Changes in nasal metachromatic cells during allergen immunotherapy in children

Immunotherapy (IT) has been successfully used in the treatment of allergic rhinitis for years. Several mechanisms have been postulated for the clinical efficacy of IT. In this study we investigated the effect of IT on the number of metachromatic cells on the nasal surface in children with perennial allergic rhinitis (PAR). Nineteen subjects were treated with IT and 12 subjects, who did not receive any treatment, constituted the 3rd and 6th months of IT by symptom scores, physical examination findings, metachromatic cell counts from nasal mucosal epithelial scrapings and nasal provocation scores. At the 3rd and 6th months of IT, nasal symptom scores, nasal provocation scores and the number of metachromatic cells in epithelial scrapings were significantly reduced compared with the pretreatment values in the IT group. These reductions were not observed in the control group. It is concluded that the reduction in the number of metachromatic cells could be at least partially responsible for the clinical efficacy of IT in children with PAR.