A39-24 Higher Corticosteroid Dose Linked to Shorter Hospitalization in Acute Exacerbations of Systemic Autoimmune Related Disease Associated Interstitial Lung Disease

Abstract Rationale Acute exacerbations of systemic autoimmune related disease associated interstitial lung disease (AE-SARD-ILD) are clinically distinct from exacerbations of idiopathic pulmonary fibrosis and may respond more favorably to corticosteroid therapy. Optimal steroid dosing strategies remain undefined, and the relationship between corticosteroid exposure and clinical outcomes has not been well characterized. Understanding this association could inform management strategies for a population at high risk for morbidity and mortality. We aimed to evaluate the association between average daily corticosteroid dose and hospital length of stay (LOS) in patients admitted with AE-SARD-ILD. Methods We performed a retrospective cohort study of adults hospitalized with AE-SARD-ILD at Temple University Hospital between 2016 and 2024. Data collected included demographics, autoimmune disease subtypes, corticosteroid dosing, LOS, and clinical outcomes, including transplant-free survival. The primary variable was average daily corticosteroid dose (mg/day) administered during hospitalization. Associations between steroid dose, LOS, and outcomes were analyzed using Spearman correlation and Mann-Whitney U tests, with 95% confidence intervals reported. Results Fifty-two patients were included (mean age 59 ± 11 years; 65% female). Rheumatologic disease subtypes included rheumatoid arthritis (19%), dermatomyositis (10%), scleroderma (17%), mixed connective tissue disease (6%), Sjogren’s syndrome (8%), anti-synthetase syndrome (4%), systemic lupus erythematous (2%), and uncharacterized (23%). Among 32 transplant-free survivors, higher average daily corticosteroid dose was associated with shorter LOS (Spearman’s rho = -0.66, 95% CI -0.82 to -0.40, p 0.001). Median daily steroid dose was higher in transplant-free survivors (Mann-Whitney U test, mean rank 29.4 vs 20.3, p = 0.034). Conclusions In this single-center cohort, higher average daily corticosteroid dose was associated with shorter hospitalization time among survivors of AE-SARD-ILD and was overall higher in patients who remained transplant-free. This suggests that steroid dosing intensity may influence short-term clinical outcomes. These findings highlight the need for prospective studies to define optimal corticosteroid regimens. This abstract is funded by: None