Anemia and Erythrocytosis After Kidney Transplantation: A 5-Year Graft Function and Survival Analysis

IntroductionBoth 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 MethodsThree 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.ResultsIn 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 m2 (39.5–48.4) vs 55.3 mL/min/1.73 m2 (53.0–57.6; P < .001). Better 12-month graft function was observed among patients with erythrocytosis, namely, 57.7 mL/min/1.73 m2 (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).ConclusionAnemia 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.