Oral tacrolimus bioavailability is increased after right split liver transplantation

Area of Science:

• Transplantation immunology
• Pharmacokinetics
• Hepatology

Background:

• Tacrolimus (Tac) is a key immunosuppressant metabolized by the liver.
• Understanding Tacrolimus bioavailability is crucial for optimizing post-transplant outcomes.
• Partial liver transplantation presents unique pharmacokinetic challenges.

Purpose of the Study:

• To evaluate Tacrolimus bioavailability following partial versus full-size liver transplantation.
• To determine factors influencing Tacrolimus dosing in liver transplant recipients.

Main Methods:

• A cohort of 33 patients undergoing partial (right split or cadaver split) or full-size liver transplantation were analyzed.
• Patients received oral Tacrolimus with dose adjustments based on trough levels (T0).
• Graft weight and body weight ratios were assessed for correlation with Tacrolimus maintenance doses.

Main Results:

• Time to reach target Tacrolimus trough levels was shorter in split liver transplant groups.
• Mean Tacrolimus maintenance doses were significantly lower in partial liver transplant recipients.
• Graft weight-to-standard liver volume and graft weight-to-body weight ratios correlated significantly with Tacrolimus maintenance doses.

Conclusions:

• Partial liver transplantation, particularly using the right hepatic lobe, enhances oral Tacrolimus bioavailability.
• Graft volume is a critical factor for determining appropriate initial Tacrolimus dosing post-transplantation.