Abstract

In order to investigate whether circulating immune complexes containing Pseudomonas aeruginosa antigens mediate pulmonary damage in cystic fibrosis, we studied lung function, serum immune complex levels, and immunoglobulin concentrations in relationship to chronic pseudomonas colonisation in 69 affected children. Sixteen of the children with cystic fibrosis had increased levels of immune complexes which contained pseudomonas antigens. There was no significant relationship between lung function corrected for the effect of chronic pseudomonas colonisation and the presence of such complexes or increased levels of complexes detected by Cl1 binding or raised serum immunoglobulin concentrations. Our results suggest that these abnormalities in cystic fibrosis are secondary effects of chronic infection and they do not provide evidence for immune complex mediated lung damage in this disease.