The contribution of Na+/H+ exchange to postreperfusion injury and recovery of transplanted kidney.

Acute kidney injury soon after reperfusion seems to anticipate short- and long-term graft prognosis. Sodium-hydrogen exchanger (NHE) is involved in several steps of kidney graft function recovery, such as the restoration of intracellular pH, acute postreperfusion inflammation, and tubular epithelium repair and proliferation. We studied 20 first kidney transplantations by measuring the erythrocyte NHE of both recipient and donor as well as recipient serum and urine indices of renal structural and functional integrity every day since grafting. Heightened exchange activity in the donor-recipient couple resulted, which was associated to a prompt graft recovery together with a short stay for the donor in the intensive care unit, brief cold ischemia time, and a nonatherogenic lipoprotein profile for the recipient. Additional positive prognostic indices were time-zero diuresis and urinary excretion rates of N-acetyl-beta-D-glucosaminidase (NAG) and albumin. Over the one-year follow-up period, a long post-transplantation hospital stay was associated with a significantly increased risk of rejection, and the urinary alanine-aminopeptide (AAP) excretion rate was confirmed as a useful criterion for evaluating the clinical course of kidney graft.