Paroxysmal Nocturnal Haemoglobinuria and Refractory Marrow Failure Treated by Marrow Transplantation

S ummary . A patient with pancytopenia and paroxysmal nocturnal haemoglobinuria (PNH) following exposure to insecticide spray developed complete marrow failure after inhalation of vapours containing benzol. There was no sign of spontaneous recovery after more than 6 mth of conventional and supportive therapy. The patient was treated with the immunosuppressive agent cyclophosphamide, 50 mg/kg on each of four days, followed in 36 hr by transplantation of marrow from a sibling compatible at the major human histocompatibility locus (HL-A). Intermittent methotrexate therapy was given for 102 days after grafting to prevent graft-versushost disease. The patient showed prompt haemopoietic engraftment indicated by restoration of marrow cellularity and a rise in peripheral blood cell counts beginning on day 11 after the graft. The patient is alive and well with normal haemopoietic function and continued absence of PNH more than 1 yr and 4 mth after transplantation.