Background: Paroxysmal nocturnal haemoglobinuria (PNH) is a rare acquired clonal disorder of haematopoietic stem cells causing intravascular haemolysis, haemoglobinuria and occasionally severe venous thrombotic complications. PNH is associated with severe aplastic anaemia.
Material and methods: A total of nine patients referred to and followed at Rikshospitalet University Hospital over a period of more than 20 years were evaluated and compared with other patient materials.
Results: All patients are alive with a median observation time of 46 months (7-258 months). One patient has only limited clinical signs of PNH six years after diagnosis, one patient underwent allogenic bone marrow transplantation with an HLA-identical sibling and is healthy and free of disease nine and a half years posttransplant. Three patients have experienced severe thrombotic episodes, two with development of Budd-Chiari's syndrome despite anticoagulant treatment. Five patients including these two patients are being treated with anticoagulant therapy. Two patients probably having PNH have gone through pregnancies with normal delivery of healthy children.
Interpretation: These nine cases illustrate the many different aspects of this rare disease, including a relatively favorable prognosis with respect to survival.