ArticleOrphanet journal of rare diseases2020
Dried blood spot versus venous blood sampling for phenylalanine and tyrosine.
Article in Orphanet journal of rare diseases, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 22 papers.
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Who cites it
22 citing papers in PubMed, 34 citations in OpenAlex.
- Lower blood phenylalanine concentrations may be of clinical benefit in adults with phenylketonuria.Molecular genetics and metabolism reports · 2026Article
- Article
- How Well Is Blood Phenylalanine Controlled in Maternal PKU in Europe? Results from 102 Pregnancies.Nutrients · 2026Article
- Blood Phenylalanine Control in Paediatric and Adult Centres in the UK: Data from 2012-2018.Nutrients · 2026Article
- Therapeutic Monitoring of Patients With Hereditary Tyrosinemia Type 1-A Belgian Monocentric Experience.JIMD reports · 2026Article
- Article
- Performance of the Egoo test for phenylalanine measurement in females with phenylketonuria.Orphanet journal of rare diseases · 2025Article
- Performance of cellulose-based card for direct genetic testing of spinal muscular atrophy.BMC biotechnology · 2025Article
- Acceptability of dried blood spot collection by primary caregivers of Filipino patients with maple syrup urine disease (MSUD) and phenylketonuria (PKU).Journal of community genetics · 2024Article
- Nucleic acid degradation after long-term dried blood spot storage.Molecular ecology resources · 2024Article
- Blood Phenylalanine Levels in Patients with Phenylketonuria from Europe between 2012 and 2018: Is It a Changing Landscape?Nutrients · 2024Article
- Investigation of the relationship between phenylalanine in venous plasma and capillary blood using volumetric blood collection devices.JIMD reports · 2023Article
- Dried Blood Spots in Neonatal Studies: A Computational Analysis for the Role of the Hematocrit Effect.Pharmaceuticals (Basel, Switzerland) · 2023Article
- Important Lessons on Long-Term Stability of Amino Acids in Stored Dried Blood Spots.International journal of neonatal screening · 2023Article
- Clinical and genetic characteristics of two patients with tyrosinemia type 1 in Slovenia - A novel fumarylacetoacetate hydrolase (Molecular genetics and metabolism reports · 2022Article
- Patterned Dried Blood Spot Cards for the Improved Sampling of Whole Blood.ACS measurement science au · 2022Article
- Non-Lethal Blood Sampling of Fish in the lab and Field With Methods for Dried Blood Plasma Spot Omic Analyses.Frontiers in genetics · 2022Article
- Differences of Phenylalanine Concentrations in Dried Blood Spots and in Plasma: Erythrocytes as a Neglected Component for This Observation.Metabolites · 2021Article
- Metabolic Control of Patients with Phenylketonuria in a Portuguese Metabolic Centre Comparing Three Different Recommendations.Nutrients · 2021Observational
- Urine Phenylacetylglutamine Determination in Patients with Hyperphenylalaninemia.Journal of clinical medicine · 2021Article
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Authors and funding
8 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThis study investigated the agreement between various dried blood spot (DBS) and venous blood sample measurements of phenylalanine and tyrosine concentrations in Phenylketonuria (PKU) and Tyrosinemia type 1 (TT1) patients. STUDY
designPhenylalanine and tyrosine concentrations were studied in 45 PKU/TT1 patients in plasma from venous blood in lithium heparin (LH) and EDTA tubes; venous blood from LH and EDTA tubes on a DBS card; venous blood directly on a DBS card; and capillary blood on a DBS card. Plasma was analyzed with an amino acid analyzer and DBS were analyzed with liquid chromatography-mass spectrometry. Agreement between different methods was assessed using Passing and Bablok fit and Bland Altman analyses.
resultsIn general, phenylalanine concentrations in LH plasma were comparable to capillary DBS, whereas tyrosine concentrations were slightly higher in LH plasma (constant bias of 6.4 μmol/L). However, in the low phenylalanine range, most samples had higher phenylalanine concentrations in DBS compared to LH plasma. Remarkably, phenylalanine and tyrosine in EDTA plasma were higher compared to all other samples (slopes ranging from 7 to 12%). No differences were observed when comparing capillary DBS to other DBS.
conclusionsOverall agreement between plasma and DBS is good. However, bias is specimen- (LH vs EDTA), and possibly concentration- (low phenylalanine) dependent. Because of the overall good agreement, we recommend the use of a DBS-plasma correction factor for DBS measurement. Each laboratory should determine their own factor dependent on filter card type, extraction and calibration protocols taking the LH plasma values as gold standard.
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