Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 47 6 2009 12 15 443 446 EN Afshin Safaei asl Department of Pediatrics, School of Medicine, Guilan University of Medical Sciences, Guilan, Iran. Shohreh Maleknejad Department of Pediatrics, School of Medicine, Guilan University of Medical Sciences, Guilan, Iran. Abtin Heidarzadeh Department of Pediatrics, School of Medicine, Guilan University of Medical Sciences, Guilan, Iran. Yazdan Ghandi Department of Pediatrics, School of Medicine, Guilan University of Medical Sciences, Guilan, Iran. 2015 09 28 To find if some indices have predictive value for renal complications. We conducted a cross sectional and included 80 patients with the age ranged 5-17 years, all with the proven diagnosis of β-thalassemia major. A urine and 5 ml of blood sample were obtained from all of the cases. Biochemical indices such as serum levels of creatinine, Na, Mg, Hb, and ferritin and also urine levels of Na, Mg, creatinine and β2 microglobulin was measured. All data analysis was performed using SPSS 14.0. P-Spearman test was applied to assess correlation between urine beta-2-microglobulin and other variables. Patients GFR was in normal range. Abnormal level of urine β2 microglobulin was reported in 44 patients (55%). P Spearman test proved correlation only between urine β2 microglobulin and FE-Mg. We concluded that renal proximal tubular dysfunction may oocur in children with β thalassemia major without clinical manifestations of renal dysfunction or decrease in GFR. We warn not to rely only on GFR as a early indicator for renal complications among children with β thalassemia major. https://acta.tums.ac.ir/index.php/acta/article/view/3625 https://acta.tums.ac.ir/index.php/acta/article/download/3625/3601