Mitochondrial DNA in bronchoalveolar lavage fluid is associated with the prognosis of idiopathic pulmonary fibrosis: a single cohort study.

BACKGROUND: Extracellular mitochondrial DNA (mtDNA) is released from damaged cells and increases in the serum and bronchoalveolar lavage fluid (BALF) of idiopathic pulmonary fibrosis (IPF) patients. While increased levels of serum mtDNA have been reported to be linked to disease progression and the future development of acute exacerbation (AE) of IPF (AE-IPF), the clinical significance of mtDNA in BALF (BALF-mtDNA) remains unclear. We investigated the relationships between BALF-mtDNA levels and other clinical variables and prognosis in IPF. METHODS: Extracellular mtDNA levels in BALF samples collected from IPF patients were determined using droplet-digital PCR. Levels of extracellular nucleolar DNA in BALF (BALF-nucDNA) were also determined as a marker for simple cell collapse. Patient characteristics and survival information were retrospectively reviewed. RESULTS: mtDNA levels in serum and BALF did not correlate with each other. In 27 patients with paired BALF samples obtained in a stable state and at the time of AE diagnosis, BALF-mtDNA levels were significantly increased at the time of AE. Elevated BALF-mtDNA levels were associated with inflammation or disordered pulmonary function in a stable state (n = 90), while being associated with age and BALF-neutrophils at the time of AE (n = 38). BALF-mtDNA ≥ 4234.3 copies/µL in a stable state (median survival time (MST): 42.4 vs. 79.6 months, p < 0.001) and ≥ 11,194.3 copies/µL at the time of AE (MST: 2.6 vs. 20.0 months, p = 0.03) were associated with shorter survival after BALF collection, even after adjusting for other known prognostic factors. On the other hand, BALF-nucDNA showed different trends in correlation with other clinical variables and did not show any significant association with survival time. CONCLUSIONS: Elevated BALF-mtDNA was associated with a poor prognosis in both IPF and AE-IPF. Of note, at the time of AE, it sharply distinguished survivors from non-survivors. Given the trends shown by analyses for BALF-nucDNA, the elevation of BALF-mtDNA might not simply reflect the impact of cell collapse. Further studies are required to explore the underlying mechanisms and clinical applications of BALF-mtDNA in IPF.

Mild elevation of pulmonary vascular resistance predicts mortality regardless of mean pulmonary artery pressure in mild interstitial lung disease.

BACKGROUND: Pulmonary hypertension (PH) is defined by elevated mean pulmonary arterial pressure (MPAP), and elevated pulmonary vascular resistance (PVR) reflects pulmonary vascular abnormalities. The clinical significance of non-severe PH in patients with various interstitial lung diseases (ILDs) has not been fully elucidated. We aimed to investigate the clinical significance of MPAP and PVR for mortality in patients with newly diagnosed ILD. METHODS: We retrospectively analysed consecutive patients with ILD at initial evaluations that included right heart catheterisation from 2007 to 2018. These patients were classified by MPAP and PVR using the 2022 the European Society of Cardiology (ESC)/the European Respiratory Society (ERS) guidelines for PH. The clinical significance of MPAP and PVR for mortality was analysed. RESULTS: Among 854 patients, 167 (19.6%) had MPAP>20 mm Hg. The proportion of patients with PVR>2 Wood units (WU) among those with MPAP≤20 mm Hg, 202 WU was associated with a higher mortality rate (HR 1.61, 95% CI 1.28 to 2.02, p<0.0001) even in a group with MPAP≤20 mm Hg. CONCLUSIONS: Mild elevation of PVR was associated with a higher mortality rate in patients with newly diagnosed ILD, even in those with MPAP≤20 mm Hg.

Disease progression and changes in KL-6 in patients with limited cutaneous systemic sclerosis-associated interstitial lung disease.

