Background Interstitial lung disease (ILD) is a frequent complication of systemic sclerosis (SSc) and is often progressive and has a poor prognosis. A restrictive ventilatory defect could suggest ILD either alone or in combination with pulmonary arterial hypertension. Nowadays, Early-SSc is well defined as preliminary stage of SSc. Patients who meet criteria for Early-SSc could benefit from an early diagnosis of pulmonary involvement.
Objectives Our aim was to assess the pulmonary function in patients diagnosed of Early SSc.
Methods Retrospective observational study of a wide and unselected series of patients diagnosed as Early-SSc from a single university hospital from June 2012 to August 2015. Patients were classified as Early-SSc following Le Roy criteria. In spite of this, patients already did not met 2013 ACR/EULAR classification criteria for SSc. We reviewed pulmonary function through conventional spirometry and diffusing capacity of lung for carbon monoxide (DLCO). Interpretation of the results of spirometry and DLCO was made according European Respiratory Society (ERS) and American Thoracic Society (ATS) standards
Results We included a total of 41 patients with a mean age of 53±15.6 years (97.6% women; 2.4% men). No one of our patients evidenced a restrictive ventilatory pattern. DLCO was under normal limits in 11 patients (26.8%). Small airway obstruction expressed according decreased maximal (mid-) expiratory flow (MMEF) 25–75 was present in 13 patients (31.7%).
After a mean follow-up period of 26.1±16.6 months, 20 (48.8%) patients fulfilled 2013 ACR/EULAR criteria. The remaining 21 patients continued classified as Early-SSc following Le Roy criteria. The analysis of the subgroup of patients who progressed to SSc showed that DLCO was decreased in 7 of those 20 patients (35%) and also 8 of 20 patients (40%) presented decreased maximal (mid-) expiratory flow (MMEF) 25–75. Comparing with the subgroup of patients which not progressed to SSc no were significant differences (Decreased DLCO: 35% vs 26.8%; p=0.8 and Decreased MMEF 25–75: 40% vs 31.7%; p=0.9).
Conclusions In our study, about a quarter of the patients classified as Early-SSc presented abnormal values of DLCO and/or signs of small airway obstruction without the presence of a restrictive ventilatory pattern. Moreover, the expression of this pulmonary dysfunction tends to be more frequent in patients who progressed to definitive SSc, although this was not statistically significant. An early assessment of pulmonary function in this context should be highly recommended.
Disclosure of Interest None declared