Background: Fibrinogen and fractional exhaled nitric oxide (FeNO) are useful markers in several conditions. In a few studies, fibrinogen was described as a potential marker of disease severity in bronchiectasis. It is not well defined whether FeNO is higher in bronchiectasis than in healthy individuals, as it was found to be lower compared to other lung diseases and to increase only at the start of exacerbations.

Aims and Objectives: We aim to investigate the alterations of fibrinogen and FeNO in non-cystic fibrosis bronchiectasis patients, and possibly correlate them with other established markers of disease severity.

Methods: A total of 23 stable bronchiectasis patients, with no exacerbation in the last 3 months, underwent fibrinogen and FeNO measurement and spirometry. In all cases, BSI, FACED, and QOL-B scores were also estimated.

Results: There was no statistically significant correlation between either FeNO (mean±SD: 22.3±13.9 ppb) or fibrinogen (mean±SD: 415.9±139.8 mg/dL) with BSI, FACED, or QOL-B scores. Interestingly, however, fibrinogen was significantly inversely correlated to FEV₁ percentage of predicted (Spearman, r=-0.4612, p=0.0268) and FEV₁/FVC (r=-0.4437, p=0.0340).

Conclusions: Preliminary results of our bronchiectasis cohort reveal high fibrinogen levels as a potential predictor of lung functional impairment. They further demonstrate that the relatively low FeNO and high fibrinogen levels cannot be used interchangeably with BSI, FACED, and QOL-B scores. Further investigation of these markers in additional patients and healthy individuals is needed to draw robust conclusions.

* NB & AMM: equally contributing authors