Induction of allergy to new aeroallergens during specific immunotherapy (SIT) in grass pollen sensitive patients

In the group of 50 patients suffering from grass pollen allergy and successfully treated with SIT for three consecutive years, we observed in 5 persons after the end of this treatment the induction of allergy to new allergens (to weeds, mites or tree) manifested by the change of the symptoms season. The induction of the new kind of allergy was confirmed by revealing of the positive skin prick tests to new allergens and by an increase of the specific IgE serum level to them. Despite disappearance of the symptoms of the illness during grass pollen season in all 5 patients we noted the higher total IgE as well as specific to grasses IgE serum level, in comparison to the value at the start of SIT. In the paper the possible mechanisms of this phenomenon are discussed, which seems to be not connected with the natural development of allergy and which confirms once more that during SIT individual changes in humoral and cellular immunity of the patient take place, sometimes very difficult to be predicted. They may among others switch clinical profile of allergy, what indicates that patient during SIT should be under the careful immunological supervision.