Immunosuppression With CD40 Costimulatory Blockade Plus Rapamycin for Simultaneous Islet-Kidney Transplantation in...

Area of Science:

• Transplantation immunology
• Regenerative medicine
• Immunosuppression

Background:

• Simultaneous islet-kidney transplantation (SIK) is limited by the lack of effective immunosuppression without islet toxicity.
• Current immunosuppressive strategies face challenges in preventing both renal and islet allograft rejection.

Purpose of the Study:

• To evaluate a novel immunosuppressive regimen for SIK in a non-human primate model.
• To compare the efficacy of anti-CD40 monoclonal antibody and rapamycin (aCD40/Rapa) against rabbit antithymocyte globulin, tacrolimus, and rapamycin (ATG/Tac/Rapa).

Main Methods:

• Seven MHC-mismatched SIKs were performed in diabetic cynomolgus monkeys.
• Two groups received different immunosuppressive protocols: ATG/Tac/Rapa or aCD40/Rapa, with additional anti-inflammatory agents.
• The aCD40/Rapa regimen was also tested in kidney-alone transplant recipients.

Main Results:

• The ATG/Tac/Rapa group showed short-term graft survival (19-26 days) with complications.
• The aCD40/Rapa regimen resulted in long-term islet and kidney allograft survival (>120 days) in most recipients.
• In kidney-alone transplants, aCD40/Rapa demonstrated superior renal allograft survival compared to a standard triple immunosuppressive regimen.

Conclusions:

• The combination of anti-CD40 mAb and rapamycin is a safe and effective immunosuppressive strategy for kidney and islet transplantation.
• This regimen offers a promising alternative for improving outcomes in simultaneous islet-kidney transplantation.
• The aCD40/Rapa protocol utilizes clinically available agents, facilitating potential clinical translation.