Haemolytic disease of the newborn due to anti-Dia and incidence of the Dia antigen in Poland.

A strong complement-fixing incomplete anti-Dia was found in the serum of a Polish mother who gave birth to a newborn suffering from a severe haemolytic anaemia. The whole family was of Polish origin. 9,661 donor blood samples from different regions of Poland were tested against antiserum derived from that mother. Dia antigen was present on red cells of 45 (0.46%) individuals. All of them were of Polish origin. In some cases, family studies were undertaken.