IMMUNE INJURY FROM ORGAN PRESERVATION

Two pairs of plasma-perfused human cadaver kidneys were rejected in a hyperacute manner by recipients who had not previously received a transplant. Crossmatches between recipient sera and donor lymphocytes were negative in all cases. A fifth kidney was plasma-perfused but not transplanted because the perfusate was shown to be cytotoxic to donor lymphocytes. IgM and complement, but not IgG, were demonstrated in these kidneys by immunofluorescent microscopy and confirmed by further immunological studies. The IgM was broadly reactive against multiple HL-A specificities and was present in 11% of sera from normal, healthy male donors. It appears from our studies that cytotoxic IgM may be present in homologous plasma and cause immune injury to the kidney during ex vivo pulsatile preservation. This may be responsible for some cases of otherwise unexplained accelerated allograft rejection.