IMMUNOTHERAPY WITH PARTIALLY PURIFIED AND STANDARDIZED TREE POLLEN EXTRACTS .4. RESULTS FROM LONG-TERM (6-YEAR) FOLLOW-UP

The long-term effect of tree pollen extract immunotherapy was investig ated 6 years after termination of the treatment. Subjective symptom ev aluation of 36 patients 6 years after a 3-year period of immunotherapy showed that rhinitis and asthma symptoms remained at the improved lev el reached just after termination of the treatment. Some 86% of the rh initis patients and 68% of the asthma patients maintained improvement. None of the rhinitis patients developed asthma in the study period. S kin prick tests reflected the outcome of the subjective symptom assess ment. The skin sensitivity of the patients decreased significantly dur ing immunotherapy, and the skin reactions 6 years after specific immun otherapy were still significantly lower than the pretreatment levels. Total IgE and birch-specific IgE levels were constant throughout the s tudy period, and both the affinity and epitope specificity of the IgE antibodies of the patients were the same before, during, and 6 years a fter treatment. In conclusion, specific immunotherapy reduces symptoms in patients suffering from rhinitis and asthma, and the effect is mai ntained 6 years after termination of the treatment. Specific immunothe rapy seems to prevent long-term development of asthma in rhinitis pati ents. IgE measurements do not reflect the overall status of the patien ts.