Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is defined as an acute and clinically significant respiratory deterioration characterized by evidence of new, widespread alveolar abnormality. In the past, AE-IPF was considered to be idiopathic, which was hard to be prevented and its prognosis was hard to be obviously improved; the latest researches have shown that AE-IPF can be triggered by known causes, including pulmonary infection, aspiration, etc. This review summarizes the etiology or risk factors, treatment and prevention of AE-IPF according to the latest researches.
ObjectiveTo investigate the causal relationship between gut microbiota and idiopathic pulmonary fibrosis (IPF). MethodsGenome-wide association studies (GWAS) data of gut microbiota and IPF were obtained from MiBioGen and Finngen databases, respectively. Instrumental variables were screened by means of significance, linkage disequilibrium, weak instrumental variable screening, and removal of confounding factors (genetics, smoking, host characteristics). Inverse variance weighted (IVW) was used as the main Mendelian randomization (MR) analysis method, and the weighted median, simple mode, MR-Egger, and weighted mode were used to perform MR to reveal the causal effect of gut microbiota and IPF. The Cochrane's Q, leave-one-out, MR-Egger-intercept, and Mendelian randomization pleiotropy residual sum and outlier (MR-PRESSO) and Steiger tests were used to analyze the heterogeneity, horizontal pleiotropy, outliers, and directionality, respectively. ResultsIVW analysis results showed that Actinomycetes [OR=1.773, 95%CI (1.323, 2.377), P<0.001], Erysipelatoclostridium [OR=2.077, 95%CI (1.107, 3.896), P=0.023], and Streptococcus [OR=1.35, 95%CI (1.100, 1.657), P=0.004] could increase the risk of IPF. Bifidobacterium [OR=0.668, 95%CI (0.620, 0.720), P<0.001], Ruminococcus [OR=0.434, 95%CI (0.222,0.848), P=0.015], and Tyzzerella [OR=0.479, 95%CI (0.304, 0.755), P=0.001] could reduce the risk of IPF. No significant heterogeneity, horizontal pleiotropy, outliers, and reverse causality were found. ConclusionActinobacteria, Erysipelatoclostridium and Streptococcus may increase the risk of IPF, while Bifidobacterium, Ruminococcus and Tyzzerella may reduce the risk of IPF. Regulation of the above gut microbiota may become a new direction in the study of the pathogenesis of IPF.
Objective To investigate the causal effect of coronavirus disease 2019 (COVID-19) on idiopathic pulmonary fibrosis (IPF). Methods Genome-wide association studies (GWAS) data were sourced from the COVID-19 Host Genetics Initiative and published research. We employed: ① linkage disequilibrium score regression to estimate heritability of individual traits and genetic correlations between COVID-19 and IPF; ② multi-trait analysis of GWAS to identify genetic loci associated with COVID-19 and IPF; ③ Mendelian randomization (MR) to assess causal effect of COVID-19 on IPF; ④ colocalization analysis to identify shared causal variants. Results ① Three COVID-19 phenotypes showed significant positive genetic correlations with IPF (P<0.05); ② Multi-trait analysis of GWAS identified loci jointly associated with COVID-19 and IPF; ③ MR indicated that COVID-19 hospitalization may increase IPF risk (P=0.006); ④ Two causal variants were identified: rs12585036 (posterior probability>0.8, mapped to ATP11A) and rs12610495 (posterior probability>0.8, mapped to DPP9). Conclusions COVID-19 hospitalization may increase IPF risk through inflammatory pathways, providing new insights for managing COVID-19-related pulmonary diseases.