Immunological and clinical evaluation during a 12 month period of immunotherapy

Serum IgE and IgG4 were evaluated in twenty adult allergic rhinitis subjects during a 12-month immunotherapy (IT) course against common inhalant allergens. The selection criteria for IT were the result of a prolonged history of allergic diseases and a positive skin test for common inhalant allergens. Twenty non-atopic adults served as the control group. By using enzyme-linked immunoassay a normal range of IgE and IgG4 were 78 +/- 40 IU/ml and 180 +/- 54 micrograms/ml, respectively. The changes in IgE and IgG4 levels were compared with significant improvements of symptoms and drug consumption. The clinical and laboratory responses to IT were considered good in 8 cases (40%), moderate in 7 cases (35%), and poor in the remaining 5 cases (25%). A regression analysis revealed a negative simple linear correlation between elevated level of IgG4 and diminished level of clinical symptom scores during 12 months of IT (Pearson's r = -0.7548). The serum IgG4 level after one year IT predicted change in clinical symptom scores.