This question was posted on Wednesday, May 23 on Pat Letendre’s Medlab list and is reposted here with Linda Stang’s permission: We have a patient with lymphoma and an IgG peak (we think). The antibodies are interfering (and I mean really interfering) in the coags: INR >5.0 but has had clinical challenges with no bleeding. Is there any way to remove IgG from samples? I am currently trying a heterophile blocking tube (HBT) hoping that it will neutralize the antibodies. Does anyone know of any other method to remove unwanted IgG from a sample, but have it remove little else? Thanks in advance for any suggestions.
Linda Stang MLT
Lab Scientist, Special Coagulation & Flow Cytometry
University of Alberta Hospital, Edmonton, Alberta, Canada
And an added comment, Friday, May 25, from Linda: The HBT tube did correct the INR somewhat, but only from 4.9 down to 3.9 (3.4 if I were to use 2 HBT tubes), and the appropriate controls did not vary much with the HBT treatment. The INR is consistently 4.8–6.0 with different reagents/analyzers, PTT is 48 or 80, depending on the PTT reagent used. I am considering purchasing a protein G column, but am a little scared of how the coag will be affected. Surgery is on hold, with us trying to verify that the underlying coags are normal.
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