Transplantation. 97(5):548-554, March 15, 2014.
Live donor nephrectomy results in a 25-30% loss of kidney function and there is on-going debate about whether or not this leads to an increased risk of cardiovascular disease. Indoxyl sulphate (IS) and p-cresyl sulphate (PCS) are two of the uremic toxins that accumulate in patients with impaired renal function and it has been suggested that they may contribute to the development of cardiovascular disease. In this issue Rossi et al report, for the first time, the effect of live donor nephrectomy on the levels of IS and PCS. In an observational cohort study of forty-two living kidney donors followed up annually for two years Rossi et al found a statistically significant and sustained increase in serum IS and PCS levels following nephrectomy. The levels of these toxins were associated with markers of cardiovascular disease, including carotid intima thickness and brachial artery reactivity, and were also found to be independent predictors of reduced kidney function (eGFR) from pre-nephrectomy levels. The clinical significance of these observations is not yet clear and, as the authors acknowledge, observational studies of this kind cannot establish a causal relationship between uremic toxins and cardiovascular risk or kidney function. However, further research in this area is clearly justified, particularly in view of the increasing number of "marginal" live donors where pre-existing hypertension and obesity already predisposes them to an increased risk of cardiovascular disease.