About Alpha-GST as a Biomarker

URINE STUDIES
In the kidney, alpha glutathione S-transferase (αGST) is found in the proximal tubule region whereas Pi glutathione S-transferase (πGST) is confined mainly to the distal tubules. Low levels of αGST are released into the urine in normal individuals, as confirmed by immunoassay and Western blot anlaysis. Any event which precipitates proximal tubular damage may cause increased release of αGST into urine and elevations of urinary αGST levels have been shown to be indicative of proximal tubule damage in nephrotoxicity, environmental toxicity, surgery, acute renal failure and transplantation. The release of πGST has been shown to be associated with distal tubular damage, thus simultaneous measurement of αGST and πGST may allow discrimination between proximal and tubular damage.

SERUM STUDIES
In liver, alpha glutathione S-transferase is located in the hepatocytes whereas pi GST (πGST) is confined to the intrahepatic bile duct cells. This heterogeneous GST subclass distribution suggests that the isoenzymes have unique in vivo functions in different hepatic regions and that the detection of GST subclass levels in biological fluids would be of significant use in monitoring the integrity of specific hepatic regions. Currently, liver injury is studied by the measurement of liver enzymes such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST). A disadvantage of these markers is that they are not distributed uniformly throughout the liver, the periportal concentration being greater than the centrilobular. In contrast, αGST has been found to be equally distributed in both the centrilobular and periportal regions. Since the centrilobular hepatocytes are very susceptible to damage in a variety of conditions including Allograft Rejection, Viral Hepatitis, and Hepatotoxicity, αGST is a more sensitive indicator of hepatic status.
 

References

For references see our publications section, here