The local immune status in cystic fibrosis.

We focused our study on concentration of immunoglobulins, lysozyme, lactoferrin, some antiproteolytic 
fractions and acute phase proteins in bronchial secretion of children with 
various pulmonary diseases, especially with cystic fibrosis. Secretory IgA is decreased 
in all studied groups of patients having chronic or recurrent infections 
of the respiratory tract (when compared to the group of healthy 
children). Groups which were characterized by the infection of the lower 
part of the respiratory tract had increased lysozyme level. The results 
obtained in the group of CF children are similar to those 
obtained in groups with bronchiectasis and chronic bronchitis, which suggests that 
the observed differences are characteristic for chronic infection rather than for 
CF. Although in CF as well as in bronchiectasis massive bacterial 
infection results in increased concentration of immunoglobulins, antiproteolytic fractions and acute 
phase proteins, the results seen in both groups are somewhat different. 
These differences may indicate some difference in the reactivity to infection 
of the respiratory tract in CF in comparison to patients with 
bronchiectasis. It seems conceivable that among children with CF who have 
very low S-IgA, chronic respiratory tract infections occur earlier and IgG 
response to permanent exposition to variety of antigens is less vigorous. 
The presented results raise also a possibility that the bacterial infection 
in CF does not stimulate defence mechanisms to the same extent 
as in bronchiectasis. 