The Janus faces of ESAs: caveat Chimaera!

Patients with chronic kidney disease (CKD) have a Janus quality as they look back whence they came in developing CKD and, in some cases, also look forwards to a potential kidney transplant with the attendant promise of improvement in quality and often quantity of life. Making the most of this often unique opportunity is key-maximising the chance that the engraftment starts as a success, and then later, preserving good kidney transplant function for as long as possible. Two recently published, independently conceived and executed studies are relevant to both aspects of this quest and thus to all kidney transplant recipients (KTRs). Both trials also simultaneously stoke and quench the continuing, heated debates over target haemoglobin (Hb) levels, and the use of erythropoiesis-stimulating agents (ESAs), in CKD patients. One study--of acute, high-dose ESA administration--adds to the plethora of adverse safety signals swirling around the use of ESAs while surprisingly also showing renal function benefits at 12 months. The other study features chronic lower-dose ESA use in stable KTRs with anaemia and impaired renal function and not only purports to show a salutary effect on 2-year renal function outcomes (and thus reducing "return to dialysis" rates), but also rebuts the now widely accepted current notion that by chronic use of ESAs to target full Hb correction/higher Hb values in anaemic CKD patients, we are potentially causing harm.