Acute exacerbations of progressive-fibrosing interstitial lung diseases

Usefulness of CT Quantification-Based Assessment in Defining Progressive Pulmonary Fibrosis

RATIONALE AND OBJECTIVES

To establish a quantitative CT threshold for radiological disease progression of progressive pulmonary fibrosis (PPF) and evaluate its feasibility in patients with connective tissue disease-related interstitial lung disease (CTD-ILD).

MATERIALS AND METHODS

Between April 2007 and October 2022, patients diagnosed with CTD-ILD retrospectively evaluated. CT quantification was conducted using a commercial software by summing the percentages of ground-glass opacity, consolidation, reticular opacity, and honeycombing. The quantitative threshold for radiological progression was determined based on the highest discrimination on overall survival (OS). Two thoracic radiologists independently evaluated visual radiological progression, and the senior radiologist's assessment was used as the final result. Cox regression was used to assess prognosis of PPF based on the visual assessment and quantitative threshold.

RESULTS

97 patients were included and followed up for a median of 30.3 months (range, 4.7-198.1 months). For defining radiological disease progression, the optimal quantitative CT threshold was 4%. Using this threshold, 12 patients were diagnosed with PPF, while 14 patients were diagnosed with PPF based on the visual assessment, with an agreement rate of 97.9% (95/97). Worsening respiratory symptoms (hazard ratio [HR], 12.73; P < .001), PPF based on the visual assessment (HR, 8.86; P = .002) and based on the quantitative threshold (HR, 6.72; P = .009) were independent risk factors for poor OS.

CONCLUSION

The quantitative CT threshold for radiological disease progression (4%) was feasible in defining PPF in terms of its agreement with PPF grouping and prognostic performance when compared to visual assessment.

Steroid therapy in acute exacerbation of fibrotic interstitial lung disease

BACKGROUND AND OBJECTIVE

Evidence for the benefit of steroid therapy in acute exacerbations (AEs) of idiopathic pulmonary fibrosis (IPF) is limited; however, they remain a cornerstone of management in other fibrotic interstitial lung diseases. This retrospective observational study assesses the effect of steroid treatment on in-hospital mortality in patients with acute exacerbation of fibrotic interstitial lung disease (AE-FILD) including IPF and non-IPF ILDs.

METHODS

AE-FILD cases over a 10-year period were filtered using a code-based algorithm followed by individual case evaluation. Binary logistic regression analysis was used to assess the relationship between corticosteroid treatment (defined as ≥0.5 mg/kg/day of prednisolone-equivalent for ≥3 days within the first 72 h of admission) and in-hospital mortality or need for lung transplantation. Secondary outcomes included readmission, overall survival, requirement for domiciliary oxygen and rehabilitation.

RESULTS

Across two centres a total of 107 AE-FILD subjects were included, of which 46 patients (43%) received acute steroid treatment. The steroid cohort was of younger age with fewer comorbidities but had higher oxygen requirements. Pre-admission FVC and DLCO, distribution of diagnoses and smoking history were similar. The mean steroid treatment dose was 4.59 mg/kg/day. Steroid use appeared to be associated with increased risk of inpatient mortality or transplantation (OR 4.11; 95% CI 1.00-16.83; p = 0.049). In the steroid group, there appeared to be a reduced risk of all-cause mortality in non-IPF patients (HR 0.21; 95% CI 0.04-0.96; p = 0.04) compared to their IPF counterparts. Median survival was reduced in the steroid group (221 vs. 520.5 days) with increased risk of all-cause mortality (HR 3.25; 95% CI 1.56-6.77; p < 0.01).

CONCLUSION

In this two-centre retrospective study of 107 patients, AE-FILD demonstrates a high risk of mortality, at a level similar to that seen for AE-IPF, despite steroid treatment. Clinicians should consider other precipitating factors for exacerbations and use steroids judiciously. Further prospective trials are needed to determine the role of corticosteroids in AE-FILD.

Alveolar epithelial cells of lung fibrosis patients are susceptible to severe virus-induced injury

Patients with pulmonary fibrosis (PF) often experience exacerbations of their disease, characterised by a rapid, severe deterioration in lung function that is associated with high mortality. Whilst the pathobiology of such exacerbations is poorly understood, virus infection is a trigger. The present study investigated virus-induced injury responses of alveolar and bronchial epithelial cells (AECs and BECs, respectively) from patients with PF and age-matched controls (Ctrls). Air-liquid interface (ALI) cultures of AECs, comprising type I and II pneumocytes or BECs were inoculated with influenza A virus (H1N1) at 0.1 multiplicity of infection (MOI). Levels of interleukin-6 (IL-6), IL-36γ and IL-1β were elevated in cultures of AECs from PF patients (PF-AECs, n = 8-11), being markedly higher than Ctrl-AECs (n = 5-6), 48 h post inoculation (pi) (P<0.05); despite no difference in H1N1 RNA copy numbers 24 h pi. Furthermore, the virus-induced inflammatory responses of PF-AECs were greater than BECs (from either PF patients or controls), even though viral loads in the BECs were overall 2- to 3-fold higher than AECs. Baseline levels of the senescence and DNA damage markers, nuclear p21, p16 and H2AXγ were also significantly higher in PF-AECs than Ctrl-AECs and further elevated post-infection. Senescence induction using etoposide augmented virus-induced injuries in AECs (but not viral load), whereas selected senotherapeutics (rapamycin and mitoTEMPO) were protective. The present study provides evidence that senescence increases the susceptibility of AECs from PF patients to severe virus-induced injury and suggests targeting senescence may provide an alternative option to prevent or treat the exacerbations that worsen the underlying disease.

Standardized 3D-CT lung volumes for patients with acute exacerbation of rheumatoid arthritis-associated interstitial lung disease

OBJECTIVES

Fibrotic interstitial lung disease (ILD) is a progressive lung disease characterized by loss of lung volume, resulting in a leading cause of death in patients with RA. Crucially, acute exacerbation (AE) of ILD shows higher morbidity and mortality with rapid deterioration of the lungs. However, a quantitative assessment for physiological changes at AE has yet to be performed. This study hypothesized that quantitative assessments of lung volume (LV) accurately indicate disease severity and mortality risk in patients with AE-RA-ILD.

METHODS

This multicentre cohorts study quantitatively assessed physiological changes of RA-ILD at diagnosis (n = 54), at AE (discovery-cohorts; n = 20, and validation-cohort; n = 33), and controls (n = 35) using 3D CT (3D-CT) images. LV was quantitatively measured using 3D-CT and standardized by predicted forced vital capacity.

RESULTS

Patients with RA-ILD at diagnosis showed decreased LV, predominantly in lower lobes, compared with controls. Further substantial volume loss was found in upper- and lower lobes at AE compared with those at diagnosis. During AE, decreased standardized 3D-CT LV was associated with a worse prognosis in both cohorts. Subsequently, standardized 3D-CT LV was identified as a significant prognostic factor independent of age, sex and the presence of UIP pattern on CT by multivariate analyses. Notably, a composite model of age and standardized 3D-CT LV successfully classified mortality risk in patients with AE-RA-ILD.

CONCLUSION

Volume loss at AE in patients with RA-ILD was associated with increased mortality. Assessing physiological change using standardized 3D-CT might help evaluate disease severity and mortality risk in patients with AE-RA-ILD.

Clinical characteristics and outcome of lung cancer in patients with fibrosing interstitial lung disease

BACKGROUND

Lung cancer (LC) is an important comorbidity of interstitial lung disease (ILD) and has a poor prognosis. The clinical characteristics and outcome of each ILD subtype in LC patients have not been sufficiently investigated. Therefore, this study aimed to evaluate the difference between idiopathic pulmonary fibrosis (IPF) and non-IPF ILD as well as prognostic factors in patients with ILD-LC.

METHODS

The medical records of 163 patients diagnosed with ILD-LC at Asan Medical Center from January 2018 to May 2023 were retrospectively reviewed. Baseline characteristics and clinical outcomes were compared between the IPF-LC and non-IPF ILD-LC groups, and prognostic factors were analyzed using the Cox proportional-hazard model.

RESULTS

The median follow-up period was 11 months after the cancer diagnosis. No statistically significant differences were observed in clinical characteristics and mortality rates (median survival: 26 vs. 20 months, p = 0.530) between the groups. The independent prognostic factors in patients with ILD-LC were higher level of Krebs von den Lungen-6 (≥ 1000 U/mL, hazard ratio [HR] 1.970, 95% confidence interval [CI] 1.026-3.783, p = 0.025) and advanced clinical stage of LC (compared with stage I, HR 3.876 for stage II, p = 0.025, HR 5.092 for stage III, p = 0.002, and HR 5.626 for stage IV, p = 0.002). In terms of treatment, surgery was the significant factor for survival (HR 0.235; 95% CI 0.106-0.520; p < 0.001).

CONCLUSIONS

No survival difference was observed between IPF-LC and non-IPF ILD-LC patients. A higher level of Krebs von den Lungen-6 may act as a prognostic marker in ILD-LC patients.

The impact of air pollution on interstitial lung disease: a systematic review and meta-analysis

Introduction

There is a growing body of evidence suggesting a causal relationship between interstitial lung disease (ILD) and air pollution, both for the development of the disease, and driving disease progression. We aim to provide a comprehensive literature review of the association between air pollution, and ILD, including idiopathic pulmonary fibrosis (IPF).

Methods

We systematically searched from six online database. Two independent authors (DL and CF) selected studies and critically appraised the risk of bias using the Newcastle-Ottawa Scale (NOS). Findings are presented through a narrative synthesis and meta-analysis. Meta-analyses were performed exclusively when there was a minimum of three studies examining identical pollutant-health outcome pairs, all evaluating equivalent increments in pollutant concentration, using a random effects model.

