I have a pregnant patient antibody screen positive on my Tango analyzer. Screening cells S2-3+, S3 2+. Peg screen same results.  ABID on the Tango  positive reactions but was able to rule out all alloantibodies, A Peg panel demonstrates an anti-c. Today patients repeat antibody screen is negative on Tango. Repeat Peg positive S2&S3 2+pos.  I don't want to miss an antibody that may require a titer.  Is this antibody an IgM?

 

2 hours ago, ESIZENSKY said:

I have a pregnant patient antibody screen positive on my Tango analyzer. Screening cells S2-3+, S3 2+. Peg screen same results.  ABID on the Tango  positive reactions but was able to rule out all alloantibodies, A Peg panel demonstrates an anti-c. Today patients repeat antibody screen is negative on Tango. Repeat Peg positive S2&S3 2+pos.  I don't want to miss an antibody that may require a titer.  Is this antibody an IgM?

 

It could be.  We see a number of pregnant women per year, with anti-c, who are either group A, but appear to have anti-A in their plasma when we group them, or are group B, but appear to have anti-B in their plasma when we group them, because the reverse grouping cells are (apparent), dce/dce and so will react with IgM anti-c.

Is she Rh neg? Could it be anti-c persisting from the Rhogam?

I hope they aren't making RhIG from someone who can make anti-D as well as anti-c.  She would have to be r'r', right?  She needs to be donating Red Cells, not plasma for RhIG.   I get the point though that the idea of a passive antibody is always worth keeping in mind.