scholarly journals Long-Term Stability of Amino Acids and Acylcarnitines in Dried Blood Spots

2007 ◽  
Vol 53 (4) ◽  
pp. 717-722 ◽  
Author(s):  
Kristina Anna Strnadová ◽  
Margareta Holub ◽  
Adolf Mühl ◽  
Georg Heinze ◽  
Rene Ratschmann ◽  
...  
Keyword(s):  
Amino Acids ◽  
Inborn Errors Of Metabolism ◽  
Dried Blood Spots ◽  
Inborn Errors ◽  
Retrospective Diagnosis ◽  
Term Stability ◽  
Long Term Stability ◽  
Blood Filter ◽  
Long Chain

Abstract Background: Dried blood filter cards, collected for newborn screening, are often stored for long periods of time. They may be suitable for the retrospective diagnosis of inborn errors of metabolism, but no data are currently available on the long-term stability of amino acids and acylcarnitine species. Methods: We analyzed amino acids and acylcarnitines by tandem mass spectrometry in 660 anonymous, randomly selected filter cards from 1989 through 2004. We assessed long-term stability of metabolites by linear regression and estimated annual decrease of concentration for each metabolite. Results: Concentrations of free carnitine increased by 7.6% per year during the first 5 years of storage and decreased by 1.4% per year thereafter. Alanine, arginine, leucine, methionine, and phenylalanine decreased by 6.5%, 3.3%, 3.1%, 7.3%, and 5.7% per year, respectively. Acetylcarnitine, propionylcarnitine, citrulline, glycine, and ornithine decreased by 18.5%, 27.4%, 8.1%, 14.7%, and 16.3% per year during the first 5 years, respectively; thereafter the decline was more gradual. Tyrosine decreased by 1.7% per year during the first 5 years and 7.9% per year thereafter. We could not analyze medium- and long-chain acylcarnitine species because of low physiological concentrations. Conclusions: Estimation of the annual decrease of metabolites may allow for the retrospective diagnosis of inborn errors of metabolism in filter cards that have been stored for long periods of time.

Long-term stability of I2S, NAGLU, GALNS, ARSB, GUSB and TPP1 enzymes in frozen dried blood spots

2017 ◽  
Vol 120 (1-2) ◽  
pp. S110
Author(s):  
Anna Potier ◽  
Jason Cournoyer ◽  
Joe Trometer ◽  
Alyssa Vranish ◽  
James DiPerna ◽  
...  
Keyword(s):  
Dried Blood Spots ◽  
Term Stability ◽  
Blood Spots ◽  
Long Term Stability

Protein-dependent inborn errors of metabolism

2020 ◽  
pp. 1942-1984
Author(s):  
Georg F. Hoffmann ◽  
Stefan Kölker
Keyword(s):  
Amino Acids ◽  
Organic Acid ◽  
Inborn Errors Of Metabolism ◽  
Intracellular Transport ◽  
Metabolic Diseases ◽  
Dried Blood Spots ◽  
Distinct Pattern ◽  
Inborn Errors ◽  
Enzyme Defects ◽  
Specific Disorders

Protein-dependent inborn errors of metabolism are caused by inherited enzyme defects of catabolic pathways or intracellular transport of amino acids. Most result in an accumulation of metabolites upstream of the defective enzyme (amino acids and/or ammonia), causing intoxication. Protein-dependent metabolic diseases usually have a low prevalence except for some high-risk communities with high consanguinity rates. However, the cumulative prevalence of these disorders is considerable (i.e. at least >1:2000 newborns) and represents an important challenge for all public health systems. Types and clinical presentation of protein-dependent inborn errors of metabolism—this chapter discusses amino acid disorders, organic acid disorders, and urea cycle defects. The disease spectrum is broad, but follows a distinct pattern in specific disorders. Investigation and management—every infant presenting with symptoms of unexplained metabolic crisis, intoxication, or encephalopathy requires urgent evaluation of metabolic parameters, including analyses of arterial blood gases, serum glucose and lactate, plasma ammonia and amino acids, acylcarnitine profiling in dried blood spots, and organic acid analysis in urine. This chapter discusses the basic principles of acute emergency therapy and of long-term treatment, which aims principally to mitigate the metabolic consequences of enzyme deficiencies by compensating for them. Successful treatment of affected individuals is often difficult to achieve. Careful supervision in metabolic centres involving an experienced multidisciplinary team is invaluable for the best outcome.

