The presence of platelet-activating factor-acetylhydrolase in human middle ear effusions.

ABSTRACT

Factors related to inflammation, including platelet-activating factor (PAF), apparently have a role in chronic otitis media with effusion. PAF is metabolized to the biologically inactive lyso-PAF by the enzyme PAF-acetylhydrolase (PAF-AH). We have obtained evidence that PAF-AH activity is present in human middle ear effusions in patients with chronic otitis media with effusion. The present study revealed the enzyme in human middle ear effusions to be the plasma type PAF-AH. We suggest that PAF-AH may be involved in regulating inflammation in the middle ear by inactivating PAF, the potent proinflammatory autacoid.