Therapeutic Membrane Plasmapheresis

Plasmapheresis in Transplantation

As a treatment, plasmapheresis is used to remove aberrant antibodies and proteins from the body. However, it does not do this with any sort of specificity; all antibodies are small enough to pass through the pores of the membrane and "good" antibodies are removed along with the bad ones. The fact that antibodies are removed without specificity provides a very intriguing possibility in the the field of organ transplantation. Plasmapheresis is slowly emerging as a therapy both pre- and post-transplant in order to prevent acute rejection of the organ due to ABO (blood type) incompatibility or anti-donor specific antibodies. This is especially the case in Japan, which has pioneered many of the advances in plasmapheresis therapy for organ transplantation.

Without going into too much detail, acute rejection of a transplanted organ occurs because of pre-existing antibodies circulating in the recipient's body. ABO incompatibility arises when the donor and the recipient have different blood types, meaning that the donor will have pre-existing antibodies that will target the organ, thus causing the rejection of the organ almost instantaneously. Anti-donor specific antibodies can have a similar effect.

 

ABO incompatibility

 

Since plasmapheresis removes antibodies without specificity, treatment with plasmapheresis will decrease the levels of the incompatible antibodies in the recipient. There have been a variety of different studies and case reports linking the prevention of acute rejection to the usage of plasmapheresis in order to decrease antibody levels in the organ recipient. In general, plasmapheresis is used pre-transplant in order to physically remove the incompatible antibodies, and is also used post-transplant if antibody levels in the recipient rise above a certain level. It is important to note that plasmapheresis does not replace immunosuppression, and organ recipients must also remain on immunosuppressants for the rest of their lives.

Most of the studies done on the use of plasmapheresis in organ transplantation have been done in liver transplants. However, increasingly there are more and more transplants performed with other organs that are also utilizing plasmapheresis as a therapy. Although the literature on the subject is based mostly on case reports and published experience, there seems to be a general agreement that plasmapheresis is a promising therapy in the prevention of acute rejection. If you are looking for more information on this subject, we strongly recommend looking up the sources below, especially the Mayo Clinic website.

 

Sources:
Kawagishi N et al. Antibody Elimination by Apheresis in Living Donor Liver Transplant Recipients. Therapeutic Apheresis 2001; 5.

Kozaki K et al. The Role of Apheresis Therapy for ABO Incompatible Living Donor Liver Transplantation: The Kyoto University Experience. Therapeutic Apheresis and Dialysis 2006; 10.

http://discoverysedge.mayo.edu/abo_posxmatch/index.cfm

Image Sources:
http://discoverysedge.mayo.edu/abo_posxmatch/images/aboposxmatch-summary.jpg