Chemotactic activity in middle ear effusions.

A study of chemotactic activity in different middle ear effusions (MEE) was undertaken using a technique that has overcome some of the pitfills of previous chemotactic investigations on MEE. In the present study, neutrophils were made to migrate upwards toward a chemotactic gradient. Chemotactic activity was differentiated from increased random migration by the use of a two-filter paper system. The study indicated that directed migration or chemotaxis was present in 65% of purulent effusions, in approximately 25% to 30% of serous and seromucinous effusions, but in less than 20% of mucoid effusions. Chemotactic agents in MEE have been discussed. Chemotactic activity for neutrophils may be an important part of the inflammatory response in otitis media with effusion (OME) and responsible for the elimination of bacteria and other foreign particles. On the other hand, prolonged chemotactic activity owing to immunologic or nonimmunologic mechanisms may be responsible for the release of lysosomal enzymes and the subsequent maintenance of an inflammatory response in middle ear tissue. The exact mechanism and nature of the underlying chemotactic response for leukocytes in OME remain to be determined.