The phenomenon of hemoglobin variability with erythropoiesis stimulating agents in renal transplant patients.

Treatment with erythropoiesis-stimulating agents (ESA) is often associated with fluctuation in hemoglobin (Hb) levels that has been considered a factor that influences morbidity/mortality in hemodialysis patients. Our aim was to describe the hemoglobin variability during ESA treatment and to study associated factors in kidney transplants. Hb variability (defined as fluctuations of Hb ± 1.5 g/dl) was assessed in 85 renal transplant patients treated with ESA for at least 3 months and with a minimum of 6 Hb measurements along 1 year. 58% of patients experienced Hb variability during follow-up. Although 71.3% of patients maintained Hb levels greater than 11 g/dl along the whole follow-up, only 3% of patients maintained stable Hb levels within the target range all the time (11 ― 13 g/dl). By multivariate analysis, clinical factors associated with variability were changes in ESA dose (RR 2.92, p = 0.04), infectious events with hospitalization (RR 1.95, p = 0.03) and the use of sirolimus (RR 1.1, p < 0.05). Excluding dose changes and hospitalization in the analysis variability was an independent predictor of graft function deterioration. In conclusion, Hb variability is common in renal transplants treated with ESA. Only few patients maintained Hb levels in the therapeutic range (11 - 13 g/dl). Dose changes, inflammatory status and graft function deterioration are the determining factors.