Long-term falls in antibodies to dust mite and pollen allergens in patients with asthma or hay fever.

'Spontaneous' improvement in, or alteration of, allergic symptoms is a common occurrence, and the immunological basis is of interest in attempts to develop effective specific therapy. In the present study we measured levels of serum antibodies to Dermatophagoides pteronyssinus in patients diagnosed as having house-dust-allergic asthma up to 40 years previously. The results show a progressive fall in both IgG and IgE antibodies to antigen P1 and RAST binding to crude D. pteronyssinus extract. By contrast changes in total serum IgE were not marked. Within each of the groups of patients diagnosed 20, 30 and 40 years previously, 70% no longer suffered severe symptoms. However, the absence of detectable IgE antibody in serum was neither a necessary nor a sufficient condition for loss of symptoms. A group of patients who had spontaneously recovered from hay fever had significantly lower IgG and IgE antibody for the major grass pollen allergen Rye I and also lower total IgE than current hay fever sufferers. In neither hay fever nor asthma was there evidence to link spontaneous improvement in symptoms with an increase in IgG antibodies.