Plasma IgG, IgG subclasses and acute-phase proteins in children with recurrent acute otitis media.

Quantitation of IgG, IgG subclasses and acute-phase proteins was performed in plasma samples from 156 children, aged 2 to 162 months, with varying degrees of otitis proneness. None of the children had acute otitis media or had received any antibiotics 3 weeks before the examination. Children with recurrent acute otitis media (rAOM) had significantly higher levels of total IgG, IgG1, and significantly lower levels of IgG2 than healthy children (p less than 0.02, p less than 0.0003, and p less than 0.03, respectively). However, the low levels of IgG2 found in the rAOM children could at least, to some extent, be explained by the observation that these children were somewhat younger than the healthy children. Except for recurrent episodes of common colds, children suffering from secretory otitis media (SOM) most often show no clinical signs of inflammatory events. Nevertheless, children with SOM had raised levels of plasma IgG1, indicating recurrent polyclonal stimulation of the immune apparatus, which seems to be less pronounced than that of rAOM children. Levels of acute-phase proteins, haptoglobin, orosomucoid and alpha 1-antitrypsin were evenly distributed in the children investigated, reflecting that they had no acute illness at the time of plasma sampling.