Results

24 observational studies conducted in 13 countries or regions were identified. Pollutants under investigation encompassed ozone (O3), nitrogen dioxide (NO2), Particulate matter with diameters of 10 micrometers or less (PM10) and 2.5 micrometers or less (PM2.5), sulfur dioxide (SO2), carbon monoxide (CO), nitric oxide (NO) and nitrogen oxides (NOx). We conducted meta-analyses to assess the estimated Risk Ratios (RRs) for acute exacerbations (AE)-IPF in relation to exposure to every 10 μg/m3 increment in air pollutant concentrations, including O3, NO2, PM10, and PM2.5. The meta-analysis revealed a significant association between the increased risk of AE-IPF in PM2.5, yielding RR 1.94 (95% CI 1.30-2.90; p = 0.001). Findings across all the included studies suggest that increased exposure to air pollutants may be linked to a range of health issues in individuals with ILDs.

Conclusion

A scarcity of available studies on the air pollutants and ILD relationship underscores the imperative for further comprehensive research in this domain. The available data suggest that reducing levels of PM2.5 in the atmosphere could potentially reduce AE frequency and severity in ILD patients.

Clinical implications of frailty assessed in hospitalized patients with acute-exacerbation of interstitial lung disease

BACKGROUND

Approximately 50% of patients with interstitial lung disease (ILD) experience frailty, which remains unexplored in acute exacerbations of ILD (AE-ILD). A better understanding may help with prognostication and resource planning. We evaluated the association of frailty with clinical characteristics, physical function, hospital outcomes, and post-AE-ILD recovery.

METHODS

Retrospective cohort study of AE-ILD patients (01/2015-10/2019) with frailty (proportion ≥0.25) on a 30-item cumulative-deficits index. Frail and non-frail patients were compared for pre- and post-hospitalization clinical characteristics, adjusted for age, sex, and ILD diagnosis. One-year mortality, considering transplantation as a competing risk, was analysed adjusting for age, frailty, and Charlson Comorbidity Index (CCI).

RESULTS

89 AE-ILD patients were admitted (median: 67 years, 63% idiopathic pulmonary fibrosis). 31 were frail, which was associated with older age, greater CCI, lower 6-min walk distance, and decreased independence pre-hospitalization. Frail patients had more major complications (32% vs 10%, p = .01) and required more multidisciplinary support during hospitalization. Frailty was not associated with 1-year mortality (HR: 0.97, 95%CI: [0.45-2.10]) factoring transplantation as a competing risk.

CONCLUSIONS

Frailty was associated with reduced exercise capacity, increased comorbidities and hospital complications. Identifying frailty may highlight those requiring additional multidisciplinary support, but further study is needed to explore whether frailty is modifiable with AE-ILD.

Algorithms Identifying Patients With Acute Exacerbation of Interstitial Pneumonia and Acute Interstitial Lung Diseases Developed Using Japanese Administrative Data

BACKGROUND

We aimed to develop algorithms to identify patients with acute exacerbation of interstitial pneumonia and acute interstitial lung diseases using Japanese administrative data.

METHODS

This single-center validation study examined diagnostic algorithm accuracies. We included patients >18 years old with at least one claim that was a candidate for acute exacerbation of interstitial pneumonia, acute interstitial lung diseases, and pulmonary alveolar hemorrhage who were admitted to our hospital between January 2016 and December 2021. Diagnoses of these conditions were confirmed by at least two respiratory physicians through a chart review. The positive predictive value was calculated for the created algorithms.

RESULTS

Of the 1,109 hospitalizations analyzed, 285 and 243 were for acute exacerbation of interstitial pneumonia and acute interstitial lung diseases, respectively. As there were only five cases of pulmonary alveolar hemorrhage, we decided not to develop an algorithm for it. For acute exacerbation of interstitial pneumonia, acute interstitial lung diseases, and acute exacerbation of interstitial pneumonia or acute interstitial lung diseases, algorithms with high positive predictive value (0.82, 95% confidence interval: 0.76-0.86; 0.82, 0.74-0.88; and 0.89, 0.85-0.92, respectively) and algorithms with slightly inferior positive predictive value but more true positives (0.81, 0.75-0.85; 0.77, 0.71-0.83; and 0.85, 0.82-0.88, respectively) were developed.

CONCLUSION

We developed algorithms with high positive predictive value for identifying patients with acute exacerbation of interstitial pneumonia and acute interstitial lung diseases, useful for future database studies on such patients using Japanese administrative data.

Clinical impact of pre-existing acute exacerbation in patients with interstitial lung disease who underwent lung transplantation

BACKGROUND

Acute exacerbation of interstitial lung disease (AE-ILD) significantly impacts prognosis, leading to high mortality rates. Although lung transplantation is a life-saving treatment for selected patients with ILD, its outcomes in those presenting with AE-ILD have yielded conflicting results compared with those with stable ILD. This study aims to investigate the impact of pre-existing AE on the prognosis of ILD patients who underwent lung transplantation.

METHOD

We conducted a single-center retrospective study by reviewing the medical records of 108 patients who underwent lung transplantation for predisposing ILD at Asan Medical Center, Seoul, South Korea, between 2008 and 2022. The primary objective was to compare the survival of patients with AE-ILD at the time of transplantation with those without AE-ILD.

RESULTS

Among the 108 patients, 52 (48.1%) experienced AE-ILD at the time of lung transplantation, and 81 (75.0%) required pre-transplant mechanical ventilation. Although the type of ILD (IPF vs. non-IPF ILD) did not affect clinical outcomes after transplantation, AE-ILD was associated with worse survival outcomes. The survival probabilities at 90 days, 1 year, and 3 years post-transplant for patients with AE-ILD were 86.5%, 73.1%, and 60.1%, respectively, while those for patients without AE-ILD were higher, at 92.9%, 83.9%, and 79.6% (p = 0.032). In the multivariable analysis, pre-existing AE was an independent prognostic factor for mortality in ILD patients who underwent lung transplantation.

CONCLUSIONS

Although lung transplantation remains an effective treatment option for ILD patients with pre-existing AE, careful consideration is needed, especially in patients requiring pre-transplant mechanical respiratory support.

Clinical significance of microscopic polyangiitis with interstitial lung disease and bronchiectasis: probability of preexisting comorbidities

BACKGROUND

The association between pulmonary involvement and microscopic polyangiitis (MPA) has been increasingly recognized in recent years. Whether interstitial lung disease (ILD) and bronchiectasis (BE) are disease manifestations of MPA, preexisting comorbidities or important complications remains unclear. The purpose of this study was to determine the clinical characteristics and prognosis of MPA with pulmonary involvement to further guide clinical management.

METHODS

The data for 97 patients with a definitive diagnosis of MPA were retrospectively reviewed. The MPA diagnosis was based on the 2012 revised Chapel Hill Consensus Conference (CHCC) criteria. The baseline clinical information and laboratory parameters were collected and analysed at each patient's initial diagnosis.

RESULTS

Forty-seven out of the 97 (48.5%) patients who were diagnosed with MPA presented with pulmonary involvement, including 37 patients with ILD, 12 patients with BE and two patients with diffuse alveolar haemorrhage (DAH). ILD and BE antedated MPA in 56.76% and 75.00% of the patients, respectively. Compared with that in the MPA-BE group, the serum LDH level (222.86 ± 68.19 vs. 171.58 ± 31.43, p = .016) in the MPA-ILD group was significantly higher. In the multivariate Cox analysis, elevated serum creatinine (HR 4.08, confidence interval (CI) 1.38-12.05, p = .011) was an independent risk factor for shorter survival in MPA patients with pulmonary involvement, and treatment with glucocorticoid pulse cyclophosphamide therapy (HR 0.095, 95% CI 0.019-0.47, p = .004) was independently associated with prolonged survival. Among the patients in the MPA-ILD group, acute exacerbations of ILD (HR 4.55 CI 1.16-17.86, p = .029) and elevated serum creatinine (HR 4.95, CI 1.39-17.54, p = .014) were independently associated with a poor prognosis, and treatment with glucocorticoids (HR 0.057, 95% CI 0.012-0.28, p < .001) was independently associated with significant prolongation of survival.

CONCLUSIONS

Patients with MPA have a high prevalence of pulmonary involvement, and ILD is the most common subtype of MPA. ILD and BE can be considered preexisting comorbidities of MPA. Elevated serum creatinine was associated with shorter survival. However, remission induction regimens with glucocorticoids and/or immunosuppressants may improve this outcome.

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.

Clinical characteristics and prognostic impact of acute exacerbations in patients with interstitial lung disease and lung cancer: A single-center, retrospective cohort study

BACKGROUND

Although acute exacerbation (AE) after treatment for lung cancer (LC) is a poor prognostic factor in patients with interstitial lung disease associated with lung cancer (ILD-LC), the risk of AE according to cancer treatment type remains unclear. Therefore, in the present study, we aimed to investigate the association between AE and treatment received for LC in patients with ILD-LC.

METHODS

We conducted a retrospective study of patients with ILD-LC who had undergone treatment for LC between January 2018 and December 2022. The primary study outcome was the incidence of AE within 12 months of treatment for LC according to treatment type. The association between AE and all-cause mortality was evaluated as a secondary outcome.

RESULTS

Among a total of 137 patients, 23 (16.8%) developed AE within 12 months of treatment for LC. The incidence of AE according to treatment type was 4.3% for surgery, 16.2% for radiotherapy, 15.6% for chemotherapy, and 54.5% for concurrent chemoradiation therapy (CCRT). Patients who received CCRT were more likely to develop AE, even after adjustment for covariables (hazard ratio [HR], 15.39; 95% confidence interval [CI]: 4.00-59.19; p < 0.001). In addition, AE within 12 months of treatment for LC was associated with an increased risk of all-cause mortality (HR, 2.82; 95% CI: 1.13-7.04; p = 0.026).

