Introduction
Bronchiectasis is a disorder resulting mainly from bronchial
inflammation caused by recurrent or chronic infections. It is
characterized by permanently dilated airways due to bronchial wall
destruction. Exacerbations have a key role in bronchiectasis as they are
associated with a negative impact on patient prognosis. Exacerbations
are generally infectious events caused mostly by bacterial
microorganisms. Infective or inflammatory agents cause neutrophil
recruitment into the airways, which leads to proteolytic enzymes such as
neutrophil elastase and matrix metalloproteinases release, resulting in
airway matrix destruction. Neutrophil to lymphocyte ratio (NLR) is used
as a biomarker of inflammation. It is calculated by dividing the number
of neutrophils by the number of lymphocytes. Our aim is to evaluate
Neutrophils to Lymphocyte Ratio in patients with bronchiectasis
exacerbation and its correlation to microbiological data.
Methods
The study involved patients with a diagnosis of bronchiectasis based on
high-resolution computerised tomography (HRCT) of the chest who
fulfilled the criteria of bronchiectasis exacerbation. Complete blood
counts with differential counts, which included total white blood cells,
neutrophils and lymphocytes, were obtained. NLR and C-reactive protein
(CRP) levels were measured in patients with bronchiectasis exacerbation
and in healthy controls. NLR was calculated as the ratio of the
neutrophils to lymphocytes. The mean NLR values in patients with
bronchiectasis exacerbation were compared to mean NLR values in healthy
controls. The NLR values were compared to CRP levels in patients with
bronchiectasis exacerbation. Sputum cultures were performed in all
patients. The mean NLR values in patients with positive sputum cultures
were compared with mean NLR values in patients with negative sputum
cultures, and mean NLR values in patients with isolated Pseudomonas
aeruginosa in sputum cultures were compared to mean NLR values in
patients with other infectious agents isolated.
Results
The study population consisted of 80 patients with bronchiectasis
exacerbation - 54 males and 26 females - with a mean age of 77.3 +/- 8.4
years, and 64 healthy controls - 36 males and 28 females - with a mean
age of 62.9 +/- 15.3 years. The mean CRP levels in patients with
bronchiectasis exacerbation were 75.03 +/- 73.87 mg/l. The mean NLR
value in patients with bronchiectasis exacerbation was 9.2 +/- 7.8 and
the mean NLR value of controls was 3.1 +/- 2.9 (p<0.001). The NLR values
in patients with bronchiectasis exacerbation had no linear correlation
with CRP values in these patients (r=0.002, p=0.992). Fifty-two patients
had positive sputum cultures and 28 patients had negative sputum
cultures. The mean NLR value in patients with positive sputum cultures
was 10.5 +/- 9.1, and in patients with negative sputum cultures, it was
6.7 +/- 3.6 (p<0.012). The mean NLR value in patients with P.aeruginosa
was 10.1 +/- 9.5, and in patients with other microorganisms isolated, it
was 10.8 +/- 8.9 (p=0.784).
Conclusions
Neutrophil to lymphocyte ratio values are statistically greater in
patients with bronchiectasis exacerbation compared to healthy controls.
There is no linear correlation between NLR and CRP in these patients.
NLR values are statistically greater in patients with positive sputum
cultures compared to those with negative sputum cultures. Therefore, NLR
can be used for predicting positive cultures in patients with
bronchiectasis exacerbation