Humoral immunity in children with proven bronchiectasis, bronchial deformations and chronic bronchitis

In 70 children with defined chronic chest disease, immunoglobulins, IgG subclass levels and antibody concentrations specific for Haemophilus influenzae b (Hib), and pneumococcal antigen, were related to disease severity. Bronchological examinations revealed 30 children with chronic bronchitis, 21 with bronchial deformations and 19 with bronchiectasis. Of the 70 children 12 (17.1%) showed an underlying immunodeficiency. The commonest finding was an IgG subclass deficiency, 7 were IgG₂ and 1 IgG₃ deficient, followed by IgA deficiency in 3 patients. All patients had normal IgG and IgM levels except one who had immunodeficiency with elevated IgM. Pneumococcal antibody levels were found to increase between patient groups in the order healthy children < chronic bronchitis < bronchiectasis < bronchial deformations (p < 0.01), but this was not the case for Hib antibodies. We found no selective deficiency of pneumococcal and Hib antibodies in our patients. Pathogens were detected in bronchial cultures from 10% of patients with chronic bronchitis, 33% of those with bronchial deformations and in 63% with bronchiectasis. This increase (p < 0.01) reflects a more severe inflammation of the respiratory tract in such patients. However, immunodeficiencies were equally distributed between patient groups. We conclude that only a subgroup of children with chronic chest disease have an underlying immunodefiency, but most patients (83%) do synthesize normal or even high antibodies in the presence of a bacterial load.