Recurrent thromboses and infections were observed in a 61-year-old man with paroxysmal nocturnal hemoglobinuria (PNH). He complained of abdominal colicky pain and bloody stool. Thromboses of mesenchymal arteries were strongly suspected. He has been also suffering from furuncles of the skin. The granulocytes revealed delayed response against Zymosan and the platelets did not aggregate with epinephrine. ADP and ATP content of the patient's platelets were decreased at the time of abdominal painful attack.
PNH has been thought to be a clonal disorder of multi-potential stem cell. In addition to its abnormal erythrocytes, granulocytes and platelets also have abnormalities in their functions and their complement sensitivity. We demonstrated decay-accelerating factor (DAF) were deficient on the membranes of his erythrocytes, granulocytes and platelets by FACS analysis and by enzyme-linked immunosorbent assay (ELISA) using monoclonal anti-DAF antibodies. DAF was able to be incorporated to his erythrocytes and the sensitivity against complement lysis was considerablely corrected. It is thought that the deficiency of DAF on blood cells has a profound significance in the presentation of complement-sensitive blood cells.
