Purinergic Compounds in Pseudoxanthoma Elasticum (PURI-PXE)

April 23, 2026 updated by: Centre Hospitalier Universitaire de Nice

Role of Purinergic Compounds in the Vascular Pathology of Pseudoxanthoma Elasticum

Pseudoxanthoma elasticum (PXE) is a rare genetic disorder, transmitted as an autosomal recessive trait, affecting approximately 1 in 50,000 people, predominantly women. It is characterised by progressive calcification of tissues rich in elastic fibres, particularly the skin, retina and arteries. It often begins in young adults and can eventually lead to central blindness, peripheral artery disease, strokes, tendon pain, recurrent kidney stones and visible skin changes.

The diagnosis is based on clinical examination (skin papules, angioid streaks) and can be confirmed by biopsy or genotyping of the ABCC6 gene, whose mutation leads to extracellular ATP deficiency. This deficiency reduces the production of pyrophosphate (PPi), a natural inhibitor of calcification, thus promoting abnormal calcium deposits in tissues. To date, there is no curative treatment, but clinical trials are evaluating oral administration of PPi, with encouraging results.

The role of purinergic metabolism is increasingly being explored in PXE. The cascade of conversion of ATP to adenosine (ADO) via ectonucleotidase pyrophosphatase 1 (ENPP1) and 5' ectonucleotidase (NT5E) indirectly regulates the activity of tissue-nonspecific alkaline phosphatase (TNAP), an enzyme that degrades PPi. An imbalance in this cascade could aggravate calcifications. The joint measurement of PPi, ADO and these enzymes, which has recently become possible, could not only refine our understanding of the disease, but also pave the way for new therapeutic strategies.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

45

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 Contact

Study Contact Backup

Study Locations

  • France
      • Angers, France
        • Not yet recruiting
        • Angers University Hospital
        • Principal Investigator:
          • Ludovic Martin
        • Contact:
        • Contact:
      • Nice, France
        • Recruiting
        • Nice University Hospital
        • Principal Investigator:
          • Georges LEFTHERIOTIS
        • Contact:

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Male or female,
  • Age >18 years
  • Covered by social security,
  • Informed and having signed the informed consent form.

PXE patients:

- with PXE defined according to current clinical criteria for PXE (REACT-PXE and PNDS consensus) and with an ABCC6 mutation.

Exclusion Criteria:

  • Patients treated with bisphosphonates, vitamin K antagonists, and dietary supplements containing calcium, phosphates, magnesium, zinc, or iron.
  • Treatments likely to alter adenosine levels (caffeine, salbutamol, beta-blockers, etc.).
  • Progressive bone diseases (osteoporosis, chondrocalcinosis, gout, etc.).
  • Progressive and/or treated cancerous diseases.
  • Progressive and/or treated inflammatory or autoimmune diseases.

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: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: PXE Patient
Biological: supplementary tubes
  • One 2.5 ml EDTA blood tube for PPi measurement.
  • Special blotting paper for collecting blood drops for ADO measurement.
  • 7.5 ml whole blood for ectoenzyme measurement
Other: NON PXE Patient
Biological: supplementary tubes
  • One 2.5 ml EDTA blood tube for PPi measurement.
  • Special blotting paper for collecting blood drops for ADO measurement.
  • 7.5 ml whole blood for ectoenzyme measurement
Radiation: SCANNER
non-injected coronary and lower limb scanner

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
potential role of the ADO
Time Frame: at inclusion
mesure of concentration
at inclusion

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
correlation between ADO, PPi and ectoenzymatic activities
Time Frame: at inclusion
correlation between concentrations
at inclusion
correlation between ADO, PPi and calcification score
Time Frame: at inclusion
correlation between concentrations and calcification score (%)
at inclusion

Collaborators and Investigators

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

Sponsor

Centre Hospitalier Universitaire de Nice

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)

January 20, 2026

Primary Completion (Estimated)

January 15, 2027

Study Completion (Estimated)

January 15, 2029

Study Registration Dates

First Submitted

December 16, 2025

First Submitted That Met QC Criteria

December 30, 2025

First Posted (Actual)

January 7, 2026

Study Record Updates

Last Update Posted (Actual)

April 24, 2026

Last Update Submitted That Met QC Criteria

April 23, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 25-PP-14

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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