[Brush technique in cytological analysis of the nasal mucosa. A critical and comparative analysis]

The cytological study of the nasal mucosa is one the essential steps toward a better understanding of the physicopathological mechanisms involved in chronic affections of the nose. The development of a reliable, reproducible noninvasive technique to obtain cells in the prerequisite for this analysis. The brush technique is based on the use of a small cylindric nylon brush which is rotated as it is moved back and forth across the nasal mucosa to harvest the various cell types present on the surface of the mucosa. The specimen obtained is centrifuged and examined under an optical microscope. A semi-quantitative analysis is carried out to determine the relative richness of the specimen in epithelial cells (ciliated, qoblet and basal cells) and in inflammatory cells (neutrophils, basophils, eosinophils, lymphocytes, and monocytes). A precise differential cell count is then performed. According to the results obtained, an immunologic marker study of lymphocyte subsets may also be done using the same specimen. This technique may be used in both children and adults and permits cell harvest from various sites within the nasal fossa. Already tested in the study of the activity of cilia, this method is promising for the cytological study of the nasal mucosa. The brush method and other techniques of cell harvest are described and compared.