Interstitial lung disease in systemic sclerosis-a retrospective cross-sectional study in Taiwan

INTRODUCTION/OBJECTIVES : Interstitial lung disease (ILD) is a crucial manifestation of systemic sclerosis (SSc), which has not been studied much in Asians.

The electronic medical records of 110 SSc patients between April 2000 and December 2020 were comprehensively examined, including clinical manifestations, laboratory tests, pulmonary functions, and high-resolution computerized tomography (HRCT) of the chest.

Among 26 men and 84 women with a median age of 61 years in SSc cohort, 52 (47.3%) presented with ILD. The actual prevalence of ILD in SSc cohort was estimated between 10.5% and 47.3%. The most common form was usual interstitial pneumonitis (UIP). The total lung capacity (TLC)/diffusion capacity of carbon monoxide (DLCO), renal function, and CRP were poorer in the SSc-ILD who smoked less than the counterpart without ILD. A weighted score incorporated from essential parameters (risk of ILD = TLC - 0.1 × ESR - 1.5 × CRP) has modest power (ROC AUC 0.7242) to predict ILD. The main causes of death in the SSc-ILD were infections (72.7%), pulmonary hypertension (PH, OR = 18.81, 95% CI = 2.11-167.70), and renal failure (OR = 33.6, 95% CI = 2.00-546.10).

The SSc-ILD have lower TLC/DLCO, higher CRP, and poorer renal function than the SSc without ILD. Early-onset dyspnea, PH, and renal failure may be independent risk factors for mortality in SSc-ILD. Key Points • 110 SSc (M: F=26:84) were retrospectively analyzed for ILD, with 10.5-47.3% presenting with ILD (UIP the most). • Risk of ILD in SSc = TLC - 0.1 ×  ESR - 1.5 × CRP can apply in this cohort. • Death originated from infections, PH, and renal failure in addition to early-onset dyspnea in this cohort.