I have a patient with allergic asthma not responding to conventional treatment and now considering immunotherapy. She has a history of RA which is well controlled off medications, but had blood work done that showed elevated IgG of almost 4000. Other immunoglobulin levels, including IgE were normal.

Would there be concern of immune modulation from SCIT that might cause any kind of mimicry that could worsen her autoimmune disease by shifting from Th2 to Th1 response and increased IL10?

More practically, if we do move forward with treatment, would it be reasonable to follow IgG levels periodically in addition to her clinical status?


Thank you for your inquiry.

I would not consider the elevated IgG in your patient a contraindication to immunotherapy, and I would not be concerned with the immunomodulatory responses to immunotherapy in this situation. Therefore, I do not think that you need to follow serial total IgG levels. However, with an IgG of 4,000, I would suggest that you assess your patient for monoclonality. With rheumatoid arthritis, it is highly likely that the IgG will be polyclonal, but a simple serum protein electrophoresis, immunofixation, or immunoelectrophoresis would answer the question easily.

Thank you again for your inquiry and we hope this response is helpful to you.

Phil Lieberman, M.D.

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