Body mass index and weight loss as risk factors for poor outcomes in patients with idiopathic pulmonary fibrosis: a systematic review and meta-analysis

OBJECTIVE

The association between nutritional status and prognosis of idiopathic pulmonary fibrosis (IPF) remains unclear. This systematic review and meta-analysis aimed to explore the effect of body mass index (BMI) and weight loss on the prognosis of IPF patients.

METHODS

We accumulated studies on IPF, BMI, and weight loss from databases including PubMed, Embase, Web of science, Scopus, Ovid and Cochrane Library up to 4 August 2023. Using Cox proportional hazard regression model for subgroup analysis, hazard ratio (HR) and 95% confidence intervals (CI) for BMI in relation to mortality, acute exacerbation (AE), and hospitalization in IPF patients were calculated, and HR, odds ratio (OR), and 95% CI for weight loss corresponding to IPF patient mortality were assessed. Sensitivity analysis was peformed by eliminating every study one by one, and publication bias was judged by Egger's test and trim-and-fill method.

RESULTS

A total of 34 eligible studies involving 18,343 IPF patients were included in the meta-analysis. The pooled results by univariate Cox regression analysis showed that baseline BMI was a predictive factor for IPF mortality (HR = 0.93, 95%CI = [0.91, 0.94]). Furthermore, the results by the multivariable regression model indicated that baseline BMI was an independent risk factor for predicting IPF mortality (HR = 0.94, 95%CI = [0.91, 0.98]). Weight loss was identified as a risk factor for IPF mortality (HR = 2.74, 95% CI = [2.12, 3.54]; OR = 4.51, 95% CI = [1.72, 11.82]) and there was no predictive value of BMI for acute exacerbation (HR = 1.00, 95% CI= [0.93, 1.07]) or hospitalization (HR = 0.95, 95% CI = [0.89, 1.02]).

CONCLUSION

Low baseline BMI and weight loss in the course of IPF may indicate a high risk of mortality in patients with IPF, so it is meaningful to monitor and manage the nutritional status of IPF patients, and early intervention should be conducted for low BMI and weight loss.

Incidence, etiology, and outcome of hospital-acquired pneumonia in patients with acute exacerbation of fibrotic idiopathic interstitial pneumonia

BACKGROUND

Acute exacerbations (AEs) of fibrotic idiopathic interstitial pneumonia (fIIP) that require hospitalization occur in some patients. During hospitalization, these patients can develop hospital-acquired pneumonia (HAP), a common hospital-acquired infection with a high mortality rate. However, the characteristics of HAP in AE-fIIP remain unknown. The purpose of this study was to determine the incidence, causative pathogens, and outcomes of HAP in patients with AE-fIIP.

METHODS

The medical records of consecutive patients who were hospitalized with AE-fIIP from January 2008 to December 2019 were analyzed for the incidence, causative pathogen, and survival of HAP. The records of patients with an obvious infection-triggered AE were excluded from analysis.

RESULTS

There were 128 patients with AE-fIIP (89 with idiopathic pulmonary fibrosis [IPF] and 39 with non-IPF fIIP) who were hospitalized a total of 155 times (111 with IPF and 44 with non-IPF fIIP). HAP occurred in 49 patients (40 with IPF and 9 with non-IPF fIIP). The incidence and the in-hospital mortality rates of HAP in patients with AE-fIIP were high, at 32.2% and 48.9%, respectively. Corynebacterium spp. was the most common causative pathogen, which was followed by human cytomegalovirus (HCMV).

CONCLUSIONS

The incidence and the in-hospital mortality rates of HAP in patients with AE-fIIP are high. To improve their survival, patients with fIIP who had AEs and HAP should receive prompt empirical treatment for possible infections with Corynebacterium spp. and testing for HCMV.

Identification of connective tissue disease autoantibodies and a novel autoantibody anti-annexin A11 in patients with "idiopathic" interstitial lung disease

BACKGROUND

Autoantibodies are a hallmark feature of Connective Tissue Diseases (CTD). Their presence in patients with idiopathic interstitial lung disease (ILD) may suggest covert CTD. We aimed to determine the prevalence of CTD autoantibodies in patients diagnosed with idiopathic ILD.

METHODS

499 patient sera were analysed: 251 idiopathic pulmonary fibrosis (IPF), 206 idiopathic non-specific interstitial pneumonia (iNSIP) and 42 cryptogenic organising pneumonia (COP). Autoantibody status was determined by immunoprecipitation.

RESULTS

2.4% of IPF sera had a CTD-autoantibody compared to 10.2% of iNSIP and 7.3% of COP. 45% of autoantibodies were anti-synthetases. A novel autoantibody targeting an unknown 56 kDa protein was found in seven IPF patients (2.8%) and two NSIP (1%) patients. This was characterised as anti-annexin A11.

