The Frequency and Causes of Erythropoietin-Resistant Anemia in Children Under Dialysis

Anemia is common in chronic kidney disease (CKD). Erythropoietin is the standard treatment for anemia of CKD. We evaluated the frequency and etiologies of erythropoietin-resistant anemia in children under dialysis. A prospective study was conducted at a tertiary academic center from October to March 2020. Erythropoietin-resistant anemia was defined as not achieving target hemoglobin ≥ 11 gr/dl four and 6 months after receiving erythropoietin 300IU/kg/week. Sixty-one patients were enrolled; 49.2% were girls with a median age of 9 years and 4 months. The median time from placement on dialysis was 20.9 months. They consisted of hemodialysis (47.5%) and peritoneal dialysis (52.5%) patients. Erythropoietin (EPO)-resistant anemia was reported in the fourth and sixth months of treatment in 43.1% and 42.85% cases, respectively. The most identified causes in the fourth month of the study were iron deficiency, hyperparathyroidism (each in 36%), drugs (24%), and infections (20%). In the sixth month of the study, iron deficiency (57.15%), hyperparathyroidism (19.04%), and drugs (14.3%) were the most commonly identified etiologies. Age, duration placed on dialysis, gender, and modality of dialysis did not significantly correlate with erythropoietin-resistant anemia (P > 0.05 for all). Mean serum urea and median parathyroid hormone (PTH) levels were significantly higher in cases with EPO-resistant versus EPO-deficient anemia (P = 0.026 and 0.049, respectively). Erythropoietin-resistant anemia was common in children under dialysis. Iron deficiency, hyperparathyroidism, and infections were the main identified etiologies. We found a significant correlation between serum urea and PTH levels with EPO-resistant anemia.