Rheumatoid factor in otitis media with effusion.

Because of the pathologic similarities between rheumatoid arthritis and otitis media with effusion (OME), rheumatoid factor (RF) was measured in 156 human middle ear effusion (MEE) and serum samples from patients with chronic OME. Using a quantitative latex agglutination test, we were able to demonstrate RF in the MEEs of 85% of patients with OME. Demonstrable RF titers were found in only 8% of the patients' serum samples. The titers of mucoid MEE samples were seven times higher than those observed in serous MEE samples. The presence of RF was not related to the age of the patient, the presence of viable bacteria in the MEEs, or history of OME.