UW is superior compared with HTK after prolonged preservation of renal grafts

In recent clinical studies, the efficacy of histidine-tryptophan-ketoglutarate (HTK) in kidney transplantation was questioned. This study compares the efficacy of University of Wisconsin (UW) and HTK solutions on transplantation outcome.

Rat kidneys were preserved for different periods of cold ischemia (CIT). Heat capacity of the solutions, temperature of the grafts, renal function (RF), and histology were assessed before and after transplantation, respectively.

After prolonged CIT, recipient survival was superior in the UW - (100%) compared with the HTK group (10%). In the latter, severe tubular necrosis, DNA damage, and renal inflammation were observed, reflected by an increased KIM-1, IL6, and P-selectin expression. CIT correlated negatively with RF in both groups. RF recovered significantly faster in the UW group. LDH-release and ATP depletion after cold storage of tubular cells were lower in UW than in HTK. Heat capacity was significantly higher for UW than for HTK. Accordingly, renal temperature was lower.

Prolonged preservation in UW solution results in a better renal function and less tissue damage compared with HTK, possibly due to improved cooling and better cell viability of the graft. The use of HTK for renal allografts should therefore be reconsidered, particularly when CIT is expected to be long.