Stability of selected serum hormones and lipids after long-term storage in the Janus Serum Bank.
Author(s): Gislefoss RE, Grimsrud TK, Mørkrid L
Publication: Clin Biochem, 2015, Vol. 48, Page 364-9
PubMed ID: 25523301 PubMed Review Paper? No
Purpose of Paper
The purpose of this paper was to determine the effects of long-term storage of serum at -25°C on measured levels of sodium, total cholesterol, high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), apolipoprotein A1 (apo-A1), apolipoprotein B (Apo-B), follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), thyroid stimulating hormone (TSH) and free thyroxin (FT4).
Conclusion of Paper
ANOVA analysis showed significant variation in all analytes measured, except FSH, after long term storage of serum. However, pairwise comparisons did not identify differences in the levels of total cholesterol, FSH, LH and TSH among specimens stored for 0 years and those stored for 4, 17 or 29 years. Compared to specimens stored for 0 years, specimens stored for 27 years had higher levels of Apo-A1, Apo-B, LDLC, and sodium and lower levels of HDLC and PRL. While FT4 levels were not significantly different between specimens stored for 0 and 29 years, they were significantly higher in specimens stored for 4 or 17 years than those stored for 0 years. Apo-A1 levels were correlated with HDLC levels, and Apo-B levels were correlated with LDLC levels at all time-points, but the correlations, especially those between Apo-A1 and HDLC levels, weakened with storage.
Studies
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Study Purpose
The purpose of this study was to determine the effects of up to 27 years of storage of serum at -25°C on measured levels of sodium, total cholesterol, HDLC, LDLC, Apo-A1, Apo-B, FSH, LH, PRL, TSH and FT4. Serum from 520 men (130 men/timepoint) was stored at -25°C for 0, 4, 17 or 29 years before analysis. Specimens were from the Janus serum bank which includes specimens used for cardiovascular risk screening as well as blood donor specimens.
Summary of Findings:
ANOVA analysis showed significant variation in all analytes except FSH. Compared to serum stored for 0 years, serum stored for 4 years had significantly higher Apo-A1 (9.5%, p<0.0001) and FT4 levels (8%, p<0.001) and lower HDLC (-32.6%, p<0.001) and PRL levels (-11.4%, p=0.0127), and the changes in Apo-A1, FT4, and HDLC levels exceeded 25% of the biological variation (Bmax). In addition to the aforementioned differences, serum stored for 17 years had higher Apo-B (27.1%, p<0.001) and LDLC levels (18.5%, p<0.001) than serum stored for 0 years, and all differences, including those in PRL levels, exceeded Bmax. Serum stored for 29 years had higher sodium levels than those measured in serum stored for 0 years (4.1%, p<0.001), but unlike serum stored for 4 or 17 years, specimens stored for 29 years did not have significantly higher FT4, though the increase in FT4 still exceeded Bmax. Pairwise comparisons did not find the levels of total cholesterol, FSH, LH and TSH to be significantly different among specimens stored for 0, 4, 17 or 29 years, but differences in TSH, LH, and cholesterol exceeded Bmax for some time-points. Apo-A1 levels were correlated with HDLC levels (r=0.291-0.876, p<0.001), and Apo-B levels were correlated with LDLC levels (r=0.693-0.880, p<0.001) at all time-points, but the correlations, especially those between Apo-A1 and HDLC, weakened with storage.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Normal
- Not specified
Platform:
Analyte Technology Platform Lipoprotein Clinical chemistry/auto analyzer Lipid Clinical chemistry/auto analyzer Electrolyte/Metal Clinical chemistry/auto analyzer Glycoprotein Clinical chemistry/auto analyzer Steroid Clinical chemistry/auto analyzer Peptide Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage duration 0 years
4 years
17 years
29 years