Blood donors at Oslo University Hospital (OUH) Blood Bank with self-reported birch pollen allergy and/or asthma were recruited for the study during last 4 months of 2015 and first 2 months of 2016. They signed an informed consent form for the study and were randomized into Andosan™ and placebo Groups. The PI (MD) had the study key and the participants in the study were handled by other staff (nurses and bioengineers) at the blood bank. The participants were given a questionnaire that was filled out before and after the study. Before, during and after the study also blood samples were taken for allergy testing (IgE, BAT) or cytokine profiles. When the participants visited the blood bank after 3.5 weeks, they brought the study medicine vessel (plastic container) that was controlled for remaining study medicine (all should have been used) and given new study medicine for the remaining study period (3.5 weeks). The participants were also asked about possible side effects of the study medicine. In the intervention arm, Agaricus blazei-based mushroom extract Andosan™, was given, which is produced as Health food in Japan and imported as food to Norway and provided for the study by Immunopharma company, Norway. Data were collected and analyzed together after the study. Statistical help was solicited from an OUH statistician.