CONCLUSION

Among treatment options for patients with ILD-LC, CCRT was associated with an increased risk for AE. In addition, patients with AE had a higher mortality rate than patients without AE.

Survival and acute exacerbation for patients with idiopathic pulmonary fibrosis (IPF) or non-IPF idiopathic interstitial pneumonias: 5-year follow-up analysis of a prospective multi-institutional patient registry

OBJECTIVE

Few prospective cohort studies with relatively large numbers of patients with non-idiopathic pulmonary fibrosis (non-IPF) of idiopathic interstitial pneumonia (IIP) have been described. We aimed to assess disease progression and cause of death for patients with non-IPF IIPs or IPF under real-life conditions.

METHODS

Data were analysed for a prospective multi-institutional cohort of 528 IIP patients enrolled in Japan between September 2013 and April 2016. Diagnosis of IPF versus non-IPF IIPs was based on central multidisciplinary discussion, and follow-up surveillance was performed for up to 5 years after patient registration. Survival and acute exacerbation (AE) were assessed.

RESULTS

IPF was the most common diagnosis (58.0%), followed by unclassifiable IIPs (35.8%) and others (6.2%). The 5-year survival rate for non-IPF IIP and IPF groups was 72.8% and 53.7%, respectively, with chronic respiratory failure being the primary cause of death in both groups. AE was the second most common cause of death for both non-IPF IIP (24.1%) and IPF (23.5%) patients. The cumulative incidence of AE did not differ significantly between the two groups (p=0.36), with a 1-year incidence rate of 7.4% and 9.0% in non-IPF IIP and IPF patients, respectively. We found that 30.2% and 39.4% of non-IPF IIP and IPF patients, respectively, who experienced AE died within 3 months after an AE event, whereas 55.8% and 66.7% of such patients, respectively, died within 5 years after registration.

CONCLUSION

Closer monitoring of disease progression and palliative care interventions after AE are important for non-IPF IIP patients as well as for IPF patients.

Pulmonary fibrosis and COVID-19

The COVID-19 pandemic has caused the death of millions and many more have been infected worldwide. The causative virus, SARS-CoV-2, affects the lung where it elicits an aggressive inflammatory response leading to respiratory failure in severe cases. This infection has been linked to pulmonary fibrosis, a process characterized by fibroproliferation and the exaggerated deposition of collagen and other extracellular matrices. These events damage the lung architecture, especially its gas-exchanging units, leading to hypoxemic respiratory failure. The mechanisms by which the virus affects the lung remain incompletely understood, but it is postulated that after entering the airways, the virus binds to Angiotensin Converting Enzyme (ACE) receptors on the surface of epithelial cells, not only stimulating oxidative stress and inflammation, but also promoting the expression of soluble pro-fibrotic factors responsible for the accumulation of fibroblasts, their activation into myofibroblasts, and their unregulated expression of extracellular matrices. These events may trigger the rapid progression or exacerbation of underlying interstitial lung disorders or promote fibrosis in a previously healthy lung. Although the natural progression of such conditions cannot always be predicted, fibrosis may progress even after the virus has been eliminated or, in cases where it does not progress, may become irreversible, leading to long-standing symptoms like shortness of breath and exercise intolerance resulting from loss of lung function. Although COVID-19 related pulmonary fibrosis is not common, preventive measures like vaccination are encouraged, as they are expected to reduce infection or its severity, thereby decreasing the possibility of life-changing respiratory conditions such as pulmonary fibrosis.

Rituximab for the treatment of acute exacerbation of interstitial lung disease associated with connective tissue disease

BACKGROUND

Acute exacerbation of interstitial lung disease (AE-ILD) is a severe complication with a poor prognosis. No clinical trials have supported the use of rituximab in AE-ILD associated with connective tissue disease.

METHODS

We present a series of four cases in which administration of rituximab was associated with appropriate clinical, radiological and functional progress.

RESULTS

The four patients were alive 30 days after discharge following their exacerbation.

CONCLUSIONS

Given the speed of action, safety and efficacy profile observed for rituximab, we believe that this agent should be further investigated in clinical trials so that it could be included in the daily clinical management of this severe condition.

Pulmonary fibrosis and type-17 immunity

Fibrosis of the lung can occur in idiopathic pulmonary fibrosis, collagen vascular diseases, and hypersensitivity pneumonitis, among other diseases. Transforming growth factor (TGF)-β, vascular epithelial growth factor, fibroblast growth factor, and platelet-derived growth factor contribute to the pathophysiology of fibrosis. TGF-β and other cytokines, including interleukin (IL)-1β, IL-6, and IL-23, activate type-17 immunity, which is involved in pulmonary fibrosis. The components of type-17 immunity include type-17 helper T cells, γδT cells, IL-17A-producing CD8-positive T cells, invariant NKT cells, and group 3 innate lymphoid cells. IL-17A, the main cytokine of type-17 immunity, is able to induce the epithelial-mesenchymal transition in epithelial cells via a production of TGF-β, directly stimulate fibroblasts and fibrocytes, and inhibit autophagy, which otherwise protects against pulmonary fibrosis. IL-23 induces type-17 immunity and plays an important role in the acute exacerbation of pulmonary fibrosis. Clinical studies have also linked type-17 immunity to the pathogenesis of pulmonary fibrosis. Consequently, targeting type-17 immunity may serve as a new therapeutic strategy to prevent the development or exacerbation of pulmonary fibrosis.

Nintedanib administration after the onset of acute exacerbation of interstitial lung disease in the real world

Nintedanib reduces the decline in forced vital capacity and extends the time to the first acute exacerbation of interstitial lung disease (AE-ILD). However, the effect of additional nintedanib administration after AE-ILD onset is unknown. This study aimed to investigate the efficacy and safety of nintedanib administration after AE-ILD development. We retrospectively collected the data of 33 patients who developed AE-ILD between April 2014 and January 2022. Eleven patients who received nintedanib after AE-ILD development and the remaining who did not were classified into the N and No-N groups, respectively. The survival time in the N group tended to be longer than that in the No-N group. The generalized Wilcoxson test revealed that the cumulative mortality at 90 days from AE-ILD onset was significantly lower in the N group. The time to subsequent AE-ILD development was significantly longer in the N group than that in the No-N group. The incidence of adverse gastrointestinal effects and liver dysfunction in the N group was 9-18%. Treatment without nintedanib after AE-ILD development and the ratio of arterial oxygen partial pressure to fractional inspired oxygen were significant independent prognostic factors in the multivariate analysis. Thus, nintedanib administration may be a treatment option for AE-ILD.

Re-hospitalisation predicts poor prognosis after acute exacerbation of interstitial lung disease

BACKGROUND

Several markers have been identified to increase the risk for acute exacerbation of interstitial lung disease (AE-ILD) or mortality related to AE-ILD. However, less is known about the risk predictors of ILD patients who have survived AE. The aim of the study was to characterise AE-ILD survivors and investigate prognostic factors in this subpopulation.

METHODS

All AE-ILD patients (n = 95) who had been discharged alive from two hospitals located in Northern Finland were selected from a population of 128 AE-ILD patients. Clinical data related to the hospital treatment and six-month follow-up visit were collected retrospectively from medical records.

RESULTS

Fifty-three patients with idiopathic pulmonary fibrosis (IPF) and 42 patients with other ILD were identified. Two thirds of the patients had been treated without invasive or non-invasive ventilation support. The clinical features of six-month survivors (n = 65) and non-survivors (n = 30) did not differ in terms of medical treatment or oxygen requirements. Of the patients, 82.5% used corticosteroids at the six-month follow-up visit. Fifty-two patients experienced at least one non-elective respiratory re-hospitalisation before the six-month follow-up visit. In a univariate model, IPF diagnosis, high age and a non-elective respiratory re-hospitalisation increased the risk of death, although re-hospitalisation was the only independent risk factor in a multivariate model. In six-month survivors, there was no statistically significant decrease in pulmonary function test results (PFT) examined at the follow-up visit compared with earlier PFT examined near the time of AE-ILD.

CONCLUSIONS

The AE-ILD survivors were a heterogeneous group of patients both clinically and in terms of their outcome. A non-elective respiratory re-hospitalisation was identified as a marker of poor prognosis among AE-ILD survivors.

The Role of Antibiotics in Nasal Fractures after Closed Reduction

Nasal fractures represent the most common fracture in facial trauma. The role of prophylactic antibiotics in these injuries is debated, given low infection rates and demonstrated risks of antibiotics. We studied the isolated effect of prophylactic antibiotics on infection rate in patients with nasal fracture after closed reduction.

Methods

Retrospective cohort study of a prospectively maintained facial trauma database was conducted. Demographics, comorbidities, fracture classifications, and management of patients who received antibiotics at the time of closed nasal reduction were compared against those who did not receive antibiotics. Infection rates between groups were analyzed. Multivariate analysis was conducted to control for confounding variables. Qualitative analysis was performed for patients who experienced infection following nasal fracture.

Results

A total of 282 patients met inclusion criteria (n = 144, antibiotic; n = 138, nonantibiotic). Six patients experienced infection. There was no difference in infection rate between antibiotic and nonantibiotic groups (2.0% versus 2.2%; P = 0.90). On multivariate regression, antibiotics did not significantly decrease odds of infection (OR 1.7 [0.17-13.6]; P = 0.64). Moreover, patients with open nasal fractures did not have significantly higher odds of infection (OR 1.9 [0.08-20.8]; P = 0.64). Similarly, increasing severity of injury based on Rohrich classification did not significantly impact odds of infection (OR 0.68 [0.23-1.9]; P = 0.46). All six infections were managed at the bedside, with zero infections following operating room management (P = 0.32).

