[Development of new sensitizations to allergic components in birch pollen extract during specific immunotherapy].

Specific immunotherapy is the only currently available allergen-orientated treatment able to modify the natural history of respiratory allergic diseases. Safety and clinical efficacy of this treatment are well documented, but evidence about the ability to reduce new sensitizations is still poor. The authors describe the development of new IgE specificities to allergenic components in birch pollen extract during specific immunotherapy. A study was carried out in 12 birch pollen-sensitive patients who received injection immunotherapy for 6 months. Eight patients not submitted to SIT were used as a control. New IgE sensitizations to Bet v 2 developed in 25% of the birch immunotherapy-treated patients and the oral allergy syndrome additionally in one of them.