Red cell alloantibody development associated with heart and lung transplantation.

The development and persistence of clinically significant red cell alloantibodies were studied in 1132 patients who underwent a heart and/or lung transplant at Harefield Hospital. Clinically significant antibodies were detected in 15 patients (1.3%) preoperatively and appeared in a further 15 (2.1%) of 704 patients followed up 1-404 weeks after surgery. Anti-D developed in only 1 of 52 D-negative recipients of a D-positive donor graft and in only 2 of 6 D-negative patients who were transfused with between 6 and 32 units of D-positive red cells. Most antibodies that appeared after transplantation remained detectable for only a few weeks. Antibodies detected preoperatively that reacted only with papain-treated cells became persistently undetectable in 4 patients who were transfused with red cells expressing the corresponding antigen specificity. By contrast, antibodies detected preoperatively by indirect antiglobulin test were still detectable after periods of up to 260 weeks in 4 patients who received only antigen-negative red cells. Immunosuppressive therapy appeared to profoundly affect the natural history of red cell alloantibody production in these patients. The underlying mechanisms warrant further study.