Exhaled nitric oxide is elevated in patients with progressive systemic sclerosis without interstitial lung disease

Area of Science:

• Pulmonary Medicine
• Rheumatology
• Biomarker Discovery

Background:

• Progressive systemic sclerosis (PSS) is a multisystem disease where interstitial lung disease (ILD) is a leading cause of mortality.
• Identifying predictors of ILD onset or progression in PSS is crucial for patient management.
• Abnormal bronchoalveolar lavage fluid (BALF) cellularity has been observed in PSS patients without evident ILD.

Purpose of the Study:

• To evaluate exhaled nitric oxide (NO) as a noninvasive marker of pulmonary inflammation in PSS patients.
• To compare exhaled NO levels with bronchoalveolar lavage fluid (BALF) cellularity.
• To test the hypothesis that elevated exhaled NO correlates with abnormal BALF cellularity in PSS patients without ILD.

Main Methods:

• Exhaled NO was measured using chemiluminescence in 12 PSS patients with ILD, 12 PSS patients without ILD, and 30 healthy controls.
• Bronchoalveolar lavage (BAL) was performed on PSS patients (with and without ILD) and six healthy controls.
• Study conducted at a university-based, tertiary referral hospital in Durban, South Africa.

Main Results:

• Subclinical inflammation was confirmed by increased inflammatory cell counts in BALF of PSS patients without ILD.
• Exhaled NO levels were significantly higher in PSS patients without ILD (9.6 ppb) compared to those with ILD (6.2 ppb) and healthy controls (6.3 ppb).
• Elevated exhaled NO in PSS patients without ILD suggests underlying pulmonary inflammation.

Conclusions:

• Exhaled nitric oxide (NO) shows promise as a noninvasive surrogate marker for inflammation in PSS patients.
• This finding could aid in early detection and monitoring of pulmonary involvement in PSS.
• Further research may establish exhaled NO as a valuable tool in managing PSS-related lung complications.