Renal Function and the oxidative status among children with thalassemia major and healthy controls: a cross-sectional study

Abstract Background Renal dysfunction is an underestimated complication of thalassemia major. Objectives The aim of this study is to compare the glomerular and tubular functions in children with β- Thalassemia major (β- TM) with healthy controls and assess the oxidative stress caused by high ferritin levels. Design and setting This prospective cross-sectional study was conducted in tertiary care hospital. Methods Complete blood count (CBC), calcium (Ca), urea, creatinine (Cr), serum cystatin C before transfusion and urinary calcium (uCa), creatinine (uCr), protein (UPr) levels were analyzed in fresh samples. Beta-2-microglobulin (uβ2-MG), N- acetylglucosaminidase (uNAG), retinol binding protein (uRBP), malonedialdehyde (uMDA) secretion and creatinine levels were analyzed. Serum total antioxidant capacity (sTAC) and total oxidant capacity (sTOC) were measured with colorimetric micro-ELISA method. Last four serum ferritin values were recorded and the mean value was used for statistical analyzes. Results Data from 47 patients and 32 controls were analyzed. The urinary RBP/Cr, Ca/Cr and Protein/Cr, were significantly higher in β-TM group. A statistically insignificant increase in urinary β2MG/Cr, uNAG/Cr, MDA/Cr was also found in the TM group. Proteinuria was present in 46% (n: 22) and hypercalciuria in 34% (n: 16) of the patients with β- TM. Serum total antioxidant capacity and total oxidant status (TOS) levels were significantly elevated in the patient group. Serum ferritin was significantly correlated with proteinuria, cystatin C levels, urinary Protein/Cr and uRBP/Cr. Conclusion Asymptomatic renal dysfunction is prevalent in β- TM patients that necessitate regular screening. Urinary RBP may be useful for early diagnosis.