Assessment of thyroid dysfunction in patients with ß- thalassemia major

The thalassemia is belived to be the most prevalent of all human genetic diseases and caused by mutations of the synthesis of hemoglobin.Regular blood transfusions are necessary in major thalassemia patients. The combination of transfusion and chelation therpy has dramatically extended the life expectancy of thalassemic patients but an important complication is iron overload in different organs of the body. Despite improved hematologic care in recent years, in these patients primary hypothyroidism and other endocrine disorders due to iron overload are still common complication and affect the patient's quality of life. The aim of this study was to identify the prevalence of thyroid dysfunction and to determine its correlation with ferritin plasma level, amount of blood transfused and liver function in thalassemic patients. In this cross sectional study, fourty patients with beta thalassemia (20 males and 20 females; mean age, 12.7 ± 5.8 yrs) were evaluated. Serum ferritin levels, SGOT, SGPT were evaluated by ELISA method and TSH were evaluated byIRMA. Hypothyroid index was defined according to the criteria of Kronberg et al. Normal thyroid hormone values were found in 34 patients (85%) and 6 (15%) had subclinical hypothyroidism. Mean ferritin levels in hypothyroid and normal patients were2220 ± 1056 mg/l and 2028 ± 1548 mg/l respectively, (p= 0.2). Thyroid dysfunction could not be correlated with amount of blood transfused, liver function or ferritin plasma level. The high rate of thyroid dysfunction may be the result of poor disease control and manegment in early life when irreversible tissue damage ocuures due to iron overload and chronic hypoxia, and indicates the importance of regular follow-up of beta thalassemia patients for early detection and manegment of associated complications.