Tacrolimus Levels 10 Years After Kidney Transplant and Long-Term Clinical Outcomes: A Propensity Score-Matched...

Area of Science:

• Nephrology
• Immunology
• Transplantation

Background:

• Tacrolimus is vital for kidney transplant immunosuppression.
• Optimal late-phase trough levels remain unclear.
• Long-term outcomes associated with varying levels need investigation.

Purpose of the Study:

• To assess the association between tacrolimus trough levels (10-15 years post-transplant) and long-term clinical outcomes in kidney transplant recipients.
• To compare outcomes between patients with tacrolimus trough levels <4 ng/mL and ≥4 ng/mL.

Main Methods:

• Retrospective review of 1747 kidney transplant recipients (1990-2005).
• Analysis of 290 patients with continuous tacrolimus use from year 10 to 15.
• Propensity score matching (1:1) to balance baseline characteristics.

Main Results:

• No significant differences in graft survival or rejection-free survival between tacrolimus level groups (<4 ng/mL vs. ≥4 ng/mL).
• No significant differences in infection, calcineurin inhibitor toxicity, or malignancy.
• Higher sepsis incidence in the lower tacrolimus level group (P=.049).

Conclusions:

• Modest variations in late-phase tacrolimus trough levels are not significantly linked to graft survival or rejection in stable long-term kidney transplant recipients.
• Observed sepsis risk and de novo donor-specific antibody formation highlight the need for personalized immunosuppression and ongoing surveillance.
• Individualized tacrolimus exposure strategies are crucial for optimizing long-term kidney transplant care.