The aim of this study was to investigate expression of the neuropeptides substance P, vasoactive intestinal peptide and heat shock protein 70 in the nasal mucosa cells of patients with seasonal allergic rhinitis, in order to obtain more information on the pathophysiological and immunological role of these markers in allergic rhinitis.

Nasal epithelium specimens obtained from 42 patients with allergic rhinitis were studied, using Shandon's Papspin liquid-based cytology method. Smears were immunostained with antibodies against substance P, vasoactive intestinal peptide and heat shock protein 70, and the results were correlated with the clinical features of seasonal allergic rhinitis.

A positive reaction for substance P, vasoactive intestinal peptide and heat shock protein 70 was observed in 73.8, 66.7 and 69.0 per cent of the allergic rhinitis mucosal smears, respectively. The Pearson chi-square test showed that 40.5 per cent of the immunostained smears had a positive reaction for one or two of the markers studied (i.e. substance P, vasoactive intestinal peptide or heat shock protein 70), and that 47.6 per cent of the smears had a positive reaction for all the markers (p < 0.0001).

We found a high level of expression of substance P and vasoactive intestinal peptide in the nasal mucosa smears of patients suffering from allergic rhinitis. This indicates a role for these neuropeptides in the neuroregulation of immunity and hypersensivity in this disease. Furthermore, expression of heat shock protein 70 may contribute to the development of allergic rhinitis.