CONCLUSION

Specific guidance on autoantibody testing and interpretation in patients with ILD could improve diagnostic accuracy. Further work is required to determine the clinical significance of anti-annexin A11.

Role of transient receptor potential ankyrin 1 in idiopathic pulmonary fibrosis: modulation of M2 macrophage polarization

Idiopathic pulmonary fibrosis (IPF) poses significant challenges due to limited treatment options despite its complex pathogenesis involving cellular and molecular mechanisms. This study investigated the role of transient receptor potential ankyrin 1 (TRPA1) channels in regulating M2 macrophage polarization in IPF progression, potentially offering novel therapeutic targets. Using a bleomycin-induced pulmonary fibrosis model in C57BL/6J mice, we assessed the therapeutic potential of the TRPA1 inhibitor HC-030031. TRPA1 upregulation was observed in fibrotic lungs, correlating with worsened lung function and reduced survival. TRPA1 inhibition mitigated fibrosis severity, evidenced by decreased collagen deposition and restored lung tissue stiffness. Furthermore, TRPA1 blockade reversed aberrant M2 macrophage polarization induced by bleomycin, associated with reduced Smad2 phosphorylation in the TGF-β1-Smad2 pathway. In vitro studies with THP-1 cells treated with bleomycin and HC-030031 corroborated these findings, highlighting TRPA1's involvement in fibrotic modulation and macrophage polarization control. Overall, targeting TRPA1 channels presents promising therapeutic potential in managing pulmonary fibrosis by reducing pro-fibrotic marker expression, inhibiting M2 macrophage polarization, and diminishing collagen deposition. This study sheds light on a novel avenue for therapeutic intervention in IPF, addressing a critical need in the management of this challenging disease.

Prognostic implication of 1-year decline in diffusing capacity in newly diagnosed idiopathic pulmonary fibrosis

The progression of idiopathic pulmonary fibrosis (IPF) is assessed through serial monitoring of forced vital capacity (FVC). Currently, data regarding the clinical significance of longitudinal changes in diffusing capacity for carbon monoxide (DLCO) is lacking. We investigated the prognostic implications of a 1-year decline in DLCO in 319 patients newly diagnosed with IPF at a tertiary hospital between January 2010 and December 2020. Changes in FVC and DLCO over the first year after the initial diagnosis were reviewed; a decline in FVC ≥ 5% and DLCO ≥ 10% predicted were considered significant changes. During the first year after diagnosis, a significant decline in FVC and DLCO was observed in 101 (31.7%) and 64 (20.1%) patients, respectively. Multivariable analysis showed that a 1-year decline in FVC ≥ 5% predicted (aHR 2.74, 95% CI 1.88-4.00) and 1-year decline in DLCO ≥ 10% predicted (aHR 2.31, 95% CI 1.47-3.62) were independently associated with a higher risk of subsequent mortality. The prognostic impact of a decline in DLCO remained significant regardless of changes in FVC, presence of emphysema, or radiographic indications of pulmonary hypertension. Therefore, serial monitoring of DLCO should be recommended because it may offer additional prognostic information compared with monitoring of FVC alone.

Eating and drinking experience in patients with idiopathic pulmonary fibrosis: a qualitative study

OBJECTIVE

To explore eating and drinking experiences of patients with idiopathic pulmonary fibrosis (IPF), the impact of any changes associated with their diagnosis and any coping mechanisms developed by patients.

SETTING

Pulmonary fibrosis support groups around the UK and the regional Interstitial Lung Diseases Clinic, Newcastle upon Tyne.

PARTICIPANTS

15 patients with IPF (9 men, 6 women), median age 71 years, range (54-92) years, were interviewed. Inclusion criteria included competent adults (over the age of 18 years) with a secure diagnosis of IPF as defined by international consensus guidelines. Patients were required to have sufficient English language competence to consent and participate in an interview. Exclusion criteria were a history of other lung diseases, a history of pre-existing swallowing problem of other causes that may be associated with dysphagia and individuals with significant communication or other memory difficulties that render them unable to participate in an interview.

DESIGN

A qualitative study based on semistructured interviews used purpose sampling conducted between February 2021 and November 2021. Interviews were conducted via video videoconferencing call platform or telephone call, transcribed and data coded and analysed using a reflexive thematic analysis.

