Oxygen consumption of middle ear and peripheral blood neutrophils in acute suppurative otitis media

Using an oxygen electrode, oxygen consumption has been measured in peripheral bloodneutrophils and the corresponding middle ear fluid neutrophils of 26 patients with acute suppurative otitis media. The data suggest that the middle ear fluid neutrophil is functional and is capable of producing an adequate oxygen burst in response to membrane stimulation by opsonized zymosan particles. Some middle ear neutrophils are actually capable of producing a greater respiratory burst than their counterparts in the peripheral blood. However, middle ear neutrophils do not show the increased metabolic activity at 40°C, which blood neutrophils regularly displayed compared with tests performed at 37°C. It is believed that this temperature (40°C) is more physiological during infection and might explain why middle ear neutrophils may not always be capable of destroying bacteria, even though they are present in adequate numbers in the middle ear fluid in some cases of acute suppurative otitis media. Further studies are needed to determine the nature of the defect(s) present in middle ear neutrophil at 40°C.