Introduction: The neutrophil-lymphocyte ratio (NLR) is a marker of inflammation involved in the prognosis of several inflammatory diseases. However, its impact on bronchiectasis disease (BD) is poorly described in the literature. Our objective was to study the association between NLR and the severity of BD and its outcome.

Methods: A retrospective study including 120 patients hospitalized in the pneumology department D of Abderrahmen Mami Hospital in Ariana for exacerbation of BD between 2015 and 2021.

Results: Our population consisted of 88 women and 32 men, with a mean age of 62,8814,68 years. A complete blood count was performed in all patients, showing a median white blood cell count of 90035084, neutrophils of 59784853 and lymphocytes of 1653775 el/mm3. The median NLR was 4,063,18. This ratio decreased with oxygen saturation (p =0,90, r = -0,12). NLR increased with the length of hospitalization (p=0,46; r = 0,68), the number of exacerbations per year (p=0,15; r =1,31) and was significantly associated with a higher mortality rate (p = 0,006). As for the evolution, the NLR was comparable in patients with hemoptysis disease (p=0,65) or pulmonary hypertension (p=0,11). The use of home non-invasive ventilation and long-term oxygen therapy were not associated with NLR with respectively p=0,8 and p=0,6. Similarly, the NLR was significantly correlated with decreased Forced Expiratory Volume in the first second FEV1(p=0,018; r= -0,22) and decreased Forced Vital Capacity FVC (p=0,024; r= -0,21).

Conclusion:Our study showed that NLR was involved in the severity of Bronchiectasis. However, studies on larger samples are needed.