Thank you for your inquiry.
Unfortunately there is no definitive answer for your question. I can, however, review the data that we do have that might help you reach a decision regarding the advisability of your patient donating plasma.
First of all, the presence of a positive chronic urticaria index (CUI) alone is insufficient to cause urticaria. According to the study performed, the specificity of a CUI can vary. In other words, not every patient with a positive CUI will have urticaria. It can be present in other conditions where urticaria is absent and in asymptomatic patients as well (see abstracts copied below).
Secondly, I was unable to find any recorded instance of urticaria being transmitted by transfusion of either whole blood or plasma via the transmission of antibodies against the Fc-epsilon receptor.
These two observations give some indication that plasma donation from your patient would be unlikely to transmit urticaria. However, unfortunately, the autoantibodies would not be removed from your patient’s plasma, and therefore the potential for transmission of urticaria could not be ruled out.
Thus, as noted, there is no definitive answer to your inquiry, and I am afraid the best we can do is to put the issue in perspective for you as noted above.
Thank you again for your inquiry and we hope this response is helpful to you.
Chronic Autoimmune Urticaria: Where we Stand?
R.K. Viswanathan et al: Autoimmune Profiling in Chronic Idiopathic Urticaria -- Is there Utility or Futility? The Journal of Allergy and Clinical Immunology Vol. 129, Issue 2, Supplement, Page AB224.
Biagtan et al: Clinical utility of the Chronic Urticaria Index. The Journal of Allergy and Clinical Immunology, Volume 127, Issue 6, Pages 1626-1627, June 2011.
Phil Lieberman, M.D.