Sublingual immunotherapy with a standardised grass pollen extract; a double-blind placebo-controlled study.

BACKGROUND

To assess the efficacy and safety of sublingual immunotherapy in patients with allergic rhinitis/conjunctivitis, a double blind placebo controlled study was performed.

METHODS AND RESULTS

Fifty-seven (57) patients with a well-documented history of seasonal grass pollen allergy were evaluated in a DBPC trial over a period of 10 months (January to November 1995) with a view to investigating the efficacy and safety of sublingual immunotherapy with a grass pollen extract, 9,500 BU/ml. The course of treatment consisted of an incremental phase of approximately 3 weeks followed by a twice weekly maintenance dosage of 9,500 BU. Compared with the placebo group (30 patients), the group treated with grass pollen extract (27 patients) showed a significant (p < 0.03) lower mean severity of allergic complaints, i.e. sneezing, and itchy nose, a watery runny nose and itching of the eyes during the maximum pollen counts of the season. The use of anti-allergic medication was similar in the two groups. Both groups showed a significant increase in grass-pollen-specific IgG serum levels. However, the increase shown in the patients treated with grass pollen extract occurred earlier in the season and was significantly (p < 0.002) higher than the increase detected in the placebo group. Side effects were limited to a small number of generally mild local reactions.

CONCLUSIONS

The treatment with sublingually applied grass pollen extract in patients suffering from allergic rhinoconjunctivitis caused by grass pollen was well tolerated and served to reduce the severity of allergic complaints, without reducing the consumption of anti-allergic medication.