Conclusions

Prophylactic antibiotics do not decrease infection rates following nasal fractures managed by closed reduction. Bedside management may be a risk factor for the development of infection; however, this finding requires further evaluation.

Use of illness severity scores to predict mortality in interstitial lung disease patients hospitalised with acute respiratory deterioration

INTRODUCTION

Hospitalisations relating to acute respiratory deteriorations (ARD) in Interstitial Lung Disease (ILD) have poor outcomes. Factors predicting adverse outcomes are not fully understood and data addressing the use of illness severity scores in prognostication are limited.

OBJECTIVE

To investigate the use of CURB-65 and NEWS-2 severity scores in the prediction of mortality following ARD-ILD hospitalisation, using prospective methodology and to validate previously determined cut-offs, derived from a retrospective study cohort.

METHODS

A dual-centre prospective observational cohort study of all adults (≥18y) hospitalised with ARD-ILD in Bristol, UK (n = 179). Gender-Age-Physiology (GAP), CURB-65 and NEWS-2 scores were calculated for each eligible admission. Receiver operating characteristics (ROC) curve analysis was used to quantify the strength of discrimination for NEWS-2 and CURB-65 scores. Univariable and multivariable logistic regression analyses were performed to explore the relationship between baseline severity scores and mortality.

RESULTS

GAP showed some merit at predicting 30-day mortality (AUC = 0.64, P = 0.015); whereas CURB-65 showed modest predictive value for in-hospital (AUC = 0.72, P < 0.001) and 90-day mortality (AUC = 0.67, P < 0.001). NEWS-2 showed higher predictive value for in-hospital (AUC = 0.80, P < 0.001) and 90-day mortality (AUC = 0.75, P < 0.001), with an optimal derived cut-off ≥6.5 found to be sensitive and specific for predicting in-hospital (83% and 63%) and 90-day (73% and 72%) mortality. In exploratory analyses, GAP score addition improved the predictive ability of NEWS-2 against 30-day mortality and CURB-65 across all time-periods.

CONCLUSION

NEWS-2 has good discriminatory value for predicting in-hospital mortality and moderate discriminatory value for predicting 90-day mortality. The optimal NEWS-2 cut-off value determined was the same as in a previous retrospective cohort, confirming the NEWS-2 score shows promise in predicting mortality following ARD-ILD hospitalisation.

Clinical significance of acute exacerbation in interstitial lung disease with antineutrophil cytoplasmic antibody: an indicator of poor prognosis

BACKGROUND

The association between interstitial lung disease (ILD) and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has been increasingly recognized in recent years. The clinical features and prognostic differences between AAV-associated ILD and isolated ANCA-positive idiopathic interstitial pneumonias (IIPs) remain unclear. The purpose of this study was to determine the clinical significance and prognosis of ANCA-positive ILD to further guide clinical management.

METHODS

This study retrospectively reviewed the data of 379 ILD patients with available ANCA results and ultimately analysed 49 ANCA-positive patients. AAV diagnosis was based on the 2012 revised Chapel Hill Consensus Conference (CHCC) criteria, and 33 of 49 patients were diagnosed with microscopic polyangiitis (MPA). The baseline clinical information and laboratory parameters were collected and analysed at each patient's initial diagnosis.

RESULTS

Among 49 ANCA-positive ILD patients, the high-resolution computed tomography (HRCT) pattern was mainly usual interstitial pneumonia (UIP) (59.18%), followed by nonspecific interstitial pneumonia (NSIP) (26.53%). The C-reactive protein (CRP) level (43.89± 40.61 versus 18.74± 20.05, p = 0.028) and erythrocyte sedimentation rate (ESR) (71.97± 42.73 versus 40.69± 28.46, p = 0.011) were significantly higher in the MPA-ILD group than in the ANCA-IIP group. Haemoglobin (113.09 ± 24.47 versus 132.19± 13.34, p = 0.006) and albumin (32.95± 5.84 versus 36.52± 3.94, p = 0.032) levels were significantly lower. Survival was shorter among MPA-ILD patients than among ANCA-IIP patients [hazard ratio (HR) 3.38, 95% confidence interval (CI) 1.32-8.67, p = 0.040]. In the multivariable Cox analysis, a diagnosis of MPA (HR 3.91, 95% CI 1.07-14.08, p = 0.038) and acute exacerbation (AE) of ILD (HR 9.43, 95% CI 2.89-30.30, p < 0.001) were significantly independently associated with shorter survival in ANCA-positive ILD patients, and the NSIP pattern (HR 0.07, 95% CI 0.01-0.41, p = 0.003) was independently associated with prolonged survival.

CONCLUSION

ANCA-ILD patients mostly have myeloperoxidase (MPO)-ANCA positivity and an MPA diagnosis. Survival was shorter among MPA-ILD patients than among ANCA-IIP patients. Respiratory failure and AE were associated with poorer prognosis. Early antifibrotic treatment may be a reasonable treatment option in fibrotic ILD patients with ANCA positivity.

Reliability and validity of the Chester step test in patients with interstitial lung disease

BACKGROUND

The Chester Step Test (CST) is a simple and inexpensive field test, which requires minimal physical space to assess exercise capacity. Such characteristics make the CST suitable to be used in different settings, however, its measurement properties in patients with interstitial lung diseases (ILD) are unknown.

METHODS

A cross-sectional study was conducted in patients with ILD. First, a CST-1 and a 6-minute walk test (6MWT) were performed. After 48-72 hours, a CST-2 was repeated. A 2nd rater was present in one of the sessions. Relative reliability was measured using intraclass correlation coefficient (ICC1,1 and ICC2,1). Absolute reliability was determined using standard error of measurement (SEM), minimal detectable change at 95% confidence interval (MDC95) and the Bland-Altman method. The values of SEM and MDC95 were also expressed as a percentage of the mean. Construct validity was explored using Spearman correlation coefficient (rs) between the number of steps taken in the best CST and the distance performed in the 6MWT.

RESULTS

Sixty-six patients with ILD (65.5±12.9 years; 48.5%men; FVC 79.4±18.8pp; DLCO 49.0±18.3pp) participated in the study. Relative (ICC 0.95-1.0) and absolute reliability were excellent without evidence of systematic bias. The SEM and MDC95 were 11.8 (14.7%) and 32.6 steps (40.7%), respectively. The correlation between CST and 6MWT was significant, positive, and high (rs=0.85, p=0.001).

CONCLUSION

The CST is a reliable and valid test and might be especially useful to assess exercise capacity in patients with ILD in limited space environments.

Current best clinical practices for monitoring of interstitial lung disease

INTRODUCTION

Interstitial lung diseases (ILDs) are a heterogeneous group of inflammatory and/or fibrotic conditions with variable outcome and often a dismal prognosis. Since many ILDs are progressive in nature, monitoring of signs and symptoms of progression is essential to inform treatment decisions and patient counseling. Monitoring of ILDs is a multimodality process and includes all aspects of the disease, e.g. measurement of pulmonary function and exercise capacity, symptom registration and quality of life (QoL), imaging, comorbidities and/or involvement of other organs to assess disease activity, symptom burden, treatment effects, adverse events, the need for supportive and palliative care, and lung transplantation.

AREAS COVERED

For this narrative review, we searched the PUBMED database to identify articles relevant for monitoring ILDs, including pulmonary function tests, exercise capacity, imaging, telemedicine, symptoms, and QoL.

EXPERT OPINION

Due to the high heterogeneity of the ILDs and their disease course, an individualized multimodality approach must be applied. Future strategies include use of telemedicine for home monitoring of lung function and symptoms, use of artificial intelligence to support automatized guidance of patients, computerized evaluation of ILD changes on imaging, and new imaging tools with less radiation dosage.

Efficacy of initial high- versus low-dose intravenous corticosteroid therapy in patients with acute exacerbation of idiopathic interstitial pneumonia: A nationwide observational study

BACKGROUND

Acute exacerbation of idiopathic interstitial pneumonias (AE-IIPs) has a high mortality. However, there is no established treatment for AE-IIPs. Therefore, we aimed to compare the efficacy of high- and low-dose corticosteroid therapies in AE-IIPs patients.

METHODS

Data were retrospectively collected from the Japanese Diagnosis Procedure Combination database from July 2010 to March 2018. Adult patients with AE-IIPs who received high-dose (methylprednisolone at a dose of 500-1000 mg/day for 3 days starting within 4 days after admission) or low-dose (methylprednisolone at a dose of 100-200 mg/day for at least 5 days starting within 4 days after admission) corticosteroid therapy were identified. Eligible patients (n = 17,317) were divided into the high-dose (n = 16,998) and low-dose (n = 319) groups. A stabilized inverse probability of treatment weighting using propensity scores was performed to compare outcomes between the groups.

RESULTS

The primary outcome was in-hospital mortality, and the secondary outcomes were 28-day mortality, infections during hospitalization, length of hospitalization, duration of steroid use, and discharge to home. The in-hospital mortality rates of the high- and low-dose corticosteroid groups were 50.6% and 47.0%, respectively. In-hospital mortality did not significantly differ between the two groups after stabilized inverse probability of treatment weighting, and the odds ratio in the low-dose corticosteroid group was 0.86 (95% confidence interval: 0.64-1.16; p = 0.33). The secondary outcomes also did not significantly differ between the groups.

CONCLUSIONS

There was no significant difference in outcomes between patients with AE-IIPs who received high- and low-dose corticosteroid therapies.

