Study of Low-grade Systemic Inflammation in Adult Patients With Phenylketonuria (INGRAPH)

December 15, 2025 updated by: University Hospital, Tours

Etude de l'INflammation systémique de Bas GRade Chez Les Patients Adultes Atteints de PHénylcétonurie

Patient suffering from phenylketonuria have chronic hyperphenylalaninemia. Hyperphenylalaninemia is known to be toxic to central nervous system and cardiovascular system in particular through oxydative stress.

In this context, research of low grade systemic inflammation through cytokine assay appears legitimate.

The primary outcome of this study is to describe inflammation profile of patients with phenylketonuria.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Phenylketonuria (PKU) is a metabolic hereditary disease due to lack of activity of phenylalanine hydroxylase. This lack of activity whom origin is genetic, results in chronic hyperphenylalaninemia, toxic to central nervous system and cardiovascular system. Without treatment, PKU is responsible for mental retardation in children.

PKU is subject to systematic screening at birth and if diagnosis is confirmed a specific diet controlled in phenylalanine is prescribed for infant. This diet allows a neurodevelopment as closed as healthy infant. Despite this diet, neurological and systemic complications are more often reported at adult age. It is therefore recommended to follow patient regularly in order to search for those complications.

In a PKU murine model, it has been shown (cf references) that a low grade systematic inflammation exists and was reversible after dietetic treatment using glycomacropeptide (through a probiotic effect of this protein naturally phenylalanine free). Existence of this low grade systematic inflammation, evaluated by plasmatic cytokine screening (TNF alpha IL2, IL6, IL10, IFNgamma, IL1Alpha, IL1Beta and protein C reactive) has not been proven in humans to date.

Primary outcome of this study is to characterize this low grade systemic inflammation profile in patient with PKU.

Study Type

Interventional

Enrollment (Actual)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • France
      • Tours, France, 37044
        • Clinical investigation center, University Hospital, Tours
      • Tours, France, 37044
        • Internal Medicine Service, University Hospital, Tours

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria (patient with PKU)

  • Age >/= 18 years old
  • Phenylketonuria diagnosis
  • Fasting condition
  • Registered with a social security system
  • Patient consent

Inclusion Criteria (healthy volunteer)

  • Age >/= 18 years old
  • No metabolic condition
  • Fasting condition
  • Paired to patient with phenylketonuria already included according to age, sex and BMI class
  • Registered with a social security system
  • Volunteer consent

Exclusion Criteria, common to healthy volunteer and patient with phenylketonuria

  • Pregnant and lactating women
  • Subject to legal protection measures.
  • Chronic or acute inflammatory disease
  • Fever on inclusion
  • Undergoing anti inflammatory treatment
  • Surgery in the previous months
  • Diabetes
  • Included in other therapeutic trial

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Screening
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Healthy subject

The intervention, specific to the study, is to take blood samples on patients healthy volunteers.

Healthy subject will be paired to patient with phenylketonuria according to body mass index and sex.
Biological: Blood samples
Plasmatic cytokine and plasmatic CRP assay will be realised using luminex in both arms. IL2, IL10,INF gamma, IL, IL6, ILB, TNF alpha will be analysed.
Other Names:
  • Plasmatic Cytokine and plasmatic CRP assay
Other: Patient with phenylketonuria
The intervention, specific to the study, is to take blood samples on patients with phenylketonuria
Biological: Blood samples
Plasmatic cytokine and plasmatic CRP assay will be realised using luminex in both arms. IL2, IL10,INF gamma, IL, IL6, ILB, TNF alpha will be analysed.
Other Names:
  • Plasmatic Cytokine and plasmatic CRP assay

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Plasma concentrations of pro-inflammatory cytokines
Time Frame: At the inclusion
Plasmatic pro-inflammatory cytokine assay in PKU patients and healthy subjects.
At the inclusion
Plasma concentrations of CRP
Time Frame: At the inclusion
Plasmatic CRP assay in PKU patients and healthy subjects.
At the inclusion

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Plasma concentrations of phenylalanine
Time Frame: At the inclusion
Plasmatic phenylalanine assay in PKU patients
At the inclusion
Plasma concentrations of tyrosine
Time Frame: At the inclusion
Plasma tyrosine assay in PKU patients
At the inclusion

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital, Tours

Investigators

  • Study Director: François MAILLOT, MD-PhD, University Hospital, Tours

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 26, 2021

Primary Completion (Actual)

August 25, 2021

Study Completion (Actual)

August 25, 2021

Study Registration Dates

First Submitted

May 4, 2021

First Submitted That Met QC Criteria

May 4, 2021

First Posted (Actual)

May 10, 2021

Study Record Updates

Last Update Posted (Estimated)

December 22, 2025

Last Update Submitted That Met QC Criteria

December 15, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • DR210098
  • 2021-A01035-36 (Other Identifier: IdRCB)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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