Friday, June 26, 2009


An 18 year old man gets into a car accident and requires blood transfusion. When he gets transfused with the first unit, he experiences anaphylaxis. He has never had a blood transfusion in the past, but testing shows IgG antibodies against IgA. The only other thing he notes is that as a child, he had recurrent upper and lower respiratory tract infections with bacteria like S. pneumoniae and H. influenza.

Challenge: What's the diagnosis here?


Stephanie said...

cross reaction of antibodies, h/o IgA nephropathy?

Alex said...

selective IgA def

Craig Chen said...

Yes, IgA is involved, its a deficiency.

This is IgA deficiency which can present with recurrent sinopulmonary infections, autoreactive antibodies and diseases, gastrointestinal abnormalities, and anaphylactic reactions to blood products.

Source: UpToDate.