RESULTS

Three main themes were identified, along with several subthemes, which were: (1) Eating, as such, is no longer a pleasure. This theme mainly focused on the physical and sensory changes associated with eating and drinking and their effects and the subsequent emotional and social impact of these changes; (2) It is something that happens naturally and just try and get on with it. This theme centred on the self-determined strategies employed to manage changes to eating and drinking; and (3) What is normal. This theme focused on patients seeking information to better understand the changes in their eating and drinking and the patients' beliefs about what has changed their eating and drinking.

CONCLUSIONS

To our knowledge, this is the first study to report on IPF patients' lived experience of eating and drinking changes associated with their diagnosis. Findings demonstrate that some patients have substantial struggles and challenges with eating and drinking, affecting them physically, emotionally and socially. There is a need to provide better patient information for this area and further study.

The impact of sleep duration on physical activity in daily life in patients with idiopathic pulmonary fibrosis

BACKGROUND

Despite the high prevalence of sleep disturbances in idiopathic pulmonary fibrosis (IPF), the relationship between physical activity in daily life (PADL) and sleep in this population remains unclear.

OBJECTIVES

Investigate the impact of sleep on different domains of PADL in IPF and characterize their PADL profile.

METHODS

Sixty-seven participants (thirty-three with IPF and thirty-four healthy subjects [control group]) were included. The subjects underwent assessments of pulmonary function, exercise capacity, respiratory and peripheral muscle strength, PADL, sleep, dyspnea, and health-related quality of life. PADL and sleep measures were assessed using an activity monitor (Actigraph®, wGT3x-BT). Associations between sleep and PADL were done using correlation and regression models.

RESULTS

In the IPF, sleep duration at night associated significantly with step counts, sedentary, light, and moderate-to-vigorous physical activity (MVPA) (-0.82 ≤ R ≤ 0.43; p < .05 for all). Lung function and sleep partially explained PADL variables (0.19 ≤ R2 ≤ 0.65, p < .05 for all). Compared to controls, the IPF subjects presented lower step counts, less time spent in MVPA, standing position, and more time spent in lying position (p < .05, for all).

CONCLUSIONS

Sleep duration is associated with PADL in IPF. The PADL profile of patients is worse than in control subjects.

Mortality surrogates in combined pulmonary fibrosis and emphysema

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) with coexistent emphysema, termed combined pulmonary fibrosis and emphysema (CPFE) may associate with reduced forced vital capacity (FVC) declines compared to non-CPFE IPF patients. We examined associations between mortality and functional measures of disease progression in two IPF cohorts.

METHODS

Visual emphysema presence (>0% emphysema) scored on computed tomography identified CPFE patients (CPFE/non-CPFE: derivation cohort n=317/n=183, replication cohort n=358/n=152), who were subgrouped using 10% or 15% visual emphysema thresholds, and an unsupervised machine-learning model considering emphysema and interstitial lung disease extents. Baseline characteristics, 1-year relative FVC and diffusing capacity of the lung for carbon monoxide (D LCO) decline (linear mixed-effects models), and their associations with mortality (multivariable Cox regression models) were compared across non-CPFE and CPFE subgroups.

RESULTS

In both IPF cohorts, CPFE patients with ≥10% emphysema had a greater smoking history and lower baseline D LCO compared to CPFE patients with <10% emphysema. Using multivariable Cox regression analyses in patients with ≥10% emphysema, 1-year D LCO decline showed stronger mortality associations than 1-year FVC decline. Results were maintained in patients suitable for therapeutic IPF trials and in subjects subgrouped by ≥15% emphysema and using unsupervised machine learning. Importantly, the unsupervised machine-learning approach identified CPFE patients in whom FVC decline did not associate strongly with mortality. In non-CPFE IPF patients, 1-year FVC declines ≥5% and ≥10% showed strong mortality associations.

CONCLUSION

When assessing disease progression in IPF, D LCO decline should be considered in patients with ≥10% emphysema and a ≥5% 1-year relative FVC decline threshold considered in non-CPFE IPF patients.

Five-Repetition Sit-to-Stand Test: Responsiveness and Minimal Important Difference in Idiopathic Pulmonary Fibrosis

