Detection of human auto-anti-idiotypic antibodies (Ab2). I. Isolation and characterization of Ab2 in the serum of a ragweed immunotherapy-treated patient.

This study documents, by means of both solid and liquid phase assays, the presence of anti-idiotypic antibodies (Ab2) in the serum of one allergic individual undergoing ragweed immunotherapy. Serum from this individual was collected and F(ab')2 fragments specific for ragweed antigen E (AgE) were prepared (Ab1). These AgE-specific F(ab')2 Ab1, following absorption with normal immunoglobulin, were studied for their capacity to specifically bind autologous Ab2. The binding of Ab1 to Ab2 was demonstrated to be inhibitable by ragweed AgE but not by another allergen (oak) to which the patient reacted. These findings demonstrate the presence and binding specificities of Ab2 in the serum of a ragweed immunotherapy patient and may serve as a model to study the role of Ab2 in the regulation of Ab1 in allergic patients.