ABO incompatible kidney transplantation --immunological aspect-.

Area of Science:

• Nephrology
• Immunology
• Transplantation Surgery

Background:

• The scarcity of cadaveric kidney donors has driven the development of ABO incompatible kidney transplantation (ABOINCKT).
• This study details the experience of 76 living-donor ABOINCKT procedures performed at a single center.

Purpose of the Study:

• To evaluate the efficacy and outcomes of ABO incompatible kidney transplantation.
• To analyze the mechanisms of acute humoral rejection in ABOINCKT.
• To assess the long-term graft and patient survival rates.

Main Methods:

• Patients underwent antibody removal via immunoadsorption or plasmapheresis and exchange.
• Immunosuppression regimens included various combinations of agents like cyclosporine, tacrolimus, steroids, cyclophosphamide, azathioprine, mycophenolate mofetil, and basiliximab.
• Splenectomy was a routine surgical procedure during transplantation.

Main Results:

• Donor blood type antigen was consistently expressed on vascular endothelium post-transplantation.
• Acute humoral rejection mechanisms involve antibody-dependent cell-mediated cytotoxicity (ADCC) and antigen-antibody reactions.
• Graft and patient survival rates improved significantly from 75% and 64% (1989-1996) to 100% (since 1997).

Conclusions:

• ABO incompatible kidney transplantation is a crucial alternative, especially for blood type O patients and pediatric recipients facing long waits.
• Recent protocol advancements have dramatically improved outcomes, achieving excellent survival rates.
• The phenomenon of accommodation, where the graft tolerates the co-existence of blood type antigen and antibody, is observed in ABOINCKT.