Study: climate therapy for respiratory tract inflammation

High-altitude climatotherapy is an established therapeutic option for improving the clinical symptoms of asthma. However, the underlying immunological mechanisms have so far been little researched. This study by the Swiss Institute of Allergy and Asthma Research investigates theinfluence of altitude climatotherapy on airway inflammation and on cellular components of the specific and non-specific immune response.

Exhaled nitric oxide (NO)decreased significantly within three weeks of therapy in patients with allergic and intrinsic, moderate to severe asthma. Interleukin-10 (IL-10)-secreting peripheral blood mononuclear cells increased in six out of eleven patients within three weeks of therapy, while blood cells secreting transforming growth factor-beta(1) (TGF-β1) remained stable. In addition, the activation of monocytes, as measured by CD80 expression, decreased significantly during therapy.

The frequency of CRTH2-expressing T cells decreased, while regulatory T cells (T(reg)) remained stable. The mRNA expression of FOXP3 and GATA-3 in CD4(+) T cells did not change, while the expression of interferon-gamma and IL-13 decreased in eight out of ten patients.

The present data show that altitude climatotherapy reduces local airway inflammation. In addition, monocytes change their profile towards a tolerogenic phenotype. The ratio of T(reg) to Th2 cells increases, but no de novo differentiation of Th2 or T(reg) cells is observed due to the absence of antigens/allergens. High-altitude climate therapy could therefore form the immunological basis for the endogenous control of allergen-related diseases.