Clinical impact of SUVmax of interstitial lesions in lung cancer patients with interstitial lung disease who underwent pulmonary resection

BACKGROUND

Acute exacerbation of interstitial lung disease often causes fatal respiratory deterioration in lung cancer patients with interstitial lung disease. Here, we examined whether the maximum standardized uptake value of a contralateral interstitial lesion was a predictive factor of acute exacerbation of interstitial lung disease within 30 days postoperatively in lung cancer patients with interstitial lung disease who underwent pulmonary resection.

METHODS

Overall, 117 consecutive lung cancer patients with interstitial lung disease who underwent pulmonary resection between August 2010 and April 2019 at the Kumamoto University Hospital were retrospectively analysed for the association between the maximum standardized uptake value of the contralateral interstitial lesions and interstitial lung disease parameters.

RESULTS

The median maximum standardized uptake value of contralateral interstitial lesions was 1.61, which was regarded as the cut-off point predictive of the incidence of acute exacerbation of interstitial lung disease. Eight patients developed postoperative acute exacerbation of interstitial lung disease. There was no significant association between the maximum standardized uptake value of the contralateral interstitial lesions and postoperative acute exacerbation of interstitial lung disease. The maximum standardized uptake value was weakly but significantly associated with lactate dehydrogenase levels (r=0.211, P=0.022), Krebs von den Lungen-6 (r=0.208, P=0.028), and % diffusing capacity for carbon monoxide (r=-0.290, P=0.002). Moreover, seven patients developed acute exacerbation of the interstitial lung disease during the clinical course after 30 postoperative days, and the incidence rate of acute exacerbation of interstitial lung disease was significantly higher in the high maximum standardized uptake value group (≥1.61) than in the low maximum standardised uptake value group (<1.61) (12.7% vs. 0%, P=0.002, Gray's test).

CONCLUSIONS

Maximum standardized uptake value was not a predictor of postoperative acute exacerbation of interstitial lung disease in lung cancer patients with interstitial lung disease after pulmonary resection, but could be a predictive tool of an association with interstitial lung disease severity and activity markers.

Interstitial lung diseases

Over 200 interstitial lung diseases, from ultra rare to relatively common, are recognised. Most interstitial lung diseases are characterised by inflammation or fibrosis within the interstitial space, the primary consequence of which is impaired gas exchange, resulting in breathlessness, diminished exercise tolerance, and decreased quality of life. Outcomes vary considerably for each of the different interstitial lung diseases. In some conditions, spontaneous reversibility or stabilisation can occur, but unfortunately in many people with interstitial lung disease, especially in those manifesting progressive pulmonary fibrosis, respiratory failure and death are a sad reality. Over the past 3 years, the field of interstitial lung disease has had important advances, with the approval of drugs to treat systemic sclerosis-associated interstitial lung disease, interstitial lung disease-associated pulmonary hypertension, and different forms of progressive pulmonary fibrosis. This Seminar provides an update on epidemiology, pathogenesis, presentation, diagnosis, disease course, and management of the interstitial lung diseases that are most frequently encountered in clinical practice. Furthermore, we describe how developments have led to a shift in the classification and treatment of interstitial lung diseases that exhibit progressive pulmonary fibrosis and summarise the latest practice-changing guidelines. We conclude with an outline of controversies, uncertainties, and future directions.

Cost-Effectiveness of Nintedanib for Patients with Progressive Fibrosing Interstitial Lung Disease (PF-ILD)

OBJECTIVES

Progressive fibrosing interstitial lung disease (PF-ILD) is characterised by increased pulmonary fibrosis, lung function decline, acute exacerbations, decreased quality of life and increased mortality. Nintedanib may slow down disease progression, but long-term outcomes are unknown. We aimed to assess the cost-effectiveness of nintedanib in comparison to placebo, both on top of usual care in patients with PF-ILD.

METHODS

An individual PF-ILD patient simulation model was created, using data and extrapolations from the nintedanib and placebo arms of the INBUILD trial. Clinical outcomes (mortality, exacerbations, lung transplants), economic outcomes (direct and indirect costs) and the cost-effectiveness of nintedanib over a 10-year time horizon were forecasted using the Netherlands as a case example. Disease progression was driven by lung function decline, with forced vital capacity (FVC) health states ranging from < 40 to ≥ 110 FVC of % predicted. Sensitivity and scenario analyses were performed to assess the impact of parameter assumptions on the cost-effectiveness and to test model robustness.

RESULTS

Over a 10-year follow-up, nintedanib gained an average of 1.31 discounted life years and an average of 0.87 discounted quality-adjusted life years (QALYs), resulting in an incremental cost-effectiveness ratio (ICER) of €60,690 per QALY. Sensitivity analyses showed cost variations had a minor impact on the ICER. Results were mainly driven by mortality probabilities and disease-related utilities. Scenario analyses indicated most sensitivity to the time horizon and lung transplantation costs.

CONCLUSION

Long-term treatment with nintedanib could result in considerable health gains for patients with PF-ILD and can be considered cost-effective under the common willingness-to-pay threshold.

Towards Treatable Traits for Pulmonary Fibrosis

Interstitial lung diseases (ILD) are a heterogeneous group of disorders, of which many have the potential to lead to progressive pulmonary fibrosis. A distinction is usually made between primarily inflammatory ILD and primarily fibrotic ILD. As recent studies show that anti-fibrotic drugs can be beneficial in patients with primarily inflammatory ILD that is characterized by progressive pulmonary fibrosis, treatment decisions have become more complicated. In this perspective, we propose that the ‘treatable trait’ concept, which is based on the recognition of relevant exposures, various treatable phenotypes (disease manifestations) or endotypes (shared molecular mechanisms) within a group of diseases, can be applied to progressive pulmonary fibrosis. These targets for medical intervention can be identified through validated biomarkers and are not necessarily related to specific diagnostic labels. Proposed treatable traits are: cigarette smoking, occupational, allergen or drug exposures, excessive (profibrotic) auto- or alloimmunity, progressive pulmonary fibrosis, pulmonary hypertension, obstructive sleep apnea, tuberculosis, exercise intolerance, exertional hypoxia, and anxiety and depression. There are also several potential traits that have not been associated with relevant outcomes or for which no effective treatment is available at present: air pollution, mechanical stress, viral infections, bacterial burden in the lungs, surfactant-related pulmonary fibrosis, telomere-related pulmonary fibrosis, the rs35705950 MUC5B promoter polymorphism, acute exacerbations, gastro-esophageal reflux, dyspnea, and nocturnal hypoxia. The ‘treatable traits’ concept can be applied in new clinical trials for patients with progressive pulmonary fibrosis and could be used for developing new treatment strategies.

Essential role of IL-17 in acute exacerbation of pulmonary fibrosis induced by non-typeable Haemophilus influenzae

Background: Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) has a poor prognosis and lacks effective therapy. Animal models that mimic AE-IPF can greatly accelerate investigation of its pathogenesis and development of effective therapy. However, there are few reports of animal models of AE-IPF caused by bacteria. Thus, our study aimed to establish a mouse model of bacterium-induced AE-IPF and explore the potential pathogenic mechanism of AE-IPF. Methods: Mice were instilled intranasally with bleomycin (BLM) followed by non-typeable Haemophilus influenzae (NTHi) strain NT127. Murine survival, bacterial load, body weight and pulmonary histopathological changes were evaluated. We analyzed the T cell and inflammatory cell responses in the lungs. Results: Infection with 10⁷ CFU NT127 triggered AE in mice with PF induced by 30 μg BLM. Compared with BLM-instilled mice, the BLM/NT127-treated mice showed more obvious airway inflammation, lower survival rate, higher inflammatory cell response, and increased proportions and numbers of IL-17⁺CD4⁺, IL-17⁺ γδ T, IL-22⁺CD4⁺ and regulatory T (Treg) cells in lungs. γδ T cells were the predominant source of IL-17. IL-17 gene knockout mice with AE-IPF had quicker body weight recovery, milder pulmonary inflammation and fibrosis, stronger IL-22⁺CD4⁺T, TGF-β⁺ γδ T and Treg cell responses, and weaker neutrophil and eosinophil responses than wild-type mice with AE-IPF. Conclusions: NTHi infection after BLM-induced IPF can cause AE-IPF in a murine model. This novel model can be used to investigate the pathogenesis of AE-IPF and develop new therapies for AE-IPF caused by bacteria. IL-17 is essential for the development of AE-IPF, and it may be a new therapeutic target for bacteria-induced AE-IPF.

Prognostic Predictive Characteristics in Patients With Fibrosing Interstitial Lung Disease: A Retrospective Cohort Study

Background: Limited data are available regarding the entire spectrum of interstitial lung disease with a progressive fibrosing feature. We investigated the prevalence and prognostic predictive characteristics in patients with PF-ILD.

Methods: This retrospective cohort study included patients with fibrosing ILD who were investigated between 1 January 2015 and 30 April 2021. We recorded clinical features and outcomes to identify the possible risk factors for fibrosing progression as well as mortality.

Results: Of the 579 patients with fibrosing ILD, 227 (39.21%) met the criteria for progression. Clubbing of fingers [odds ratio (OR) 1.52, 95% confidence interval (CI) 1.03 to 2.24, p = 0.035] and a high-resolution computed tomography (HRCT)-documented usual interstitial pneumonia (UIP)-like fibrotic pattern (OR 1.95, 95% CI 1.33 to 2.86, p = 0.001) were risk factors for fibrosis progression. The mortality was worse in patients with PF with hypoxemia [hazard ratio (HR) 2.08, 95% CI 1.31 to 3.32, p = 0.002], in those with baseline diffusion capacity of the lung for carbon monoxide (DLCO) % predicted &lt;50% (HR 2.25, 95% CI 1.45 to 3.50, p &lt; 0.001), or in those with UIP-like fibrotic pattern (HR 1.68, 95% CI 1.04 to 2.71, p &lt; 0.001).