BACKGROUND: Little is known about the annual change in Krebs von Lungen-6 (KL-6) and its correlation with forced vital capacity (FVC) in limited cutaneous systemic sclerosis-associated interstitial lung disease (lcSSc-ILD). We aimed to clarify the correlation during the clinical course. METHODS: We retrospectively reviewed data from consecutive patients with lcSSc-ILD. We measured FVC and KL-6 annually and calculated their annual changes using the difference in absolute values. Decline in FVC was defined as annual decline in FVC ≥5 %. RESULTS: Thirty-eight patients with SSc-ILD were included. The median age was 62 years and 58 % were female. The median FVC was 87.3 % and the median KL-6 was 1629 U/ml. The median observation period was 55.2 months and the annual changes in FVC and KL-6 were evaluated 151 times simultaneously. The annual change in KL-6 had a significant negative correlation with that in FVC in the first year from the initial evaluation (from the baseline to one-year follow-up) (r = -0.819, p < 0.01), but not after the first year. In the multivariable analysis adjusted by age, sex, and FVC at each year, the annual change of KL-6 (per 100 U/ml) was significantly associated with decline in FVC in the first year (odds ratio: 3.03, 95 % confidence interval: 1.21-7.59, p = 0.02), but not after the first year. CONCLUSIONS: Only in the first year from the initial evaluation, there was negative correlation between the annual change in FVC and that in KL-6 and the annual elevation in KL-6 was associated with decline in FVC in patients with lcSSc-ILD.

Effectiveness of remdesivir-based therapy for moderate COVID-19: comparison of Omicron and other variant phases.

Remdesivir is an antiviral drug for the treatment of coronavirus disease 2019 (COVID-19), and the sustained antiviral activity against Omicron variants of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been reported. In this single-center retrospective study, we first compared the clinical effectiveness of remdesivir-based therapy between Omicron and other variant phases of moderate COVID-19 in a real-world setting. Between Dec 2020 and July 2022, a total of 406 patients with COVID-19 pneumonia were treated with remdesivir-based therapy on admission. The oxygen deterioration rate after initiation of treatment significantly decreased in the Omicron variant phase compared to the alpha and delta variant phases. In an adjusted multivariate Cox proportional hazards model, Omicron variant phase was significantly associated with delayed oxygen deterioration and early recovery from hypoxia. These favorable outcomes during the Omicron variant phase, compared to previous variant phases, might be due to the attenuation and the popularization of vaccination.

COVID-19 and interstitial lung diseases: A multifaceted look at the relationship between the two diseases.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although it has been a fatal disease for many patients, the development of treatment strategies and vaccines have progressed over the past 3 years, and our society has become able to accept COVID-19 as a manageable common disease. However, as COVID-19 sometimes causes pneumonia, post-COVID pulmonary fibrosis (PCPF), and worsening of preexisting interstitial lung diseases (ILDs), it is still a concern for pulmonary physicians. In this review, we have selected several topics regarding the relationships between ILDs and COVID-19. The pathogenesis of COVID-19-induced ILD is currently assumed based mainly on the evidence of other ILDs and has not been well elucidated specifically in the context of COVID-19. We have summarized what has been clarified to date and constructed a coherent story about the establishment and progress of the disease. We have also reviewed clinical information regarding ILDs newly induced or worsened by COVID-19 or anti-SARS-CoV-2 vaccines. Inflammatory and profibrotic responses induced by COVID-19 or vaccines have been thought to be a risk for de novo induction or worsening of ILDs, and this has been supported by the evidence obtained through clinical experience over the past 3 years. Although COVID-19 has become a mild disease in most cases, it is still worth looking back on the above-reviewed information to broaden our perspectives regarding the relationship between viral infection and ILD. As a representative etiology for severe viral pneumonia, further studies in this area are expected.

Changes in patient-reported outcomes in patients with non-idiopathic pulmonary fibrosis fibrotic interstitial lung disease and progressive pulmonary fibrosis.

