Quantifying change in pulmonary function as a prognostic marker in systemic sclerosis-related interstitial lung...

Area of Science:

• Pulmonary Medicine
• Rheumatology
• Radiology

Background:

• Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is a major cause of morbidity and mortality.
• Clinically meaningful changes in pulmonary function that predict outcomes in SSc-ILD are not well-defined.

Purpose of the Study:

• To quantify changes in pulmonary function tests (PFTs) as predictors of adverse outcomes in patients with SSc-ILD.
• To identify specific thresholds for PFT decline that indicate a poor prognosis.

Main Methods:

• Retrospective analysis of PFTs (FVC, DLCO, KCO) in 264 SSc-ILD patients.
• ROC curve analysis to determine cut-off points for predicting adverse events (death, oxygen, transplant) within the first four years.
• Evaluation of PFT changes over one year and four years.

Main Results:

• Rates of decline in FVC, DLCO, and KCO over time predicted adverse outcomes.
• Stable PFTs over four years showed high negative predictive values (88-96%) for adverse outcomes.
• A decline of 10% in FVC or 15% in DLCO/KCO within one year was associated with adverse outcomes (NPVs 92-93%).

Conclusions:

• The prognostic course of SSc-ILD is discernible within 1-4 years of follow-up.
• Patients with stable PFTs over four years experience better outcomes.
• A significant decline in DLCO or KCO within one year is a poor prognostic indicator, warranting closer monitoring and consideration for therapy.