Development of Humoral Immunity in Children with Cystic Fibrosis

Overview

Cystic fibrosis is an autosomal recessive disease with known mutated genes and a range of clinical problemswhich are dominated besides other clinical conditions by the chronic inflammation of the lungs. The immune systemplays a major role in the defense against chronic and usually lifetime infection with strains of the Pseudomonasspecies, which represent the major pathogenic problem in patients with cystic fibrosis. In the current study wefollowed the development of immunoglobulin isotypes in patients with CF during childhood. We found mildhypogammaglobulinaemia in the earliest period of life, between the first and the third year, followed later by typicalhyperimmunoglobulinemia characteristic for cystic fibrosis. Hypogammaglobulinaemia was mainly due to the lowlevels of IgG2. As IgG2 plays a major role in the defense against Pseudomonas we suggest that this decrease ofIgG2 may predispose children to the chronic infection later in their lives. The study opens the possibility tosubstitute the patients with immunoglobulins in these critical periods. Besides these developmental changes inhumoral immunity we frequently observe positivity of antineutrophil cytoplasmic antibodies in children with cysticfibrosis. These antibodies do not follow any age related changes and can have a complex influence on the immuneresponse in cystic fibrosis patients.

Key words:
cystic fibrosis, immunoglobulins, IgG, IgG2, autoantibodies, ANCA