To test whether the administration of the antigen, OVA IN and IG route after the establishment of chronic asthma model could reverse the characteristicfeatures of lung histopathology in BALB/c mice.

Mice were divided into 4 groups. Chronic asthma model was established in groups I, II and III as per protocol. Mice in group I were treated with 100 μg ovalbumin (OVA) intranasally route on consecutive days starting from day 68. (days 68-73). Mice in group II were treated with 5 mg of ovalbumin (OVA) in 300 μl saline by intragastric route on alternate day (68-71-74). Group IV served as controls. On day 92 lungs were taken out for histopathologic evaluation.

All of the histopathological parameters in all airways were significantly more in group III when compared to controls. All of the histopathologic parameters were significantly less in group I when compared with group III. No significant difference was detected between in any of the parameters in the comparison of Group I and controls. Comparison of Group II with that of Group III revealed that all the parameters were significantly less in Group II. Comparison of Group II with controls revealed no significant difference. There was no significant difference is any of the evaulated airway histopathological parameters in the comparison of Group I and Group II.

We concluded that low dose intranasal allergen immunotherapy, as well as high dose intragastric allergen immunotherapy are efficent therapeutic strategies for ameliorating the choronic histopathological changes iin asthmatic airways of BALB/c mice.