Cystatin C and Beta 2 Microglobulin as Biochemical Markers for Early Detection of Renal Impairment in Children With Beta Thalassemia

Thalassemia syndromes are the most common single gene disorders worldwide especially in developing countries. The use of regular and frequent blood transfusions in patients with beta thalassemia major has improved patients' life spans and quality of life, but can lead to chronic iron overload. Many factors contribute to the functional abnormalities found in beta thalassemia patients such as decreased red cell life span, rapid iron turnover, tissue deposition of excess iron and also, specific iron chelators can affect kidneys. The success in management of patients of beta thalassemia has led to chronic hemosiderosis in different organs like liver and heart and long-term complications in other organs like pancreas and kidneys have recently been studied. The evidence of proximal tubular damage has been observed in beta thalassemia patients. Also, low-molecular-weight proteinuria has been found in almost all patients. Unlike other organs, it is unclear whether kidney damage results solely from intravascular haemolysis, chronic transfusion or as a complication of iron chelation therapy. Although the early identification of patients at high risk of renal impairment is of great importance as it may allow specific measures to be taken to delay renal impairment, there are limited studies about renal dysfunction in pediatric thalassemic patients. Thus, in this study we will use different measurements for early detection of renal impairment even if the patients have no symptoms to handle with the disease in its reversible stage before being irreversible. Beside the usual investigations of renal function we will measure cystatin c and beta2 microglobulin as early markers of renal impairment.