THE PRESENCE OF PLATELET-ACTIVATING FACTOR-ACETYLHYDROLASE IN HUMAN MIDDLE-EAR EFFUSIONS

Factors related to inflammation, including platelet-activating factor (PAF), apparently have a role in chronic otitis media with effusion. P AF is metabolized to the biologically inactive lyso-PAF by the enzyme PAF-acetylhydrolase (PAF-AH). We have obtained evidence that PAF-AH ac tivity is present in human middle ear effusions in patients with chron ic otitis media with effusion. The present study revealed the enzyme i n 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 e ar by inactivating PAF, the potent proinflammatory autacoid.