Assessment of human thyroid function using radioimmunoassay and enzyme-linkedimmuno- sorbent-assay

Thyroid function has been evaluated using Radioimmunoassay (RIA) and enzyme-linked-immuno-sorbent-assay (ELISA) techniques as a comparative study to determine the accuracy, sensitivity and specificity in addition to correlation with body mass index (BMI). For triiodothyronine (T3) measured by RIA, relatively ELISA showed sensitivity, specificity and accuracy of 93.8%, 100% and 99.1% respectively and for thyroxin (T4), ELISA showed sensitivity, specificity and accuracy of 79.3%, 89.4% and 86.8% respectively. And for thyroid-stimulating hormone (TSH) ELISA showed a sensitivity, specificity and accuracy of 72.4%, 90.6% and 86% respectively and relative to RIA technique which is considered as standard goal. And for compensating the ELISA results to be same as RIA the following coefficient 0.72, 6.8 and 0.23 for T3, T4 and TSH respectively could be used. Also there is inverse linear relationship between the BMI and T3 and T4 using ELISA whereas the amount of T3 and T4 decreases by 0.006 nmol/kg/m2 and 0.051nmol/kg/m2 respectively. But TSH shows a direct linear relationship with BMI where TSH slightly increased by 0.007nmol/kg/m2. J. Exp. Clin. Med., 2013; 30:317-321