Comparison of different chemiluminecence immunoassay analyzers for determination of serum thyroid stimulating hormone in patients with suspicious subclinical hypothyroidism / 中华核医学与分子影像杂志

ABSTRACT

Objective To evaluate the differences of serum TSH of suspicious subclinical hypothyroidism determined by four automatic biochemical analyzers and the impact on clinical diagnosis and treatment.Methods Taking results of Roche Cobas e601 laboratory test as a reference, 103 serum samples with TSH 2.50-10.00 mU/L(90 with TSH≥4.27 mU/L) and normal FT3, FT4 were selected.Four different automatic biochemical analyzers (Cobas e601, Immulite2000, Centaur XP, I2000) were used to measure TSH of the serum samples at the same time.Wilcoxon signed rank test, Spearman correlation analysis were used for data analysis.Results TSH (M(P25, P75)) measured by 4 methods were 5.20(4.73, 6.40), 2.95(2.59, 3.48), 3.30(2.94, 4.15) and 4.10(3.43, 4.75) mU/L, which varied significantly from one assay to another (z values-8.78,-8.41,-7.64,-8.09,-8.50, all P<0.05).The correlations between methods were of great differences (rs ranged from 0.45 to 0.92).Significant differences existed in each other for subclinical hypothyroidism diagnosis based on TSH cutoff respectively.Conclusion Results from different automatic immunoassay analyzers in patients with TSH of 2.50-10.00 mU/L varied widely, hence, it is indeterminate to diagnose subclinical hypothyroidism only relies on a single serum TSH test.