Conclusion: Clubbing of fingers and an HRCT-documented UIP-like fibrotic pattern were more likely to be associated with progressive fibrosing with varied prevalence based on the specific diagnosis. Among patients with progressive fibrosing, those with hypoxemia, lower baseline DLCO% predicted, or UIP-like fibrotic pattern showed poor mortality.

Elevated Expression of Growth Differentiation Factor-15 Is Associated With Acute Exacerbation of Idiopathic Pulmonary Fibrosis

Backgrounds

Growth differentiation factor 15 (GDF-15) is a highly divergent member of the TGF-β superfamily and has been implicated in various biological functions. However, the expression of GDF-15 in patients with acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is unclear.

Method

The study included 47 AE-IPF patients, 61 stable IPF (S-IPF) subjects, and 31 healthy controls (HCs). Serum GDF-15 levels and their expression in the lung were measured. The correlation between serum GDF-15 and other clinical parameters and the risk factors for AE occurrence and the survival of IPF patients were analyzed.

Results

Serum GDF-15 levels were significantly elevated in AE-IPF patients (1279.22 ± 540.02 pg/ml) as compared with HCs (891.30 ± 479.90 pg/ml) or S-IPF subjects (107.82 ± 14.21 pg/ml) (both p < 0.001). The protein and mRNA expressions of GDF-15 in the lung of AE-IPF patients were significantly increased as compared with S-IPF cases (p = 0.007 and p = 0.026, respectively). The serum GDF-15 level was correlated with the clinical variables of inflammation, metabolism, and disease severity in IPF subjects (all p < 0.05). The GDF-15 serum concentration was significantly higher in decedents than in survivors (p = 0.005). A serum GDF-15 level above 989.3 pg/ml was a risk factor for AE occurrence (p = 0.04), and the level above 1,075.76 pg/ml was an independent predictor for survival in IPF cases (p = 0.007).

Conclusions

The GDF-15 level was significantly elevated in subjects with AE-IPF. GDF-15 could be a promising biomarker for AE occurrence and survival in IPF patients.

Acute exacerbation of rheumatoid arthritis-associated interstitial lung disease: mortality and its prediction model

Background

Patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD), like those with idiopathic pulmonary fibrosis (IPF), might develop an unexpected acute exacerbation (AE)—a rapidly progressing and deadly respiratory decline. Although AE incidence and risk factors in RA-ILD patients are known, their post-AE clinical course remains unknown owing to the rarity of AE-RA-ILD. This multicentre retrospective study evaluated post-AE mortality and prognostic variables in AE-RA-ILD patients and created a mortality prediction model for AE-RA-ILD.

Methods

This research comprised 58 patients with AE-RA-ILD and 96 with AE-IPF (a control disease). Multivariate Cox regression analysis was performed to identify prognostic variables. A prediction model was created with recursive partitioning (decision tree).

Results

The post-AE 90-day mortality rate in the overall AE-RA-ILD group was 48.3%; percent predicted forced vital capacity within 12 months before AE onset (baseline %FVC) and PaO₂/FiO₂ ratio at AE onset (P/F at AE) were independent predictors of mortality. Post-AE 90-day mortality rates were 40.6% and 43.8%, respectively, in AE-RA-ILD and AE-IPF patients propensity score-matched for age, sex, baseline %FVC and P/F at AE (P = 1.0000). In AE-RA-ILD patients, C-indices of baseline %FVC and P/F at AE to predict post-AE 90-day mortality were 0.604 and 0.623, respectively. A decision tree model based on these prognostic factors classified AE-RA-ILD patients into mild, moderate and severe groups (post-AE 90-day mortality rates: 20.8%, 64.0% and 88.9%, respectively; P = 0.0002); the C-index improved to 0.775.

Conclusions

Post-AE mortality was high in AE-RA-ILD patients similar to AE-IPF patients. The discovered prognostic factors and our mortality prediction model may aid in the management of AE-RA-ILD patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01978-y.

6-Gingerol, a functional polyphenol of ginger, reduces pulmonary fibrosis by activating Sirtuin1

Pulmonary fibrosis in general is the final common outcome of various interstitial lung diseases. In recent years, the incidence of pulmonary fibrosis has been rising with poor prognosis. 6-gingerol is deemed as a functional polyphenol of ginger. The aim of the present study was to investigate the effect of 6-gingerol, on pulmonary fibrosis. Mice were randomly divided into four groups: control, bleomycin, bleomycin + 6-gingerol 100 mg/kg, bleomycin + 6-gingerol 250 mg/kg, and the survival rates of the groups were recorded. Pathological and fibrotic changes in the lungs were identified by H&E and Masson staining, respectively. The levels of hydroxyproline and protein deposited in lung tissues were then, respectively, determined by colorimetry and western blotting. Subsequently, the proportion of cells and inflammatory factors in the alveolar lavage fluid were estimated. Following the identification of the possibility of Sirtuin1 (SIRT1) in the pharmacological mechanism through molecular docking and western blotting, human embryonic lung fibroblasts MRC-5 were treated with TGF-β1 and SIRT1 inhibitor to study the role of SIRT1 in the regulatory effect of 6-gingerol. From the results, 6-gingerol was found to increase the survival rate of mice and reduce lung pathology and fibrosis in mice. And, it significantly reduced the levels of hydroxyproline and the proteins deposited in lung tissues. Moreover, the number of neutrophils, basophils, monocytes, and the levels of inflammatory factors in the alveolar lavage fluid were also reduced. SIRT1 inhibitor blocked the function of 6-gingerol to inhibit fibrosis. To sum up, 6-gingerol relieves pulmonary fibrosis via activating SIRT1. This finding expands the pharmacological effect of 6-gingerol, and it is expected to advance the development of treatments for pulmonary fibrosis.

The Burden of Progressive-Fibrosing Interstitial Lung Diseases

Despite conventional treatment, a proportion of interstitial lung disease (ILD) patients develop a progressive phenotype known as “fibrosing ILD with a progressive phenotype” (PF-ILD), characterized by worsening respiratory symptoms, decline in lung function, and early mortality. This review describes the epidemiology, and the humanistic and economic burden of PF-ILDs other than idiopathic pulmonary fibrosis (non-IPF PF-ILD). A structured review of the literature was conducted, using predefined search strategies in Ovid MEDLINE and EMBASE, and supplemented with gray literature searches. The search identified 3,002 unique articles and an additional 3 sources were included from the gray literature; 21 publications were included. The estimated prevalence of non-IPF PF-ILD ranges from 6.9 to 70.3/100,000 persons and the estimated incidence from 2.1 to 32.6/100,000 person-years. Limited evidence demonstrates that PF-ILD has a significant impact on patients' quality of life, affecting their daily lives, psychological well-being, careers, and relationships. PF-ILD is also associated with significant economic burden, demonstrating higher healthcare resource use and direct costs compared with the non-progressive phenotype, and indirect costs, which include job losses. This review indicates that PF-ILD places a considerable humanistic burden on both patients and caregivers, and a substantial economic burden on healthcare systems, patients, and society.

The role of antifibrotics in the treatment of rheumatoid arthritis–associated interstitial lung disease

The major pulmonary complication of rheumatoid arthritis (RA) is interstitial lung disease (ILD), which causes significant morbidity and mortality and influences the natural course of disease. Recent advances in the management of arthritis have improved patient outcomes. However, exceptionally high medical needs still remain for effective therapies for the patients with ILD in RA. Better understanding of the shared and distinct pathophysiology of fibrotic diseases led to the development of novel antifibrotic agents such as nintedanib and pirfenidone. The further stratification analysis of the phase III INBUILD trial demonstrated beneficial effects of nintedanib in RA-ILD with a progressive phenotype by reducing the rate of decline in forced vital capacity (FVC) over 52 weeks by 60%. Pirfenidone is another antifibrotic agent currently under phase II clinical study (TRAIL1) aiming to evaluate its effects for RA-ILD. This review provides an overview of state-of-the-art pathogenesis and the current therapeutic options for RA-ILD, with a focus on antifibrotic strategies.

Acute exacerbation of interstitial lung disease associated with rheumatic disease

Interstitial lung disease (ILD) is a cause of morbidity and mortality in patients with rheumatic diseases, such as connective-tissue diseases, rheumatoid arthritis and systemic vasculitis. Some patients with ILD secondary to rheumatic disease (RD-ILD) experience acute exacerbations, with sudden ILD progression and high mortality during or immediately after the exacerbation, and a very low 1-year survival rate. In the ILD subtype idiopathic pulmonary fibrosis (IPF), an acute exacerbation is defined as acute worsening or development of dyspnoea associated with new bilateral ground-glass opacities and/or consolidations at high-resolution CT, superimposed on a background pattern consistent with fibrosing ILD. However, acute exacerbation in RD-ILD (AE-RD-ILD) currently has no specific definition. The aetiology and pathogenesis of AE-RD-ILD remain unclear, but distinct triggers might include infection, mechanical stress, microaspiration and DMARD treatment. At this time, no effective evidence-based therapeutic strategies for AE-RD-ILD are available. In clinical practice, AE-RD-ILD is often empirically treated with high-dose systemic steroids and antibiotics, with or without immunosuppressive drugs. In this Review, we summarize the clinical features, diagnosis, management and prognosis of AE-RD-ILD, enabling the similarities and differences with acute exacerbation in IPF to be critically assessed.

