Elsevier

Respiratory Medicine

Volume 127, June 2017, Pages 33-39
Respiratory Medicine

The heterogeneity of systemic inflammation in bronchiectasis

https://doi.org/10.1016/j.rmed.2017.04.009Get rights and content
Under an Elsevier user license
open archive

Highlights

  • Patterns of systemic inflammatory protein concentrations in bronchiectasis are heterogeneous.

  • Increasing clinical severity of bronchiectasis is associated with increased plasma fibrinogen.

  • People with bronchiectasis in the context of CVID are characterised by an exaggerated systemic IL-17 response.

Abstract

Background

Systemic inflammation in bronchiectasis is poorly studied in relation to aetiology and severity. We hypothesized that molecular patterns of inflammation may define particular aetiology and severity groups in bronchiectasis.

Method

We assayed blood concentrations of 31 proteins from 90 bronchiectasis patients (derivation cohort) and conducted PCA to examine relationships between these markers, disease aetiology and severity. Key results were validated in two separate cohorts of 97 and 79 patients from other centres.

Results

There was significant heterogeneity in protein concentrations across the derivation population. Increasing severity of bronchiectasis (BSI) was associated with increasing fibrinogen (rho = 0.34, p = 0.001 –validated in a second cohort), and higher fibrinogen was associated with worse lung function, Pseudomonas colonisation and impaired health-status. There were generally similar patterns of inflammation in patients with idiopathic and post-infectious disease. However, patients with primary immunodeficiency had exaggerated IL-17 responses, validated in a second cohort (n = 79, immunodeficient 12.82 pg/ml versus idiopathic/post-infectious 4.95 pg/ml, p = 0.001), and thus IL-17 discriminated primary immunodeficiency from other aetiologies (AUC 0.769 (95%CI 0.661–0.877)).

Conclusion

Bronchiectasis is associated with heterogeneity of systemic inflammatory proteins not adequately explained by differences in disease aetiology or severity. More severe disease is associated with enhanced acute-phase responses. Plasma fibrinogen was associated with bronchiectasis severity in two cohorts, Pseudomonas colonisation and health status, and offers potential as a useful biomarker.

Keywords

Bronchiectasis
Inflammation
Acute-phase reaction
Fibrinogen
Interleukin-17

Cited by (0)