Rationale: Standing from a sitting position is an important activity of daily living. The five-repetition sit-to-stand test (5STS) is a simple physical performance test that measures the fastest time taken to stand five times from a chair with arms folded. It can be measured in most healthcare settings and at home, where traditional field walking tests may not be possible. The 5STS has been validated in community-dwelling older adults and people with chronic obstructive pulmonary disease, but data in idiopathic pulmonary fibrosis (IPF) are limited.Objectives: The aims of this cohort study were to establish the construct validity, responsiveness to pulmonary rehabilitation (PR), and minimal important difference (MID) of the 5STS in IPF.Methods: In 149 people with IPF, we compared the 5STS with measures of lung function, exercise capacity, quadriceps strength, breathlessness, and health-related quality of life. Responsiveness and effect sizes were determined by measuring the 5STS before and after PR. The MID was estimated using anchor- and distribution-based methods.Results: The 5STS correlated significantly with incremental shuttle walk test (ISW) (r = -0.55), isometric quadriceps maximum voluntary contraction (QMVC) (r = -0.45), Medical Research Council dyspnea scale score (r = 0.40), Chronic Respiratory Questionnaire-Total (r = -0.21), and King's Brief Interstitial Lung Disease Questionnaire-Total (r = -0.21) but not forced vital capacity percentage predicted or quadriceps one-repetition maximum (1RM). There was a significant but very weak correlation between change in 5STS and changes in Medical Research Council (r = 0.18), ISW (r = -0.21), and Chronic Respiratory Questionnaire-Total (r = -0.26) but no significant correlation with change in 1RM (r = -0.12) or QMVC (r = -0.18). 5STS time improved with PR (median [25th percentile, 75th percentile] change, -1.97 [-3.47, -0.62] s; P < 0.001). The effect size for the 5STS was 0.66 and higher than quadriceps 1RM, QMVC, and ISW. The mean (range) MID estimate was -1.93 (-1.85 to -2.10) seconds.Conclusions: In people with IPF, the 5STS is a valid physical performance measure that is responsive to exercise-based interventions and suitable for use in most healthcare settings.

Similarities and differences of interstitial lung disease associated with pathogenic variants in SFTPC and ABCA3 in adults

BACKGROUND AND OBJECTIVE

Variants in surfactant genes SFTPC or ABCA3 are responsible for interstitial lung disease (ILD) in children and adults, with few studies in adults.

METHODS

We conducted a multicentre retrospective study of all consecutive adult patients diagnosed with ILD associated with variants in SFTPC or ABCA3 in the French rare pulmonary diseases network, OrphaLung. Variants and chest computed tomography (CT) features were centrally reviewed.

RESULTS

We included 36 patients (median age: 34 years, 20 males), 22 in the SFTPC group and 14 in the ABCA3 group. Clinical characteristics were similar between groups. Baseline median FVC was 59% ([52-72]) and DLco was 44% ([35-50]). An unclassifiable pattern of fibrosing ILD was the most frequent on chest CT, found in 85% of patients, however with a distinct phenotype with ground-glass opacities and/or cysts. Nonspecific interstitial pneumonia and usual interstitial pneumonia were the most common histological patterns in the ABCA3 group and in the SFTPC group, respectively. Annually, FVC and DLCO declined by 1.87% and 2.43% in the SFTPC group, respectively, and by 0.72% and 0.95% in the ABCA3 group, respectively (FVC, p = 0.014 and DLCO , p = 0.004 for comparison between groups). Median time to death or lung transplantation was 10 years in the SFTPC group and was not reached at the end of follow-up in the ABCA3 group.

CONCLUSION

SFTPC and ABCA3-associated ILD present with a distinct phenotype and prognosis. A radiologic pattern of fibrosing ILD with ground-glass opacities and/or cysts is frequently found in these rare conditions.

TAPSE/SPAP ratio stratifies mortality risk in mild-to-moderate idiopathic pulmonary fibrosis

BACKGROUND: Due to paucity of literature data, we aimed at evaluating the prognostic role of the ratio of tricuspid annular plane systolic excursion (TAPSE) to systolic pulmonary artery pressure (SPAP) in idiopathic pulmonary fibrosis (IPF) patients without severe pulmonary hypertension and at assessing its correlation with effective arterial elastance index (EaI). METHODS: Multi-instrumental data obtained in 60 IPF patients (73.2 ± 6.8 years) and 60 matched controls were retrospectively analysed. Primary endpoint was all-cause mortality, while secondary endpoint was the composite of all-cause mortality and re-hospitalisations for all-causes over medium-term follow-up. RESULTS: ;At baseline, TAPSE/SPAP was significantly lower in patients with IPF than in controls (0.36 ± 0.25 vs. 0.77 ± 0.18 mm/mmHg; P < 0.001). TAPSE/SPAP was inversely correlated with EaI (r = -0.96) in IPF patients. During follow-up (3.5 ± 1.5 years), 21 patients died and 25 were re-hospitalised due to cardiopulmonary causes. TAPSE/SPAP was independently associated with both primary (HR 0.79, 95%CI 0.65-0.97) and secondary (HR 0.94, 95%CI 0.92-0.97) endpoints. A TAPSE/SPAP ratio of <0.20 and <0.44 mm/mmHg showed the greatest sensitivity and specificity for predicting primary (AUC 0.98) and secondary (AUC 0.99) endpoints, respectively. CONCLUSIONS: TAPSE/SPAP is a strong predictor of adverse outcomes in mild-to-moderate IPF. The strong correlation between TAPSE/SPAP and EaI might be an expression of a systemic fibrotic process which involves the heart, lungs and circulation.