The Role of Radiology in Progressive Fibrosing Interstitial Lung Disease

In this article, we describe the role of radiology for diagnosis and follow-up of progressive fibrosing interstitial lung disease (PF-ILD). Patients with PF-ILD are at increased risk for early death without treatment. Clinical diagnosis of PF-ILD has been described in the literature. This manuscript reviews the radiographic diagnosis of PF-ILD and the unique CT characteristics associated with specific types of fibrosis. Ultimately, we believe that radiology has the potential to recognize progression early and thus make an important contribution to the multidisciplinary discussion for this important diagnosis.

Monogenic gene variants in lung transplant recipients with usual interstitial pneumonia

Aim

The prevalence of monogenic disease-causing gene variants in lung transplant recipients with idiopathic pulmonary fibrosis is not fully known. Their impact on clinical outcomes before and after transplantation requires more evidence.

Patients and methods

We retrospectively performed sequence analysis of genes associated with pulmonary fibrosis in a cohort of 23 patients with histologically confirmed usual interstitial pneumonia that had previously undergone double lung transplantation. We evaluated the impact of confirmed molecular diagnoses on disease progression, clinical outcomes and incidence of acute rejection or chronic lung allograft dysfunction after transplantation.

Results

15 patients out of 23 (65%) had a variant in a gene associated with interstitial lung disease. 11 patients (48%) received a molecular diagnosis, of which nine involved genes for telomerase function. Five diagnostic variants were found in the gene for Telomerase reverse transcriptase. Two of these variants, p.(Asp684Gly) and p.(Arg774*), seemed to be enriched in Finnish lung transplant recipients. Disease progression and the incidence of acute rejection and chronic lung allograft dysfunction was similar between patients with telomere-related disease and the rest of the study population. The incidence of renal or bone marrow insufficiency or skin malignancies did not differ between the groups.

Conclusion

Genetic variants are common in lung transplant recipients with pulmonary fibrosis and are most often related to telomerase function. A molecular diagnosis for telomeropathy does not seem to impact disease progression or the risk of complications or allograft dysfunction after transplantation.

A molecular diagnosis is common in lung transplant recipients with usual interstitial pneumonia and frequently reveals variants in genes related to telomerase function. This finding is not associated with increased risk of allograft dysfunction.https://bit.ly/30ucMQy

The effect of domiciliary high flow nasal cannula treatment on dyspnea and walking distance in patients with interstitial lung disease - A pilot study

INTRODUCTION

Interstitial Lung Diseases (ILD) affect the lung parenchyma and are often complicated by respiratory failure (RF) and impaired physical activity. High Flow Nasal Cannula (HFNC) has proved effective in other disease entities with RF. The aim of this study is to investigate the effect of domiciliary HFNC in ILD on dyspnea and walking distance.

METHODS

A 6 weeks cross-over study with domiciliary HFNC-treatment/6 weeks' observation in ILD-patients requiring ambulatory oxygen therapy or with newly prescribed (within 12 months) long term oxygen therapy. Patients were advised to use HFNC 8 h/day, recommended night-time use. Body phletysmography; 6-min walk test (6MWT) including BORG-score, oxygen saturation (SO2) at start, minimum SO2 and time to recovery after 6MWT; arterial blood gasses; modified Medical Research Council (mMRC)-score; quality of life, by the St George Respiratory Questionnaire (SGRQ) and QoS, by the Richards-Campbell Sleep Questionnaire (RCSQ) were investigated at baseline; six weeks and 12 weeks.

RESULTS

10 patients were included; one later withdrew consent. Patients used HFNC between 8-<1 h/day. There were no differences in lung function; blood gasses; SGRQ or RCSQ over the observational period). Walking distance improved significantly (393-441 m p = 0.049) as did time to recovery (3.4-2-2 min, p = 0.001). When correcting for HFNC use (hours/day) significant improvement was also seen in mMRC-score (p = 0.035) and minimum saturation during 6MWT (p = 0.01).

CONCLUSION

Despite a very heterogenous group and no effect on quality of life and -sleep, the study indicates an improvement in dyspnea and physical ability of HFNC in ILD patients.

Impact of timing of nintedanib initiation among patients newly diagnosed with idiopathic pulmonary fibrosis

AIMS

While nintedanib treatment has been shown to slow the progression of idiopathic pulmonary fibrosis (IPF) in patients across varying levels of lung function, the effect of treatment timing on outcomes has not been examined. We assessed hospitalization risk and medical costs among patients with IPF based on the timing of nintedanib initiation after IPF diagnosis.

MATERIALS AND METHODS

This retrospective administrative claims study included data from 04/01/2014-09/30/2019 for patients aged ≥40 years who initiated nintedanib within 1 year of IPF diagnosis. Patients were assigned to study cohorts based on the time from IPF diagnosis to nintedanib initiation. All-cause hospitalization and all-cause medical costs were modeled using marginal structural models including inverse probability weights to adjust for both baseline and time-varying characteristics.

RESULTS

Of 11,195 patients diagnosed with IPF during the identification period, 449 met the study selection criteria (mean age 72.3 years, 68% male, mean follow-up time 13.3 months). Adjusted hospitalization risk and medical costs both varied significantly by the timing of nintedanib initiation (p < .001 and p = .020, respectively). Adjusted weighted hospitalization risk was higher among untreated vs. treated patients in months 2-3, months 4-6, and months 7-12 after diagnosis (hazard ratio [95% CI] 1.97 [1.09-3.56], p = .026; 2.62 [1.22-5.63], p = .014; and 5.57 [2.31-13.45], p < .001, respectively). Medical costs were 69% higher for patients initiating treatment in months 2-3 vs. month 1 (cost ratio [95% CI] 1.69 [1.20-2.38], p = .003).

LIMITATIONS

Disease severity could not be assessed because clinical data were unavailable; however, proxies such as oxygen use were included to adjust for between-cohort differences in disease severity.

CONCLUSIONS

Patients who initiate nintedanib promptly after IPF diagnosis may have reduced hospitalization risk and medical costs compared with those who start treatment later. Additional studies are warranted to improve understanding of the impact of prompt antifibrotic therapy on patient outcomes.

Autoimmune Progressive Fibrosing Interstitial Lung Disease: Predictors of Fast Decline

A subset of interstitial lung diseases (ILDs) with autoimmune traits-including connective tissue disease-associated ILD (CTD-ILD) and interstitial pneumonia with autoimmune features (IPAF)-develops progressive fibrosing (PF)-ILD. The aim of our study was to evaluate the clinical characteristics and predictors of longitudinal lung function (LF) changes in autoimmune PF-ILD patients in a real-world setting. All ILD cases with confirmed or suspected autoimmunity discussed by a multidisciplinary team (MDT) between January 2017 and June 2019 (n = 511) were reviewed, including 63 CTD-ILD and 44 IPAF patients. Detailed medical history, LF test, diffusing capacity of the lung for carbon monoxide (DLCO), 6-min walk test (6MWT), blood gas analysis (BGA), and high-resolution computer tomography (HRCT) were performed. Longitudinal follow-up for functional parameters was at least 2 years. Women were overrepresented (70.1%), and the age of the IPAF group was significantly higher as compared to the CTD-ILD group (p < 0.001). Dyspnea, crackles, and weight loss were significantly more common in the IPAF group as compared to the CTD-ILD group (84.1% vs. 58.7%, p = 0.006; 72.7% vs. 49.2%, p = 0.017; 29.6% vs. 4.8%, p = 0.001). Forced vital capacity (FVC) yearly decline was more pronounced in IPAF (53.1 ± 0.3 vs. 16.7 ± 0.2 ml; p = 0.294), while the majority of patients (IPAF: 68% and CTD-ILD 82%) did not deteriorate. Factors influencing progression included malignancy as a comorbidity, anti-SS-A antibodies, and post-exercise pulse increase at 6MWT. Antifibrotic therapy was administered significantly more often in IPAF as compared to CTD-ILD patients (n = 13, 29.5% vs. n = 5, 7.9%; p = 0.007), and importantly, this treatment reduced lung function decline when compared to non-treated patients. Majority of patients improved or were stable regarding lung function, and autoimmune-associated PF-ILD was more common in patients having IPAF. Functional decline predictors were anti-SS-A antibodies and marked post-exercise pulse increase at 6MWT. Antifibrotic treatments reduced progression in progressive fibrosing CTD-ILD and IPAF, emphasizing the need for guidelines including optimal treatment start and combination therapies in this special patient group.

Interstitial lung disease on the acute take for the non-respiratory physician

Interstitial lung diseases (ILDs) are a heterogeneous group of diseases characterised by varying degrees of fibrotic and/or inflammatory abnormalities of the lung parenchyma. Management of ILD is often challenging for non-respiratory physicians. We discuss the respiratory assessment and management of patients with ILD presenting with acute breathlessness on the acute take, including acute exacerbations of ILD.

