Identification of Clinical and Radiologic Markers of Disease Presentation in Patients with Scleroderma Related Interstitial Lung Disease (SSc-ILD) in a Cohort from Ontario, Canada

Abstract

Objectives Systemic sclerosis (SSc) is a multisystem autoimmune disease characterized by vasculopathy, inflammation and fibrosis of multiple organs including the skin, lungs, heart, and GI tract.[1] Lung involvement, characterized by interstitial lung disease (SSc-ILD) and pulmonary hypertension, occurs in 50-70% of individuals and represents the leading cause of death for patients with SSc.[1,2] Prior studies have identified risk factors for development of SSc-ILD, including older age, male sex, the presence of diffuse disease, those with anti-Scl-70/anti-topoisomerase I antibody, and the absence of anti-centromere antibody.[1-3] In this study, we examined the clinical risk factors that predict incident ILD in patients with SSc. We also examined 2 quality improvement measures: 1) whether patients with evidence of fibrosis on chest x-ray undergo high-resolution computed tomography (HRCT), and 2) whether patients with evidence of pulmonary hypertension on echocardiogram undergo right heart catherization (RHC). Methods We analyzed data from 162 patients with SSc in Hamilton, Ontario who are registered in the Canadian Scleroderma Research Group registry, a national longitudinal registry of adult SSc patients. We summarized clinical risk factors between patients who do vs do not develop ILD during the follow-up period of the CSRG and compared them using logistic regression modeling. We also determined the proportion of patients with abnormal chest x-rays who did and did not receive HRCT, as well as the proportion of patients with pulmonary hypertension on echocardiogram who did and did not undergo RHC. Results In this cohort of SSc patients, the presence of interstitial lung disease was associated with the diffuse cutaneous subtype of the disease (p = 0.01), anti-topoisomerase I antibody positivity (p < 0.01), lower baseline DLCO (p < 0.01), lower baseline FVC (p < 0.01), and elevated RVSP (> 40mmHg) on echocardiogram (p < 0.01). Among patients with abnormal chest X-rays, 84.6% underwent HRCT, whereas only 40% of patients with elevated RVSP underwent RHC. Conclusion These findings further validate clinical predictors of SSc-ILD, highlight potential new ones, and document practice patterns on the assessment of key pulmonary complications associated with SSc. These findings underscore the need for both early recognition and improved quality of care in this population. References [1.] Gabrielli A. N Engl J Med 2009;360:1989-2003. [2.] Steen VD. Semin Arthritis Rheum 2005;35:35-42. [3.] Nihtyanova SI. Arthritis Rheumatol 2014;66:1625-35.