Radioimmunoassay for plasma glutathione S-transferase-pi and its clinical application in gastrointestinal cancer.
BACKGROUND
Plasma acidic glutathione S-transferase (GST-pi) concentrations in 135 patients with gastrointestinal cancer were measured by an improved radioimmunoassay (RIA).


METHODS
Blood was collected into a silicified glass tube containing a specific anticoagulant. The plasma, which was separated rapidly by centrifugation with adequate force, underwent RIA procedures (double antibody and polyethylene glycol separation method).


RESULTS
The improved RIA for plasma GST-pi was specific and sensitive. Plasma GST-pi in 75% of patients with esophageal cancer, 64.44% of those with gastric cancer, 74.41% of those with colon cancer, 85.19% of those with hepatocellular carcinoma, and 60.00% of those with pancreatic cancer was elevated higher than 13.99 micrograms/l (mean + 1.96 standard deviation of normal controls). Plasma GST-pi levels in patients with gastric cancer with Stages I-II, III and IV disease increased in proper order. Plasma GST-pi concentrations in 57% of patients with colon cancer decreased to the normal range 14 days after surgery. Plasma GST-pi levels of patients with recurrent colon cancer were higher than of those with primary colon cancer.


CONCLUSIONS
The procedure for specimen collection must be critical. Plasma GST-pi may be useful in diagnosing gastrointestinal cancer and in monitoring its clinical course.
Fan
K C
KC
Department of Gastroenterology, Great Wall Hospital, Beijing, People's Republic of China.
Huang
Y C
YC
Li
C H
CH
D003110:Colonic Neoplasms / Q000201:enzymology; D004067:Digestive System Neoplasms / Q000201:enzymology* / Q000473:pathology; D004938:Esophageal Neoplasms / Q000201:enzymology; D005982:Glutathione Transferase / Q000097:blood* / Q000302:isolation & purification; D006801:Humans; D007457:Iodine Radioisotopes; D008113:Liver Neoplasms / Q000201:enzymology; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000201:enzymology; D011863:Radioimmunoassay; D013274:Stomach Neoplasms / Q000201:enzymology
D007457:Iodine Radioisotopes; D005982:Glutathione Transferase