Improving long-term stability of retinol in dried blood spots and quantification of its levels via a novel LC-MS/MS method

2019 ◽  
Vol 411 (30) ◽  
pp. 8073-8080 ◽  
Author(s):  
Min Zhang ◽  
YiRan Wu ◽  
Fang Wang ◽  
HongJun Liu ◽  
ShuYi Zhang ◽  
...  
Keyword(s):  
Dried Blood Spots ◽  
Term Stability ◽  
Blood Spots ◽  
Long Term Stability

scholarly journals Long-Term Stability of Folate in Dried Blood Spots Stored in Several Conditions

2013 ◽  
Vol 163 (2) ◽  
pp. 596-597.e1 ◽  
Author(s):  
Rheanne K. Zimmerman ◽  
Megan E. Slater ◽  
Erica K. Langer ◽  
Julie A. Ross ◽  
Logan G. Spector
Keyword(s):  
Dried Blood Spots ◽  
Term Stability ◽  
Blood Spots ◽  
Long Term Stability

scholarly journals Reference intervals of amino acid for newborns in North Asia: Diagnosing Inborn Errors of Metabolism Using Liquid Chromatography Tandem Mass Spectrometry

2021 ◽  
Author(s):  
Tatyana Ananievna Bairova ◽  
Aleksey Vladimirovich Belskikh ◽  
Alina Valerievna Atalyan ◽  
Olga Vitalievna Bugun ◽  
Nadezhda Vladimirovna Nemchinova ◽  
...  
Keyword(s):  
Amino Acids ◽  
Inborn Errors Of Metabolism ◽  
Dried Blood Spots ◽  
Reference Intervals ◽  
Tandem Mass ◽  
Inborn Errors ◽  
Chromatography Tandem Mass Spectrometry ◽  
North Asia ◽  
The World ◽  
Liquid Chromatography Tandem Mass

Aim. To establish reference intervals for blood amino acids in healthy newborns of North Asia measured by liquid chromatography tandem mass spectrometry and evaluate their differences from respective reference values for newborns from other populations. Objectives. A cross-sectional study of 381 healthy newborns was conducted. De-identified dried blood spots annotated by age, birth-weight, and sex were obtained from 381 healthy newborns aged 0-7 days. Data was collected from April to May of 2020. Methods. Dried blood spots collected from filtered paper were used to analyze and measure of 13 derivatized amino acids using LC-MS/MS method. Nonparametric statistical approaches were used to generate 2.5th-97.5th percentile distributions for newborns in North Asia in accordance with CLSI EP28-A3с. Results. Reference intervals (RI) for phenylalanine, tyrosine, citrulline, alanine, ornithine, proline in North Asian newborns differ slightly from those of newborns in other countries around the world. This allows for the use of universal RI in the diagnosis of congenital metabolic disorders of the indicated amino acids (AA) in different populations around the world. The RI for branched-chain essential AA (valine, leucine, and isoleucine are metabolic criteria for maple syrup disease) are higher in North Asian infants as compared to infants in other populations. In addition, the RI for arginine, aspartic acid, and glutamic acid in North Asian newborns are higher than in newborns in other countries around the world. In our study, the RI for methionine in newborns were lower than in many countries worldwide [McHugh D, 2011]. For optimal clinical practice, RI for certain AA in newborns (valine, leucine, isoleucine, methionine, arginine, aspartic acid, glutamic acid) should be determined for specific populations - further augmenting the diagnosis of inborn errors of metabolism.

scholarly journals Two-Step Derivatization of Amino Acids for Stable-Isotope Dilution GC–MS Analysis: Long-Term Stability of Methyl Ester-Pentafluoropropionic Derivatives in Toluene Extracts

