Pulmonary function in progressive systemic sclerosis. Comparison of CREST syndrome variant with diffuse scleroderma.

Area of Science:

• Rheumatology
• Pulmonology
• Radiology

Background:

• Progressive systemic sclerosis (PSS), also known as scleroderma, is an autoimmune disease affecting connective tissues.
• The CREST syndrome is a variant of PSS characterized by Calcinosis, Raynaud's phenomenon, esophageal dysmotility, Sclerodactyly, and Telangiectasias.
• Pulmonary involvement is a significant complication of PSS, impacting patient morbidity and mortality.

Purpose of the Study:

• To evaluate pulmonary function and chest roentgenograms in patients with PSS-CREST.
• To compare pulmonary findings in PSS-CREST patients with those having diffuse PSS.
• To identify specific radiographic and functional patterns associated with PSS-CREST.

Main Methods:

• Pulmonary function tests (spirometry, diffusing capacity) were performed.
• Chest roentgenograms were analyzed for interstitial infiltrates and other abnormalities.
• Findings were compared between 88 PSS-CREST patients and 77 diffuse PSS patients.

Main Results:

• 72% of PSS-CREST patients exhibited abnormal pulmonary function, most commonly decreased diffusing capacity.
• 33% of PSS-CREST patients had chest roentgenograms showing interstitial infiltrates suggestive of pulmonary fibrosis.
• PSS-CREST patients showed a lower mean diffusing capacity and higher mean vital capacity compared to diffuse PSS patients, suggesting pulmonary vascular disease. Calcified granulomata were more frequent in PSS-CREST, while rib notching was exclusive to diffuse PSS.

Conclusions:

• The PSS-CREST variant frequently presents with pulmonary function and radiographic abnormalities comparable to diffuse PSS.
• Distinct pulmonary function patterns in PSS-CREST may indicate primary pulmonary vascular disease.
• Specific radiographic findings like calcified granulomata and rib notching can help differentiate PSS variants.