Renal stone formation is a complex multifactorial disease, and it is b
elieved that the initial step in the pathogenesis of urolithiasis must
be the precipitation of an organic matrix of mucoproteins followed by
precipitation of minerals onto this matrix. An important factor in th
is process may be the activity and/or concentration of the urinary enz
yme, urokinase, which would affect the level of urinary mucoproteins s
uch as uromucoid. In support of this hypothesis, ELISA studies were co
nducted to investigate the urokinase concentrations in urine obtained
from males (22-60 years) with and without renal stones. These results
showed a significant decrease in urinary urokinase concentration of re
nal stone patients which, once again, underlines the possible involvem
ent of urokinase in renal stone formation. Therefore, it seems logical
to conclude that urokinase may play an integral role in this multifac
torial disease.