Urinary biomarkers of early kidney injury in children with beta-thalassemia

Beta-thalassemia is considered as one of the most common genetic disorders in the world caused by the reduced or absent synthesis of b-globin chain. The aim of this work was to evaluate renal function in children with b-thalassemia using predictive biomarkers such as urinary neutrophil gelatinase-associated lipocalin (NGAL) and N-acetyl-b-D-glycosaminidase (NAG). This prospective case–control study was carried out on 80 subjects aged between 3 and 17 years. The subjects were divided into two equal groups: thalassemia group which included 40 children with b-thalassemia major, and control group which included 40 age- and gender-matched healthy, non-anemic controls without any diseases that could potentially affect renal function, who underwent routine check-ups. All thalassemia patients received chelation therapy: 35 (87.5%) of them were treated with deferasirox and 5 (12.5%) patients received deferasirox + deferoxamine. The results of echocardiography, kidney function tests (serum creatinine, urea and estimated glomerular filtration rate as well as urinary albumin/creatinine ratio and urinary NGAL/urinary albumin–creatinine ratio were insignificantly different between the two groups. Abdominal ultrasound findings were significantly different between both groups. Total WBC counts, platelet counts, the results of liver function tests (total bilirubin, direct bilirubin, alanine transaminase and aspartate aminotransferase), urinary NAG/creatinine ratios, urinary NGAL/creatinine ratios and serum ferritin levels were significantly higher in the thalassemia group, while hemoglobin, urinary NAG/urinary albumin–creatinine ratios were significantly lower in this group. Urinary markers NGAL and NAG could be used as predictive markers of renal disease in b-thalassemia major patients. The study was initiated after obtaining approval from the Ethical Committee of Menoufia University Hospital. Informed written consent was obtained from the parents of the children involved in the study.