The heterogeneity of systemic inflammation in bronchiectasis.

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.