Relative incidence of interstitial lung diseases in Brazil

OBJECTIVE

To assess the relative frequency of incident cases of interstitial lung diseases (ILDs) in Brazil.

METHODS

This was a retrospective survey of new cases of ILD in six referral centers between January of 2013 and January of 2020. The diagnosis of ILD followed the criteria suggested by international bodies or was made through multidisciplinary discussion (MDD). The condition was characterized as unclassifiable ILD when there was no specific final diagnosis following MDD or when there was disagreement between clinical, radiological, or histological data.

RESULTS

The sample comprised 1,406 patients (mean age = 61 ± 14 years), and 764 (54%) were female. Of the 747 cases exposed to hypersensitivity pneumonitis (HP)-related antigens, 327 (44%) had a final diagnosis of HP. A family history of ILD was reported in 8% of cases. HRCT findings were indicative of fibrosis in 74% of cases, including honeycombing, in 21%. Relevant autoantibodies were detected in 33% of cases. Transbronchial biopsy was performed in 23% of patients, and surgical lung biopsy, in 17%. The final diagnoses were: connective tissue disease-associated ILD (in 27%), HP (in 23%), idiopathic pulmonary fibrosis (in 14%), unclassifiable ILD (in 10%), and sarcoidosis (in 6%). Diagnoses varied significantly among centers (c2 = 312.4; p < 0.001).

CONCLUSIONS

Our findings show that connective tissue disease-associated ILD is the most common ILD in Brazil, followed by HP. These results highlight the need for close collaboration between pulmonologists and rheumatologists, the importance of detailed questioning of patients in regard with potential exposure to antigens, and the need for public health campaigns to stress the importance of avoiding such exposure.

Utility of peripheral protein biomarkers for the prediction of incident interstitial features: a multicentre retrospective cohort study

INTRODUCTION/RATIONALE

Protein biomarkers may help enable the prediction of incident interstitial features on chest CT.

METHODS

We identified which protein biomarkers in a cohort of smokers (COPDGene) differed between those with and without objectively measured interstitial features at baseline using a univariate screen (t-test false discovery rate, FDR p<0.001), and which of those were associated with interstitial features longitudinally (multivariable mixed effects model FDR p<0.05). To predict incident interstitial features, we trained four random forest classifiers in a two-thirds random subset of COPDGene: (1) imaging and demographic information, (2) univariate screen biomarkers, (3) multivariable confirmation biomarkers and (4) multivariable confirmation biomarkers available in a separate testing cohort (Pittsburgh Lung Screening Study (PLuSS)). We evaluated classifier performance in the remaining one-third of COPDGene, and, for the final model, also in PLuSS.

RESULTS

In COPDGene, 1305 biomarkers were available and 20 differed between those with and without interstitial features at baseline. Of these, 11 were associated with feature progression over a mean of 5.5 years of follow-up, and of these 4 were available in PLuSS, (angiopoietin-2, matrix metalloproteinase 7, macrophage inflammatory protein 1 alpha) over a mean of 8.8 years of follow-up. The area under the curve (AUC) of classifiers using demographics and imaging features in COPDGene and PLuSS were 0.69 and 0.59, respectively. In COPDGene, the AUC of the univariate screen classifier was 0.78 and of the multivariable confirmation classifier was 0.76. The AUC of the final classifier in COPDGene was 0.75 and in PLuSS was 0.76. The outcome for all of the models was the development of incident interstitial features.

CONCLUSIONS

Multiple novel and previously identified proteomic biomarkers are associated with interstitial features on chest CT and may enable the prediction of incident interstitial diseases such as idiopathic pulmonary fibrosis.

[Pulmonary artery stenosis after single lung transplantation: a case report and literature review]

