Comparison of the Performance of Second (Fast TSH) and Third (HYPERsensitive TSH) Generation Automated TSH Immunoassays in Healthy Euthyroid Subjects

Abstract

Objective: We aimed to compare the performances of HYPERsensitive and Fast thyroid-stimulating hormone (TSH) methods in euthyroid subjects. Materials and Methods: The study included 500 euthyroid subjects. We measured the TSH levels of study subjects using HYPERsensitive and Fast TSH methods. We compared the performances of the two methods. Moreover, free triiodothyronine and thyroxine, anti-thyroglobulin, and anti-thyroperoxidase levels were determined in study subjects. Results: Mean serum TSH levels were determined as 1.76 +/- 1.06 and 1.85 +/- 1.12 mu IU/mL using Fast and HYPERsensitive TSH methods, respectively. Differences were statistically significant (p<0.05). We found a positive correlation between Fast and HYPERsensitive TSH methods (r=0.960, p<0.001). Conclusion: Although the sensitivity and precision of HYPERsensitive TSH method is better than that of Fast TSH method, the Fast TSH method needs lower sample volume, and the reaction time is shorter than that in HYPERsensitive TSH method. Thus, clinical biochemistry laboratories should select an appropriate method according to their requirements.