In this survey 20 patients with AHA were studied. The youngest patient was 2 months old and the eldest 13 years. In the majority of patients

anemia is severe with a sudden onset. In 75% of these patients the disease were induced by various acute infections. 18 cases contain the warmreacting antibody in the serum

1 case was diagnosed as acute cold agglutinin disease and 1 case had paroxysmal cold hemoglobinuria. All of these cases were followed-up for 3 months to61/2 years

two cases died from the underlying diseases. In this paper the etiology

the characteristics of clinical manifestations

and the antibody type

particularly for red cell autoagglutination (RAA) were discussed. It is suggested that warm antibody type AHA too may show RAA.