Early risk factors for persistent anemia after kidney transplantation.

Study Objective: To identify predictors of persistent posttransplant anemia that appear within the first week after kidney transplantation in order to determine the high-risk patients who might receive the most benefit from erythropoiesis-stimulating agents.

Study Design: Retrospective cohort study.

Setting: University-affiliated hospital and outpatient clinic.

Patients: One hundred sixty-four adult kidney transplant recipients (January 1, 2002-June 30, 2007) with anemia on posttransplant day 7 who were followed at the clinic for at least 2 months after transplantation.

Measurements And Main Results: Data from deidentified electronic medical records of the kidney transplant recipients were collected and included demographic characteristics, primary cause of renal failure, pertinent laboratory data, and donor information. To detect early predictors of persistent anemia, patients with persistent posttransplant anemia, defined as a hemoglobin level below 11 g/dl for 2 months (day 60) after transplantation, were compared with those who had nonpersistent posttransplant anemia, defined as a hemoglobin level below 11 g/dl on day 7 but 11 g/dl or greater on day 60. Of the 164 patients classified as having anemia on posttransplant day 7, 39 (23.8%) had persistent posttransplant anemia on day 60. In univariate analyses, hemoglobin level of 9 g/dl or below on day 7, donor age younger than 10 years, and female sex were variables associated with increased risk of persistent posttransplant anemia. In a multivariate analysis, donor age younger than 10 years was the most significant predictor of persistent posttransplant anemia, followed by hemoglobin level of 9 g/dl or below.

Conclusion: Patients receiving transplants from donors younger than 10 years and those with hemoglobin levels of 9 g/dl or below on postoperative day 7 were found to be at highest risk for persistent posttransplant anemia and may receive the most benefit from early initiation of erythropoiesis-stimulating agent therapy. In most of the kidney transplant recipients, posttransplant anemia resolved without the use of these agents.