Background: Health-related quality of life (HRQoL) captures different aspects of the fibrotic interstitial lung disease (FILD) evaluation from the patient's perspective. However, little is known about how HRQoL changes in patients with non-idiopathic pulmonary fibrosis (IPF) FILD, especially in those with progressive pulmonary fibrosis (PPF). The aim of this study is to clarify whether HRQoL deteriorates in patients with non-IPF FILD and to evaluate the differences in the changes in HRQoL between those with and without PPF. Methods: We collected data from consecutive patients with non-IPF FILD and compared annual changes in HRQoL over 2 years between patients with PPF and those without. The St George's respiratory questionnaire (SGRQ) and COPD assessment test (CAT) were used to assess HRQoL. Changes in the SGRQ and CAT scores for 24 months from baseline were evaluated with a mixed-effect model for repeated measures. Results: A total of 396 patients with non-IPF FILD were reviewed. The median age was 65 years and 202 were male (51.0%). The median SGRQ and CAT scores were 29.6 and 11, respectively. Eighty-six (21.7%) showed PPF. Both SGRQ and CAT scores were significantly deteriorated in patients with PPF compared to those without PPF (p < 0.01 for both). Clinically important deterioration in the SGRQ and CAT scores were observed in 40.0 and 35.7% of patients with PPF and 11.7 and 16.7% of those without, respectively. PPF was significantly associated with clinically important deterioration in the SGRQ score (odds ratio 5.04; 95%CI, 2.61-9.76, p < 0.01) and CAT score (odds ratio 2.78; 95%CI, 1.27-6.06, p = 0.02). Conclusion: The SGRQ and CAT scores were significantly deteriorated in patients with non-IPF FILD and PPF. Considering an evaluation of HRQoL would be needed when assessing PPF.

Real-World Experience of the Comparative Effectiveness and Safety of Molnupiravir and Nirmatrelvir/Ritonavir in High-Risk Patients with COVID-19 in a Community Setting.

Molnupiravir (MOV) and nirmatrelvir/ritonavir (NMV/r) are efficacious oral antiviral agents for patients with the 2019 coronavirus (COVID-19). However, little is known about their effectiveness in older adults and those at high risk of disease progression. This retrospective single-center observational study assessed and compared the outcomes of COVID-19 treated with MOV and NMV/r in a real-world community setting. We included patients with confirmed COVID-19 combined with one or more risk factors for disease progression from June to October 2022. Of 283 patients, 79.9% received MOV and 20.1% NMV/r. The mean patient age was 71.7 years, 56.5% were men, and 71.7% had received ≥3 doses of vaccine. COVID-19-related hospitalization (2.8% and 3.5%, respectively; p = 0.978) or death (0.4% and 3.5%, respectively; p = 0.104) did not differ significantly between the MOV and NMV/r groups. The incidence of adverse events was 2.7% and 5.3%, and the incidence of treatment discontinuation was 2.7% and 5.3% in the MOV and NMV/r groups, respectively. The real-world effectiveness of MOV and NMV/r was similar among older adults and those at high risk of disease progression. The incidence of hospitalization or death was low.

BMP3b Is a Novel Antifibrotic Molecule Regulated by Meflin in Lung Fibroblasts.

Fibroblasts play a central role in the lung fibrotic process. Our recent study identified a novel subpopulation of lung fibroblasts expressing meflin (mesenchymal stromal cell- and fibroblast-expressing Linx paralogue), antifibrotic properties of which were confirmed by murine lung fibrosis model. Meflin-expressing fibroblasts were resistant to fibrogenesis induced by TGF-ß (transforming growth factor-ß), but its underlying mechanisms remain unknown. In this study, evaluation of a silica-nanoparticle-induced lung fibrosis model confirmed the antifibrotic effect of meflin via the regulation of TGF-ß signaling. We conducted comparative gene expression profiling in lung fibroblasts, which identified growth differentiation factor 10 (Gdf10) encoding bone morphogenic protein 3b (BMP3b) as the most downregulated gene in meflin-deficient cells under the profibrotic condition with TGF-ß. We hypothesized that BMP3b can be an effector molecule playing an antifibrotic role downstream of meflin. As suggested by single-cell transcriptomic data, restricted expressions of Gdf10 (Bmp3b) in stromal cells including fibroblasts were confirmed. We examined possible antifibrotic properties of BMP3b in lung fibroblasts and demonstrated that Bmp3b-null fibroblasts were more susceptible to TGF-ß-induced fibrogenic changes. Furthermore, Bmp3b-null mice exhibited exaggerated lung fibrosis induced by silica-nanoparticles in vivo. We also demonstrated that treatment with recombinant BMP3B was effective against TGF-ß-induced fibrogenesis in fibroblasts, especially in the suppression of excessive extracellular matrix production. These lines of evidence suggested that BMP3b is a novel humoral effector molecule regulated by meflin which exerts antifibrotic properties in lung fibroblasts. Supplementation of BMP3B could be a novel therapeutic strategy for fibrotic lung diseases.

