Epilepsy (Treatment Refractory), Inborn Errors of Metabolism
Conditions
Brief summary
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.
Interventions
OTHERObservational Study
no intervention
Sponsors
University Children's Hospital, Zurich
ETH Zurich (Switzerland)
Study design
Observational model
OTHER
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
4 Years to No maximum
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Concentration (μmol/L) of metabolites of clinical interest in venous blood, capillary blood and breath of participants. | Baseline | 1. Concentration of beta-hydroxybutyrate in venous and capillary blood 2. Concentration of acetone in exhaled breath 3. Concentration of ammonia in venous blood and exhaled breath 4. 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
| Measure | Time frame | Description |
|---|---|---|
| Correlation of metabolite concentrations in different matrices | Baseline | 1. 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 2. Correlation between concentration of ammonia in venous blood and exhaled breath captured directly by a handheld device with a chemiresistor sen 3. 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 |
| Participant self-report questionnaire on a 4-point Likert scale on the burden of each sampling method | Baseline | Likert scale: 1, Strongly Agree. 2, Agree. 3, Disagree. 4, Strongly Disagree. The lower the score, the lower the burden of sampling method. |
| Participant self-report questionnaire on a 4-point Likert scale on the usability of the handheld breath sensor for remote measurements of metabolites | Baseline | 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. |
| Untargeted SESI-based mass spectrometry analysis of exhaled breath captured in a bag | Baseline | abundance (parts per million) of all detectable and identifiable metabolites in exhaled breath |
Contacts
CONTACTJohannes Häberle
Outcome results
None listed