PROGNOSTIC FACTORS FOR SEVERE PULMONARY INVOLVEMENT IN SYSTEMIC SCLEROSIS

Abstract

Background. Lung involvement is the main disease related death cause in patients with systemic sclerosis (SSc). The most frequent lung manifestations in SSc are interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH). Objectives. Evaluation of lung involvement in patients with SSc and identification of predictive factors for severe lung involvement. Patients and methods. All patients with SSc of the EUSTAR100 center, having at least two visits between 2004 and 2016, were included. Survival status, cause of death, dyspnea, ILD on thorax radiography or high resonance thorax computer tomography (HRCT) and lung function tests were recorded during the entire follow-up. Severe lung involvement was defined as severe or end-stage lung involvement on the Medsger severity scale at any time during follow-up, or death. Cox proportional hazards regression was used in univariate and multivariate analysis to identify prognostic factors. Results. 89 patients were included (12.4% males, mean age±SD 49.2±12.2 years, disease duration 4.1±7.5 years), with a follow-up duration up to 13 years. 14 deaths were reported, half due to lung involvement (4 deaths due to ILD, 3 deaths due to PAH). Pulmonary involvement was identified in a large proportion: at first visit 28/55 present ILD on thorax radiography, 7/12 on HRCT scans; at the most recent visit 41/71 present ILD on X-ray, 18/24 on HRCT scans. At least 10% decrease of pulmonary diffusion capacity for carbon monoxyde (DLCO) and of forced vital capacity (FVC) was observed in 18/32 and 8/35 respectively; 24/48 developed severe or end-stage pulmonary involvement on the Medsger scale or have died. Risk factors for severe lung involvement were age>60 years, disease duration<3 years and diffuse cutaneous subset. Conclusion. SSc often presents unfavourable disease course, mostly due to pulmonary involvement. While half of the deaths reported were due to lung involvement, only about half of the patients presenting ILD-typical findings on Rx develop end-stage lung involvement or death. It is of great importance to screen at baseline for ILD and PAH, following up annually, even while patients are asymptomatic.

Keywords

• systemic sclerosis
• prognostic factors
• lung involvement