Camilo Fuentes Peña, María Cecilia Opazo, Luis Méndez, Claudia Riedel, Bernard Hauquier, Lionel Marcelis, Frederic Cotton, Rodrigo Moreno-Reyes
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引用次数: 0
Abstract
Background: Thyroglobulin (Tg) is a biomarker of iodine status. Newborn Tg is a more sensitive marker than neonatal TSH in detecting variations in iodine intake. This study aims to validate a Tg enzyme-linked immunosorbent assay (ELISA) for Tg determination on dried blood spots (DBS) in newborns. This study also set out to assess the stability of Tg and the influence of newborns' hematocrit on Tg determination.
Methods: A commercially available ELISA Tg assay was adapted for use on DBS. DBS-Tg in cord blood were measured in 209 newborns delivered from healthy euthyroid pregnant women. Sensitivity, linearity, repeatability, and intermediate fidelity were determined using the appropriate standards and quality control materials.
Results: The limit of detection (LoD) of the DBS-Tg assay was 2.4 µg/L, and the limit of quantification (LoQ) was 5.8 µg/L. Repeatability and intermediate fidelity were 7.7-8.3% and 11.0-11.2%, respectively. The median cord plasma Tg and DBS-Tg values in newborns were not significantly different, 30.2 (21.3-44.4) µg/L and 31.6 (19.3-48.7) µg/L (p=0.48) with the ELISA respectively, and 76.5 (40.0-101.5) µg/L with the Elecsys assay with an R=0.88. DBS-Tg concentrations decrease with increasing hematocrit values (p<0.05). DBS-Tg values were stable at a concentration of 25 µg/L for 12 months at -20ºC and 4ºC.
Conclusion: This DBS-Tg assay demonstrated good analytical performances over a wide range of Tg concentrations, suggesting it is well suited to detecting variations in Tg concentrations. Studies comparing populations with different prevalence of anemia should consider the effect of hematocrit on DBS-Tg determination. The availability of a DBS-Tg assay for newborns makes it possible to integrate iodine status monitoring with newborn screening for inherited metabolic diseases.
期刊介绍:
The ''European Thyroid Journal'' publishes papers reporting original research in basic, translational and clinical thyroidology. Original contributions cover all aspects of the field, from molecular and cellular biology to immunology and biochemistry, from physiology to pathology, and from pediatric to adult thyroid diseases with a special focus on thyroid cancer. Readers also benefit from reviews by noted experts, which highlight especially active areas of current research. The journal will further publish formal guidelines in the field, produced and endorsed by the European Thyroid Association.