Identical twin marrow transplantation for venous thrombosis in paroxysmal nocturnal hemoglobinuria; long-term complete remission as assessed by flow cytometry.

Paroxysmal nocturnal hemoglobinuria (PNH), an acquired clonal hematopoietic disorder characterized by protean clinical manifestations, is associated with significant morbidity and mortality. We report a 24-year-old patient with PNH complicated by deep vein thrombosis who underwent syngeneic bone marrow transplantation. No clinical symptomatology or stigmata of disease have recurred. Immunophenotyping of this patient over 12 years after her procedure revealed all peripheral circulating cells to express normal levels of CD59. Histocompatible marrow transplantation remains the definitive method of treatment for PNH with modern immunophenotyping capable of sensitive follow-up post-transplant.