HIGH-ALTITUDE CLIMATE THERAPY REDUCES PERIPHERAL-BLOOD T-LYMPHOCYTE ACTIVATION, EOSINOPHILIA, AND BRONCHIAL OBSTRUCTION IN CHILDREN WITH HOUSE-DUST MITE ALLERGIC-ASTHMA

Asthma is a multifactorial disease of unknown etiology but often assoc iated with atopy and inflammation. Previous studies in adult asthma ha ve demonstrated the presence of activated T cells in blood, bronchoalv eolar lavage (BAL) fluid, and bronchial tissue, and the relevance of t heir soluble products for eosinophil function. In view of these observ ations, it was hypothesized that similar pathogenetic mechanisms also occur in childhood asthma. In fact, peripheral blood T lymphocytes in 14 children with house-dust mite allergic asthma showed clear evidence of T cell activation as measured by the expression of CD25 and HLA-DR antigen. Without changing medication, significant reduction of the IL -2 receptor a-chain expression within the CD4+ lymphocyte population w as observed after only 3 weeks of allergen avoidance. Within this time period, absolute and relative eosinophil numbers decreased to normal levels. After 5 weeks in an area of low house-dust mite exposure, lung function also presented evidence for clinical improvement of the asth matic disease. These results indicate similar pathogenetic mechanisms in childhood and adult asthma. Furthermore, they suggest that allergen avoidance may contribute to the efficient therapy of asthma in patien ts with house-dust mite IgE-meditated allergy. (C) 1994 Wiley-Liss, In c.