Tumor necrosis factor in middle ear effusions.

The presence of tumor necrosis factor (TNF) was determined in middle ear effusions from 27 ears of children with chronic otitis media with effusion. Cytotoxic activity was assessed by quantitation of target (HeLa) cell death after incubation with the aspirate. Moderate cytotoxic activity was found in 17 of 27 samples (mean cell death of 53% and 32% at 1:2 and 1:4 dilutions, respectively). In ten (37%) of the middle ear effusion aspirates no cytotoxic activity was detected. To confirm that cytotoxicity was due to TNF, 13 of the samples with cytotoxic activity were incubated with a monoclonal anti-TNF antibody and retested. Cytotoxicity was blocked by the anti-TNF antibodies in all cases. Tumor necrosis factor, derived most probably from macrophages or mast cells in the middle ear, may mediate various pathologic processes associated with otitis media, such as generation of mucoid effusion, fibroblast proliferation, and bone resorption.