Decreasing the Risk of Early Sub-Therapeutic Tacrolimus Troughs on Short-Term Outcomes in Low-Moderate Risk Kidney...

Area of Science:

• Nephrology
• Transplant Surgery
• Immunosuppression Management

Background:

• Sub-therapeutic tacrolimus levels post-kidney transplant are linked to poor outcomes.
• The impact of rabbit anti-thymocyte globulin (rATG) induction on early tacrolimus levels and graft outcomes is not well understood.
• This study investigates if rATG induction mitigates the negative effects of low discharge tacrolimus levels.

Purpose of the Study:

• To compare short-term graft outcomes in kidney transplant recipients based on tacrolimus trough levels at discharge.
• To determine if rabbit anti-thymocyte globulin (rATG) induction influences the association between sub-therapeutic tacrolimus levels and graft outcomes.
• To assess the necessity of achieving therapeutic tacrolimus troughs before hospital discharge.

Main Methods:

• Retrospective cohort study of adult kidney transplant recipients (KTx) from 10/2017 to 12/2019.
• Patients received rATG induction and tacrolimus-based immunosuppression, with discharge tacrolimus troughs <8 ng/mL (sub-therapeutic) versus ≥8 ng/mL (therapeutic).
• Primary outcome was a composite of rejection, graft loss, or de novo donor-specific antibodies (dnDSA) within 3 months post-transplant.

Main Results:

• Of 411 KTx recipients, 81.5% had sub-therapeutic discharge tacrolimus levels.
• The study population had low immunological risk characteristics.
• No significant difference in the 3-month composite outcome was observed between sub-therapeutic and therapeutic tacrolimus groups (13.4% vs. 9.2%, p=0.44).
• Cox regression analysis found no association between sub-therapeutic discharge tacrolimus troughs and adverse short-term graft outcomes.

Conclusions:

• Kidney transplant recipients induced with rATG and discharged with sub-therapeutic tacrolimus levels show comparable short-term graft outcomes to those with therapeutic levels.
• Discharge tacrolimus trough levels may not require strict adherence to therapeutic ranges in patients receiving rATG induction.
• Delaying discharge solely to achieve therapeutic tacrolimus troughs may not be necessary in this patient population.