Autoimmune haemolytic anaemias in Thailand

100 cases of autoimmune haemolytic anaemias (AIHA) in Thailand were analyzed. Clinical and immunological aspects of the disease were compared with those described in other parts of the world. Racial differences, especially between Thais and Caucasian, were emphasized. Thai patients show the following distinctions: (1) AIHA tends to occur in people of a younger age group, predominantly in females, (2) a rare occurrence of AIHA of cold-antibody type, an incidence which significantly differs from that in Caucasians, and (3) the autoantibodies consist of more than one immunoglobulin class in more than 50% of cases. Possible factors that might contribute to these differences were discussed.