Determination of proliferative activity in nasal polyps.

AIMS To determine the level of proliferative activity in 39 nasal polyps with clear cut distinct clinical behaviour patterns. METHODS The 39 nasal polyps included 11 polyps labelled as "single" and taken from the lateral nasal wall and the middle turbinate; 12 polyps labelled as "massive" and relating to diffuse polyposis involving the entire nasal cavity; six polyps labelled as "ASA" and relating to nasal polyps from patients with acetylsalicylic acid intolerance and asthma; and 10 polyps from cystic fibrosis related polyposis. Cell proliferation was determined by two independent methods: first, the computer assisted microscope analysis of isolated Feulgen stained nuclei for the measurement of the percentage of cells in the S phase of the cell cycle; and second, the immunohistochemical evaluation of a proliferation associated protein by means of the MIB 1 monoclonal antibody. RESULTS The cystic fibrosis related polyposis exhibited the highest proliferative activity of all the clinically identified nasal polyp groups. Acute inflammatory nasal polyps exhibited a higher cell proliferation than chronic ones. The results also show that while the immunohistochemical determination of cell proliferation by means of the MIB 1 monoclonal antibody is a valuable tool in determining cell proliferation in nasal polyps, the cytometrical image analysis of Feulgen stained nuclei is not useful for this purpose. CONCLUSION Cell proliferation activity identifies cystic fibrosis as being distinct from the other nasal polyp groups.