Clinical Characteristics Based on the New Criteria of Acute Exacerbation in Patients with Idiopathic Pulmonary Fibrosis

Prognostic factors associated with mortality in acute exacerbations of idiopathic pulmonary fibrosis: A systematic review and meta-analysis

BACKGROUND

Acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF) increases mortality risk, but which factors increase mortality is unknown. We aimed to perform a prognostic review of factors associated with mortality in patients with IPF.

STUDY DESIGN

and methods: We searched MEDLINE, EMBASE, and CINAHL for studies that reported on the association between any prognostic factor and AE-IPF. We assessed risk of bias using the QUIPS tool. We conduced pairwise meta-analyses using REML heterogeneity estimator, and GRADE approach to assess the certainty of the evidence.

RESULTS

We included 35 studies in our analysis. We found that long-term supplemental oxygen at baseline (aHR 2.52 [95 % CI 1.68 to 3.80]; moderate certainty) and a diagnosis of IPF compared to non-IPF ILD (aHR 2.19 [95 % CI 1.22 to 3.92]; moderate certainty) is associated with a higher risk of death in patients with AE-IPF. A diffuse pattern on high resolution computed tomography (HRCT) compared to a non-diffuse pattern (aHR 2.61 [95 % CI 1.32 to 2.90]; moderate certainty) is associated with a higher risk of death in patients with AE-IPF. We found that using corticosteroids prior to hospital admission (aHR 2.19 [95 % CI 1.26 to 3.82]; moderate certainty) and those with increased neutrophils (by % increase) in bronchoalveolar lavage (BAL) during the exacerbation is associated with a higher risk of death (aHR 1.02 [1.01 to 1.04]; moderate certainty).

INTERPRETATION

Our results have implications for healthcare providers in making treatment decisions and prognosticating the clinical trajectory of patients, for researchers to design future interventions to improve patient trajectory, and for guideline developers in making decisions about resource allocation.

Animal models of acute exacerbation of pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive scarring interstitial lung disease with an unknown cause. Some patients may experience acute exacerbations (AE), which result in severe lung damage visible on imaging or through examination of tissue samples, often leading to high mortality rates. However, the etiology and pathogenesis of AE-IPF remain unclear. AE-IPF patients exhibit diffuse lung damage, apoptosis of type II alveolar epithelial cells, and an excessive inflammatory response. Establishing a reliable animal model of AE is critical for investigating the pathogenesis. Recent studies have reported a variety of animal models for AE-IPF, each with its own advantages and disadvantages. These models are usually established in mice with bleomycin-induced pulmonary fibrosis, using viruses, bacteria, small peptides, or specific drugs. In this review, we present an overview of different AE models, hoping to provide a useful resource for exploring the mechanisms and targeted therapies for AE-IPF.

Elevation of serum lactate dehydrogenase during methylprednisolone pulse therapy as a predictor of high mortality in acute respiratory failure: A single-center, retrospective study

Background

Corticosteroids are common treatments in certain diseases that cause acute respiratory failure (ARF) and are sometimes administered empirically for patients with critical ARF. Associations between changes in clinical parameters following initiation of steroid pulse therapy and mortality in patients with ARF have not been previously investigated.

Methods

This was a single-center and retrospective cohort study. Parameters on the day of methylprednisolone pulse therapy initiation (day 1) and the day following the end of methylprednisolone therapy (day 4) in patients who were admitted because of ARF and underwent methylprednisolone pulse therapy between October 2008 and July 2021 were reviewed.