COVID-19-Triggered Acute Exacerbation of IPF, an Underdiagnosed Clinical Entity With Two-Peaked Respiratory Failure: A Case Report and Literature Review.

Because severe coronavirus disease 2019 (COVID-19) affects the respiratory system and develops into respiratory failure, patients with pre-existing chronic lung disorders, such as idiopathic pulmonary fibrosis (IPF), are thought to be at high risk of death. Patients with IPF often suffer from a lethal complication, acute exacerbation (AE), a significant part of which is assumed to be triggered by respiratory viral infection. However, whether mild to moderate COVID-19 can trigger AE in patients with IPF remains unknown. This is the case report of a 60-year-old man with a 4-year history of IPF who successfully recovered from moderate COVID-19 but subsequently developed more severe respiratory failure, which was considered to be a COVID-19-triggered acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF). It is important to be aware of the risk of AE-IPF after COVID-19 and to properly manage this deadly complication of IPF. Recent literature reporting cases with chronic interstitial lung diseases which developed respiratory failure by complications with COVID-19 is also reviewed and discussed.

Overexpression of bone morphogenetic protein receptor type 2 suppresses transforming growth factor ß-induced profibrotic responses in lung fibroblasts.

MATERIALS AND METHODS: We investigated BMPR2 expression in pulmonary fibrosis and TGF-ß/BMP signaling in lung fibroblasts. Then we evaluated the impact of BMPR2 upregulation using adenoviral transduction on TGF-ß-induced Smad2/3 phosphorylation and fibronectin production in lung fibroblasts. RESULTS: BMPR2 was distributed in airway epithelium and alveolar walls in rat lungs. BMPR2 expression was decreased in fibrotic lesions in the lungs of rats with bleomycin-induced pulmonary fibrosis and in human lung fibroblasts (HLFs) stimulated with TGF-ß. Although Smad2/3 phosphorylation and fibronectin production were not suppressed solely by BMPs, phosphorylated Smad2/3 was decreased in BMPR2-transduced cells even without BMP stimulation. Fibronectin was decreased only when BMPR2-transduced HLFs were stimulated with BMP7 (but not BMP4). Similar results were also observed in IPF patient HLFs and rat lung fibroblasts. CONCLUSIONS: BMPR2 expression was reduced in fibrotic lungs and lung fibroblasts stimulated with TGF-ß. BMPR2 transduction to lung fibroblasts reduced Smad2/3 phosphorylation, and reduced fibronectin production when treated with BMP7. Upregulation of BMPR2 may be a possible strategy for treating pulmonary fibrosis.

Clinical burden of immune checkpoint inhibitor-induced pneumonitis.

Immune checkpoint inhibitors (ICIs) have been a breakthrough in medical oncology. However, many patients experience a novel type of adverse drug reaction that has a unique clinical presentation, called immune-related adverse events (irAEs). A breakdown of self-tolerance and an exaggerated autoimmune reaction by the host are assumed to be the underlying mechanisms. Therefore, special attention to the optimal diagnosis and management is required. Among the various effects of irAE, pneumonitis has been recognized as an important manifestation because of its high morbidity and mortality. As the application of ICIs is expanding to a wider variety of tumor types, as well as its use with cytotoxic agents and radiation, clinicians are highly likely to encounter this complication. In this review, we will summarize the current understanding of the underlying mechanisms, incidence, risk factors, optimal diagnostic workup, and management of ICI-related pneumonitis (IRP). We will also review fundamental information on drug-induced lung toxicity in the oncology setting. In addition, research perspectives focused on better risk stratification and management to avoid serious complications in the future are presented.

Probable usual interstitial pneumonia pattern on chest CT: is it sufficient for a diagnosis of idiopathic pulmonary fibrosis?

