The unjustified classification of kidney donors as patients with CKD: critique and recommendations.

Unilateral nephrectomy for kidney donation results in loss of about 30% of baseline GFR, leaving some donors with GFR <60 ml/min per 1.73 m(2), the threshold for the diagnosis CKD. This has resulted in insurability problems for some donors. This article reviews the definition of CKD, risks associated with CKD, and large follow-up studies on the vital status and risk of ESRD in kidney donors. It also provides evidence that kidney donors, despite having reduced GFR, are not at increased risk for CKD-associated morbidity and mortality. Epidemiologic studies, most with follow-up <10 years, have shown an association between GFR <60 ml/min per 1.73 m(2) and higher mortality and progression to ESRD. Low GFR in the absence of any other markers for kidney disease, however, conveys attenuated or minimal risk. Of note, studies of long-term kidney donor outcomes (6-45 years) have not shown excess mortality or ESRD. The limitation of the collective evidence is that the increased risks associated with GFR <60 ml/min per 1.73 m(2) were demonstrated in much larger cohorts than those reported for kidney donor outcomes, but donor outcome studies have substantially longer follow-up. On the basis of current findings, kidney donors with low GFR and no other signs of kidney disease should not be classified as having CKD. This is definitely not the reward they deserve, and, more important, the implications of reduced GFR in donors are not associated with unfavorable outcomes.