Results

A total of 98 patients were included in our analysis, and 45 (46%) died at our hospital. Change in lactate dehydrogenase (LDH) from day 1 to day 4 (ΔLDH) was significantly higher in the in-hospital death group than in the survival group (-68 IU/L in the survival group versus 46 IU/L in the in-hospital death group, p < 0.01). Multivariate logistic analyses showed that age >75 years old (odds ratio (OR), 3.88; 95% confidence interval (CI), 1.38-10.9; p < 0.01), previously diagnosed interstitial lung disease (OR, 3.43; 95% CI, 1.10-10.7; p = 0.03), ΔLDH > 0 (OR, 6.47; 95% CI, 2.30-18.2; p < 0.01), and ΔSequential Organ Failure Assessment score > 0 (OR, 3.06; 95% CI, 1.10-8.51; p = 0.03) were significantly associated with in-hospital mortality.

Conclusions

This study showed that elevation of serum LDH level during methylprednisolone pulse therapy was a predictive factor for high in-hospital mortality in patients with ARF.

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

The revised definition of acute exacerbation (AE) in idiopathic pulmonary fibrosis (IPF) was proposed in 2016, but changes in the incidence and impact on prognosis of the re-defined AE compared to those of the previous definition remain unclear. Clinical data of 445 patients with IPF (biopsy proven cases: 165) were retrospectively reviewed. The median follow-up period was 36.8 months and 17.5% (n = 78) experienced AE more than once. The 1- and 3-year incidence rates of AE were 6.7% and 16.6%, respectively, and idiopathic AE accounted for 82.1% of AE. Older age, lower diffusing capacity of the lung for carbon monoxide and 10% relative decline in forced vital capacity for 6 months were independently associated with AE. The in-hospital mortality rate following AE was 29.5%. In the multivariable analysis, AE was independently associated with poor prognosis in patients with IPF. Compared to the old definition, the revised definition relatively increased the incidence of AE by 20.4% and decreased the in-hospital mortality by 10.1%. Our results suggest that the revised definition affects approximately 20% increase in the incidences and 10% reduction in the in-hospital mortality of AE defined by the past definition.

Inflammatory indices obtained from routine blood tests show an inflammatory state associated with disease progression in engineered stone silicosis patients

Patients with silicosis caused by occupational exposure to engineered stone (ES) present a rapid progression from simple silicosis (SS) to progressive massive fibrosis (PMF). Patient classification follows international rules based on radiology and high-resolution computed tomography (HRCT), but limited studies, if any, have explored biomarkers from routine clinical tests that can be used as predictors of disease status. Our objective was thus to investigate circulating biomarker levels and systemic inflammatory indices in ES silicosis patients whose exposure to ES dust ended several years ago. Ninety-one adult men, ex-workers in the manufacturing of ES, 53 diagnosed with SS and 38 with PMF, and 22 healthy male volunteers (HC) as controls not exposed to ES dust, were recruited. The following circulating levels of biomarkers like lactate dehydrogenase (LDH), angiotensin-converting-enzyme (ACE), protein C reactive (PCR), rheumatoid factor, alkaline phosphatase and fibrinogen were obtained from clinical reports after being measured from blood samples. As biochemical markers, only LDH (HC = 262 ± 48.1; SS = 315.4 ± 65.4; PMF = 337.6 ± 79.3 U/L), ACE (HC = 43.1 ± 18.4; SS = 78.2 ± 27.2; PMF = 86.1 ± 23.7 U/L) and fibrinogen (HC = 182.3 ± 49.1; SS = 212.2 ± 43.5; PMF = 256 ± 77.3 U/L) levels showed a significant sequential increase, not been observed for the rest of biomarkers, in the HC → SS → PMF direction. Moreover, several systemic inflammation indices neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), systemic inflammation response index (SIRI), systemic immune-inflammation index (SII), aggregate index of systemic inflammation (AISI) derived from whole blood cell counts showed significant differences between the HC, SS and PMF groups. All these biomarkers were analyzed using receiver operating characteristic (ROC) curves, and the results provided moderately high sensitivity and specificity for discriminating between ES silicosis patient groups and healthy controls. Our study reveals that some inflammatory biomarkers, easily available from routine blood analysis, are present in ES silicosis patients even several years after cessation of exposure to ES silica dust and they could help to know the progression of the disease.