Recent studies have suggested that in patients with an idiopathic interstitial pneumonia (IIP), a probable usual interstitial pneumonia (UIP) pattern on chest computed tomography (CT) is sufficient to diagnose idiopathic pulmonary fibrosis (IPF) without histopathology.We retrospectively compared the prognosis and time to first acute exacerbation (AE) in IIP patients with a UIP and a probable UIP pattern on initial chest CT.One hundred and sixty IIP patients with a UIP pattern and 242 with a probable UIP pattern were identified. Probable UIP pattern was independently associated with longer survival time (adjusted hazard ratio 0.713, 95% CI 0.536-0.950; p=0.021) and time to first AE (adjusted hazard ratio 0.580, 95% CI 0.389-0.866; p=0.008). In subjects with a probable UIP pattern who underwent surgical lung biopsy, the probability of a histopathological UIP pattern was 83%. After multidisciplinary discussion and the inclusion of longitudinal behaviour, a diagnosis of IPF was made in 66% of cases. In IPF patients, survival time and time to first AE were not associated with CT pattern. Among subjects with a probable UIP pattern, compared to non-IPF patients, survival time and time to first AE were shorter in IPF patients.In conclusion, IIP patients with a probable UIP pattern on initial chest CT had a better prognosis and longer time to first AE than those with a UIP pattern. However, when baseline data and longitudinal behaviour provided a final diagnosis of IPF, CT pattern was not associated with these outcomes. This suggests diagnostic heterogeneity among patients with a probable UIP pattern.

Acute exacerbations of fibrotic interstitial lung diseases.

BACKGROUND AND OBJECTIVE: Acute exacerbation (AE) is a severe complication of idiopathic pulmonary fibrosis (AE-IPF). In 2016, an international working group revised its definition and diagnostic criteria; however, few studies have assessed the frequency and prognosis of AE in patients with other fibrotic interstitial lung diseases (FILD). METHODS: We used data from 1019 consecutive interstitial lung disease (ILD) patients initially evaluated between January 2008 and July 2015. All subject diagnoses were made by multidisciplinary discussion in December 2018. ILD was categorized as IPF (n = 462) and other FILD which included non-specific interstitial pneumonia (n = 22), chronic hypersensitivity pneumonitis (n = 29), connective tissue disease-associated ILD (n = 205) and unclassifiable ILD (n = 209). Using the 2016 definition of AE-IPF, we identified all subjects with an AE. RESULTS: During the observational period, 193 patients experienced a first AE (AE-FILD n = 69, AE-IPF n = 124). The time to first AE was significantly longer in FILD than IPF (log-rank test, P < 0.001). After adjusting for potentially influential confounders, FILD remained a significant predictor of longer time to first AE compared with IPF (hazard ratio: 0.453; 95% CI: 0.317-0.647, P = 0.006). In a multivariate Cox proportional analysis, baseline disease severity was closely associated with the incidence of AE-ILD. Even after adjustment for other clinical variables, AE had a negative impact on overall survival. AE-FILD and AE-IPF showed similar poor short-term outcomes. CONCLUSION: All forms of ILD are at risk of AE and have a similar outcome to AE-IPF.

Prognostic Impact and Risk Factors of Immune-Related Pneumonitis in Patients With Non-Small-Cell Lung Cancer Who Received Programmed Death 1 Inhibitors.

INTRODUCTION: Pneumonitis is one of the immune-related adverse events of programmed death 1 (PD-1) inhibitors that sometimes cause lethal outcomes. Although some recent reports have described PD-1 inhibitors as more effective in non-small-cell lung cancer (NSCLC) patients with immune-related adverse events than in those without, few data are available on the prognosis of those treated with PD-1 inhibitors who developed immune-related pneumonitis (IRP). Additionally, the robust risk factors of IRP have not been well elucidated. PATIENTS AND METHODS: A retrospective review of patients with recurrent or advanced NSCLC who took a PD-1 inhibitor (nivolumab or pembrolizumab monotherapy) between January 2016 and March 2018 was undertaken. Radiologic findings such as unilateral infiltration were also defined as IRP as long as they were deemed relevant to PD-1 inhibitors. RESULTS: Twenty-seven (16%) of 170 patients developed IRP. Although 22 (81%) of 27 patients with IRP recovered with drug cessation with or without corticosteroid therapy, 8-week landmark analysis showed the overall survival after administration of the PD-1 inhibitor was significantly shorter in patients with IRP than in those without (8.7 vs. 23.0 months, P = .015). Patients with IRP tended to not receive next-line treatment and choose best supportive care after cessation of PD-1 inhibitor therapy. In the multivariate analysis, pembrolizumab (vs. nivolumab) and low serum albumin were independent risk factors for IRP. CONCLUSION: Development of IRP was correlated with poor prognosis in patients with NSCLC. Further study is necessary for establishing the best prediction and management strategies for IRP.

