Acute exacerbation of idiopathic pulmonary fibrosis a narrative review primary focus on treatments.

Background and Objective: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrotic interstitial pneumonia, which is the commonest type of idiopathic interstitial pneumonia in the clinic. For most patients, the course of the disease is slow and prolonged, but a percentage of them develop an acute respiratory worsening during the disease, known as an acute exacerbation of IPF (AE-IPF). The updated guidelines define AE-IPF as an acute worsening of dyspnea in an IPF patient within 1 month and exclude other conditions such as left heart failure and pulmonary embolism. However, the prevention and treatment of AE-IPF are still unclear. Based on the high mortality rate caused by AE, in this article, we will focus on the latest research advances in AE-IPF treatment strategies and provide a comprehensive review of its pathogenesis, risk factors, clinical features, and diagnosis. Methods: This study searched for relevant literature published from 2018 to 2023 in the PubMed database. The search terms used were as follows: "Acute exacerbation", "Idiopathic pulmonary fibrosis", "Biomarker", "Pathogenesis", "Treatment", "HRCT", "Antifibrotic", "Infection", "Immunosuppressant", "Autoantibody", "Oxygen therapy", "Hemoperfusion", "Inflammation". Key Content and Findings: The review found that corticosteroids are still the primary treatment strategy at present, although there is some controversy regarding the dosing and tapering of corticosteroids. However, corticosteroids combined with intravenous cyclophosphamide have been shown to be detrimental to the prognosis of patients with AE-IPF. Given its deadly high mortality rate, early intervention is crucial. Pirfenidone and nintedanib have been proven to reduce incidence of AE. Meanwhile, in the future, the lung microbiome may also be a break-through. Conclusions: This study reviewed the pathogenesis and risk factors of AE-IPF and updated the current and potential treatment strategies regarding AE-IPF. The pathogenesis of AE-IPF is not exact, multiple mechanisms may be involved simultaneously. Corticosteroids remain the mainstream treatment modality in the medical treatment of AE-IFP. Many other treatment modalities have been proposed in succession, but no clear conclusions can be drawn about the effectiveness and safety of these interventions.