Marrow transplantation for paroxysmal nocturnal hemoglobinuria.

Between 1971 and 1990, nine patients ranging in age from 14-38 years received marrow transplants for paroxysmal nocturnal hemoglobinuria (PNH). Six were transplanted for aplastic complications of PNH. Four of these were from HLA-identical siblings, and the patients were conditioned with cyclophosphamide. One graft was form a syngeneic twin without conditioning, and one from a two HLA-antigen nonidentical father after conditioning with cyclophosphamide and total body irradiation. Three of the four recipients of allogeneic marrow developed acute and two chronic graft-versus-host disease (GVHD). Five of six transplanted for severe aplastic anemia are long-term survivors with follow-up ranging from more than 6.2 to more than 19.1 years. The HLA nonidentical transplant recipient experienced graft rejection and died of a pulmonary hemorrhage. Three patients were transplanted for nonaplastic complications of PNH consisting of life threatening recurrent thromboses or refractory hemolysis. Two of these patients received marrow grafts from HLA-identical siblings after conditioning with busulfan and cyclophosphamide. They are surviving with normal hemograms greater than 2.2 and greater than 2.5 years and had mild chronic GVHD which resolved, although one has biochemical evidence of PNH in 15% of the red cells. One received a syngeneic marrow graft without conditioning but reverted to PNH. He is alive greater than 8.6 years after transplantation. Marrow transplantation for aplastic complications of PNH is successful, well tolerated, and compatible with long-term survival when an HLA-identical sibling or a syngeneic donor is available. For patients without aplasia, one must weigh the complications of transplantation with the life threatening nature of thrombotic episodes and hemolysis.