Systemic Lupus Erythematosus and Antiphospholipid Syndrome Accompanied by Mixed-Type Autoimmune Hemolytic Anemia

Systemic lupus erythematosus (SLE) is an autoimmune disease that leads to a wide spectrum of clinical and immunological abnormalities. Hematologic abnormalities are an important manifestation of SLE. The incidence of autoimmune hemolytic anemia (AIHA) has been reported in approximately 10% of patients with SLE. Among them, mixed-type AIHA, which is caused by warm autoantibodies and cold hemagglutinin, is relatively rarely reported. We report the case of a 72-year-old woman, who was admitted to our hospital due to shortness of breath, jaundice, and severe anemia, with SLE and antiphospholipid syndrome (APS) complicated by mixed-type AIHA. Laboratory data revealed severe hemolytic anemia (low hemoglobin, high indirect bilirubin, and high lactate dehydrogenase levels), low complement levels, and the presence of antinuclear antibodies and lupus anticoagulant. Imaging results revealed pleural effusion and pulmonary embolisms, and echocardiogram revealed high estimated right ventricular pressure. She was diagnosed with SLE and APS complicated by mixed-type AIHA based on positive direct antiglobulin and cold agglutinin tests (thermal amplitude ≥30°C). As mixed-type AIHA is a severe and chronic condition, she was administered potent treatments with immunosuppressants. However, because she was a carrier of human T-cell leukemia virus type-1, only a moderate amount of prednisolone was administered. She refused to take warfarin. Fortunately, her symptoms and laboratory abnormalities improved after prednisolone administration, and no relapse occurred after tapering the prednisolone dose. Although mixed-type AIHA is characterized by fewer clinical symptoms than cold agglutinin disease, hemolytic anemia is more severe and chronic. Therefore, it is important to confirm the presence of cold agglutinins, which are active at ≥30°C in patients with SLE and warm AIHA. In addition, it is important to consider that AIHA is associated with thromboembolism, and patients with lupus anticoagulant or anticardiolipin antibodies having a history of AIHA are at a high risk of developing thrombosis.