Page 55 - Škrgat, Sabina, ed. 2023. Severe Asthma Forum - Monitoring and Treatable Traits in Severe Asthma. Koper: University of Primorska Press. Severe Asthma Forum, 2
P. 55
Induced Sputum Role in Severe Asthma 3.1
Phenotyping
Sanja Popović-Grle1,2, Gordana Pavliša1,2, Marina Lampalo1,3, Anamarija Štajduhar1, Branko Pevec1,
Mira Pevec1, Dina Rnjak1, Valentina Fiket1, Ivana Rubil1, Silvana Smojver-Ježek1,4
Abstract 1 University Hospital Centre
Induced sputum is a method which, by inhaling hypertonic saline, provoke a person to expec- Zagreb, Clinical Department
torate certain amount of bronchial secretion. Sputum sample obtained consists of liquid and for Lung Diseases Jordanovac,
celullar phase. It is used over the years to investigate airway inflammation in patients with Zagreb, Croatia
asthma and chronic obstructive pulmonary disease (COPD). Results of cell counts in induced
sputum is essential in differentiation of airway eosinophilia or neutrophilia or both, or a deter- 2 School of Medicine,
mination of paucigranulocytic phenotype. Obtained severe asthma phenotype due to airway University of Zagreb, Zagreb,
inflammation help us to select biological therapy and predict responders. Croatia
The correlation between “noninvasive” measures such as b lood eosinophilia, or fraction of ex-
haled nitric oxide (FeNO) with sputum eosinophils is suboptimal. Induced sputum is a good 3 Faculty of Health Studies,
and reproducible discriminator for eosinophilic asthma. There are some safety concerns as in- University of Rijeka, Rijeka,
duced sputum procedure can provoke adverse effects such as bronchoconstriction and dysp- Croatia
nea, which is reversible to standardized therapy. Sputum induction is safe and well tolerated by
patients with severe asthma, which supports its use in clinical and research practice. 4 University Hospital Centre
Zagreb, Clinical Department
Keywords: severe asthma, sputum induction, a sthma phenotypes, safety of Pathology and Citology, Zagreb,
Croatia
Introduction valid results2 sputum induction quickly gained
an important place in clinical practice. The
Asthma is a chronic inflammatory disease of correlation between “noninvasive” measures
the airways that causes variable airflow ob- such as blood eosinophilia, or fraction of ex-
struction and bronchial hyperresponsiveness. haled nitric oxide (FeNO) with sputum eosin-
Many cells and cellular elements play a role in ophils is suboptimal, making them poor surro-
the pathogenesis of asthma. Cellular quantifi- gate measures of airway eosinophilia3. Based
cation in sputum samples is one of the nonin- on sputum eosinophil and neutrophil propor-
vasive methods of assessing asthmatic airway tions in induced sputum we could categorized
inflammation. Sputum induction with hyper- four inflammatory subtypes of an airway in-
tonic saline is used frequently for investigation flammation in asthma: neutrophilic asthma,
of airway inflammation in patients with asth- eosinophilic asthma, mixed granulocytic ast-
ma or chronic obstructive pulmonary disease hma and paucigranulocytic asthma4. Asthma
(COPD). The method was introduced in asth- phenotypes based on different types of airway
ma by Pin et al. in 1992 and has been evolv- inflammation allow us to individually tailor
ing ever since1. As it is relatively non-inva- treatment. It has been well known for decades
sive technique which provides repeatable and that sputum eosinophilia can predict response
https://doi.org/10.26 493/978 -961-293 -297-8.55 - 61
Phenotyping
Sanja Popović-Grle1,2, Gordana Pavliša1,2, Marina Lampalo1,3, Anamarija Štajduhar1, Branko Pevec1,
Mira Pevec1, Dina Rnjak1, Valentina Fiket1, Ivana Rubil1, Silvana Smojver-Ježek1,4
Abstract 1 University Hospital Centre
Induced sputum is a method which, by inhaling hypertonic saline, provoke a person to expec- Zagreb, Clinical Department
torate certain amount of bronchial secretion. Sputum sample obtained consists of liquid and for Lung Diseases Jordanovac,
celullar phase. It is used over the years to investigate airway inflammation in patients with Zagreb, Croatia
asthma and chronic obstructive pulmonary disease (COPD). Results of cell counts in induced
sputum is essential in differentiation of airway eosinophilia or neutrophilia or both, or a deter- 2 School of Medicine,
mination of paucigranulocytic phenotype. Obtained severe asthma phenotype due to airway University of Zagreb, Zagreb,
inflammation help us to select biological therapy and predict responders. Croatia
The correlation between “noninvasive” measures such as b lood eosinophilia, or fraction of ex-
haled nitric oxide (FeNO) with sputum eosinophils is suboptimal. Induced sputum is a good 3 Faculty of Health Studies,
and reproducible discriminator for eosinophilic asthma. There are some safety concerns as in- University of Rijeka, Rijeka,
duced sputum procedure can provoke adverse effects such as bronchoconstriction and dysp- Croatia
nea, which is reversible to standardized therapy. Sputum induction is safe and well tolerated by
patients with severe asthma, which supports its use in clinical and research practice. 4 University Hospital Centre
Zagreb, Clinical Department
Keywords: severe asthma, sputum induction, a sthma phenotypes, safety of Pathology and Citology, Zagreb,
Croatia
Introduction valid results2 sputum induction quickly gained
an important place in clinical practice. The
Asthma is a chronic inflammatory disease of correlation between “noninvasive” measures
the airways that causes variable airflow ob- such as blood eosinophilia, or fraction of ex-
struction and bronchial hyperresponsiveness. haled nitric oxide (FeNO) with sputum eosin-
Many cells and cellular elements play a role in ophils is suboptimal, making them poor surro-
the pathogenesis of asthma. Cellular quantifi- gate measures of airway eosinophilia3. Based
cation in sputum samples is one of the nonin- on sputum eosinophil and neutrophil propor-
vasive methods of assessing asthmatic airway tions in induced sputum we could categorized
inflammation. Sputum induction with hyper- four inflammatory subtypes of an airway in-
tonic saline is used frequently for investigation flammation in asthma: neutrophilic asthma,
of airway inflammation in patients with asth- eosinophilic asthma, mixed granulocytic ast-
ma or chronic obstructive pulmonary disease hma and paucigranulocytic asthma4. Asthma
(COPD). The method was introduced in asth- phenotypes based on different types of airway
ma by Pin et al. in 1992 and has been evolv- inflammation allow us to individually tailor
ing ever since1. As it is relatively non-inva- treatment. It has been well known for decades
sive technique which provides repeatable and that sputum eosinophilia can predict response
https://doi.org/10.26 493/978 -961-293 -297-8.55 - 61
