Thank you for your inquiry.
I will try and answer both of your questions.
1. Has Gammagard liquid been tolerated subcutaneously in patients with undetectable IgA levels?
The answer to this question is best found in Reference Numbers 1 and 2 below. As you will see from these references, reactions to immunoglobulin infusion in patients with low IgA are unpredictable and we do not entirely understand the pathogenesis. We do know, however, that some people with very low IgA have been able to tolerate Gammagard subcutaneously, and you will see from Reference Number 3 that subcutaneous infusion may be safer for these patients than intravenous infusion.
2. Has Gammagard S/D been used off-label subcutaneously?
The answer to this question is yes. In Reference Number 3, you will see that the authors use 10% Gamimune N subcutaneously. Gamimune N is the former name of Gammagard S/D. So there is at least one report in the literature of safe subcutaneous administration of a preparation equivalent to Gammagard S/D.
In addition, although I have no personal experience with the use of Gammagard S/D subcutaneously, by anecdote via discussion with my colleagues, it is clear that some have employed this agent subcutaneously.
Thank you again for your inquiry and we hope this response is helpful to you.
1. Rachid R and Bonilla F. The role of anti-IgA antibodies in causing adverse reactions to gammaglobulin infusion in immunodeficient patients: a comprehensive review of the literature. J Allergy Clin Immunol 2012; 129:628-634.
2. Rachid R, Castells M, Cunningham-Rundles C, Bonilla F. Association of anti-IgA antibodies with adverse reactions to gammaglobulin infusion. J Allergy Clin Immunol, available online March 21, 2011; published July 2011 edition.
3. Stiehm ER, et al. Slow subcutaneous human intravenous immunoglobulin in the treatment of antibody immunodeficiency: use of an old method with a new product. J Allergy Clin Immunol 1998; 101(6):848.
Phil Lieberman, M.D.