The investigator aim to identify the role of inorganic pyrophosphate and other anti-calcifying molecules in vascular disease in children with chronic kidney disease, with a view to developing therapeutic approaches aimed at limiting the onset of vasculopathy.

The study of pro- and anti-calcifying molecules in children with chronic kidney disease will be carried out using dosages made on serum in comparison with the dosage of these same molecules in control children matched according to age and sex. without chronic kidney disease. An evaluation of vascular function by clinical (auscultation, palpation) and ultrasound techniques (measurement of intima-media thickness and measurement of pulse wave velocity) will also be carried out in children with chronic kidney disease and compared to norms of children without chronic kidney disease. These evaluations aim to improve understanding of the pathophysiology of vascular calcification and thus open up therapeutic perspectives in these children.

Inclusion Criteria:

All groups :

• Minor patients (<18 years)
• Patients of both sexes
• Informed patients and parents who have signed the informed consent form
• Patients affiliated to social security

Control group :

- Patients with no particular pathology undergoing surgery and receiving a preoperative check-up

CKD groups :

• Patients on dialysis for more than 3 months, regardless of technique
• Kidney transplant patients
• Patients with CKD, whatever the cause

Exclusion Criteria:

• Progressive cancer or kidney disease
• Treatments that may modify PPi concentration (e.g. bisphosphonates)