Induced sputum as a tool for early detection of airway inflammation in connective diseases-related lung involvement.
BACKGROUND
Induced sputum (IS) sampling is a safe and validated approach to study bronchial inflammation in chronic obstructive lung diseases. Although promising results have also been reported in various diffuse interstitial lung disorders, the potential use of IS in the assessment of connective tissue diseases (CTD)-related lung involvement has not yet been investigated.


OBJECTIVE
To evaluate the clinical usefulness of IS in the early management of patients suffering from rheumatoid arthritis (RA) and systemic sclerosis (SSc) at the onset of respiratory symptoms.


METHODS
The study population included 19 patients (RA=12; SSc=7) and 14 age- and sex-matched healthy volunteers. Lung function testing, high resolution computed tomography (HRCT) of the thorax and IS collection were performed in all cases. Broncho-alveolar lavage (BAL) was obtained in selected patients.


RESULTS
IS samples from patients contained a significantly higher percentage of neutrophils and a lower percentage of macrophages compared to healthy subjects (p=0.002 and 0.001, respectively), while the total cell number showed no differences. In addition, sputa yielded both higher cell counts and higher neutrophils than BAL samples (p=0.02 in all instances). No correlations were found between IS findings and lung function parameters, HRCT and BAL findings.


CONCLUSIONS
This is the first study investigating the inflammatory cell pattern in IS from CTD patients with early clinical evidence of lung involvement. Future studies are needed to determine whether the assessment of airway inflammation adds significant information that may result in a relevant improvement of disease management.
Vatrella
Alessandro
A
Respiratory Medicine Division, University of Naples Federico II, Via Pansini 5, 80131 Naples, Italy. vatrella@unina.it
Bocchino
Marialuisa
M
Perna
Francesco
F
Scarpa
Raffaele
R
Galati
Domenico
D
Spina
Sergio
S
Pelaia
Girolamo
G
Cazzola
Mario
M
Sanduzzi
Alessandro
A
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000150:complications*; D018893:Bronchoalveolar Lavage / Q000379:methods; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D016516:CD4-CD8 Ratio; D016022:Case-Control Studies; D002452:Cell Count; D042241:Early Diagnosis; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000473:pathology; D012595:Scleroderma, Systemic / Q000150:complications*; D013048:Specimen Handling / Q000379:methods; D013183:Sputum / Q000166:cytology*; D014109:Total Lung Capacity; D014797:Vital Capacity