Systemic sclerosis (SSc) is a connective tissue disorder of unknown ehat is often complicated by pulmonary involvement, with pulmonary hypertensio and interstitial lung disease (ILD) being the major causes of death. It has been sughat the amount of nitric oxide (NO) in exhaled air may predict the onset of complications.
The aim of the study was to measure exhaled NO in SSc patients and investige its relationship with pulmonary involvement with and without pulmonary hypertension.
Methods: Fifty patients (5 males, 45 females; mean age 59.1 ? 11.7 years) with a diagnosis of SSc based on the preliminary criteria of the American Rheumatism Association and 40 healthy control subjects (5 males; 35 females; mean age 58.3 ? 12.2 years) underwent exhaled NO measurements by means of a chemiluminescence analyser, pulmonary function tests, high-resolution thorax CT, Doppler echocardiography.
Exhaled NO concentrations were significantly higher in SSc patients than controls (p=0.02), and significantly lower in the patients with ILD and/or PH than in those without(p
<0.01). There was a significant inverse correlation between pulmonary artery systolic pressure and exhaled NO concentration in all of the studied patients (r = -0.5; p
Our results indicate that exhaled air NO concentrations are lower in SSc patients with lung involvement than in those without, and that SSc patients without ILD or PH have higher exhaled NO values than healthy subjects.