Study of nasal cytology in atopic patients after nasal allergen challenge.

In order to study the normal and pathological inflammatory cell population in nasal secretions, nasal microsuction has been performed in 18 atopic patients and 10 healthy volunteers after nasal allergen and/or PBS challenge. After cytospin, the samples have been stained with May-Grünwald-Giemsa solution. Three hundred inflammatory cells have been counted by light microscopy, and the percentage of each cell type has been calculated. Results show that only a significant increase (p < 0.01) in the percentage of eosinophils 1-10 h after nasal allergen challenge occurs. In general, this finding correlates well with the symptom of nasal obstruction as measured by passive anterior rhinomanometry (PAR) during the late phase, but not with the number of sneezes. In agreement with the literature, late-phase nasal obstruction is shown to be accompanied by an increase in the percentage of eosinophils in nasal secretions. The potential role of eosinophils in the pathogenesis of the late phase in the inflammatory events after nasal allergen challenge has again been confirmed by our study. This study further confirms the usefulness of nasal microsuction as a sampling technique, providing uniform and adequate nasal cytological specimen for the analysis of nasal cytology.