DOUBLE-BLIND, PLACEBO-CONTROLLED EVALUATION OF SUBLINGUAL IMMUNOTHERAPY WITH STANDARDIZED OLIVE POLLEN EXTRACT IN PEDIATRIC-PATIENTS WITH ALLERGIC RHINOCONJUNCTIVITIS AND MILD ASTHMA DUE TO OLIVE POLLEN SENSITIZATION

For evaluation of the efficacy and the safety of specific sublingual i mmunotherapy with high allergen dose, 66 children with seasonal asthma , rhinitis, and conjunctivitis due to sensitization to olive pollen we re enrolled in a double-blind, randomized, placebo-controlled study be tween October 1994 and October 1996 in Greece. Thirty-four patients we re randomly allocated to the active group, and 32 received placebo. Im munotherapy consisted of olive-allergen extracts (Stallergenes SA) adm inistered sublingually pre- and coseasonally from January to July for 2 consecutive years. Serial concentrations from 1 to 300 IR were used up to the maintenance dose of 20 drops of 300 IR daily. The cumulative dose for each patient was 300 times higher than in parenteral immunot herapy, and the cumulative dose of the major allergen Ole e 1 was 8.1 mg/2 years. The patients were assessed by clinical parameters (symptom and medication scores from patients' daily diaries) and immunologic m easurements (specific IgE, IgG4, eosinophil cationic protein [ECP]) we re performed. The actively treated patients had a significantly lower score for dyspnea (P<0.04 during the first season; P<0.03 during the s econd season). At the pollinic peak during the second year, a lower sc ore of conjunctivitis was recorded (P<0.05) in the actively treated pa tients. The analysis of intragroup evolution showed that the total sco re of rhinitis increased significantly during the pollinic peak in the group under placebo, whereas there was no symptomatic peak for the sa me period in the group under active treatment. However, the difference between the groups was not significant. The medication score did not differ significantly between the groups. Oral steroids were the only v ariables with a P value near the significance level (P=0.06) in favor of the actively treated group. A significant decrease in skin reactivi ty was recorded in the active group after 2 years of treatment. No sig nificant variation in specific IgE and IgG4 was detected. A significan tly lower level of serum ECP was observed at the pollinic peak in the actively treated patients during the first pollen season (P=0.01), but this was not confirmed the second year when the ECP levels doubled in both groups without correlation to the clinical findings. Tolerance w as excellent with only a few minor side-effects reported. In conclusio n, high-dose specific sublingual immunotherapy appears to be safe and effective in improving mild seasonal asthma and conjunctivitis linked to olive-pollen sensitization.