Specificity of auto-antibodies in acquired haemolytic anaemia.

Until recently it has been assumed that the autoantibodies found in acquired haemolytic anaemia are non-specific; that is to say they react with all types of human red cells and are unrelated to any known blood group antibodies. However, Weiner, Battey, Cleghorn, Marson, and Meynell (1953) have described a patient in whom the auto-antibody had the specificity anti-e, the patient's red cells having the genotype CDe/CDe: the same phenomenon had previously been suspected in a patient investigated by Dr. Ruth Sanger (personal communication). In the course of investigating a severe case of acquired haemolytic anaemia (Case 1), we noted that the patient's serum strongly agglutinated red cells of the genotypes CDe/CDe and cde/cde but not those of cDE /cDE. Further investigation showed that the patient's serum contained anti-C and anti-e, despite the fact that the patient's genotype was CDe/cde. This observation led to the re-investigation of nine other cases of acquired haemolytic anaemia whose warm auto-antibodies had been considered to be non-specific; the findings are described briefly in the present report.