Evaluation of a Novel Content-Based Image Retrieval System for the Differentiation of Interstitial Lung Diseases in CT Examinations

To evaluate the reader's diagnostic performance against the ground truth with and without the help of a novel content-based image retrieval system (CBIR) that retrieves images with similar CT patterns from a database of 79 different interstitial lung diseases. We evaluated three novice readers' and three resident physicians' (with at least three years of experience) diagnostic performance evaluating 50 different CTs featuring 10 different patterns (e.g., honeycombing, tree-in bud, ground glass, bronchiectasis, etc.) and 24 different diseases (sarcoidosis, UIP, NSIP, Aspergillosis, COVID-19 pneumonia etc.). The participants read the cases first without assistance (and without feedback regarding correctness), and with a 2-month interval in a random order with the assistance of the novel CBIR. To invoke the CBIR, a ROI is placed into the pathologic pattern by the reader and the system retrieves diseases with similar patterns. To further narrow the differential diagnosis, the readers can consult an integrated textbook and have the possibility of selecting high-level semantic features representing clinical information (chronic, infectious, smoking status, etc.). We analyzed readers' accuracy without and with CBIR assistance and further tested the hypothesis that the CBIR would help to improve diagnostic performance utilizing Wilcoxon signed rank test. The novice readers demonstrated an unassisted accuracy of 18/28/44%, and an assisted accuracy of 84/82/90%, respectively. The resident physicians demonstrated an unassisted accuracy of 56/56/70%, and an assisted accuracy of 94/90/96%, respectively. For each reader, as well as overall, Sign test demonstrated statistically significant (p < 0.01) difference between the unassisted and the assisted reads. For students and physicians, Chi²-test and Mann-Whitney-U test demonstrated statistically significant (p < 0.01) difference for unassisted reads and statistically insignificant (p > 0.01) difference for assisted reads. The evaluated CBIR relying on pattern analysis and featuring the option to filter the results of the CBIR by predominant characteristics of the diseases via selecting high-level semantic features helped to drastically improve novices' and resident physicians' accuracy in diagnosing interstitial lung diseases in CT.

Prognostic value of radiological findings indeterminate for UIP pattern and anterior upper lobe honeycomb-like lesion in chronic fibrosing interstitial lung disease associated with MPO-ANCA

Background

Myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) is often positive in patients with interstitial lung disease (ILD), which is also often present in patients with microscopic polyangiitis (MPA). A possible association between MPO-ANCA, MPA, and idiopathic ILD remains unclear. The objective of this study was to determine whether high-resolution computed tomography (HRCT) classification based on recent idiopathic pulmonary fibrosis guideline and specific CT findings can obtain new knowledge of prognostic factors in all MPO-ANCA-positive patients with ILD including both idiopathic ILD and MPA-ILD.

Methods

We analyzed 101 consecutive MPO-ANCA-positive patients with respiratory disease. We assessed the diagnostic accuracy of CT findings, HRCT pattern, and specific radiological signs. Prognostic predictors were determined using Cox regression models.

Results

Subjects with chronic ILD included 22 patients with MPA-ILD and 39 patients with ILD but without MPA. A quarter of the patients were radiological indeterminate for usual interstitial pneumonia (UIP) pattern, which resulted in a better prognosis than that for UIP pattern. “Increased attenuation around honeycomb and traction bronchiectasis” and “anterior upper lobe honeycomb-like lesion” were found to be highly frequent radiological findings (39% and 30%, respectively). In addition, the latter finding was a significant negative prognostic factor.

Conclusions

Radiological indeterminate for UIP was a useful HRCT classification in MPO-ANCA-positive patients with ILD. In addition, anterior upper lobe honeycomb-like lesion was found to be specific radiological finding that was a significant prognostic factor. The present results might aid in the assessment of appropriate strategies of diagnosis in these patients.

Essential role of IL-23 in the development of acute exacerbation of pulmonary fibrosis

Acute exacerbation of idiopathic pulmonary fibrosis has a poor prognosis associated with neutrophilic inflammation. Interleukin-23 is a proinflammatory cytokine involved in neutrophilic inflammation. However, little is known about its role in acute exacerbation of pulmonary fibrosis. This study was performed to determine the role of interleukin-23 in acute exacerbation of pulmonary fibrosis. For assessment of acute exacerbation of pulmonary fibrosis, mice were intratracheally administered bleomycin followed by lipopolysaccharide. Inflammatory cells, cytokine levels, and morphological morphometry of the lungs were analyzed. Cytokine levels were measured in the bronchoalveolar lavage fluid of idiopathic pulmonary fibrosis patients with or without acute exacerbation. Interleukin-23, -17A, and -22 levels were increased in the airway of mice with acute exacerbation of pulmonary fibrosis. Interleukin-23p19-deficient mice with acute exacerbation of pulmonary fibrosis had markedly reduced airway inflammation and fibrosis associated with decreased levels of interleukin-17A and -22 compared with wild-type mice. Treatment with an anti-interleukin-23 antibody attenuated airway inflammation and fibrosis and reduced interleukin-17A and -22 levels in mice with acute exacerbation of pulmonary fibrosis. T-helper type 17 cells were the predominant source of interleukin-17A in mice with acute exacerbation of pulmonary fibrosis. Interleukin-23 levels in bronchoalveolar lavage fluid tended to be higher in idiopathic pulmonary fibrosis patients with than without acute exacerbation. The data presented here suggest that interleukin-23 is essential for the development of acute exacerbation of pulmonary fibrosis and that blockade of interleukin-23 may be a new therapeutic strategy for acute exacerbation of pulmonary fibrosis.

Diagnosis and management of lung involvement in systemic lupus erythematosus and Sjögren's syndrome: a literature review

Lung involvement in systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) has extensively been outlined with a multiplicity of different manifestations. In SLE, the most frequent finding is pleural effusion, while in pSS, airway disease and parenchymal disorders prevail. In both cases, there is an increased risk of pre-capillary and post-capillary pulmonary arterial hypertension (PAH) and pulmonary venous thromboembolism (VTE). The risk of VTE is in part due to an increased thrombophilic status secondary to systemic inflammation or to the well-established association with antiphospholipid antibody syndrome (APS). The lung can also be the site of an organ-specific complication due to the aberrant pathologic immune-hyperactivation as occurs in the development of lymphoma or amyloidosis in pSS. Respiratory infections are a major issue to be addressed when approaching the differential diagnosis, and their exclusion is required to safely start an immunosuppressive therapy. Treatment strategy is mainly based on glucocorticoids (GCs) and immunosuppressants, with a variable response according to the primary pathologic process. Anticoagulation is recommended in case of VTE and multi-targeted treatment regimens including different drugs are the mainstay for PAH management. Antibiotics and respiratory physiotherapy can be considered relevant complement therapeutic measures. In this article, we reviewed lung manifestations in SLE and pSS with the aim to provide a comprehensive overview of their diagnosis and management to physicians taking care of patients with connective tissue diseases.

Efficacy and safety of nintedanib in Japanese patients with progressive fibrosing interstitial lung diseases: Subgroup analysis of the randomised, double-blind, placebo-controlled, phase 3 INBUILD trial

BACKGROUND

The efficacy of nintedanib in progressive fibrosing interstitial lung diseases (ILDs) was demonstrated in the randomised, double-blind, placebo-controlled INBUILD trial. This subgroup analysis evaluated the efficacy and safety of nintedanib in the Japanese population.

METHODS

Patients with progressive fibrosing ILDs (evaluated by physicians within 24 months of screening) were randomised (1:1) to twice-daily 150-mg nintedanib or placebo; treatment continued until the last patient completed 52 weeks. The primary endpoint was the annual rate of decline in forced vital capacity (FVC) over 52 weeks. Time-to-first acute ILD exacerbation or death and time-to-death up until the last patient had completed the week 52 visit were evaluated. This subgroup analysis included 108 Japanese patients.

RESULTS

The adjusted annual rates of FVC decline (mL/year) over 52 weeks for Japanese patients were -148.31 (nintedanib) and -240.36 (placebo), adjusted difference: 92.05 (95% CI: -10.69-194.80) and for non-Japanese patients were -67.41 (nintedanib) and -177.65 (placebo), adjusted difference: 110.24 (95% CI: 64.97-155.52). No heterogeneity in treatment effect between Japanese and non-Japanese subgroups was observed (treatment-by-subgroup interaction, p = 0.75). The risks of "acute exacerbation or death" (hazard ratio, 0.30 [95% CI: 0.10-0.91]) and mortality (hazard ratio, 0.54 [95% CI: 0.14-2.11]) in Japanese patients were numerically lower for nintedanib than placebo. There were no new or unexpected safety findings.

CONCLUSIONS

In Japanese patients, nintedanib slowed ILD progression, evidenced by a reduction in the annual rate of decline in FVC vs placebo. The efficacy and safety of nintedanib in Japanese patients were consistent with the overall INBUILD population. CLINICALTRIALS.GOV: NCT02999178 (21-Dec-2016).

Differences between Acute Exacerbations of Idiopathic Pulmonary Fibrosis and Other Interstitial Lung Diseases

Interstitial lung diseases (ILDs) comprise a wide group of pulmonary parenchymal disorders. These patients may experience acute respiratory deteriorations of their respiratory condition, termed "acute exacerbation" (AE). The incidence of AE-ILD seems to be lower than idiopathic pulmonary fibrosis (IPF), but prognosis and prognostic factors are largely unrecognized. We retrospectively analyzed a cohort of 158 consecutive adult patients hospitalized for AE-ILD in two Italian university hospitals from 2009 to 2016. Patients included in the analysis were divided into two groups: non-IPF (62%) and IPF (38%). Among ILDs included in the non-IPF group, the most frequent diagnoses were non-specific interstitial pneumonia (NSIP) (42%) and connective tissue disease (CTD)-ILD (20%). Mortality during hospitalization was significantly different between the two groups: 19% in the non-IPF group and 43% in the IPF group. AEs of ILDs are difficult-to-predict events and are burdened by relevant mortality. Increased inflammatory markers, such as neutrophilia on the differential blood cell count (HR 1.02 (CI 1.01-1.04)), the presence of pulmonary hypertension (HR 1.85 (CI 1.17-2.92)), and the diagnosis of IPF (HR 2.31 (CI 1.55-3.46)), resulted in negative prognostic factors in our analysis. Otherwise, lymphocytosis on the differential count seemed to act as a protective prognostic factor (OR 0.938 (CI 0.884-0.995)). Further prospective, large-scale, real-world data are needed to support and confirm the impact of our findings.