Background Scleroderma interstitial lung disease (SSc-ILD) has a variable and poorly predictable course. Data on independent role of bronchoalveolar lavage fluid (BALF) analysis in prognostic stratification of SSc-ILD patients are conflicting. We wanted to retrospectively evaluate the role of BALF analysis to predict severe course of disease in our cohort of SSc-ILD.

Objectives We wanted to retrospectively evaluate the role of BALF analysis to predict severe course of disease in our cohort of SSc-ILD.

Methods Forty SSc-ILD patients naive to immunosuppressants underwent comprehensive clinical evaluation, bronchoalveolar fluid analysis with total and differential leukocyte count, pulmonary function tests (PFTs), high-resolution computed tomography (HRCT). All the patients had fibrosing lung disease affecting more than 10% of lung volume on HRCT. Baseline alveolar (AS) and interstitial score (IS) on HRCT were computed. The 15-year crude mortality rate was retrospectively assessed.

Results The enrolled patients (pts) (male 20.0%, aged 53.9±13.0 years) had a disease duration of 4.3±3.4 years. Diffuse LeRoy variant was reported in 47.5% of patients and anti-Scl70 and anti-centromere antibodies were detected in 57.5% and 12.5% of pts, respectively. The average AS and IS were 6.5±4.8 and 6.2±2.7, respectively, while 25.0% had FVC≤80% and 35.0% had DLco≤50%. During follow-up 18 pts received immunosuppressants. BALF neutrophilia (≥3.0%), eosinophilia (≥1.0%) and lymphocytosis (≥15.0%) were reported in 40.0%, 16.0% and 5.0% of patients, respectively. Twenty-five pts (62.5%) died within 15 years after bronchoscopy with a mean survival of 12.7 years (95% IC 11.5-13.9) overall. Fifteen-year mortality was predicted by BALF alveolitis (HR 2.87, 95% IC 1.26-6.56), and neutrophilia (HR 3.74, 95% IC 1.64-8.55), log-transformed absolute count of total cells (HR 2.52, 95% IC 1.12-5.58), neutrophils (HR 1.80, 95% IC 1.28-2.54), and eosinophils (HR 1.31, 95% IC 1.05-1.62), and percentages of neutrophils (HR 1.8, 95% IC 1.26-2.73) and eosinophils (HR 1.32, 95% IC 1.01-1.73). Only absolute and relative neutrophil counts were independently associated with mortality also in all models adjusted for demographics (age, gender), main disease traits (diffuse LeRoy variant, anti-Scl70 positivity), baseline pulmonary function tests (FVC, DLco), baseline HRCT involvement (AS, IS) and presence of vascular involvement (pulmonary hypertension, digital ulcers).

Conclusion High BALF neutrophils were associated with high 15-year mortality independently from other established clinical risk factors. Given the negative prognosis of SSc-ILD, its poorly predictable clinical course, and the availability of new promising biomarkers, BALF analysis may be considered in assessing these pts to improve prognosis prediction.

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Acknowledgements: NIL.

Disclosure of Interests None Declared.

Keywords: Lungs, Innate immunity, Systemic sclerosis

DOI: 10.1136/annrheumdis-2023-eular.5871