Comparison of the Effects of Belatacept and Anticalcineurins on Endothelial Function in Renal Transplant Patients - <BELAFENDO>

Inclusion criteria

For the Belatacept group:

• Patients who have undergone a graft biopsy due to impaired renal function finding criteria for chronic toxicity of anticalcineurins leading to the introduction of Belatacept.

For the anticalcineurin group:

• Renal transplant patients treated with anticalcineurins for more than a year.
• Stable renal function (defined by a creatinine level in µmol/l stable for 3 months (variation +/-20%)

For both groups:

• Date of kidney transplant greater than 1 year
• Age between 18 and 75 years inclusive
• Patient having received clear information from one of the investigators, having read and understood the information letter and signed the consent form
• Women :

• of childbearing age (defined by the CTFG as a fertile woman, after menarche and until menopause, except in cases of permanent sterility (including hysterectomy, bilateral salpingectomy or bilateral oophorectomy)

• using effective contraception according to the WHO (combined hormonal contraception (containing estrogens and progestins), progestin-only contraception, intrauterine device (IUD), male or female condoms) for at least 4 weeks before inclusion and during the study And,
• presenting a negative urine pregnancy test at inclusion;
• menopausal: menopause according to the CTFG is defined as the absence of periods for 12 months without any other medical cause. An elevated follicle-stimulating hormone (FSH) level in the postmenopausal interval can be used to confirm a postmenopausal state in women who are not using hormonal contraception or hormone replacement therapy. However, in the absence of 12 months of amenorrhea, a single FSH measurement is insufficient.
• Patient benefiting from a social protection scheme

Exclusion criteria

• Stage 5 chronic renal failure (defined by a CKD-EPI GFR<15 ml/min/1.73m²)
• Dialysis patient
• History of myocardial infarction or stroke less than 6 months old
• Systolic heart failure requiring hospitalization in the 6 months preceding inclusion or known heart failure with an LVEF <30%
• BMI>35 kg/m²
• Severe hepatic insufficiency (Child-Pugh class C)
• Contraindication to NATISPRAY 0.30 mg/dose, solution for oral spray (and in particular hypersensitivity to nitrates in accordance with the SPC (Summary of Product Characteristics) of NATISPRAY)
• Person deprived of liberty by an administrative or judicial decision or person placed under judicial protection, or guardianship or curatorship
• Previous or current treatment with Belatacept
• Severe high blood pressure (DBP ≥ 110 mm Hg and/or SBP ≥ 180 mm Hg)
• Presence or history of functional or ligated or thrombosed bilateral arteriovenous fistula, preventing explorations
• Pregnant, breastfeeding woman, or absence of proven effective contraception
• Excessive alcohol consumption (no more than 10 drinks per week)
• Active smoking with a daily consumption of more than 21 mg of nicotine per day or taking nicotine substitutes with a dose greater than 21 mg/24 hours
• Drug addiction or suspected illicit drug use
• Patient participating or having participated in the 4 weeks preceding inclusion in a clinical trial