Progressive lung fibrosis and mortality can occur in early systemic sclerosis patients without pulmonary abnormalities at baseline assessment

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.