Cytological changes in nasal secretions accompanying delayed nasal response to allergen challenge

Patients with allergic rhinitis when challenged with allergen develop various types of nasal response, such as an immediate nasal response (INR), late nasal response (LNR), dual late nasal response (DLNR), or delayed nasal response (DYNR), probably because of different hypersensitivity mechanisms. This study was designed to investigate the cytological changes in the nasal secretions (NSs) during the DYNR, beginning 24-32 hours, reaching maximum at 32-36 hours, and resolving within 56 hours after the nasal provocation tests (NPTs) with allergens.

In 45 allergic rhinitis patients developing 45 positive DYNRs (p < 0.01), the NPTs and the phosphate-buffered saline (PBS) controls were repeated and supplemented with cytological examination of the NSs and determination of interferon (IFN) γ and IL-4 in nasal lavage fluid (NLF).

The repeated DYNR (p < 0.001) was accompanied by significant changes (p < 0.05) in the counts of neutrophils, monocytes, lymphocytes, epithelial and goblet cells, and, to a limited extent, of plasma cells and platelets in the NSs and increased concentrations of IFN-γ but not of IL-4, in NLF between 24 and 48 hours after the NPT. No significant cytological changes were found in NSs during the PBS controls (p > 0.1).

The DYNR is associated with cytological profiles in the NS different from those observed during the INR or LNR. The significant count changes of neutrophils, monocytes, lymphocytes, epithelial and goblet cells in NSs, and increased IFN-γ but not of IL-4 concentrations in the NLF, suggest a possible involvement of the cell-mediated hypersensitivity in the DYNR. These results also emphasize the diagnostic value of NPTs combined with cytological examination of the NSs in patients with nasal allergy.