RENAL TUBULAR FUNCTION IN BETA-THALASSEMIA

Studies of the renal involvement in thalassemic syndromes have been va ried and few. This study was designed to define the renal abnormalitie s associated with beta-thalassemia and to correlate the renal findings with clinical parameters. One hundred and four beta-thalassemic child ren with various disease severity were studied. The patients were divi ded into three groups: 48 with severe anemia [hematocrit(Hct) <25%], 3 1 on a hypertransfusion program and desferrioxamine treatment, and 25 with moderate anemia (Hct > 25%). The results were compared with 15 no rmal children. Significantly higher levels of proteinuria and low mole cular weight proteinuria were found in all patients compared with norm al children. Aminoaciduria was detected in one-third of patients. Thal assemic patients had significantly lower morning urine osmolarity, hig her urine N-acetyl-beta-D-glucoseminidase and malondialdehyde (MDA, an indicator of lipid peroxidation). Patients with severe anemia had sig nificantly higher low-molecular weight proteinuria and MDA, and lower confirmed the high frequency of renal abnormalities in beta-thalassemi a patients and indicated some degree of proximal tubular dysfunction. Severity of the abnormalities correlated with the degree of anemia and were least severe in patients on hypertransfusion and desferrioxamine therapy. This suggested that the damage might be caused by anemia and increased oxidation induced by excess iron deposits.