The value of total IgE determination in mite allergy

Our aim was to study the behaviour of patients with perennial respiratory allergy in relation to total IgE production. We chose patients allergic to house dust mite Dermatophagoides pteronyssinus, because this is the most representative perennial antigen. The total IgE in a wide group of patients was evaluated in relation to diagnosis, clinical activity, and seasonal changes. We also studied the possible changes in relation to immunotherapy. The total IgE was measured through enzyme immunoassay (Kallestad). To compare the results, a Student's test for independent data was performed and a statistically significant difference (p less than 0.001) in the IgE levels was found between the rhinitis and asthma groups with or without associated rhinitis. We did not obtain any differences between the groups in relation to clinical activity or seasonal changes. In relation to the possible changes in IgE levels according to the duration of immunotherapy, we observed a mild elevation before 7 months and between 13 and 24 months of treatment, without any significant differences with respect to basal levels. The determination of total IgE seems to us a valid and necessary test to complete the diagnosis of the existence of a cytotropic hypersensitivity mechanism in respiratory pathology. However, it seems to be less sensitive because it does not detect changes with respect to clinical activity, seasonal changes or duration of immunotherapy when dealing with perennial antigens.