation therapy. 2. The reduction in excretion of both free amino acids and peptides is purely quantitative, there being no significant change in the percentage composition of amino acids, either free or combined, in relation to their total urinary output. 3. Arguments are advanced that the peptiduria of the disease is usually due to a proximal renal tubular reabsorption defect, but in rare cases it may be due to excess bone breakdown or even to a combination of bone and renal tubular disease in the same patient.