EOSINOPHILIC-CHEMOTACTIC ACTIVITY IN THE CHEMOKINE FRACTION OF NASAL POLYPS

Introduction: The selective accumulation of eosinophils in the nasal m ucosa is a feature of chronic polypous sinusitis and allergic rhinitis . The reasons are still unknown. Chemotaxins play an important role in the leukocyte tissue immigration of chronic inflammatory processes. C hemokines include heparin-binding proteins, of which RANTES shows sele ctive chemotactic activity for eosinophils and memory T-lymphocytes bu t not neutrophils. Therefore we addressed the question whether human n asal polyps contain chemotactic activity for eosinophils. Methods: pro tein fractions were extracted from tissue of nasal polyps using fluid nitrogen, citratebuffer (pH 2,5) and ultrasound homgenization, Chemota ctic activity for eosinophils was investigated by bioassay in pooled e xtracts from nasal polyps of 30 patients after separation with heparin binding gelelectrophoresis. An enzyme linked immunoassay was performed to detect the amount of RANTES-protein in the single twenty samples. Results: eosinophil chemotactic activity could be detected in the hepa rinbinding fraction of pooled extracts from 20 patients without sympto ms of neither asthma bronchiale nor allergy but not in the non-heparin binding fraction. RANTES was identified in the heparinbinding fraction . Therefore it was detected in the twenty single extracts of nasal pol yps in concentrations known to elicit significant biological activity in vitro resigns, ranged between 3.1 ng/mg polyp and 0.3 ng/mg polyp. Conclusion: thus RANTES secretion in nasal polyps could be shown in a proteinfraction with eosinophilic chemotactic activity and it suggest to be one important reason for eosinophil immigration in chronic polyp ous sinusitis, Therefore more detailed investigations are needed to de tect other eosinophilic chemotactic substances in nasal polyps.