[Comparative studies of the effectiveness of specific immunotherapy in house dust mite allergy]

In a prospective study, 60 patients with allergic rhinoconjunctivitis and/or asthma due to house dust mites were chosen for hyposensitization treatment with Migen (M) or Pharmalgen (P). Immunotherapy stretched over a whole year and every 3 months clinical results were evaluated by the patient's symptom score, by results of skin prick and conjunctival provocation tests, as well as by RIA and ELISA regarding the total and specific IgE and also specific IgG and IgG4 levels. Out of 30 patients of the M group, 15 were followed up over the whole therapeutic regimen, 4 of whom showed a very good, 7 a good to moderate clinical outcome and 4 showed no improvement at all. In the P group, 17 out of 30 patients were followed up whereby 9 showed a very good and 8 a good to moderate response. In both groups of patients a statistically significant decrease in skin and conjunctival sensitivity to mite allergens was observed after 12 months of therapy. However, there was no correlation between this observation and the failure or success of immunotherapy. Furthermore, in both groups there was significant increase in total and specific IgE (with a slight decrease after 6 to 12 months) and also in specific IgG and IgG4 (especially in the P group), but again these changes in antibody levels gave no indication of a good or bad clinical outcome. Hence, we believe other reasons than the usually presented thesis of inducing "blocking antibodies" by immunotherapy to be responsible for the well-known effects of hyposensitization.