Different groups of inflammatory mediators were identified in the human middle ear mucosa, fluids and effusions. A lot of different mediators participate in initiation and early stages of the middle ear inflammation, including arachidonic acid metabolites (prostaglandin E 2 and leukotrienes LT-B 4 , LT-C 4 ), 75, 76 histamine, 77,78 platelet-activating factor, 79 surface cell adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, endothelial leukocyte adhesion molecule-1, platelet endothelial cell adhesion molecule), 80,81 soluble cell adhesion molecules (soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1), 82, 83 chemokine RANTES, 84 complement C3a anaphylatoxin 85 and interferon-g. 86 However, cytokines are the key mediators of the middle ear inflammation. Cytokines regulate different stages of inflammation, are responsible for resolution of inflammation and can initiate local molecular processes leading to histopathological changes in the middle ear mucosa and submucosa, and the chronic condition of otitis media. Different groups of cytokines have been identified in the middle ear effusions and mucosa: the pro-inflammatory TNF-a, IL-1b, IL-6 and IL-8; the immunoregulatory IL-2, IL-10 and TGF-b; and the allergy-associated IL-4, IL-5 and GM-CSF.