A 69-year-old woman first admitted to the Keio University Hospital on May 1, 1975, for the further examination of leukocytosis. On admission, her hemoglobin was 11.3 gm/dl, reticulocytes 8‰, platelets 19.2×104/mm3, WBC 27,700/mm3 with 88.5% of lymphocytes. Her bone marrow smear revealed 47.4% of lymphocytes. From these data the diagnosis of CLL was made. During the examination without treatment severe anemia of hemoglobin 6.1 gm/dl suddenly appeared. Positive direct Coombs test, elevated reticulocytes (74‰), increased serum bilirubin, markedly decreased haptoglobin, and increased LDH (especially LDH1) led to make the diagnosis of AIHA. Anemia was improved by the administration of prednisolone. Although she developed the second and the third attacks of hemolysis in June, 1976, and in April, 1977, anemia was ameliorated with an increase of prednisolone and an addition of azathioprine. To our knowledge, our case was the fourth case of CLL complicated with AIHA in Japan. It is also very interesting in the view point of genetic predisposition of lymphocytic malignancy that her sister died of malignant lymphoma.
