Background: Some antihistamines are capable of inducing decreased expression of adhesion molecules in nasal and conjunctival tissues of allergic rhinoconjunctivitis patients. This study aimed to determine if one month of therapy with loratadine 10 mg once daily would also induce any decrease in serum levels of soluble ICAM-1 (sICAM-1) or VCAM-1 (sVCAM-1).
Material and methods: 40 monosensitized House Dust Mite (HDM) mild-to-moderate allergic rhinitis patients were included in the study. During the study, twenty patients randomly received 10 mg loratadine daily, the other twenty did not take any antihistamine. All patients were treated with nasal budesonide daily and sodium cromoglycate nasal spray when needed. Serum soluble ICAM-1 and VCAM-1 levels were determined by immunoenzimatic assay before and in the end of the study period.
Results: After one month of loratadine sVCAM-1 levels had a significant decrease (from 724.8 to 625 ng/ml) while sICAM-1 levels had a slight but not significant increase. Control patients did not have significant variations in sVCAM-1 or sICAM-1 serum levels. During regular antihistamine therapy patients improved their clinical scores.
Conclusions: Loratadine 10 mg daily during one month induced a decrease in sVCAM-1 but not in sICAM-1 levels in HDM allergic rhinitis patients.