The Th17 pathway in cystic fibrosis lung disease

Am J Respir Crit Care Med. 2011 Jul 15;184(2):252-8. doi: 10.1164/rccm.201102-0236OC. Epub 2011 Apr 7.


Rationale: Cystic fibrosis (CF) is characterized by bronchoalveolar neutrophilia and submucosal lymphocytosis. We hypothesized that Th17 lymphocytes are part of this submucosal infiltrate.

Objectives: Quantification and phenotyping of the lymphocytic infiltrate in the bronchial submucosa of patients with CF (n = 53, of which 20 were newly diagnosed), non-CF bronchiectasis (n = 17), and healthy control subjects (n = 13).

Methods: We measured IL-17 levels in bronchoalveolar lavage and CD4(+), CD8(+), and IL-17(+) cell counts in endobronchial biopsies. Correlations were made with infection status and other inflammatory markers. Potential cellular sources of IL-17 were determined by double staining.

Measurements and main results: IL-17(+) cell counts (median [interquartile range] cells/mm(2)) were significantly higher in patients with established CF (205 [115-551]) and non-CF bronchiectasis (245 [183-436]) than in control subjects (53 [12-82]) (P < 0.01 for both). Patients with newly diagnosed CF had intermediate counts (171 [91-252]). IL-17-positive CD4(+) T cells, γδT cells, natural killer T cells, and neutrophils were identified. Bronchoalveolar lavage IL-17 levels (pg/ml) were highest in established CF (14.6 [2.2-38.4]), low in newly diagnosed CF and control subjects (1.7 [1.7-1.74]; 1.7 [1.7-3]), and intermediate in non-CF bronchiectasis (9.1 [1.7-34] pg/ml) (Kruskal-Wallis P = 0.001). There was a significant correlation between IL-17 and neutrophil counts (P < 0.001, R = 0.6) as well as IL-4 (P < 0.001, R = 0.84).

Conclusions: Th17 lymphocytes are present in the airway submucosa in CF, even in a young, newly diagnosed group. Other IL-17(+) cells include neutrophils, γδ T cells, and natural killer T cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biopsy
  • Bronchoalveolar Lavage Fluid / immunology
  • Child
  • Child, Preschool
  • Cystic Fibrosis / immunology*
  • Cystic Fibrosis / pathology
  • Female
  • Humans
  • Infant
  • Lung / immunology
  • Lung / pathology
  • Male
  • Th17 Cells / immunology*