Allergy: the discovery of igeThe discovery of IgE was a breakthrough for classical allergists. Laboratory tests showed raised levels of total IgE in most patients displaying classical allergic symptoms..If the patient knew what antigen caused their symptoms, then a radioallergosorbent test or RAST (described on p79) could be applied to measure IgE for that specific antigen. The RAST result usually confirmed that there was an excessive amount of IgE antibody that would bind the incriminated antigen. In a very short space of time, IgE became the touchstone of respectability for classical allergists. Some even changed the definition of allergy, yet again, to mean reactions involving IgE only. This definition is still used by a few allergists. When immunologists tried RASTs on patients diagnosed as food-allergic, they found a basic division. Those like Jane, with immediate, violent reactions, even to a very small amount of the offending food, almost always had high levels of IgE for that food, confirming the status of such reactions as classical allergies. Those like Susan, with 'delayed' or 'masked' reactions to foods, rarely produced positive RAST results for their culprit foods. More recently, some studies have shown that a small IgE reaction in the gut wall could be a contributing factor in people, but IgE is certainly not the major cause of the problem. *8\180\8* Allergies «Prescription Medications» |