Systematic review and meta-analysis of prognostic factors of acute exacerbation of idiopathic pulmonary fibrosis

OBJECTIVE

To clarify prognostic factors of acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF).

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

Medline, Embase and Science Citation Index Expanded were searched from 2002 through 1 March 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

The review included primary studies addressing the association between the outcomes such as all-cause mortality of AE of IPF and its potential prognostic factors, which were designated as any clinical information related to the outcomes.

DATA EXTRACTION AND SYNTHESIS

Two reviewers extracted relevant data independently and assessed risk of bias. Univariate results were pooled using a random-effect model if at least three studies were available. Prognostic factors were determined based on significant and consistent results on both univariate and multivariate analyses in the majority of studies.

RESULTS

Out of a total of 6763 articles retrieved, 37 were eligible and 31 potential prognostic factors for all-cause mortality were selected. Each study was subject to certain methodological shortcomings. The following five factors were statistically significant by a meta-analysis of univariate results, which was confirmed by multivariate analysis, that is, Acute Physiology and Chronic Health Evaluation (APACHE) II score (HR 1.10, 1.01 to 1.19), partial pressure of arterial oxygen to fraction of inspired oxygen (PaO₂/FiO₂) ratio (ORs 0.99 in two studies and HRs 0.31 and 0.99 in two studies, respectively), lactate dehydrogenase (LDH) (HRs 1.002, 1.003, 1.01 and 1.02), white blood cell (WBC) count (OR 1.38, 1.04 to 1.83) and oxygen therapy before AE (HRs 3.68, 1.05 to 12.9 and 2.34, 1.04 to 5.28) (multivariate analysis, 95% CI).

CONCLUSIONS

APACHE II score, PaO₂/FiO₂ ratio, LDH, WBC count and oxygen therapy before AE were deemed as prognostic factors of AE of IPF. Although there are some methodological limitations in this study, these findings are reliable due to consistent results by both univariate and multivariate analyses.

PROSPERO REGISTRATION NUMBER

CRD42018106172.

Acute exacerbations of idiopathic pulmonary fibrosis (AE-IPF): an overview of current and future therapeutic strategies

Introduction: Idiopathic pulmonary fibrosis (IPF), the most common of the idiopathic interstitial pneumonias, is a disease with a poor prognosis, and a highly heterogeneous and unpredictable clinical course. While most patients experience a relatively slow clinical, functional and radiological deterioration, a significant minority develops episodes of acute respiratory worsening termed acute exacerbations of IPF (AE-IPF). AE-IPF cannot be predicted or prevented and precede approximately half of IPF-related deaths. An international working group has recently proposed new diagnostic criteria and definition of AE-IPF.Areas covered: Despite their clinical significance, the optimal treatment of AE-IPF remains undetermined. In this review, we discuss the huge unmet need for an improved understanding of AE-IPF, with emphasis on current and potential therapeutic strategies.Expert opinion: The recently revised definition and diagnostic criteria of AE-IPF will facilitate future research into the etiology, pathobiology and clinical management of these life-threatening events. Efforts should be made to identify patients at higher risk for AE-IPF and detect early signs of these events. Potential treatment options should be studied in randomized, controlled trials. To this end, the importance of international collaborations cannot be overemphasized.

