Study of uric acid excretion in children with beta-thalassemia major attending Alexandria University Children’s Hospital

Background It is evident that high cell turnover rate is present in patients suffering from β-thalassemia. This is mainly the result of not only chronic hemolysis but also ineffective erythropoiesis. It is thus expected that hyperuricemia will occur. Aim Our study was conducted to study uric acid excretion in β-thalassemia major patients and to determine its relationship to tubular dysfunction in those patients. Patients and methods This case–control study was performed on 60 patients with β-thalassemia major and 15 children who were healthy and well, playing the role of the control group. Thorough history taking, review of medical records, and complete physical examination were done for all patients. Evaluation of uric acid excretion, glomerular and tubular renal functions were performed and compared between patients and the control group. Results Hyperuricemia was found in 48.8% of patients; however, none of the patients had evidence of gouty arthritis or nephrolithiasis. Serum uric acid (SUA) levels in patients who had positive correlation with serum creatinine, urine P/Cr ratio and urine uric acid/glomerular filtration rate (UUA/GFR), negative correlation with eGFR and no correlation with urine calcium/creatinine (UCa/UCr) ratio, blood urea nitrogen (BUN), urine β2 MG, and urinary uric acid/creatinine (UUa/UCr) ratio were assessed. The mean SUA level, BUN, serum creatinine, and levels of eGFR were significantly higher in β-thalassemia patients in comparison to the control group. Urinary P/Cr ratio, urine uric acid/ glomerular filtration rate (UUA/GFR) ratio, β-2 microglobulin levels, UCa/UCr, and UUa/UCr were also higher in β-thalassemia patients in comparison to the control group. The present study has a mean age of 8.62 years for the cases studied, and investigations in patients revealed the following results: mean SUA 5.17 mg/dl, mean BUN 16.58 mg/dl, mean serum creatinine 0.49 mg/dl, mean urine P/Cr ratio 1.40, mean eGFR 141.42 ml/min/1.73 m2, mean UUA/GFR 0.55, mean urine β2 MG 0.18 µg/ml, mean UCa/UCr 0.44, UUa/UCr 1.46, and these results were statistically significantly higher in patients compared with controls. Conclusion Renal dysfunction and hyperuricemia are prevalent among patients with β-thalassemia major, mostly related to hyperfiltration and tubular dysfunction. Early markers of tubular dysfunction (urine β2 MG, UCa/UCr, UUa/UCr) and glomerular dysfunction (urine P/Cr ratio and urinary uric acid/GFR ratio) should be followed up regularly in β-thalassemia major patients.