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NCT Number: NCT07704606

Metabolites in Blood and Breath in Metabolic Conditions

In patients with inborn errors of metabolism (IEM) and in those requiring a ketogenic diet for the treatment of medical conditions, relevant biochemical analytes are routinely and regularly measured in venous or capillary blood samples. Repeated venipuncture for blood collection is invasive, burdensome, and resource-intensive. As an alternative, capillary blood sampling can provide some relief for the measurement of a limited number of metabolites. Nevertheless, the frequent finger pricks required to obtain capillary blood samples can still be uncomfortable for patients. Therefore, patients could benefit if non-invasive breath measurements were to replace the currently invasive biochemical monitoring methods in the future.

In this study, the usability of metabolite measurements across matrices (venous blood, capillary blood, breath captured by a handheld sensor and breath in a collection bag) in IEM patients, individuals prescribed special health-related diets, and healthy volunteers will be investigated. The usability of a handheld breath sensor for remote monitoring of patients will also be tested. Lastly, exploratory investigations will be performed to identify new disease biomarkers in breath.

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Key information

Conditions

Inborn Errors of Metabolism Brain Diseases Central Nervous System Diseases Congenital, Hereditary, and Neonatal Diseases and Abnormalities Epilepsy Epilepsy (treatment Refractory) Genetic Diseases, Inborn Metabolic Diseases Metabolism, Inborn Errors Nervous System Diseases Nutritional and Metabolic Diseases

Age range

4 year and older

Sex eligibility

All sexes

Study type

Observational

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients aged 4-20 years old with refractory epilepsy on a ketogenic diet, or
  • Patients aged 4 years old and above with a confirmed diagnosis of urea cycle disorders, organic acidurias, amino acidopathies and fatty acid oxidation defects, or
  • healthy adults and
  • informed consent

Exclusion criteria

  • Physical findings at screening that would compromise safety of the participant or quality of study data. Examples include presentation of fever, pulmonary complications, presence of disease comorbidities that might interfere with study result and inability to comply with study procedures.

Treatment and study plan

observational study

Other

no intervention

Primary outcomes

  1. Concentration (μmol/L) of metabolites of clinical interest in venous blood, capillary blood and breath of participants.

    Time frame: 2 hours to 2 weeks

    • Concentration of beta-hydroxybutyrate in venous and capillary blood
    • Concentration of acetone in exhaled breath
    • Concentration of ammonia in venous blood and exhaled breath
    • Concentration of amino acids (alanine, arginine, asparagine, aspartic acid, citrulline, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine) in venous blood, capillary blood and exhaled breath.

Secondary outcomes

  1. Correlation of metabolite concentrations in different matrices

    Time frame: 2 hours to 2 weeks

    • Correlation between concentration of beta-hydroxybutyrate in venous and capillary blood and concentration of acetone in exhaled breath captured directly by a handheld device with a chemiresistor sensor and breath captured in a collection bag and measured by mass spectrometry
    • Correlation between concentration of ammonia in venous blood and exhaled breath captured directly by a handheld device with a chemiresistor sen
    • Correlation between concentration of amino acids in venous and capillary blood and in exhaled breath captured directly by a handheld device with a chemiresistor sensor and breath captured in a collection bag and measured by mass spectrometry

  2. Participant self-report questionnaire on a 4-point Likert scale on the burden of each sampling method

    Time frame: 2 hours to 2 weeks

    Likert scale: 1, Strongly Agree. 2, Agree. 3, Disagree. 4, Strongly Disagree. The lower the score, the lower the burden of sampling method.

  3. Participant self-report questionnaire on a 4-point Likert scale on the usability of the handheld breath sensor for remote measurements of metabolites

    Time frame: 2 hours to 2 weeks

    Likert scale: 1, Strongly Agree. 2, Agree. 3, Disagree. 4, Strongly Disagree. The lower the score, the higher the acceptance of using the handheld breath sensor.

  4. Untargeted SESI-based mass spectrometry analysis of exhaled breath captured in a bag

    Time frame: 2 hours

    abundance (parts per million) of all detectable and identifiable metabolites in exhaled breath

Study contacts

Contact information is provided by the study sponsor or research team.

Johannes Häberle

CONTACT

[email protected]

+41 44 249 59 88

Sponsors and collaborators

Lead sponsor

University Children's Hospital, Zurich

Other

Collaborators

  • ETH Zurich (Switzerland)

Registry information

Official study title

Measurement of Metabolites in the Breath and Blood in Patients With Altered Metabolism and Healthy Individuals

Important dates

Study start
2026
Primary completion
2036
Study completion
2037
First posted
Jul 15, 2026
Registry last updated
Jul 15, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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