Objective: To summarize and analyze the clinical features, treatment, and prognosis of pulmonary artery stenosis post-lung transplantation. Methods: A 62-year-old male patient was admitted to the hospital with a cough and chest tightness of over a year's duration, which had worsened in the last two months, leading to the diagnosis of idiopathic pulmonary fibrosis. The clinical data were observed and reviewed post-left allograft single lung transplantation. Literature searches were conducted using the keywords "lung transplantation" "stenosis, pulmonary artery" and "postoperative complications" in CNKI, Wanfang Medical Network, and PubMed databases up to December 2022. Results: On January 26, 2022, a left allograft single lung transplantation was performed under general anesthesia. Postoperatively, extracorporeal membrane oxygenation and mechanical ventilation were successfully weaned off at 22 hours and 2 days, respectively, with transfer from the intensive care unit 12 days after surgery. PaO2 and PaCO2 were 50 mmHg and 40 mmHg after deoxygenation. Both pulmonary CT angiography and ventilatory-perfusion imaging indicated stenosis of the left pulmonary anastomosis. Balloon dilation and pulmonary artery stenting were performed, with PaO2 and PaCO2 improving to 87 mmHg and 42 mmHg, respectively. The patient was discharged 102 days post-surgery, and was followed up for 1 year, with a good prognosis. Additionally, 36 related articles were retrieved, encompassing 69 cases with a median age of 53 years (38.5-59.0 years). Of these, 27.54% (19/69) were diagnosed with idiopathic pulmonary fibrosis, 46.38% (32/69) underwent single lung transplantation, with the primary clinical symptom being hypoxemia in 71.01% (49/69) cases. Left pulmonary artery anastomotic stenosis was observed in 43.48% (30/69), with 65.22% (45/69) being diagnosed in the late postoperative period. Interventional therapy was performed to 44.93% (31/69), with a mortality rate of 21.74% (15/69). Conclusions: The primary clinical manifestation of post-lung transplantation pulmonary artery stenosis is hypoxemia and can be diagnosed by pulmonary artery CT angiography, transesophageal echocardiography, and pulmonary angiography. Early diagnosis can significantly reduce mortality, and interventional therapy is an effective treatment for severe pulmonary artery stenosis post-lung transplantation.

Disease trajectories in interstitial lung diseases - data from the EXCITING-ILD registry

BACKGROUND

Interstitial lung diseases (ILD) comprise a heterogeneous group of mainly chronic lung diseases with different disease trajectories. Progression (PF-ILD) occurs in up to 50% of patients and is associated with increased mortality.

METHODS

The EXCITING-ILD (Exploring Clinical and Epidemiological Characteristics of Interstitial Lung Diseases) registry was analysed for disease trajectories in different ILD. The course of disease was classified as significant (absolute forced vital capacity FVC decline > 10%) or moderate progression (FVC decline 5-10%), stable disease (FVC decline or increase < 5%) or improvement (FVC increase ≥ 5%) during time in registry. A second definition for PF-ILD included absolute decline in FVC % predicted ≥ 10% within 24 months or ≥ 1 respiratory-related hospitalisation. Risk factors for progression were determined by Cox proportional-hazard models and by logistic regression with forward selection. Kaplan-Meier curves were utilised to estimate survival time and time to progression.

RESULTS

Within the EXCITING-ILD registry 28.5% of the patients died (n = 171), mainly due to ILD (n = 71, 41.5%). Median survival time from date of diagnosis on was 15.5 years (range 0.1 to 34.4 years). From 601 included patients, progression was detected in 50.6% of the patients (n = 304) with shortest median time to progression in idiopathic NSIP (iNSIP; median 14.6 months) and idiopathic pulmonary fibrosis (IPF; median 18.9 months). Reasons for the determination as PF-ILD were mainly deterioration in lung function (PFT; 57.8%) and respiratory hospitalisations (40.6%). In multivariate analyses reduced baseline FVC together with age were significant predictors for progression (OR = 1.00, p < 0.001). Higher GAP indices were a significant risk factor for a shorter survival time (GAP stage III vs. I HR = 9.06, p < 0.001). A significant shorter survival time was found in IPF compared to sarcoidosis (HR = 0.04, p < 0.001), CTD-ILD (HR = 0.33, p < 0.001), and HP (HR = 0.30, p < 0.001). Patients with at least one reported ILD exacerbation as a reason for hospitalisation had a median survival time of 7.3 years (range 0.1 to 34.4 years) compared to 19.6 years (range 0.3 to 19.6 years) in patients without exacerbations (HR = 0.39, p < 0.001).

CONCLUSION

Disease progression is common in all ILD and associated with increased mortality. Most important risk factors for progression are impaired baseline forced vital capacity and higher age, as well as acute exacerbations and respiratory hospitalisations for mortality. Early detection of progression remains challenging, further clinical criteria in addition to PFT might be helpful.

Neutrophil-lymphocyte ratio being associated with mortality risk in patients receiving antifibrotic therapy

BACKGROUND

Antifibrotic therapy is widely used for patients with progressive fibrotic interstitial lung disease (ILD), regardless of etiology. There is an urgent need for a simple, inexpensive, and repeatable biomarker to evaluate disease severity and mortality risk.

