Post-transplant haemoglobin levels and host kidney status

Erythrocytosis after renal transplantation has been ascribed to inappropriate production of erythropoietin by the recipient's native kidneys. In a retrospective analysis we examined the effect of pre-transplant bilateral nephrectomy on post-transplant haemoglobin level (Hb) and haematocrit (Ht) in 370 renal transplant patients. Hb and Ht were significantly higher in the 341 patients with host kidneys in situ compared with the 29 patients who had undergone bilateral nephrectomy (Hb, 8.5 +/- 1.2 mmol/l vs 7.8 +/- 1.3 mmol/l, P = 0.005; Ht, 41 +/- 6% vs 38 +/- 7%, P = 0.02). Moreover, a very high Hb and/or Ht (defined as a value above the 80th percentile of the whole group) occurred more frequently in patients with host kidneys in situ (20.5% vs 3.5%, P = 0.02). It thus appears that host kidneys significantly contribute to the unexpectedly high haemoglobin levels occurring after renal transplantation.