Exhaled matrix metalloproteinase-9 (MMP-9) in different biological phenotypes of asthma.
OBJECTIVE
Airway remodeling is a main feature of asthma. Different biological phenotypes of severe asthma have been recently recognized by the ENFUMOSA study group and among these one is characterized by neutrophilic airway inflammation. Concentrations of MMP-9 in airways have been suggested as a marker to monitor airway remodeling in asthma.


OBJECTIVE
The aim of the present study was to explore airway remodeling in different biological phenotypes of asthma by measuring MMP-9 in EBC and correlating these with other variables.


METHODS
Sixty consecutive subjects with asthma and 20 healthy controls were enrolled in the study. Exhaled MMP-9, pH and NO levels and inflammatory cells in sputum were measured in all subjects enrolled.


RESULTS
We observed an increase of exhaled MMP-9 in asthmatic subjects compared to controls. Higher exhaled MMP-9 concentrations were described in severe asthmatics compared to mild to moderate especially in those with neutrophilic airway inflammation. We further found a correlation between exhaled MMP-9 and percentage of neutrophils in sputum, FEV1, exhaled NO and pH.


CONCLUSIONS
Our results seem to substantiate the feasibility of measuring exhaled MMP-9 in the breath of asthmatic patients. MMP-9 may be considered a proxy of the amount of the ongoing airway remodeling in asthma. MMP-9 has been shown to be differentially released in different phenotypes of asthma. The measure of exhaled MMP-9 could help to monitor the ongoing airway remodeling, recognize severe stages of asthma, and possibly help determine the appropriate choice of therapy.
Institute of Respiratory Disease, Medical and Surgical Sciences Department, University of Foggia, Italy. Electronic address: mariapia.foschino@unifg.it.
Maria P Foschino
MP
Barbaro
Institute of Respiratory Disease, University of Insubria, Varese, Italy; Fondazione Salvatore Maugeri, IRCCS, Tradate, Italy. Electronic address: antonio.spanevello@fsm.it.
Antonio
A
Spanevello
Institute of Respiratory Disease, Medical and Surgical Sciences Department, University of Foggia, Italy. Electronic address: gp.palladino@unifg.it.
Grazia P
GP
Palladino
Fondazione Salvatore Maugeri, IRCCS, Cassano delle Murge, Italy. Electronic address: francesco.salerno@fsm.it.
Francesco G
FG
Salerno
Institute of Respiratory Disease, Medical and Surgical Sciences Department, University of Foggia, Italy. Electronic address: donato.lacedonia@unifg.it.
Donato
D
Lacedonia
Institute of Respiratory Disease, Medical and Surgical Sciences Department, University of Foggia, Italy. Electronic address: giovannaelisiana.carpagnano@unifg.it.
Giovanna E
GE
Carpagnano
D000328:Adult; D001249:Asthma / Q000276:immunology / Q000378:metabolism*; D015415:Biomarkers; D001944:Breath Tests; D016022:Case-Control Studies; D004802:Eosinophilia / Q000276:immunology / Q000378:metabolism; D004804:Eosinophils / Q000166:cytology* / Q000276:immunology; D005541:Forced Expiratory Volume; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007249:Inflammation; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D009504:Neutrophils / Q000166:cytology* / Q000276:immunology; D009569:Nitric Oxide / Q000378:metabolism*; D010641:Phenotype; D012720:Severity of Illness Index; D013183:Sputum / Q000166:cytology* / Q000276:immunology
D015415:Biomarkers; D009569:Nitric Oxide; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9
ASM; Airways; Asthma; BAL; FEV(1); FVC; MMP-9; NO; Nitric oxide; Non-invasive methods; Phenotype; TIMPs; airway smooth muscle; broncho-alveolare lavage; forced expiratory volume in one second; forced vital capacity; matrix metalloproteinase-9; tissue inhibitors of metalloproteinases