An automated chemiluminescence assay (Immulite 2000sr; Abbott, Shanghai, China) was used to evaluate the thyroid function profile, including TT3, TT4, fT3, fT4, TSH, TgAb, and TPOAb, immediately after sampling at the central laboratory of the Sichuan Provincial People’s hospital under routine external quality control. Based on data showing an analytical sensitivity of 0.0025 IU/ml for TSH, 1.5 pg/ml for fT3, and 0.22 ng/dl for fT4, the test was given regulatory approval. The intra- and inter-assay coefficients of variance were 5% and 10%, respectively, across all assays. TSH 0.35-4.94 mIU/l, fT3 2.43-6.01 pmol/l, fT4 9.01-19.05 pmol/l, TT3 (0.88-2.44nmol/L), and TT4 (62.68-150.8nmol/L) are the reference ranges used in our lab. TPOAb has a 30 IU/mL upper limit, while TgAb has a 75 IU/mL upper limit.
The presence of both a normal serum TSH level (0.35–4.94 mIU/L) and a serum T3 level below the lowest laboratory normal limit (0.88nmol/L) was used to diagnose ESS (16 (link)).
The presence of both a normal serum TSH level (0.35–4.94 mIU/L) and a serum T3 level below the lowest laboratory normal limit (0.88nmol/L) was used to diagnose ESS (16 (link)).