We have a pancreatic cancer patient who swears he has never been transfused and doesn't appear to have had major surgeries that require transfusion but who has an anti-Fyb.  No evidence of a source of passive antibodies.  Negative antibody screen elsewhere in recent months.  Are there reports of naturally occurring anti-Fyb?

The only report I can find is Michalewska B.  Naturally occurring anti-Fyb + Cw.  Vox Sanguinis 2001; 80: 235.  In this (which is a letter to the Editor, rather than a "paper"), the author writes about another unpublished observation cited in Issitt PD.  Applied Blood Group Serology.  3rd edition.  Miami. Montgomery Scientific Publications, 1985: 278.  While I have a copy of this book, I can't get to it at the moment.

I once came across a male patient with a very strong anti-Fya.  He said that, despite fighting in the army and having undergone surgery, he had never been transfused.  We didn't delve too deeply, as he was a Jehovah's Witness, but we were a little sceptical!

I know this is a late response but re-reading some posts brings up old ponderings.    I have always been interested in the non-immune stimulated antibody specificities (naturally occurring).  When we have seen these in different patient populations, i.e. malignancies, pregnancies, and autoimmune anemias.   There was some papers that put forth the term "mimicking" antibody specificities, we may occur from immune malignancies, drugs, herbs, etc., or due to a dilutional effect or specific enhancement methods.   At the time we attempted to absorb and elute the antibody specificity in question with red cells that were negative for the antigen of the specificity in question.   With some success but not 100%.   Maybe the antibody was actually directed to some specific epitope that was part of or in common with the antigen in question?   Is the ultimate test to transfuse the patient to determine if the red cell survival is affected by this apparent mis-match?    I do not see a lot of red cell survival studies anymore.   However, I will stop there.  Only to say to Ms. Adams thank you for your non-immune stimulation of my old days immunohematology...…it is a naturally occurring problem I have reading BB posts......