[Clinical and immunological analysis of Birch pollenosis].

In recent years, the number of cases Birch pollenosis has increased, but there have been very few reports, and therefore we decided to carry on this clinical and immunological analysis as follows. (1) Statistical analysis of Birch pollenosis patients who visited the Department of Otorhinolaryngology of Hokkaido University School of Medicine, Sapporo. (2) Study of atmospheric birch pollen counts and investigation of the relationship between the incidence of pollenosis and pollen count. (3) Allergen analysis of Japanese Birch pollen using Western blotting method. (1) From 1990 to 1992, 392 cases of nasal allergy visited our hospital and 74 cases (18.9% of all cases) were birch pollenosis. There was a significant increase in the number of cases birch pollenosis, compared with previous reports. (2) Atmospheric pollen grains of birch pollen were collected by Durham's pollen trap at Hokkaido University School of Medicine, Sapporo from 1990 to 1992. In this study, birch pollen was collected from the beginning of April to the middle of June. The first day when birch pollen was collected in this study was about one month earlier than previously reported. We suspected that the mean temperature rise of Sapporo city in April is one of the factors that lead to the increase of incidence of birch pollenosis. (3) Allergens in birch pollens from Betula platyphylla Sukatchev var. japonica and Betula Ermanii Cham in Japan were identified by Western blotting, following separation by SDS-PAGE, transfer to PVDF membranes and incubation with sera from 35 birch pollenosis patients. In almost all cases, 17kd molecular from B. platyphylla and B. Ermanii pollen proteins were detected as the major IgE binding components.