Some immune system abnormalities have been reported in cystic fibrosis, particularly the presence of antineutrophil cytoplasmic antibodies (ANCAs). The purpose of this study was to determine the frequency of these antibodies in a population of patients with cystic fibrosis and to assess their relationship with the disease progression.
Population and methods: This retrospective study looked for the presence of these antibodies in sera from 64 patients (30 boys and 34 girls) aged one to 29 years. All patients were followed up within the Cystic Fibrosis Center of the University Hospital of Angers. The serum samples were collected in 2001 during the yearly check-up to evaluate disease status.
Results: Seven of the 64 patients presented the antibodies. Univariate analysis showed that these patients were significantly older and more often chronically infected with Pseudomonas aeruginosa than the other patients. They also scored significantly more poorly on pulmonary radiography and showed significantly higher IgG and CRP. Multivariate analysis revealed that the two following independent factors were associated with the presence of ANCAs: chronic P. aeruginosa infection and high IgG level.
Conclusion: This work confirms the abnormally high frequency of antineutrophil cytoplasmic antibodies in patients with cystic fibrosis. These antibodies were observed in the sickest patients with severe infection status. They reflect the impact of inflammatory processes in the pathogenesis of the disease. Detection of these antibodies might be an indication for intensified treatment of bronchial infections.