关键词: 先天性甲状腺功能减低症, 促甲状腺素, 全自动荧光免疫分析仪, 切值, 河南地区

Abstract: Objective To evaluate the feasibility of genetic screening processor(GSP) applied in the screening for congenital hypothyroidism(CH) in newborns by detecting thyroxine stimulating hormone(TSH) in blood, and to establish the cut-off value of TSH in screening for CH in newborns in Henan province.  Methods 1) The precision and accuracy of GSP were calculated by detecting the dired blood spots specimen of Centers for Disease Control and Prevention. The linear sample of 6 concentration gradient specimens was tested to calculate the linearity of GSP. 2) The samples of 1 273 newborns were tested by both Victor₂D 1420 and GSP, and the consistency of the two Methods was analyzed by paired t test. 3) The neonatal heel blood samples were collected and the TSH in the dried-blood spots was detected using the Perkin Elmer GSP test kit. TSH cut-off value was determined by the percentile method and the receiver operating characteristic(ROC) curve method. Results 1) The within-run coefficient of variation of GSP screening system was 4.32%—5.87%. The between-run variation was 4.45%—9.08%, which were less than 1/3 of the total error(TEa). The bias detected by the GSP system was -7.89%—0.12%, less than 1/2 TEa. The linear equation for observed TSH value by expected value was y=0.908x-0.915, and the correlation coefficient(R²) was 0.998. 2) The difference on TSH level in 1 273 neonatal samples detected by GSP and Victor₂D 1420 was statistically significant(t=7.764, P<0.01). 3) The cut-off value of TSH determined by percentile method of 99% confidence interval was 6.1 μU/ml and it was 6.45 μU/ml by the ROC curve method. Conclusion The quantitative performance of the GSP system can meet the laboratory requirements, and it is proved to be a feasible method for neonatal CH screening. However, the cut-off value of TSH needs to be reset to 6.1 μU /ml.

Key words: congenital hypothyroidism, thyroid stimulating hormone, genetic screening processor, cut-off value, Henan province