Background: The lungs are affected in 70 - 90% of cases diagnosed with systemic sclerosis. Pulmonary involvement is associated with increased morbidity and mortality.
Materials and methods: Fifty-five cases of systemic sclerosis underwent plethysmography, diffusion lung capacity for carbon monoxide (DLCO) measurement, high resolution computed tomography scanning, and bronchoalveolar lavage (BAL) to evaluate their diagnostic roles in grading the severity of lung involvement and their relationships to each other.
Results: The indices of DLCO% (measured DLCO to predicted ratio) and DLCO value, total lung capacity (TLC) value and TLC% (measured TLC to predicted ratio), forced vital capacity (FVC) and FVC% (measured FVC to predicted FVC) were significantly lower in patients who presented with a severer degree of lung involvement on high resolution computed tomography scan. No meaningful correlation between bronchoalveolar lavage findings and the degree of involvement on high resolution computed tomography scan was noted.
Conclusion: Although there is a correlation between imaging and lung capacities in physiologic studies. Bronchoalveolar lavage findings did not correlate with either imaging or physiologic tests. It seems that DLCO, TLC, and FVC are the most valuable measures with which to evaluate disease severity.