Third generation time-resolved immunofluorometric TSH assay for automatic immunoassay system evaluated

Abstract

We evaluated a new, third generation assay for serum thyrotropin (TSH) based on time-resolved fluorescence (AutoDelfia ®hTSH Ultra) for the 1235 AutoDelfia automatic immunoassay system. The functional sensitivity of the TSH assay was 0.007 mIU 1⁻¹ (between-assay CV, 20%). The between-assay imprecision was CV 4.1–7.7%, between TSH concentrations of 0.026 and 23.8 mIU 1⁻¹. The within-assay imprecision was CV 1.2–1.5% between TSH concentrations of 0.5 and 12 mIU 1⁻¹. The degree of agreement between the AutoDelfia hTSH Ultra assay and a second generation TSH-IRMA was studied. The mean difference was - 0.04 (SD 0.28) mIU 1⁻¹ at concentrations between 0.22 and 52 mIU 1⁻¹. Serum TSH concentrations of euthyroid subjects, hypothyroid and hyperthyroid patients as well as those of patients with non-thyroidal illness, and thyroid carcinoma patients with TSH suppressive thyroxine treatment were analysed. The AutoDelfia automatic immunoassay system offers many benefits in sensitivity, precision, speed, output rate, time and convenience. Overnight runs are possible, and the system is easy to operate.

Key Words:

• third generation TSH assay
• thyroid
• time-resolved fluorescence