METHODS

This retrospective multicohort study assessed the neutrophil-lymphocyte ratios (NLRs) of 416 patients with ILD who received antifibrotic therapy (Hamamatsu cohort, n = 217; Seirei cohort, n = 199). The mortality risk vs. NLR relationship was evaluated at therapy initiation and 1 year. The optimal NLR cutoff of 2.7 was selected according to the mortality risk.

RESULTS

Survival was shorter in patients with high NLR than with low NLR (median: 2.63 vs. 4.01 years). The NLR classification results (cutoff: 2.7) were longitudinally preserved in >70 % of the patients, and patients with consistently high NLR had a higher risk of mortality than others (median, 2.97 vs. 4.42 years). In multivariate analysis, high NLR was significantly associated with mortality independent of age, sex, forced vital capacity, lung diffusing capacity for carbon monoxide (DLCO), or the gender-age-physiology (GAP) index. A combined GAP index-NLR assessment classified mortality risk into four groups. Subset analyses revealed that NLR assessment was more applicable to patients without advanced disease, not taking steroids, and with idiopathic pulmonary fibrosis (IPF) than to patients with advanced disease, taking steroids, and patients with Non-IPF.

CONCLUSION

High NLR was associated with an increased mortality risk in patients with ILDs receiving antifibrotic therapy. Assessment of NLR may help predict disease severity and mortality risk in antifibrotic therapy.

Associations of Plasma Omega-3 Fatty Acids With Progression and Survival in Pulmonary Fibrosis

BACKGROUND

Preclinical experiments suggest protective effects of omega-3 fatty acids and their metabolites in lung injury and fibrosis. Whether higher intake of omega-3 fatty acids is associated with disease progression and survival in humans with pulmonary fibrosis is unknown.

RESEARCH QUESTION

What are the associations of plasma omega-3 fatty acid levels (a validated marker of omega-3 nutritional intake) with disease progression and transplant-free survival in pulmonary fibrosis?

STUDY DESIGN AND METHODS

Omega-3 fatty acid levels were measured from plasma samples of patients with clinically diagnosed pulmonary fibrosis from the Pulmonary Fibrosis Foundation Patient Registry (n = 150), University of Virginia (n = 58), and University of Chicago (n = 101) cohorts. The N-3 index (docosahexaenoic acid + eicosapentaenoic acid) was the primary exposure variable of interest. Linear-mixed effects models with random intercept and slope were used to examine associations of plasma omega-3 fatty acid levels with changes in FVC and diffusing capacity for carbon monoxide over a period of 12 months. Cox proportional hazards models were used to examine transplant-free survival. Stratified analyses by telomere length were performed in the University of Chicago cohort.

RESULTS

Most of the cohort were patients with idiopathic pulmonary fibrosis (88%) and male patients (74%). One-unit increment in log-transformed N-3 index plasma level was associated with a change in diffusing capacity for carbon monoxide of 1.43 mL/min/mm Hg per 12 months (95% CI, 0.46-2.41) and a hazard ratio for transplant-free survival of 0.44 (95% CI, 0.24-0.83). Cardiovascular disease history, smoking, and antifibrotic usage did not significantly modify associations. Omega-3 fatty acid levels were not significantly associated with changes in FVC. Higher eicosapentaenoic acid plasma levels were associated with longer transplant-free survival among University of Chicago participants with shorter telomere length (P value for interaction = .02).

INTERPRETATION

Further research is needed to investigate underlying biological mechanisms and whether omega-3 fatty acids are a potential disease-modifying therapy.

The tolerability and efficacy of antifibrotic therapy in patients with idiopathic pulmonary fibrosis: Results from a real-world study

BACKGROUND

Idiopathic pulmonary fibrosis is a progressive and fatal lung disease lacking effective therapeutics. Treatment with pirfenidone or nintedanib is recommended for patients to delay the progression of their disease. Adverse reactions caused by anti-fibrosis drugs can sometimes interrupt treatment and even change the progression of the disease.

OBJECTIVE

This study aimed to investigate the clinical use, adverse reactions, tolerability of pirfenidone and nintedanib in patients with idiopathic pulmonary fibrosis and the efficacy of antifibrotic therapy in a real world.

METHODS

We recruited patients with idiopathic pulmonary fibrosis treated with pirfenidone or nintedanib at China-Japan Friendship Hospital from February 2017 to February 2022. We investigated the medication situation, adverse reactions, tolerability and survival of patients taking medications.

