Shortage of donors has significantly limited the renal transplantation procedures. In order to overcome this profound donor shortage, the immunological barriers that are considered to be an absolute contradiction to transplantation are being broadly evaluated. Below mentioned are two such barriers:
- ABO Blood group barrier (Incompatible- ie. Transplant without a blood type match)
- Highly sensitized transplants of individuals who are pre-disposed to antigens from other persons either due to multiple blood product transfusions or with a history of previous transplantations and have a higher risk of rejection of donor kidney.
Thus, ‘Renal Transplant’ is the most effective way for treating end-stage renal disease. But due to shortage of donors, the treatment is limited. With better understanding of underlying mechanisms and availability of sensitive tests to check pre-existing antibodies, the outcomes have improved over the past few years and such transplants are regularly being performed at major centres throughout the world.
How is a successful ABO-I transplant Done?
There is a need to understand and target the antibody mediated response for a successful ABO-I transplant. Thus, over the past 20 years, several strategies have been developed to resolve or modulate this response. The strategies and desensitization protocols are all based on the same principles of removing the pre-existing anti-bodies to a certain low threshold, which prevents them from triggering an immune mediated response.
Meanwhile, strategy also involves prevention of development of newer such antibodies. The depletion techniques used are:
- Therapeutic plasma exchange, which unselectively removes all the antibodies and double filtration plasmapheresis.
- Antigen specific immune-adsorption, which removes donor specific antibodies.
In ABO-I transplants, the selective removal of antibodies is safe and involves an effective way of desensitization as it prevents removal of coagulation factors and useful antibodies that are required to fight infections.
Is the transplant affordable?
Cost is an important confounding factor for such transplants. But, with better accessibility of specific immune-adsorption filters, better protocols and care, these risks are decreasing significantly and procedures are becoming more economically viable.