Retrospective Analysis of Predictive Biomarkers of Survival in Acute Exacerbation of Fibrosing Interstitial Lung Disease: A Single-Center Study in Spain

<b>Background</b>: Fibrosing interstitial lung diseases can evolve into acute exacerbations, which significantly impact morbidity and mortality. Currently, no routinely used clinical biomarkers can discern the potential progression in these patients. This study aims to analyze different biological markers used in routine clinical practice as possible predictive biomarkers for patients with acute fibrosing interstitial lung disease exacerbation. <b>Methods</b>: We conducted a retrospective, single-center study including patients diagnosed with acute exacerbation of fibrosing interstitial lung disease who required hospitalization between 2018 and 2019 at Vall d'Hebron Hospital, Spain. Patient demographics, clinical data, respiratory function, and comorbidities were collected at baseline. The primary outcome was survival at 30 days, 90 days, and 365 days, using Kaplan-Meier survival analysis and Cox regression. <b>Results</b>: Twenty-nine patients were included (mean age 70.4 years). At the 3-month follow-up, patients with ischemic heart disease showed higher survival rates (<i>p</i> = 0.02). Identifying an infection as the etiology of the exacerbation was associated with worse one-year survival rates compared to idiopathic cases (<i>p</i> = 0.03). Elevated levels of leukocytes (<i>p</i> < 0.01), neutrophils (<i>p</i> < 0.01), and fibrinogen (<i>p</i> = 0.03) were predictors of mortality. Additionally, patients who received a cumulative dose of corticosteroids between 501 and 1000 mg during the exacerbation showed higher one-year survival (<i>p</i> < 0.01). <b>Conclusions</b>: Routine clinical markers can help predict outcomes in AE-f-ILD. Further multicenter studies should validate these findings and assess the role of therapies in its management.