A study of IgE in immunoglobulin preparations for intravenous administration. I. IgE in intravenous IgG.

We have studied the IgE content of different lots of commercial intravenous IgG preparations used in our day hospital as replacement therapy for patients with agammaglobulinemia. Two enzymatic methods were used: Phadezym and FAST. The average amounts of IgE detected in Endobulin and Sandoglobulin lots were very high with respect to serum values in the general population. In some lots we found low titers of specific IgE (RAST class 1) to house dust mite, rye grass and cow's milk. We also found in most preparations the presence of IgG anti-IgE which are usually present in sera from atopic patients. Despite a low post-infusion increase of serum IgE and the absence of sensitization or adverse reactions observed, a careful selection of donors with normal IgE levels may need to be recommended to manufacturers in the future.