Hyperacute rejection from antibody against class II HLA antigens

The clinical significance of anti‐B‐cell antibodies in kidney and pancreas transplantation remains unresolved. Here, we report an isolated hyperacute rejection of the kidney, but not the pancreas, during a simultaneous kidney‐pancreas (SKP) transplant. The hyperacute rejection was due to IgG antibodies directed against class II antigens expressed on B‐cells. Antibodies directed against class II antigens are generally not thought to produce hyperacute rejection, since class II antigens allegedly are minimally expressed on vascular endothelium in the kidney. The pancreas was spared and continues to function normally, suggesting that class II antigens were not strongly expressed in this pancreas. The differential susceptibility to B‐cell antibodies of the two transplanted organs is noteworthy and should call attention to the danger from IgG antibodies to class II antigens in kidney transplantation.