An IgG-type anti-IgA antibody was detected in 3 of 22 patients who developed blood transfusionrelated side effects in our hospital in 1998. These patients were females, and developed blood transfusion-related side effects during chemotherapy for malignant diseases. None of the patients had IgA deficiency. With regard to the subclass and allotype of the anti-IgA antibody, IgA1 and IgA2m (1) were common among the 3 patients. IgA2m (2) was present in 1 patient. A washed blood preparation (washed red blood cells, washed platelets) was transfused to 1 of the patients. In the remaining 2, a standard non-washed blood preparation was administered. The anti-IgA antibody titer markedly decreased in the patient treated with the washed preparation. In the remaining 2 patients treated with the non-washed blood preparation, in contrast, no decrease in anti-IgA antibody titer was seen. No side effects of blood transfusion occurred in the patient with a marked decrease in anti-IgA antibody titer, whereas in 1 of 2 patients without reduction of anti-IgA antibody titer, 3 adverse events related to blood transfusion were observed. Administration of washed blood preparation to patients with anti-IgA antibody may be required to prevent complications of blood transfusion.
