Objective: To study the role of cytokines and nitric oxide (NO) in the pathogenesis of secretory otitis media (SOM).
Methods: The content of NO, interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-alpha) in blood plasma and middle ear effusion (MEE) were measured in 58 (80 ears) patients with secretory otitis media and in 23 normal subjects, respectively.
Results: NO, IL-8 and TNF-alpha were found in 100%, 82.2% and 71.4% of MEE respectively. NO, IL-8 or TNF-alpha of blood plasma in the SOM group was higher than those in the normal control group (P < 0.05). The concentration of NO, IL-8 or TNF-alpha in MEE was remarkably higher than those in blood plasma (P < 0.01). It revealed that the shorter the course, the higher the concentration of IL-8 in MEE (P < 0.01), and the longer the course, the higher the concentration of NO or TNF-alpha in MEE (P < 0.05). IL-8 concentration of MEE in serous fluid group was remarkably higher than that in the mucous fluid group (P < 0.01), and the concentration of NO or TNF-alpha of MEE in the mucous fluid group was higher than that in the serous fluid group (P < 0.05). NO level of MEE was positively correlated with TNF-alpha (r = 0.696 P < 0.01).
Conclusion: NO IL-8 and TNF-alpha might be important mediators in MEE secretion in SOM. IL-8 might participate in the defensive reaction of organism during the early stages of SOM, and play a role in serous effusion secretion. NO and TNF-alpha might be closely related to the persistence of SOM, and might be a mediator of mucin secretion in SOM.