Renal tubule function in beta-thalassemia after hematopoietic stem cell transplantation

Advances in hematopoietic stem cell transplantation (HSCT) for beta-thalassemia major make the long-term outcome of these patients very important. Few data on long-term renal function of thalassemia patients are available. We evaluated the renal function in children after successful allogeneic HSCT for beta-thalassemia. Twenty-nine patients were included; the mean age at HSCT was 4.9 years. Mean follow-up time was 7.6 years. After HSCT, two patients developed acute renal failure and two had graft versus host disease. At last follow up, height standard deviation score (SDS) remained the same, but weight SDS had improved. Mean hemoglobin was 12.5 g/dl, and serum ferritin level was 545 ng/ml. All children had normal estimated glomerular filtration rate (GFR). One patient had hypertension and proteinuria, 10 years after HSCT. When comparing 39 children of the same age with beta-thalassemia of similar disease severity but who had not experienced HSCT, we found that the parameters of renal tubule function were better in patients that had undergone HSCT, as demonstrated by urine protein level (0.36 mg/mg creatinine vs 3.03 mg/mg creatinine, P < 0.001), osmolality (712 mosmol/kg vs 573 mosmol/kg, P=0.006), N-acetyl-beta-D-glucosaminidase (17.7 U/g creatinine vs 42.9 U/g creatinine, P=0.045), and beta 2 microglobulin (0.09 mu g/mg creatinine vs 0.13 mu g/mg creatinine, P=0.029). This study showed a low incidence of long-term renal impairment after HSCT and indicated that renal tubule function may be better in beta-thalassemia patients after HSCT.