Renal tubular function in patients with beta-thalassaemia major in Zahedan, southeast Iran

In patients with beta-thalassaemia major, impaired biosynthesis of the beta-globin leads to accumulation of unpaired alpha-globin chain. Shortened red cell lifespan and iron overload cause functional and physiological abnormalities in various organ systems. Thus, in patients with beta-thalassaemia major, the most important cause of mortality and morbidity is organ failure due to deposits of iron. The aim of this study is to investigate renal tubular and glomerular functions in patients with beta-thalassaemia major.

166 subjects with beta-thalassaemia major (96 male, 70 female) were enrolled in the study. Fasting blood and 24-hour urine samples were obtained for haematological and biochemical analyses.

Patients with beta-thalassaemia major showed significant signs of renal tubulopathy, such as hypercalciuria (12.9 percent), proteinuria (8.6 percent), phosphaturia (9.2 percent), magnesiumuria (8.6 percent), hyperuricosuria (38 percent) and excretion of beta-2 microglobin (13.5 percent). We found that 95.1 percent of patients had iron overload (ferritin more than 1,000 ng/ml).

The determination of biochemical indices of renal function might help prevention of serious kidney damage before any clinical symptom is observed. Beta-thalassaemia patients present multiple renal abnormalities which may be due to iron overload. We suggest the appropriate chelation therapy and regular monitoring of the status of iron overload.