Impact of P-gp, MRP2, ENT-1 and CNT3 on the Blood Concentration / Intra-PBMC Concentration of Tacrolimus

Membrane transporters supporting tacrolimus at the lymphocyte level may play a role in the variability of the relationship between tacrolimus blood concentration and intracellular concentration, or may be the main explanatory factors. Nevertheless, most of the studies carried out on the subject, have been by genetic approach, neglecting in fact the membrane expression of these transporters, which could testify more to the real effect on the transport of tacrolimus. A better understanding of the cellular transport mechanisms of tacrolimus in the T lymphocyte could thus make it possible to identify sub-populations of patients under-exposed at the intra-lymphocyte level, despite satisfactory systemic exposure.

Inclusion criteria

• Adult of 18 or over;
• fully and honestly informed, and not having reported his non-opposition to the use of his samples for research;
• Affiliated to a social security scheme;
• Hepatic and / or renal transplant stable between two and twenty-four months after transplantation, treated with tacrolimus;
• Without modification of immunosuppressive treatment or treatment likely to modify their pharmacokinetics (imidazoles, macrolides ...) during the last two weeks;
• Each patient can only be included once.

Exclusion criteria

• Participation in another protocol whose procedures are incompatible with the realization of the study;
• Pregnant woman ;
• Major person subject to legal protection (safeguard of justice, guardianship, tutorship);
• Person deprived of liberty;
• Opposition to the use of clinical data and remnants of samples taken from care for research purposes.