Booster immunotherapy (BIT).

This study tries to answer two questions: 1) how long does the therapeutic effect of successful immunotherapy (IT) last after termination of the treatment? and 2) what is the best treatment for recidivist patients? To answer the first question, we asked 108 patients with rye/grass pollen allergy who had previously undergone IT for 3-4 years and had responded well to treatment to complete a questionnaire on the course of their recovery after termination of the therapy. Evaluation of the answers revealed a recidivist rate of approximately 30% in the first 3 years. According to our results, the risk of a relapse after this period seems to be low. To answer the second question, we included 40 patients suffering from type I allergy to grass/rye pollen in a clinical study. Each of them had previously undergone specific IT with a grass pollen extract mixture and had terminated this therapy after 3-4 years practically free of symptoms during the grass pollen season. As the symptoms returned and increased from year to year after the end of IT, new therapeutic steps had to be considered. We investigated the efficacy of a short preseasonal injection treatment called "booster immunotherapy" (BIT). BIT was performed with two different injection-regimens, a low-dose schedule comprising six injections and a high-dose schedule with 11 injections, in both cases administered as a build-up regimen. In the next pollen season, 28/40 (70%) patients reported strong improvement or even complete remission of the allergy symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)