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1726 ◽  
Author(s):  
Svetlana Baskal ◽  
Alexander Bollenbach ◽  
Dimitrios Tsikas
Keyword(s):  
Amino Acids ◽  
Methyl Ester ◽  
Stable Isotope ◽  
Internal Standards ◽  
Term Stability ◽  
Long Term Stability ◽  
Endogenous Amino Acids ◽  
Derivatives Of

Analysis of amino acids by gas chromatography-mass spectrometry (GC–MS) requires at least one derivatization step to enable solubility in GC–MS-compatible water-immiscible organic solvents such as toluene, to make them volatile to introduce into the gas chromatograph and thermally stable enough for separation in the GC column and introduction into the ion-source, and finally to increase their ionization by increasing their electronegativity using F-rich reagents. In this work we investigated the long-term stability of the methyl esters pentafluoropropionic (Me-PFP) derivatives of 21 urinary amino acids prepared by a two-step derivatization procedure and extraction by toluene. In situ prepared trideuteromethyl ester pentafluoropropionic derivatives were used as internal standards. GC–MS analysis (injection of 1 µL aliquots and quantification by selected-ion monitoring of specific mass fragments) was performed on days 1, 2, 8, and 15. Measured peak areas and calculated peak area ratios were used to evaluate the stability of the derivatives of endogenous amino acids and their internal standards, as well as the precision and the accuracy of the method. All analyses were performed under routine conditions. Me-PFP derivatives of endogenous amino acids and their stable-isotope labelled analogs were stable in toluene for 14 days. The peak area values of the derivatives of most amino acids and their internal standards were slightly higher on days 8 and 15 compared to days 1 and 2, yet the peak area ratio values of endogenous amino acids to their internal standards did not change. Our study indicates that Me-PFP derivatives of amino acids from human urine samples can easily be prepared, are stable at least for 14 days in the extraction solvent toluene, and allow for precise and accurate quantitative measurements by GC–MS using in situ prepared deuterium-labelled methyl ester as internal standard.

scholarly journals Instability of Acylcarnitines in Stored Dried Blood Spots: The Impact on Retrospective Analysis of Biomarkers for Inborn Errors of Metabolism

2020 ◽  
Vol 6 (4) ◽  
pp. 83
Author(s):  
Willemijn J. van Rijt ◽  
Peter C. J. I. Schielen ◽  
Yasemin Özer ◽  
Klaas Bijsterveld ◽  
Fjodor H. van der Sluijs ◽  
...  
Keyword(s):  
Validation Studies ◽  
Inborn Errors Of Metabolism ◽  
Room Temperature ◽  
Dried Blood Spots ◽  
Positive Trend ◽  
Inborn Errors ◽  
Retrospective Diagnosis ◽  
Screening Programs ◽  
Blood Spots ◽  
The Impact

Stored dried blood spots (DBS) can provide valuable samples for the retrospective diagnosis of inborn errors of metabolism, and for validation studies for newborn blood spot screening programs. Acylcarnitine species are subject to degradation upon long-term storage at room temperature, but limited data are available on the stability in original samples and the impact on acylcarnitine ratios. We analysed complete acylcarnitine profiles by flow-injection tandem mass spectrometry in 598 anonymous DBS stored from 2013 to 2017, at +4 °C during the first year and thereafter at room temperature. The concentrations of C2-, C3-, C4-, C5-, C6-, C8-, C10:1-, C10-, C12:1-, C12-, C14:1-, C14-, C16:1-, C16-, C18:2-, C18:1-, C18-, C5OH+C4DC-, C18:1OH-, and C16DC-carnitine decreased significantly, whereas a positive trend was found for free carnitine. Only the C4/C8-, C8/C10-, C14:1/C10- and C14:1/C16-carnitine ratios appeared robust for the metabolite instability. The metabolite instability may provoke the wrong interpretation of test results in the case of retrospective studies and risk the inaccurate estimation of cut-off targets in validation studies when only stored control DBS are used. We recommend including control DBS in diagnostic, retrospective cohort studies, and, for validation studies, we recommend using fresh samples and repeatedly re-evaluating cut-off targets.

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