The following was submitted to the CBBS panelists for consideration:

The background:

After ABO incompatible bone marrow transplants, it is a standard practice to give the patient plasma that is compatible with both the recipient and donor red cell types. For example, a group B patient who is given a group O marrow should be given group B FFP; a group B patient who is given a group A marrow should be given group AB FFP.

At an institution that has a large BMT program, exchange plasmapheresis is sometimes required for post-transplant HUS/TTP. In these cases, large volumes of plasma are required. It may be difficult to obtain and provide large volumes of group B or group AB plasma on an ongoing basis or for more than one patient at a time.

The question:

Is it really necessary to provide plasma that is compatible with the recipient's original ABO group, once recipient-group red cells are no longer detectable?Presumably, the recipient's body tissues continue to express their original ABO group post-transplantation. What are the clinical consequences if one were to plasma exchange a patient with plasma that is incompatible with a patient's original red cell (and presumably current tissue) group? At at least one institution, practitioners have been hesitant to do this because of the knowledge that transplanting hearts or kidneys across anti-A or anti-B barriers results in hyperacute rejection, presumably because of a reaction of the anti-A or B with the A or B antigens on the endothelium of the tranplanted organ. Would passively transfused anti-A or anti-B cause damage to a patient's organs? The author of this question is aware of a couple of anecdotal cases (in BMT patients) in which patients were inadvertently pheresed with plasma incompatible with the recipient's original ABO group without apparent adverse effects, but the patients were apparently not evaluated in great detail.

The following ideas have been submitted in response to the posed question. These opinions are paraphrased and are being presented without attribution. They do not represent an official opinion or position of the CBBS.

Regarding the question about the ABO type of plasma for apheresis procedures following ABO non-identical BMT:

The panelist reviewed much of the transplant literature not long ago with particular emphasis on antibody-induced problems (especially with hemolysis in mind). There was no data that specifically addressed the question of plasma exchange of patients in the post-transplant setting. Some data that may be of some relevance are as follows.

Lasky et al (Transfusion 1983;23:277) reported the presence of ABO isohemagglutinins more than 1 year after BMT in three of five recipients of minor ABO incompatible transplants (anti-A in AB or A recipients) who survived longer than 5 months after BMT. Buckner et al (Transplantation 1978;26:233) reported two group AB patients who were recipients of group O marrows who had persistent anti-A which was obviously produced by the donor's immune system. Although A antigen is known to be widely distributed in the tissues, no symptomatology could be ascribed to the presence of anti-A. Other reports of isohemagglutinins long after minor ABO incompatible BMT are those of Needs et al (Acta Haematologica 1987;13:78), Gale et al (Blood 1977;50, 185) and Robertson et al (Transplant Proceed 1987;19:4612). No adverse affects attributed to the antibodies were mentioned in these reports.

Patients who develop severe hemolysis as part of the passenger lymphocyte syndrome following minor incompatible BMT may develop renal failure but that would seem to be accountable on the basis of immune hemolysis rather than the mere presence of the antibody.

All in all, there are scant data about adverse effects of incompatible plasma in the post-transplant setting. The panelist cannot recall being forced to use plasma incompatible with the recipient's original type for plasma exchange in this setting but the panelist did not do a comprehensive review of institutional records.

Since it is certainly true that transplanting kidneys across ABO barriers is a cause of hyperacute rejection, the panelist shares the concern that large doses of ABO incompatible plasma might cause a problem, but the panelist does not know of any such examples.

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Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator