The effect of freezing, thawing, and short- and long-term storage on serum thyrotropin, thyroid hormones, and thyroid autoantibodies: implications for analyzing samples stored in serum banks.

Author(s): Männistö T, Surcel HM, Bloigu A, Ruokonen A, Hartikainen AL, Järvelin MR, Pouta A, Vääräsmäki M, Suvanto-Luukkonen E

Publication: Clin Chem, 2007, Vol. 53, Page 1986-7

PubMed ID: 17954505 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   This study assessed the stability of thyroid hormones (T3, T4), thyroid-stimulating hormone (TSH), thyroid autoantibodies (TPO-Ab), and thyroglobulin antibody (TG-Ab) after short-term refrigerated storage, as well as among fresh and frozen serum specimens.

   Summary of Findings:

   T3, T4, TSH, and TPO-Ab did not vary significantly with refrigerated storage of serum specimens for up to 6 days. When fresh and frozen serum specimens were compared, T3 alone differed significantly, with higher concentrations observed among frozen specimens.

   Biospecimens

   • Bodily Fluid - Serum

   Preservative Types

   • None (Fresh)
   • Other Preservative
   • Frozen

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Glycoprotein	Clinical chemistry/auto analyzer
   Peptide	Clinical chemistry/auto analyzer
   Protein	Clinical chemistry/auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage temperature	4 degrees C
   Storage	Storage duration	0 d 1 d 3 d 6 d
   Biospecimen Preservation	Type of fixation/preservation	Frozen None (fresh) Refrigeration

   View more

2. Study Purpose

   This study assessed the stability of thyroid hormones (T3, T4), thyroid-stimulating hormone (TSH), thyroid autoantibodies (TPO-Ab), and thyroglobulin antibody (TG-Ab) after long-term frozen storage (6 mon-23 y) of serum specimens.

   Summary of Findings:

   Serum T4 levels differed significantly in specimens stored at -25 degrees C for 10, 12, and 20-23 years when compared to 6 month controls, although no difference was observed among controls and specimens stored from 14-18 years. Further, linear regression analysis revealed that only 5.5% of total T4 variation was attributable to storage duration. TPO-Ab and TG-Ab increased significantly after more than 2 or 6 years of storage, respectively.

   Biospecimens

   • Bodily Fluid - Serum

   Preservative Types

   • Frozen

   Diagnoses:

   • Not specified

   Platform:

   Analyte	Technology Platform
   Glycoprotein	Clinical chemistry/auto analyzer
   Peptide	Clinical chemistry/auto analyzer
   Protein	Clinical chemistry/auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage temperature	-25 degrees C
   Storage	Storage duration	6 mon 2-23 y

   View more