Lung Metastases from Bile Duct Adenocarcinoma Mimicking Chronic Airway Infection and Causing Diagnostic Difficulty.

We herein report a case of lung metastases with unusual radiological appearances that mimicked those of chronic airway infection, causing diagnostic difficulty. A 60-year-old woman who underwent liver transplantation from a living donor was incidentally diagnosed with bile duct adenocarcinoma after a histopathological analysis of her explanted liver. Six months later, chest computed tomography (CT) revealed bilateral bronchogenic dissemination that had gradually worsened, suggesting chronic airway infection. A biopsy with bronchoscopy from a mass lesion beyond a segmental bronchus revealed adenocarcinoma identical to that of her bile duct adenocarcinoma, leading to the diagnosis of multiple lung metastases from bile duct adenocarcinoma.

Hemosiderin-laden macrophages are an independent factor correlated with pulmonary vascular resistance in idiopathic pulmonary fibrosis: a case control study.

BACKGROUND: Increases in hemosiderin-laden macrophages (HLM) are reported to be observed in idiopathic pulmonary fibrosis (IPF). According to a recent study, significant correlation between hemosiderin deposition in the lung tissue of IPF and pulmonary hypertension evaluated by echocardiography has been suspected. In this study, we aimed to evaluate whether HLM in bronchoalveolar lavage fluid (BALF) is a factor correlated with pulmonary hemodynamic parameters evaluated by right heart catheterization in patients with IPF. METHODS: Initial data from 103 consecutive patients with IPF who underwent surgical lung biopsy between November 2007 and March 2014 were retrospectively analyzed. The "HLM score" of BALF was established by dividing the number of Perls' Prussian blue stain positive macrophages by the total number of macrophages counted. RESULTS: BALF showed an elevated HLM score (38.2%). Right heart catheterization revealed mean pulmonary arterial pressure (mPAP) of 16.3 mmHg and pulmonary vascular resistance (PVR) of 1.55 Wood units. HLM score was positively correlated with mPAP (ρ = 0.204; p = 0.038) and PVR (ρ = 0.349, p < 0.001). In multivariate analysis, 6-min walk distance (standardized partial regression coefficient [ß], -0.391; p < 0.001), minimum oxygen saturation during 6-min walk distance (ß, -0.294; p = 0.001) and HLM score (ß, 0.265; p = 0.002) were independently correlated with PVR. CONCLUSIONS: HLM score in BALF is an independent factor correlated with PVR in patients with IPF.

Nintedanib (OFEV) in the treatment of idiopathic pulmonary fibrosis.

INTRODUCTION: Nintedanib is a new anti-fibrosis agent that is an intracellular tyrosine kinase inhibitor targeting platelet derived growth factor receptor, fibroblast growth factor receptor and vascular endothelial growth factor receptor. Although nintedanib is attracting much attention as a new treatment option for patients with idiopathic pulmonary fibrosis (IPF), the clinical evidence is limited mainly to the results from the dose-deciding phase II TOMORROW trial and phase III INPULSIS trials, which evaluated efficacy and safety of nintedanib for patients with IPF, prespecified subgroup analyses, pooled analyses and meta-analyses derived from those trials. Areas covered: In this document, we mainly reviewed reports on working mechanisms of nintedanib, and efficacy and safety of nintedanib for patients with IPF. The literature search was undertaken using Pub Med. Expert commentary: It is unknown whether the efficacy of nintedanib in patients enrolled in the clinical trials will be the same for the entire spectrum of patients, including patients unfit for the clinical trials due to age, severity, timing of IPF diagnosis or diagnosis of interstitial pneumonias other than IPF. Sufficient consideration should be given when selecting candidates for nintedanib in the real world.