PAROXYSMAL-NOCTURNAL HEMOGLOBINURIA WITH MYELOFIBROSIS - PROGRESSION TO ACUTE MYELOBLASTIC-LEUKEMIA

A 58-year-old male was diagnosed as having paroxysmal nocturnal hemogl obinuria (PNH) with myelofibrosis in 1984. The administration of hydro xyurea and low dose splenic irradiation were initiated for abdominal d istention due to splenomegaly in 1987. In May 1990 the patient develop ed smouldering acute myeloblastic leukemia (AML); and the blasts proli ferated in response to G-CSF administered for refractory pneumonia. Th e patient died of pneumonia and pleural involvement of leukemia in Sep tember 1990. FACS analysis of the blasts using anti-decay accelerating factor (DAF) (CD55) and CD59 (membrane attack complex inhibition fact or: MACIF) monoclonal antibodies demonstrated that 25.5% and/or 87.3% of die blasts were negative for DAF or CD59 respectively. There is the earlier evidence that about 90% leukemic myeloblasts from non-PNH AML patients are positive for DAF,1 and nearly 100% of non-PNH neutrophil s have been shown to be positive for both DAF and CD59.2 Our data sugg est that the leukemic blasts from this patient may have derived from t he PNH clone.