The Demonstration of a ‘Plasmatic Factor’ in a Case of Coombs' Negative Haemolytic Anaemia

The clinical history of a patient with acute auto‐immune haemolytic disease with a persistently negative antiglobulin test (Coombs' test) is given. The erythrophagocytosis test (ET) and its use in demonstrating the presence of a ‘plasmatic factor’ is described. That a ‘plasmatic factor’ was responsible for the haemolytic disease was substantiated by showing reduced survival of compatible donor cells in the patient's circulation. The diagnosis of the case as acute auto‐immune haemolytic disease is supported by the exclusion of intracorpuscular and other known extracorpuscular causes of haemolysis, by the good response on two occasions to steroid therapy and finally by the good result of splenectomy.