A first report of IgM.LAMBDA. type of anti-Pr1d after rubella infection in Japan.

The secondary cold agglutinin disease is almost always caused by the autoantibodies of κ-type: the report of the disease caused by the antibodies of λ-type is very rare. We now report the case of the disease by anti-Prld antibody of IgM-λ type, which is probably the first case in Japan. The patient, an 8-year-old boy, revealed such symptons as severe intravascular hemolysis, acute renal failure and disturbance of consciousness on the 10th days after rubella infection. He was then sent to a hospital and the labolatory test showed a very high titer of the cold agglutinin. He was treated with immunosuppressive agents (prednisolone and cyclophosphamide), exchange transfusion and peritoneal dialysis. The treatment was effective and he recovered within a week.The antibody from the patient was not inhibited by carbodiimide treatment and periodate oxidation of SGP, and reacted with dog erythrocytes. The cold agglutinin was therefore shown to be anti-Prld antibody, which is a very rare cause of severe cold agglutinin disease.