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AADC/TDC in Advanced Parkinson's Disease

NCT05558787 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 48

Last updated 2024-08-19

No results posted yet for this study

Summary

Rationale: Many persons with Parkinson's disease (PD) develop a progressive resistance to levodopa, which is the pharmacological mainstay of PD treatment. Recently, two enzymatic pathways have been identified that could be (partially) responsible for this: 1) breakdown of levodopa by bacterial tyrosine decarboxylase (TDC), an enzyme which normally decarboxylates dietary tyrosine but which is also able to decarboxylate levodopa. Accumulation of bacterial TDC in the small intestine, such as in the context of small-intestinal bacterial overgrowth (SIBO) - for which persons with PD are at increased risk - has the potential to prematurely metabolize levodopa, hence limiting its bioavailability and effect. 2) paradoxical induction of activity of the enzyme aromatic L-amino acid decarboxylase (AADC) in chronic users of levodopa combined with a peripheral decarboxylase inhibitor, also leading to a premature breakdown of levodopa and limitation of its bioavailability and effect.

Primary objective: in a cross-sectional sample of advanced (≥5 years) Parkinson's disease determining the prevalence of increased bacterial TDC activity in feces, and the prevalence of increased AADC activity in serum.

Secondary objective: correlating these biomarkers to clinical parameters, correlating composition of the microbiome to TDC activity, to the presence of levodopa resistance, and to factors related to socio-economic status.

Study design: using feces, serum and urine samples and clinical data from n=50 participants, the relevant enzymes' activity will be measured and the composition of the gut microbiome will be determined. These will be correlated to the clinical and demographic parameters.

Conditions

  • Parkinson Disease

Sponsors & Collaborators

  • University of Groningen

    collaborator OTHER

  • Predica Diagnostics

    collaborator UNKNOWN

  • ParkinsonNL

    collaborator UNKNOWN

  • Maag Lever Darm Stichting

    collaborator OTHER

  • Stichting Woelse Waard

    collaborator UNKNOWN

  • Stichting Alkemade-Keuls

    collaborator UNKNOWN

  • Radboud University Medical Center

    lead OTHER

Eligibility

Min Age
25 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2023-06-28
Primary Completion
2024-08-14
Completion
2024-08-14

Countries

  • Netherlands

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT05558787 on ClinicalTrials.gov