Elevated Selenoprotein P Levels in Thalassemia Major Patients

Previous studies have measured selenium levels and glutathione peroxidase 3 (GPX3) activity in patients with thalassemia major (TM). However, Selenoprotein P (SEPP), which is responsible for the storage and transport of selenium, has not been studied in thalassemia patients. This study aims to correlate thyroid functions of TM patients with their SEPP and GPX3 levels.

Eighty subjects (40 controls, 40 TM patients) were included in this study. GPX3 and SEPP concentrations were measured in all subjects using sandwich ELISA. Iron, ferritin, urinary iodine, thyroxine (T₄), triiodothyronine (T₃), thyrotropin (TSH), anti-thyroid peroxidase (anti-TPO), and anti-human thyroglobulin (anti-hTG) concentrations were also measured.

Mean SEPP concentration was higher in the TM group compared to the control group. A slight elevation in GPX3 levels was also observed in thalassemia patients, yet it was not statistically significant. In both TM patients and controls, ferritin was inversely correlated with free T₄ concentration and GPX3 was inversely correlated with free T₄ and T₃ concentrations. There was also a negative correlation between SEPP and TSH concentrations in healthy subjects.

This is the first study, which has measured SEPP concentrations in thalassemia patients. SEPP levels were higher in TM patients compared to controls. Correlations between thyroid hormones and selenoproteins may indicate that selenium is necessary for thyroid function. Detailed studies are required to elaborate the role of SEPP in thyroid metabolism in thalassemia patients.