Trial reportMolecular genetics and metabolism2011
Using change in plasma phenylalanine concentrations and ability to liberalize diet to classify responsiveness to tetrahydrobiopterin therapy in patients with phenylketonuria.
Trial report in Molecular genetics and metabolism, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers, 2 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
11 citing papers in PubMed, 2 syntheses or guidelines pooled it, 26 citations in OpenAlex.
- Protein Substitute Requirements of Patients with Phenylketonuria on BH4 Treatment: A Systematic Review and Meta-Analysis.Nutrients · 2021Pooled it
- Consensus guideline for the diagnosis and treatment of tetrahydrobiopterin (BHOrphanet journal of rare diseases · 2020Guideline
- One-year follow-up of B vitamin and Iron status in patients with phenylketonuria provided tetrahydrobiopterin (BH4).Orphanet journal of rare diseases · 2018Trial
- Long-term follow-up of patients with phenylketonuria treated with tetrahydrobiopterin: a seven years experience.Orphanet journal of rare diseases · 2015Trial
- Tetrahydrobiopterin responsiveness in phenylketonuria: prediction with the 48-hour loading test and genotype.Orphanet journal of rare diseases · 2013Trial
- Two Cases of 6-Pyruvoyl Tetrahydropterin Synthase Deficiency: Case Report and Literature Review.Children (Basel, Switzerland) · 2023Article
- Genotype-phenotype correlations and BHMolecular genetics & genomic medicine · 2019Article
- The complete European guidelines on phenylketonuria: diagnosis and treatment.Orphanet journal of rare diseases · 2017Review
- Recommendations for the nutrition management of phenylalanine hydroxylase deficiency.Genetics in medicine : official journal of the American College of Medical Genetics · 2014Review
- Longitudinal quality of life analysis in a phenylketonuria cohort provided sapropterin dihydrochloride.Health and quality of life outcomes · 2013Article
- Utility of phenylalanine hydroxylase genotype for tetrahydrobiopterin responsiveness classification in patients with phenylketonuria.Molecular genetics and metabolism · 2012Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors at 1 institution in 1 country.
Funding
Abstract
Tetrahydrobiopterin (BH(4)) responsiveness is currently defined as a decrease in plasma phenylalanine concentrations in patients with phenylketonuria (PKU). This definition does not offer insight beyond the initial assessment of patients, which may lead to treatment ambiguity in patients who only experience an initial decrease in plasma phenylalanine concentrations. We present our experience with a novel classification approach using sequentially-applied criteria. Plasma phenylalanine concentrations were measured at baseline and after one month of BH(4) therapy (20 mg/kg/day) in 58 PKU patients (34 M, 24 F; age 17.3±11.0 years). Thirty-two patients (55.2%) were classified as "preliminary responders" at one month, experiencing at least a 15% decrease in plasma phenylalanine concentrations. Preliminary responders' ability to liberalize their dietary restrictions was then systematically assessed. "Definitive responders" were defined as preliminary responders who could increase their dietary phenylalanine tolerance by at least 300 mg/day and lower prescribed medical food needs by at least 25% while maintaining metabolic control (plasma phenylalanine ≤360 μmol/L) and consuming adequate dietary protein. Preliminary responders who could not liberalize their diets according to these criteria were classified as "provisional responders." Nineteen patients (32.8% of patients initiating BH(4) therapy) met the definitive responder criteria, increasing dietary phenylalanine tolerance from 704±518 mg/day to 1922±612 mg/day and reducing medical food to 16.7±19.5% of their baseline prescription. Nine patients (15.5% of patients initiating BH(4) therapy) were classified as provisional responders, all remaining on 100% of their baseline medical food prescription. From this classification approach, a subgroup of provisionally responsive patients emerged who experienced an initial decrease in plasma phenylalanine concentrations but who could not substantially increase their dietary phenylalanine tolerance or decrease medical food needs. Diet liberalization is an essential component of BH(4)-responsiveness classification.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.