Catastrophic relapse of Evans syndrome five years after allogeneic BMT notwithstanding full donor chimerism. Terminal hemolytic-uremic syndrome

A patient with severe Evans syndrome received an allo-BMT from his HLA-identical sister on November, 2000. Full marrow and blood donor chimerism were achieved only after 5 donor lymphocyte infusions (DLI), and coincided with complete clinical remission and disappearence of auto-antibodies. Five years later, hemolytic anemia recurred with rapid increase of serum bilirubin to over 50 mg%: he responded to combined therapy, but died on day +17 from admission of an acute hemolytic uremic syndrome (HUS). All circulating blood cells, including erythrocytes, were 100% donor. Ex vivo cultured and expanded T and B cells from the peripheral blood were also 100% donor. The supernatants from B cell cultures, containing either IgM or IgG, did not react with a panel of erythrocytes. Thus in this typical autoimmune disease with a predominant B cell pathogenesis the donor immune system resulted "innocent of autoimmunity". The persistence of long-lived recipient autoreactive plasma-cell lines in survival niches, still producing autoantibodies, may be hypothesized for this and similar cases. The postulated graft-versus-autoimmunity (GVA) effect was apparently not sufficient to eradicate autoimmunity in this patient.