METHODS: BALB/c mice were immunized with non-modified extract D1 (50 µg/mouse) with aluminum hydroxide (2 mg/mouse) 3 times at 3 week intervals and 6 weeks after challenged by intranasal 50 µl/mouse of D1. AIT occurred between immunization and the beginning of challenge: Group 1 "sham AIT" with 16 SQ injections of PBS; Group 2 16 SQ injections of non-modified D1 in increasing doses; Group 3 8 SQ injections of sD1 in increasing doses; Group 4 combined AIT of 4 SQ injections of sD1in doses of 100, 550, 1000 µg/mouse and 4 sublingual (SL) administrations of sD1 1000 µg/mouse; Group 5 negative control with sham immunization, AIT and PBS challenge. Sneezing (cpm) and breath frequency (plethysmography) were evaluated after challenge with animals sacrificed for histology. Levels of anti-Der p IgE, IgG1, IgG2a in sera were determined by ELISA.
RESULTS: Groups 2, 3, and 4 had significantly reduced sneezes, especially Group 3. Breath frequency was greater in Groups 2 and 4 then Group 1. Anti-Der p IgE in Groups 1, 2, 3 and 4 was elevated versus Group 5. Anti-Der p IgG1 was significantly increased in Groups 2, 3, 4 during AIT and after challenge. Histology showed complete suppression of inflammation in Groups 3 and 4.
CONCLUSIONS: AIT with monomeric succinylated allergoid from house dust mite was effective, with combined subcutaneous and sublingual AIT being most effective.