Introduction: Both anemia and erythrocytosis frequently occur after kidney transplantation. The aim of this study was to analyze the influence of both anemia and erythrocytosis on kidney graft function and long-term patient outcomes following kidney transplantation.
Patients and methods: Three hundred eight-five consecutive patients with at least 12 months of follow-up after successful kidney transplantation were enrolled into this study. Of the total, 88.3% of patients completed a 5-year follow-up. Anemia occurred in 30.4% of patients (with 17.7% showing a hemoglobin concentration (Hb) <11.0 g/dL), whereas erythrocytosis was observed in 19.0% of patients, including 9.6% with hematocrit (HTC) >55%. We also analyzed graft function every 6 months after transplantation for the impact of anemia or erythrocytosis on the 5-year risk of patient death or graft loss.
Results: In 57.3% of anemia patients the Hb did not reach the normal range during the observation time. The mean eGFR-Modification of Diet in Renal Disease (MDRD) at 12 months after transplantation was significantly lower among patients with anemia: 43.9 mL/min/1.73 m(2) (39.5-48.4) vs 55.3 mL/min/1.73 m(2) (53.0-57.6; P < .001). Better 12-month graft function was observed among patients with erythrocytosis, namely, 57.7 mL/min/1.73 m(2) (53.5-62.0). Anemia but not erythrocytosis was associated with an increased risk of graft loss (hazard ratio [HR] = 4.11 [95% confidence interval (CI) 2.02-8.37]; P < .001).
Conclusion: Anemia after transplantation was associated with worse kidney graft function and was a strong predictor of graft loss. Erythrocytosis occurs among patients with excellent allograft function; when properly treated it did not increase the risk of graft loss or death.