There is no report of exhaled NO (eNO) in subjects with different phenotypes of α 1-anti-trypsin (AAT) deficiency. Exhaled nitric oxide was evaluated by means of single-breath chemiluminescence analysis (fractional exhaled concentration at the plateau level [plFE NO]) in 40 patients with AAT deficiency. Patients were divided according to the protease inhibitor (Pi) phenotype: PiMZ/MS, n = 25; PiSZ n = 6; PiZZ, n = 9. Nineteen healthy subjects served as controls. Levels of eNO in PiZZ patients were also compared with those of subjects, without AAT deficiency (PiMM), matched for diagnosis, sex, age, smoking habit and forced expiratory volume in 1 sec (FEV 1). In AAT deficiency subjects airway hyper-responsiveness to methacholine (PD 20 FEV 1) was also assessed. p1FE NO was significantly lower in the PiZZ group (4.5 ± 1.4 ppb) than in matched PiMM subjects (8.2±3.8 ppb), in healthy controls (9.3±2.8 ppb) and in patients of other phenotypes. Dynamic lung volumes and DL CO were significantly lower in PiZZ than in other AAT-deficient patients. Bronchial hyper-responsiveness was not different among AAT phenotypes. These results suggest that eNO may be significantly reduced in PiZZ as compared to healthy control subjects and to AAT subjects with other phenotypes, independent of the level of airway obstruction. Whether, at least potentially, eNO may be considered as an early marker of lung involvement in AAT deficiency must be confirmed with studies on larger number of subjects.
- Bronchial hyper-responsiveness
- Chronic airway obstruction
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine