No allergic origin for infusion reactions during infliximab treatment

Researchers of Sanquin Biologics found no association between IgE anti-infliximab antibodies and infusion reactions during infliximab treatment. Such adverse reactions to infliximab are relatively rare, but occasionally occur and are associated with immunogenicity. For long, a role of IgE anti-drug antibodies (IgE-ADA) in infusion reactions (IR) upon infliximab treatment has been suggested. However, due to the lack of a positive control used for assay validation, the role of IgE has remained controversial.

For this reason Karin van Schie and colleagues developed a robust assay to specifically detect IgE ADA against infliximab. They created a recombinant human IgE anti-infliximab antibody to use as a standard. Special care was taken to prevent aspecific reaction caused by rheumatoid factor, IgG4 or anti-hinge antibodies. The assay was not disturbed by high levels of IgG-ADA and modestly drug tolerant.

Van Schie found IgE-ADA against infliximab in only 11% of IR-positive rheumatoid arthritis patients, and even in these cases, the levels were very low, too low to be associated with allergic symptoms. Furthermore, all IgE-ADA positive patients were also positive for IgG-ADA.
Van Schie, of the research group of Theo Rispens: “If ADA do play a role in eliciting an IR, we expect IgG to be a more dominant risk factor than IgE”.