Immunoglobulin levels in bronchoalveolar lavage fluid of children with recurrent obstructive bronchitis.

Bronchoalveolar lavage was performed in 22 children with recurrent obstructive bronchitis and the recovered lavage fluid samples were analysed for concentration of IgA, IgG, IgM, IgE and C3. Previously a significant influx of exudate macrophages and persistence of bacteria on the bronchoalveolar surface were detected in these patients and a severe mucosal inflammation was observed bronchoscopically. The relative lavage fluid levels of immunoglobulins to albumin were significantly higher than in serum, indicating a local production of these proteins. The elevated levels of C3 indicated a high activity of the macrophages and the complement system. It is concluded that the mucosal inflammation in patients with recurrent obstructive symptoms cannot be attributed to a deficiency of immunoglobulins either in blood or in bronchial secretions.