Longitudinal functional evaluation of interstitial lung disease in systemic sclerosis

Scleroderma interstitial lung disease (SSc-ILD) is the leading cause of SSc related mortality. As limited data are available about longitudinal lung function evaluation in prevalent SSc- ILD patients, our aim was longitudinal evaluation of lung disease progression. We retrospectively analyzed clinical manifestations and pulmonary function changes in SSc- ILD patients in a time period of 18 months at our university center. SSc-ILD was identified using ICD criteria for both diseases in 54 cases, while 41 had at least 2 visits in this time period. Patients characteristic, pulmonary symptoms, spirometry with pletysmography, CO diffusion (DLco and KLco), high resolution CT (HRCT) pattern and treatment were analyzed. Data of 41 SSc-ILD patients were analyzed (12% men, mean age 58±13 years), majority never smokers (74%). Dyspnea and/or cough was present in 25%, 70% of patients had a history of Raynaud-syndrome and 20% pulmonary hypertension. Pulmonary function tests showed minimal decrease in FVC (89.8 ± 23.2% predicted) with a moderate impairment in CO diffusion (DLco: 75.2 ± 22.0%; KLco: 70.0 ± 18.2% predicted). HRCT confirmed usual interstitial pneumonia, non-specific interstitial pneumonia or isolated ground glass opacities in similar numbers. All patients received immunosuppressive therapy. Longitudinal functional examinations showed an annual decrease of 3.9 ± 6.0% in FVC, 4.8 ± 6.6% in DL CO and 6.7 ± 7.6% in KL CO . Our prevalent SSc-ILD patients presented with mild restrictive ventilatory disorder, showing small annual decline in FVC and more pronounced decline in DL CO and KLco. Identification of progressive phenotypes needs regular functional follow-up especially in symptomatic patients.