Association between initial treatment response and prognosis in acute exacerbations of idiopathic pulmonary fibrosis treated with steroid pulse therapy

<bold>Background:</bold> Steroid pulse therapy is recommended for acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF). While previous studies on AE-IPF have focused on steroid dosages, the treatment course remains unexplored. Our study aims to evaluate the relationship between treatment course and patient prognosis. Methods: We conducted a single-center, retrospective cohort study. Patients showing an increase in the ratio of percutaneous oxygen saturation to inspired oxygen fraction (SpO2/FiO2) following 3 days of steroid pulse therapy were categorized as the "responder group". Those with decreased or unchanged SpO2/FiO2 were labeled the "non-responder group". Our primary outcome was the mortality rate at day 28; secondary outcomes involved a comparative analysis of the SpO2/FiO2 transitions observed on days 1, 4, and 28. Results: The final analysis included 100 AE-IPF patients treated with steroid pulse therapy. The 28-day mortality rate was 14% (8/59) in the responder group and 43% (17/40) in the non-responder group. The Responder group exhibited a significantly lower mortality rate at 28 days. Cox proportional hazards model revealed that the non-responder group (HR: 0.22, CI: 0.10–0.52) and a lower SpO2/FiO2 ratio on day 1 (HR: 0.18, CI:0.06–0.53) were independent predictors of 28-day mortality. At the same time, age and KL-6 levels were not significant factors. Of the responder group, 7 out of 60 patients exhibited a decline in SpO2/FiO2 from day 3 to day 28. Conclusion: The initial response to steroid pulse therapy in AE-IPF patients may be associated with mortality at day 28.