Changes in thymus- and activation-regulated chemokine (TARC) associated with allergen immunotherapy in patients with perennial allergic rhinitis.

BACKGROUND Thymus- and activation-regulated chemokine (TARC), which is a CC chemokine receptor (CCR) 4 ligand with ability to recruit Th2 cells to inflammatory sites, is pathogenetically important in allergic rhinitis. Specific immunotherapy (IT), among the most effective therapies for allergic rhinitis, has incompletely understood mechanisms of action. TARC might be involved in some benefits of IT. METHODS TARC in sera was assayed, obtained from 50 patients with house dust mite allergic rhinitis before and 1 year after beginning IT. Their ages ranged from 6 to 34 years (mean, 10), 30 were male and 20 were female. RESULTS In patients whose nasal obstruction responded to IT, TARC decreased significantly with IT, while when response was defined in terms of sneezing or rhinorrhea, TARC did not change significantly. CONCLUSION TARC might be an important target of IT in reducing obstructive allergic rhinitis.