Molecular analysis of urinary AT III related antigen in liver cirrhosis

Urinary antithrombin III (AT III) related antigen was analyzed by SDS-polyacrylamide gel electrophoresis and Western blotting, and the nitrocellulose membrane was scanned with a 2-wavelength TLC scanner. The urinary AT III related antigen was found to be located in three different molecular weight regions: the AT III region, and molecular weight regions higher and lower than that of AT III. The ratio of the higher molecular weight region to the AT III region divided by the urinary creatinine, was taken as an "index" and was analyzed in liver cirrhosis patients as well as in normal controls. The "index" in liver cirrhosis was higher than that in the controls. Further, the "index" revealed a significant proportional correlation with the total bilirubin and direct bilirubin, and also a significant inversely proportional correlation with the plasma AT III, suggesting that the "index" tends to become higher as liver function decreases. The pathophysiological significance of the "index" is briefly discussed.