Objectives: This study investigated the frequency of glomerular dysfunction in children with beta thalassaemia major (β-TM) by using different markers and correlating them with serum ferritin and iron chelation therapy.
Methods: The study, carried out between August 2011 and May 2012, included 100 patients with β-TM, in two groups. Group Ia (n = 62) received chelation therapy (deferoxamine). Group Ib (n = 38) received follow-up care at the Pediatric Hematology Outpatient Clinic, Minia University Children's Hospital, Egypt. Group II included 50 apparently healthy controls, age- and sex-matched to Group I. All patients underwent a thorough history-taking, clinical examination and laboratory investigations.
Results: Compared to Group II, Groups Ia and Ib had significantly higher levels of cystatin C, serum creatinine and serum ferritin, and a higher albumin/creatinine ratio in their urine, and a significantly lower estimated glomerular filtration rate (eGFR) and creatinine clearance (P <0.05). Moreover, Group Ia had a significantly lower eGFR and creatinine clearance than Group Ib. Cystatin C had a highly significant strong negative correlation with eGFR and creatinine clearance and a significantly strong positive correlation with serum ferritin, and a higher sensitivity and specificity than serum creatinine and creatinine clearance for small changes in GFR.
Conclusion: β-TM patients had a high frequency of glomerular dysfunction-possibly attributable to chronic anaemia, iron overload or chelation therapy. Periodic renal assessment is mandatory to detect renal complications. Cystatin C is a promising marker to monitor glomerular dysfunction, having a higher sensitivity and specificity than serum creatinine and creatinine clearance for small changes in GFR.
Keywords: Abnormalities, glomerular; Chelation Therapy; Cystatin C; Egypt; beta-Thalassemia.