Possible Serological Markers to Predict Mortality in Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Background and objectives: Idiopathic pulmonary fibrosis (IPF) has a particularly poor prognosis, and most IPF-related deaths are due to acute exacerbation (AE) of this condition. Few reports about biomarkers to predict prognosis of AE-IPF have been published since the release of the new AE-IPF criteria in 2016. The present study investigated relationships between serological markers and in-hospital mortality after the onset of AE-IPF. Methods: Demographic, serological, and imaging data from patients hospitalized at the Maebashi Red Cross Hospital (Gunma, Japan) between 1 January 2013, and 31 December 2017, were retrospectively reviewed. Subjects fulfilling the diagnostic criteria for AE-IPF were divided into those who survived or died; statistical analysis of risk factors was performed using data from these two groups. Results: Diagnostic criteria for AE-IPF were fulfilled by 84 patients (59 males (70.2%)), with a median age of 78 years (range, 56-95 years). IPF was diagnosed before hospitalization in 50 (59.5%) patients and 38 (45.2%) died in hospital. Among the serological markers at hospitalization in the deceased group, C-reactive protein (CRP) was significantly higher than in the survivor group (p = 0.002), while total serum protein (p = 0.031), albumin (p = 0.047) and total cholesterol (p = 0.039) were significantly lower. Cox hazard analysis of factors predicting mortality, corrected for age, sex and BMI, revealed the following: CRP (hazard ratio (HR) 1.080 (95% confidence interval (CI) 1.022-1.141); p = 0.006), LDH (HR 1.003 (95% CI 1.000-1.006); p = 0.037), and total cholesterol (HR 0.985 (95% CI 0.972-0.997); p = 0.018). Conclusions: Our data suggest that CRP, LDH, and total cholesterol may be biomarkers predicting mortality in patients with AE-IPF. However, only prospective controlled studies can confirm or not our observation as a generalizable one.

Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is the most common form of idiopathic interstitial pneumonia. Idiopathic pulmonary fibrosis is often seen in elderly men who smoke. A diagnosis of IPF is based on a combination of a detailed clinical history, specific physical examination, laboratory findings, pulmonary function tests, high-resolution computed tomography (HRCT) of the chest, and histopathology. Idiopathic pulmonary fibrosis has a heterogeneous clinical course, from an asymptomatic stable state to progressive respiratory failure or acute exacerbation (AE). Acute exacerbation of IPF has several important differential diagnoses, such as heart failure and volume overload. The International Working Group project proposed new criteria for defining AE of IPF in 2016, which divides it into triggered and idiopathic AE. On the basis of these criteria, physicians can detect AE of IPF more easily. The recent international IPF guidelines emphasized the utility of chest HRCT. In addition, two antifibrotic agents have become available. We should focus on both the management and prevention of AE. The diagnostic process, laboratory findings, typical chest imaging, management, and prognosis of AE are comprehensively reviewed in this article.

Acute exacerbation of idiopathic pulmonary fibrosis: a 10-year single-centre retrospective study

Introduction

In 2016, an international working group proposed a revised definition and new diagnostic criteria for the acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF). Based on these criteria, AE-IPF was diagnosed regardless of the presence or absence of a known trigger and categorised as triggered (T-AE) or idiopathic (I-AE) AE-IPF. However, the clinical characteristics of the newly defined AE-IPF and clinical differences between T-AE and I-AE are unresolved.

Methods

We retrospectively analysed 64 patients with AE-IPF (I-AE (42), T-AE (22)) admitted to our hospital over a 10- year period.

Results

I-AE and T-AE cases did not show differences in in-hospital and long-term outcomes (in-hospital mortality: I-AE 52.4%, T-AE 59.1%, p=0.61; long-term mortality: p=0.68). In the I-AE group, significantly more patients received corticosteroid therapy before an AE (I-AE 35.7%, T-AE 4.5%; p=0.01). Significantly more patients in the T-AE group had lung cancer (I-AE 7.1%, T-AE 59.1%, p<0.001). I-AE occurred more frequently in winter while T-AE did not show seasonality. The white blood cell (WBC) count and haemoglobin (Hb) level were independent predictors of in-hospital deaths in I-AE (WBC: OR 1.87; 95% CI 1.09 to 4.95, p=0.01; Hb: OR 0.26, 95%  CI 0.04 to 0.78, p=0.01) but not T-AE.

Discussion

With the introduction of new criteria for AE-IPF, a retrospective study over a 10-year period showed a lack of prognostic difference between I-AE and T-AE. The WBC count and Hb level predicted in-hospital outcome in I-AE cases.