Bile acids identified in middle ear effusions of children with otitis media with effusion

Abstract

Several studies have shown the presence of pepsin in the middle ear effusions of children with otitis media with effusion (OME). When gastric reflux is the cause, other noxious reflux products might be present. We therefore investigated the presence of bile acids in the middle ear effusions of children with OME. We evaluated 38 children (63 samples of middle ear secretions (ME samples)) in a prospective study at a tertiary care children's hospital. ME samples were collected from children with OME during ventilation tube insertion. Most ME samples were diluted with albumin. The presence of bile acids was measured with the 3alpha-hydroxy steroid dehydrogenase enzymatic method. A ME sample was considered positive when it contained at least 5 mumol/l bile acids, independent of dilution. Blood samples were taken simultaneously as a reference to determine bile acids serum levels. We found bile acids in 32 % (20/63) of all ME samples and in 42% (16/38) of all children. Bile acids concentrations of 12 well-soluble ME samples ranged from 5.9-40.9 mumol/L and were 3.1-19.7 times higher than the serum concentrations. In 4 of the corresponding serums, no bile acids were measurable at all. Bile acids are present in a number of the ME samples of children with OME. Because of dilution, it is possible that more ears contain bile acids. Bile acids are known to be noxious to mucosal cells at a higher (pH) than pepsin and, therefore, might play a role in the pathology of OME.