A NEW COLLECTION METHOD FOR THE EVALUATION OF NASAL MUCUS PROTEINS

Background Different sampling techniques for collecting nasal mucus ha ve been used. The eosinophil and its granule toxin proteins, especiall y the eosinophil cationic protein (ECP), is an important inflammatory cell. Objective In the healthy subjects (with no acute or chronic dise ase of the respiratory tract), no detailed quantitative data on mucus nasal proteins have been reported, so the aim of the study is to demon strate a simple and reliable method for the collection of nasal mucus and for measuring nasal ECP. Methods Our method consists in collecting two specimens of mucus from each nasal fossa, using a square of steri le pre-humidified gauze, centrifuged at 2000 g for 20 min and stored a t -20 degrees C until tested. To evaluate the reproducibility of the t echnique, 30 healthy subjects were retested after 24 h. Results The am ounts of secretion gathered in the 89 collections did not show any sta tistical difference between the sexes. In the pooled subjects (n = 59) , the mean levels of ECP were 108 ng/mL and 325 ng/g and total protein (TP) levels were 701 mg/dL and 2.5 mg/g (expressed in absolute concen tration and concentration related to the weight in grams). In the clas ses, according to age, no statistical differences were found on analys is of the groups by: sex, recovery rate, and ECP and TP concentrations . The Reproducibility Index was very good for the recovery rate (0.78) , ECP (ng/mL = 0.95, ng/g = 0.83) and TP (mg/dL = 0.89, mg/g = 0.76). Conclusion With our method, the sample collections were taken with min imal stimulation of the mucosa and it was well tolerated by the subjec ts; the low known dilution factor is also adequate for analysing small quantities of mucus recovered, and the protein concentration can be m easured as an absolute value.