Increasing levels of hemoglobin improve renal transplantation outcomes

Several studies have reported various data on prevalence of posttransplant anemia (PTA). We have little information about its impact on long-term graft outcomes and few studies of the optimal hemoglobin (Hb) target in kidney transplantation.

We examined retrospectively 144 kidney transplant recipients of mean age 44.4 ± 12.3 years and follow-up of 40.5 ± 4.6 months. Exclusion criteria were age below 18 years, multiorgan transplantation, and graft failure in the first year. Using simple and multiple linear regression models, we evaluated the potential prediction of a serum concentration of Hb at 1 year after renal transplantation on allograft outcome as measured by Δ% estimated glomerular filtration rate (eGFR), the difference between eGFR, measured with the Modification of Diet in Renal Disease (MDRD) formula, at the end of follow-up, and at 1 year. Multiple models were adjusted for recipient sex, recipient age, donor age, ESA therapy, acute rejection episodes (ARE), days of delayed graft function, human leukocyte antigen mismatches and cold ischemia time.

At 1 year after transplantation, the mean Hb level was 13.77 ± 1.87 g/dL in males and 12.52 ± 1.53 g/dL in females. The average eGFR at 1 year was 63.07 ± 25.88 mL/min. At the end of follow-up, the mean Δ% eGFR was -5.73% ± 27.30%. Blood concentration of Hb correlated with donor, recipient sex, ARE, and eGFR at 1 year. There was a close correlation between the Δ% Hb and eGFR upon univariate analysis and the multiple linear regression model. Hb was the only predictor of transplant outcome.

Many factors are involved in kidney allograft function. Among these, Hb is important. In this work we demonstrated that increasing levels of Hb at 1 year after transplantation seemed to predict better preservation of graft function, representing a marker of a good quality graft.