Background: In "-thalassemia, profound anemia and severe hemosiderosis cause functional and physiological
abnormalities in various organ systems. In recent years, there have been few published studies mainly in adult
demonstrating renal involvement in "-thalassemia. This prospective study was aimed to investigate renal involvement
in pediatric patients with transfusion dependant beta-thalassemia major (TD-"TM), using both conventional and early
markers of glomerular and tubular dysfunctions, and to correlate findings to oxidative stress and iron chelation therapy.
Methods: Sixty-nine TD-"TM patients (aged 1-16 years) and 15 healthy controls (aged 3-14 years) were enrolled in this
study. Based on receiving chelation therapy (deferoxamine, DFO), patients were divided into two groups: group [I] with
chelation (n = 34) and group [II] without chelation (n = 35). Levels of creatinine (Cr), calcium (Ca), inorganic phosphorus
(PO4), uric acid (UA) and albumin were measured by spectrophotometer. Serum (S) levels of cystatin-C (SCysC) and total
antioxidant capacity (STAC) and urinary (U) levels of "2-microglobulin (U"2MG) were measured by immunosorbent assay
(ELISA). Urinary N-acetyl-beta-D-glucosaminidase (UNAG) activity and malondialdehyde (UMDA) were measured by
chemical methods. Estimated glomerular filtration rate (eGFR) was determined from serum creatinine.
Results: In patient with and without chelation, glomerular [elevated SCysC, SCr, Ualbumin/Cr and diminished eGFR]; and
tubular dysfunctions [elevated SUA, SPO4, UNAG/Cr, U"2MG/Cr] and oxidative stress marker disturbances [diminished STAC
and elevated UMDA/Cr] were reported than controls. In patients with chelation, SCysC was significantly higher while, STAC
was significantly lower than those without chelation. In all patients, SCysC showed significant positive correlation with
SCr and negative correlation with eGFR; STAC showed significant positive correlation with eGFR and negative correlation
with SCysC, SCr, UNAG/Cr; UMDA/Cr showed significant positive correlation with Ualbumin/Cr, U"2MG/Cr, UNAG/Cr.
Conclusions: Our data confirm high frequency of glomerular and tubular dysfunctions in TD-"TM pediatric patients
which could be attributed to oxidative stress and DFO therapy.