NCT06342505

Tacrolimus in CD3+ T Lymphocytes

The Intracellular Pharmacokinetics of Tacrolimus in CD3+ T Lymphocytes

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 28 (actual)
• Sponsor: Erasmus Medical Center · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The goal of this study is to measure concentrations of the drug tacrolimus in both whole blood and within T lymphocytes. It will also learn on the correlation between the concentration in T lymphocytes and the effects of the drug. The main questions are: (i) What is the ratio between the tacrolimus concentration within T lymphocytes and in whole blood?; (ii) What is the correlation between tacrolimus concentrations and the effects of the drug? Participants will: * Receive standard clinical care; * Undergo two extra venipunctures for the collection of blood.

Detailed description

Rationale: The immunosuppressive drug tacrolimus is routinely monitored after kidney transplantation by measuring the whole blood, pre-dose concentration (C0). However, the C0 has a poor correlation with clinical events, most notably the risk of acute rejection. Since tacrolimus' site of action is within immune cells, the intracellular tacrolimus concentration in peripheral blood mononuclear cells (PBMCs) has recently been proposed to better represent the active concentration. However, several studies could not demonstrate an association between the intracellular tacrolimus concentration and acute rejection. One of the possible explanations for this surprising finding is the fact the PBMC fraction is composed of several cells including lymphocytes and monocytes. In this study, the tacrolimus concentration in CD3+ T lymphocytes will be investigated as this may be a more relevant cell population than PBMCs. Objective: To prospectively measure the intracellular tacrolimus concentration in CD3+ T lymphocytes in kidney transplant recipients. The area under the concentration-vs-time curve (AUC) of the intracellular tacrolimus concentration will be determined and used for the development of a population pharmacokinetic model. The pharmacokinetics of intra-CD3+ tacrolimus will be compared with the whole-blood concentration and will be related to important clinical events. Study design: Observational study with additional blood sampling. Study population: Twenty-five de novo kidney transplant recipients receiving once-daily tacrolimus- as maintenance immunosuppression. Intervention: Two extra venipunctures for the collection of blood.

Conditions

• Immunosuppression

Interventions

Type	Name	Description
PROCEDURE	Venipunctures	Extra venipunctures

Timeline

• Start date: 2022-05-30
• Primary completion: 2022-10-10
• Completion: 2022-11-10
• First posted: 2024-04-02
• Last updated: 2024-04-02

Locations

1 site across 1 country: Netherlands