Objectives: In systemic sclerosis, baseline extent of radiological involvement is an important outcome predictor and baseline absence of radiological involvement suggests a more favourable prognosis. As current predictive models are based on cohorts with variable disease duration, we aim to assess disease dynamics in early disease.
Methods: Patients were included from the prospective longitudinal Belgian Systemic Sclerosis Cohort. We included patients with a disease duration < = 36 months at baseline with available baseline thoracic high-resolution computed tomography (HRCT) images and longitudinal pulmonary function test (PFT) results until 42 months of follow-up.
Results: Fifty-two patients were included; 50% were male and 44% suffered from diffuse cutaneous systemic sclerosis. A total of 46% carried anti-topoisomerase 1 antibodies. The mean disease duration at baseline visit was 11 months. At baseline visit, 40.4% (21/52) patients had HRCT abnormalities. Patients with abnormal HRCT findings more frequently suffered from diffuse cutaneous systemic sclerosis (p < 0.05) and less frequently carried anti-centromere antibodies (p < 0.05). Patients without CT abnormalities at baseline had a shorter disease duration (9 ± 7 months versus 14 ± 12 months). After 42 months, 8/52 patients, including 3 patients with normal HRCT findings at baseline, died due to SSc-related manifestations. Progression of lung fibrosis occurred in 16 patients at month 42, including 7 patients with normal CT at baseline. No clear predictors of progression could be identified.
Conclusion: In early SSc patients, the disease dynamics differ from the large published cohorts. Progressive lung fibrosis and mortality can also occur in patients without radiological abnormalities at baseline. Key Points • Disease dynamics in early SSc differ from more established SSc. • In early SSc, progressive pulmonary fibrosis can occur in patients without CT abnormalities at baseline. • In early SSc, more stringent pulmonary follow-up is warranted both in lcSSc and dcSSc.
Keywords: High-resolution computed tomography; Interstitial lung disease; Mortality; Pulmonary fibrosis; Systemic sclerosis.