Comparison of fluorescent immunoassay (FIA) and electrochemiluminescence immunoassay (ECLIA) for the measurement of serum TSH in congenital hypothyroid screening

This study aimed to compare the serum thyroid-stimulating hormone (TSH) measurement using fluorescent immunoassay (FIA) and electrochemiluminescence immunoassay (ECLIA) for CH screening. CH is not yet regularly screened since the gold standard methods for measuring TSH in newborns (i.e., enzyme-linked immunosorbent assay (ELISA) and fluorescence enzyme  immunoassay (FEIA)) are high-cost or difficult to perform in remote areas. A cross-sectional study was conducted. Serum samples were consecutively taken from newborns aged 2–7 days in January–April 2018. Serum TSH was measured simultaneously by FIA (FREND™ TSH) and ECLIA (Cobas e411 Roche) methods. Comparison and correlation analysis were performed. Of 95 samples, no significant proportion differences of high TSH levels measured by FIA compared to ECLIA were detected. A strong correlation of TSH levels measured by FIA and ECLIA was found (r = 0.971). Three neonates were found to have high levels of TSH. The maximum detection limit of the FIA method was 25.0 mIU/L. This study demonstrated a comparable TSH measurement between FIA (FREND™ TSH) and ECLIA (Cobas e411) methods and a strong correlation between those methods. TSH measur ement using the FIA method can be used in CH screening.
Source: Comparative Clinical Pathology - Category: Pathology Source Type: research