Level of renal function and serum erythropoietin levels independently predict anaemia post-renal transplantation.

Background: Post-renal transplant anaemia is a potentially reversible cardiovascular risk factor. Graft function, immunosuppressive agents and inhibition of the renin-angiotensin system have been implicated in its aetiology. The evaluation of erythropoietin (EPO) levels may contribute to understanding the relative contributions of these factors.

Methods: Two-hundred and seven renal transplant recipients attending the Belfast City Hospital were studied. Clinical and laboratory data were extracted from the medical records and laboratory systems.

Results: Of the 207 patients (126 male), 47 (22.7%) were found to be anaemic (males, haemoglobin (Hb)<12 g/dl, females Hb<11 g/dl). The anaemic group had a significantly higher mean serum creatinine level (162.8 micromol/l vs 131.0 micromol/l, P<0.001) and lower mean estimated glomerular filtration rate (eGFR) (41.5 ml/min vs 54.9 ml/min, P<0.001) than the non-anaemic group. Individual immunosuppressive regimens were comparable between those with and those without anaemia. Angiotensin converting enzyme inhibitor (ACE-I) or angiotensin receptor blocker (ARB) administration was not more prevalent in those with anaemia compared with those without (36.2 vs 38.8%, P=0.88). There was a significant inverse correlation between Hb levels and serum EPO levels (R=-0.29, P<0.001), but not between EPO levels and eGFR (R=0.02, P=0.74). Higher EPO levels were predictive of anaemia, independent of eGFR in multivariate analysis.

Conclusion: Anaemia is common in post-renal transplant patients. The levels of renal function and serum EPO and not immunosuppressive regimens or ACE-I/ARB use, are strong and independent predictors of anaemia.