THE EFFECT OF IMMUNOTHERAPY ON T-CELL SUBSETS IN PERIPHERAL-BLOOD ANDBRONCHOALVEOLAR LAVAGE FLUID IN POLLEN-ALLERGIC PATIENTS

The effect of immunotherapy (IT) on T-cell subsets in peripheral blood and bronchoalveolar lavage fluid (BAL) was examined in 15 patients wi th rhinoconjunctivitis and asthma caused by sensitivity to birch polle n. They were treated with IT for 3 years. Seven patients were treated with highly standardized birch-pollen extract (Pharmacia, Sweden). Eig ht untreated patients served as controls. Histamine challenge, blood s ampling, and BAL were performed before (January, February), and at the peak of, the birch-pollen season (May). The subpopulations of T cells in peripheral blood and BAL fluid were investigated by immunocytochem istry and flow cytometry. During the birch-pollen season, the percenta ge of CD3+ and CD4+ cells of blood mononuclear cells in the IT patient s increased significantly (P < 0.03 and P < 0.02, respectively). The p ercentage of CD8+ cells remained unaltered. In control patients, no ch anges of T-cell subsets in the peripheral blood were observed. T-cell subsets in BAL did not change during the season in relation to preseas onal values for either IT-treated or non-IT-treated patients.