Serum IgA deficiency with anti IgA antibodies at the high titer was found in a patient with renal failure due to SLE. Before detection of anti IgA antibodies, she had experienced severe anaphylactoid reactions at the start of the plasma exchange therapy. Afterwards anti IgA antibodies were found by double diffusion in agarose gel and in the IgG fraction of the patient serum, and were directed against only IgA1 subclass. IgA2 was detected by double diffusion method with commercial anti IgA2 antisera. The patient was lacking in IgA, but had secretory component in her saliva.
The patient is now well controlled by hemodialysis three times a week for renal failure and by transfusion of washed red blood cells without leukocytes for anemia. Accordingly, irk case of a patient who has little amount of serum IgA requires blood or blood products, anti IgA antibodies should be investigated carefully before administration to avoid anti IgA mediated transfusion reactions.
