Impact of the revised definition on incidence and outcomes of acute exacerbation of idiopathic pulmonary fibrosis

The Impact of Chronic Comorbidities on Outcomes in Acute Exacerbations of Idiopathic Pulmonary Fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis is a chronic progressive lung disease of unknown cause with a high associated mortality. We aimed to compare the impact of chronic medical conditions on hospital outcomes of patients with acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF).

METHODS

This was a retrospective cohort study using the NIS database from 2016 to 2018. We included patients aged 60 and older hospitalized in academic medical centers with the diagnoses of IPF and acute respiratory failure. We examined factors associated with hospital mortality and length of stay (LOS) using survey-weighted multivariate logistic and negative binomial regression.

RESULTS

Out of 4975 patients with AE-IPF, 665 (13.4%) did not survive hospitalization. There was no difference in the mean age between survivors and non-survivors. Patients were more likely to be male, predominantly white, and have Medicare coverage. Most non-survivors were from households with higher median income. Hospital LOS was longer among non-survivors than survivors (9.4 days vs. 9.8 days; p < 0.001). After multivariate-logistic regression, diabetes was found to be protective (aOR 0.62, 95% CI 0.50-0.77; p < 0.0001) while chronic kidney disease (CKD) conferred a significantly higher risk of death after AE-IPF (aOR 6.85, 95% CI 1.90-24.7; p = 0.00). Our multivariate adjusted negative binomial regression model for LOS identified obesity (IRR 0.85, 95% CI 0.76-0.94; p ≤ 0.00) and hypothyroidism (IRR 0.90, 95% CI 0.83-0.98; p = 0.02) to be associated with shorter hospital LOS.

CONCLUSIONS

Our results suggest that CKD is a significant contributor to hospital mortality in AE-IPF, and diabetes mellitus may be protective. Obesity and hypothyroidism are linked with shorter hospital LOS among patients hospitalized with AE-IPF in US academic medical centers.

Acute exacerbation of idiopathic pulmonary fibrosis model in the rats using bleomycin and lipopolysaccharides

Objective

This study was conducted to establish a rat model of acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) using the combination of bleomycin (BLM) and lipopolysaccharides (LPS).

Materials and Method

Twenty-four male Sprague Dawley rats were allocated into two equal groups: the sham or the bleomycin and lipopolysaccharides-induced AE-IPF group (BLM-LPS). On Day 7, BLM intratracheally and LPS intraperitoneally were both used to administer AE-IPF. The BLM-LPS group and its respective sham group were terminated on Days 8, 14, or 21. Samples of bronchoalveolar lavage fluid (BALF) and lungs were taken and investigated for cell count and histopathology.

Results

On Day 8, histological analysis revealed inflammatory cell infiltration with edema and hyaline membrane, and the BALF differential cell count revealed high neutrophil counts. By having a higher collagen density area and Ashcroft modified score than the sham group on Day 14, the BLM-LPS group displayed significantly lower oxygen saturation, alveolar air area, and a fibrotic appearance. However, there was a spontaneous resolution in inflammation and fibrotic appearance on Day 21 after the BLM administration.

Conclusions

By combining BLM and LPS, it was possible to create a successful rat model of AE-IPF. The present model showed the peak exacerbation on Day 8 and the fibrotic peak on Day 14, which gradually improved. The optimal time for the new AE-IPF therapeutic intervention was determined to be between Days 8 and 14.

A Systematic Review and Meta-analysis of Clinical, Respiratory, and Biochemical Risk Factors for Acute Exacerbation of idiopathic Pulmonary Fibrosis

BACKGROUND

A better capacity to identify patients with idiopathic pulmonary fibrosis (IPF) at risk of acute exacerbation (AEIPF) might improve outcomes and reduce healthcare costs.

AIMS

We critically appraised the available evidence of the differences in clinical, respiratory, and biochemical parameters between AEIPF and IPF patients with stable disease (SIPF) by conducting a systematic review and meta-analysis.

METHODS

PubMed, Web of Science and Scopus were reviewed up until August 1, 2022, for studies reporting differences in clinical, respiratory, and biochemical parameters (including investigational biomarkers) between AEIPF and SIPF patients. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the risk of bias.

RESULTS

Twenty-nine cross-sectional studies published between 2010 and 2022 were identified (all with a low risk of bias). Of the 32 meta-analysed parameters, significant differences were observed between groups, assessed through standard mean differences or relative ratios, with age, forced vital capacity, vital capacity, carbon monoxide diffusion capacity, total lung capacity, oxygen partial pressure, alveolar-arterial oxygen gradient, P/F ratio, 6 min walk test distance, C-reactive protein, lactate dehydrogenase, white blood cell count, albumin, Krebs von den Lungen 6, surfactant protein D, high mobility group box 1 protein, and interleukin-1β, 6, and 8.

CONCLUSIONS

We identified significant differences between AEIPF and SIPF patients in age and specific parameters of respiratory function, inflammation, and epithelial lung damage. Prospective studies are warranted to determine the capacity of these parameters to predict AEIPF more accurately (PROSPERO registration number: CRD42022356640).

Epigenetics Approaches toward Precision Medicine for Idiopathic Pulmonary Fibrosis: Focus on DNA Methylation

Genetic information is not transmitted solely by DNA but by the epigenetics process. Epigenetics describes molecular missing link pathways that could bridge the gap between the genetic background and environmental risk factors that contribute to the pathogenesis of pulmonary fibrosis. Specific epigenetic patterns, especially DNA methylation, histone modifications, long non-coding, and microRNA (miRNAs), affect the endophenotypes underlying the development of idiopathic pulmonary fibrosis (IPF). Among all the epigenetic marks, DNA methylation modifications have been the most widely studied in IPF. This review summarizes the current knowledge concerning DNA methylation changes in pulmonary fibrosis and demonstrates a promising novel epigenetics-based precision medicine.

A Systematic Review of the Prognostic Significance of the Body Mass Index in Idiopathic Pulmonary Fibrosis

The identification of novel prognostic biomarkers might enhance individualized management strategies in patients with idiopathic pulmonary fibrosis (IPF). Although several patient characteristics are currently used to predict outcomes, the prognostic significance of the body mass index (BMI), a surrogate measure of excess fat mass, has not been specifically investigated until recently. We systematically searched PubMed, Web of Science, and Scopus, from inception to July 2022, for studies investigating associations between the BMI and clinical endpoints in IPF. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the risk of bias. The PRISMA 2020 statement on the reporting of systematic reviews was followed. Thirty-six studies were identified (9958 IPF patients, low risk of bias in 20), of which 26 were published over the last five years. Significant associations between lower BMI values and adverse outcomes were reported in 10 out of 21 studies on mortality, four out of six studies on disease progression or hospitalization, and two out of three studies on nintedanib tolerability. In contrast, 10 out of 11 studies did not report any significant association between the BMI and disease exacerbation. Our systematic review suggests that the BMI might be useful to predict mortality, disease progression, hospitalization, and treatment-related toxicity in IPF (PROSPERO registration number: CRD42022353363).