Functional relationship of α-glutathione S -transferase and glutathione S -transferase activity in machine-preserved non-heart-beating donor kidneys

Abstract

alpha-Glutathione S-transferase (alpha-GST) is a biochemical parameter used to estimate the amount of proximal tubule damage to a kidney. In normal clinical practice, the concentration of alpha-GST in urine is determined by a rather time-consuming immunochemical test, the enzyme-linked immunosorbent assay (ELISA). Kidneys from non-heart-beating (NHB) donors are perfused prior to transplantation. The determination of alpha-GST concentration in the perfusate to monitor damage is also done by means of an ELISA test. However, because this is a time-consuming method, it would be helpful to find a parameter proportional to GST concentrations that would be available within minutes. We therefore compared the method of determining alpha-GST concentration via ELISA with that of determining the enzymatic activity of GST, which is much faster (results available within 10 min). The comparison was made using 150 preserved kidneys that had been perfused for 6 h. The correlation was found to be very good, as indicated by the linear regression data: r=0.954, P<0.001. pi-Glutathione S-transferase (pi-GST) was also determined by means of an ELISA test, and the concentration of pi-GST was compared with the enzymatic activity of the "total" GST. The precision of the enzymatic method, given by intra- and interassay variation, was 1.5% and 10.5%, respectively.

Redox-Active Iron Released During Machine Perfusion Predicts Viability of Ischemically Injured Deceased Donor Kidneys

“…Perfusate LDH was determined by standard colorimetric assay (Boehringer Mannheim, Almere, The Netherlands). Total GST activity in the perfusate samples was measured as described previously (21). Oxyhemoglobin was identified by absorption spectrum and quantified by absorption at 540 nm.…”