Effect of specimen storage conditions on newborn dried blood spots used to assess Toxoplasma gondii immunoglobulin M (IgM).

Author(s): Mei JV, Li L, Rasmussen SA, Collier S, Frias JL, Honein MA, Shaw GM, Lorey F, Meyer R, Chaing S, Canfield MA, Jones J, Hannon WH

Publication: Clin Chim Acta, 2011, Vol. 412, Page 455-9

PubMed ID: 21114968 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of storage temperature and conditions on the measurement of newborn screening biomarkers in DBS.

   Summary of Findings:

   The authors report that many DBS specimens stored without desiccant at ambient temperatures were difficult to elute into the assay buffer, while all specimens stored with desiccant at -20 degrees C eluted completely. Although no Toxo-IgM positive specimens were found among those stored at ambient temperatures without desiccant, the background levels of Toxo-IgM in these specimens were significantly higher than background levels seen in Toxo-IgM negative specimens stored at -20 degrees C with desiccant (p<0.0001). In addition, the levels of thyroid-stimulating hormone, phenylalanine, leucine, methionine, tyrosine, valine, and citrulline were significantly lower in DBS stored at ambient temperatures without desiccant when compared to those stored at -20 degrees C with desiccant.

   Biospecimens

   • Bodily Fluid - Blood

   Preservative Types

   • Other Preservative

   Diagnoses:

   • Normal
   • Other diagnoses

   Platform:

   Analyte	Technology Platform
   Glycoprotein	Immunoassay
   Small molecule	MS/MS

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Preaquisition	Diagnosis/ patient condition	Hydrocephalus
   Preaquisition	Patient age	Infant
   Immunoassay Specific	Targeted peptide/protein	Toxo-specific IgM Thyroid-stimulating hormone
   Storage	Storage temperature	-20 degrees C Ambient temperature (-1 to 40 degrees C)
   Storage	Storage conditions	With desiccant No desiccant
   Storage	Storage duration	3-5 y 4-5 y 5-13 y

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2. Study Purpose

   The purpose of this study was to determine the effects of storage duration on the stability of Toxo-specific IgM in DBS.

   Summary of Findings:

   Toxo-specific IgM was stable for at least two years when high-titre DBS were stored at -20 degrees C with desiccant.

   Biospecimens

   • Bodily Fluid - Blood

   Preservative Types

   • Other Preservative

   Diagnoses:

   • Other diagnoses

   Platform:

   Analyte	Technology Platform
   Glycoprotein	Immunoassay

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Preaquisition	Diagnosis/ patient condition	Exposed to T. gondii
   Immunoassay Specific	Targeted peptide/protein	Toxo-specific IgM
   Storage	Storage temperature	-20 degrees C
   Storage	Storage conditions	With desiccant
   Storage	Storage duration	0-125 weeks

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