RESULTS

A total of 303 patients with idiopathic pulmonary fibrosis were enrolled in the study. Treatment was divided between 205 patients receiving pirfenidone and 98 patients receiving nintedanib. Baseline data between the two groups were not significantly different. Patients treated with nintedanib had a higher overall discontinuation rate than those treated with pirfenidone (61.22 vs. 32.68 %, p < 0.001). Across all patient groups, the most common reason for discontinuing treatment was medication-related adverse effects. Compared to pirfenidone, nintedanib had a significantly higher discontinuation rate due to adverse events (48.98 % vs 27.80 %, p < 0.001). The most common side effect of both drugs was diarrhea. Pirfenidone was associated with a higher rate of extra-digestive adverse effects than nintedanib. Survival was not significantly different between the two drugs and using pirfenidone above 1200 mg/day did not confer significant survival benefits. The survival rate of patients who adhere to anti-fibrosis therapy for more than 6 months can be significantly improved (HR = 0.323, p = 0.0015).

CONCLUSION

Gastrointestinal adverse effects were the most common adverse effects and the main reason of discontinuation of antifibrotic therapy, especially nintedanib. Consistent adherence to antifibrotic therapy may make the patients benefit from adjusting their antifibrotic medications, dosage, and active management of side effects.

Unraveling the interplay between vital organelle stress and oxidative stress in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease characterized by excessive accumulation of extracellular matrix, leading to irreversible fibrosis. Emerging evidence suggests that endoplasmic reticulum (ER) stress, mitochondrial stress, and oxidative stress pathways play crucial roles in the pathogenesis of IPF. ER stress occurs when the protein folding capacity of the ER is overwhelmed, triggering the unfolded protein response (UPR) and contributing to protein misfolding and cellular stress in IPF. Concurrently, mitochondrial dysfunction involving dysregulation of key regulators, including PTEN-induced putative kinase 1 (PINK1), Parkin, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and sirtuin 3 (SIRT3), disrupts mitochondrial homeostasis and impairs cellular energy metabolism. This leads to increased reactive oxygen species (ROS) production, release of pro-fibrotic mediators, and activation of fibrotic pathways, exacerbating IPF progression. The UPR-induced ER stress further disrupts mitochondrial metabolism, resulting in altered mitochondrial mechanisms that increase the generation of ROS, resulting in further ER stress, creating a feedback loop that contributes to the progression of IPF. Oxidative stress also plays a pivotal role in IPF, as ROS-mediated activation of TGF-β, NF-κB, and MAPK pathways promotes inflammation and fibrotic responses. This review mainly focuses on the links between ER stress, mitochondrial dysfunctions, and oxidative stress with different signaling pathways involved in IPF. Understanding these mechanisms and targeting key molecules within these pathways may offer promising avenues for intervention.

Neighborhood Health and Outcomes in Idiopathic Pulmonary Fibrosis

Rationale: Living in a disadvantaged neighborhood has been associated with worse survival in people with idiopathic pulmonary fibrosis (IPF), however, prior studies have only examined the impact of neighborhood health on outcomes in IPF as a composite measure. Objectives: To investigate the association between neighborhood health and disease severity, measured by pulmonary function at presentation, and death in follow-up, with an additional focus on the contributions of the neighborhood's underlying physical and social factors to these outcomes. Methods: In a retrospective study of participants from the University of California, San Francisco, IPF Cohort (2001-2020), geocoded home addresses were matched to the California Healthy Places Index (HPI), a census-tract measure of neighborhood health. The HPI comprises 25 indicators of neighborhood health that are organized into eight physical and social domains, each of which is weighted and summed to provide a composite HPI score. Regression models were used to examine associations between the HPI as a continuous variable, in quartiles, and across each physical and social domain of the HPI (higher values indicate greater advantage) and forced vital capacity (FVC) percent predicted (% predicted), diffusing capacity of the lung for carbon monoxide (DlCO) % predicted, and death, adjusting for demographic and clinical covariates. We also studied the interaction between disease severity at presentation and neighborhood health in our time-to-event models. Results: In 783 participants with IPF, each 10% increase in HPI was associated with a 1% increase in FVC % predicted and DlCO % predicted (95% confidence intervals [CIs] = 0.55, 1.72; and 0.49, 1.49, respectively). This association appeared primarily driven by the economic, education, access, and social HPI domains. We also observed differences in the associations of HPI with mortality depending on disease severity at presentation. In participants with normal to mildly impaired FVC % predicted (⩾70%) and DlCO % predicted (⩾60%), decreased HPI was associated with higher mortality (hazard ratio = 2.91 Quartile 1 vs. Quartile 4; 95% CI = 1.20, 7.05). No association was observed between the HPI and death for participants with moderate to severely impaired FVC % predicted and DlCO % predicted. Conclusions: Living in disadvantaged neighborhoods was associated with worse pulmonary function in participants with IPF and was independently associated with increased mortality in participants with normal to mild physiological impairment at presentation.