Purinergic Compounds in Pseudoxanthoma Elasticum
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: supplementary tubes, SCANNER.
- Who it may be relevant to
- Registry conditions: Pseudoxanthoma Elasticum. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- France
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Role of Purinergic Compounds in the Vascular Pathology of Pseudoxanthoma Elasticum
Overview
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.
Interventions
- 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
Primary outcome measures
- potential role of the ADO [Time frame: at inclusion]
Secondary outcome measures (2)
- correlation between ADO, PPi and ectoenzymatic activities [Time frame: at inclusion]
- correlation between ADO, PPi and calcification score [Time frame: at inclusion]
Eligibility criteria
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.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Non-randomized
- Model
- Parallel assignment
- Masking
- Open label
- Primary purpose
- Basic science
Study locations
France · 2 centers
- Angers University hospital — Angers
- Nice University hospital — Nice
Identifiers
NCT: NCT07323082 · 25-PP-14