Immunotherapy in Spring-Time Hay Fever.

Abstract

In a study of efficacy of 2 different treatment schedules for perennial immunotherapy, 47 adult patients with spring-time hay fever due to allergy against birch and other deciduous trees were randomly assigned to 3 treatment groups; 1 group received birch, alder and hazel allergen in Allpyral, another group received the same Allpyral mixture and all relevant tree pollens in aqueous extract and a control group received no injections. For determination of antibody titers, the radioallergosorbent test (RAST) and the ammonium sulfate precipitation (ASP) technique were used. Cellular responsiveness was studied by measuring birch pollen (BP) induced leukocyte histamine release in peripheral blood. The clinical and immunological response was similar in the 2 treated groups. Treated patients had less symptoms and lower consumption of antihistamine tablets during the pollen season than the control group. Non-Ig[immunoglobulin]E BP antibodies and IgE antibodies recorded with the ASP technique increased after immunotherapy while RAST values did not change significantly. A decrease of RAST values from postseasonal values during the 1st yr to preseasonal values in the following year was seen in all patient groups but was less pronounced in treated than in untreated patients. The decrease was more pronounced in patients with high RAST values of postseasonal sera than in those with low RAST values. Cellular reactivity increased slightly during the 1st phase of therapy but later returned to the pre-treatment level. Clinical improvement was positively correlated to the percentage increase of non-IgE antibody titer and to the pre-treatment non-IgE/IgE antibody ratio. Patients with high preseasonal RAST titers or high cellular sensitivity tended to have more severe symptoms during the pollen season. A mixture of birch, alder and hazel was sufficient for immunotherapy in spring-term hay fever. Changes of a single immunological variable do not account for the therapeutic results in immunotherapy.