Background:

Asthma is a chronic inflammatory disease of airways. Neutrophil to lymphocyte ratio (NLR) is used as a marker of subclinical inflammation. It has been used as a prognostic factor for certain inflammatory or neoplastic pathologies. It is inexpensive and easy to calculate

Aim:

Determine the contribution of NLR in assessing the severity of asthma exacerbation.

Methods:

It was a retrospective study, focused on records of patients hospitalized for asthma exacerbation in the pulmonology department of the Mongi Slim La Marsa University Hospital, in Tunis-Tunisia during the period from 2018 to 2022. Blood count on arrival at hospital for asthma exacerbation was collected as well as data related to the severity of this exacerbation. NLR is considered abnormal if over 3.

Results:

A total of 101 records was consulted. The average age of patients was 44 years (16-75 years-old) with a gender-ratio M/F= 0,53. Asthma exacerbation on admission was: moderate in 62.3% of cases and severe in 27.7%. The average value of NLR was 4.32, that of the CRP was 18mg/l, that of SpO2 was 94%, that of respiratory rate was 21 cycle/mn, that of white blood cells 9900/mm3 and that of length of hospitalization was 10 days. NLR was abnormal in 47.5% of cases. Its absolute value was correlated to CRP (p<0.001 ; r=0.628) and white blood cells (p=0.005 ; r=0.298). Abnormal NLR was correlated with respiratory rate (p=0.006), with SpO2 (p=0.018), with severe exacerbation (p=0.001), transfer to intensive care unit (0.048) and with length of stay (p<0,001).

Conclusion:

Abnormal NLR was predictive of severe asthma exacerbation with longer length of hospitalization and probability of transfer to intensive care unit.