Serum β2-microglobulin as a marker of renal tubular damage in transfusion-dependent β-thalassemia

Background: β-thalassemia major is a hereditary disorder characterized by transfusion-dependent anemia and associated complications. In patients with β-thalassemia major, one of the long-term complications of regular blood transfusion is renal dysfunction. This study aimed to evaluate serum β2-microglobulin as a marker of the severity of renal tubular dysfunction and to examine the clinical factors associated with the severity of renal tubular dysfunction in children with β-thalassemia major. Methods: This cross-sectional analytical study was conducted on 134 non-diabetic children with β-thalassemia major who attended thalassemia centers in Mazandaran Province, Iran. Data were collected using a structured checklist that included demographic information, laboratory findings, and clinical parameters. The severity of renal tubular dysfunction was assessed using serum β2-microglobulin levels. Glomerular filtration rate was estimated using the revised Schwartz formula. Pearson correlation analysis was used for statistical analysis. Results: A significant positive correlation was observed between β2-microglobulin levels and age (r = 0.311, p < 0.001), number of blood transfusions per year (r = 0.390, p < 0.001), serum creatinine (r = 0.732, p < 0.001), blood urea nitrogen (r = 0.715, p < 0.001), and serum ferritin (r = 0.505, p < 0.001). In contrast, significant negative correlations were found with serum hemoglobin (r = −0.433, p < 0.001) and creatinine clearance (r = −0.383, p < 0.001). Conclusion: Renal tubular dysfunction in children with β-thalassemia major showed significant correlations with age, iron overload, anemia severity, and transfusion frequency. Serum β2-microglobulin may serve as a useful marker for the early detection of tubular damage and may help guide preventive strategies in clinical practice.