Previous studies have shown the importance of frailty in patients with fibrotic interstitial lung disease (ILD).
Is the Clinical Frailty Scale (CFS) a valid tool to improve risk stratification in ...patients with fibrotic ILD?
Patients with fibrotic ILD were included from the prospective multicenter Canadian Registry for Pulmonary Fibrosis. The CFS was assessed using available information from initial ILD clinic visits. Patients were stratified into fit (CFS score 1-3), vulnerable (CFS score 4), and frail (CFS score 5-9) subgroups. Cox proportional hazards and logistic regression models with mixed effects were used to estimate time to death or lung transplantation. A derivation and validation cohort was used to establish prognostic performance. Trajectories of functional tests were compared using joint models.
Of the 1,587 patients with fibrotic ILD, 858 (54%) were fit, 400 (25%) were vulnerable, and 329 (21%) were frail. Frailty was a risk factor for early mortality (hazard ratio, 5.58; 95% CI, 3.64-5.76, P < .001) in the entire cohort, in individual ILD diagnoses, and after adjustment for potential confounders. Adding frailty to established risk prediction parameters improved the prognostic performance in derivation and validation cohorts. Patients in the frail subgroup had larger annual declines in FVC % predicted than patients in the fit subgroup (−2.32; 95% CI, −3.39 to −1.17 vs −1.55; 95% CI, −2.04 to −1.15, respectively; P = .02).
The simple and practical CFS is associated with pulmonary and physical function decline in patients with fibrotic ILD and provides additional prognostic accuracy in clinical practice.
Biological sex, gender, and race are important considerations in patients with interstitial lung diseases (ILDs).
Does a patient’s sex assigned at birth, and race, influence ILD treatment initiation?
...Patients with ILD from three longitudinal prospective registries were compared in this observational study. ILD-related medications included antifibrotics and immunomodulating medications. Race was dichotomized as “White” vs “non-White.” Time to treatment initiation was determined from the date of the initial ILD registry visit to the date of first medication initiation. Proportions of treated patients were compared between groups by χ2 test. Cox proportional analysis was used to determine how sex and race were associated with time to treatment initiation stratified by ILD diagnosis.
A total of 4,572 patients were included across all cohorts. The proportion of men who received treatment was higher than for women in the Canadian cohort (47% vs 40%; P < .001), and the proportion of White patients who received treatment was also higher compared with non-White patients (46% vs 36%; P < .001). In contrast, the proportion of treated men in the Chicago cohort was lower compared with women (56% vs 64%; P = .005), and that of White patients was lower compared with non-White patients (56% vs 69%; P < .001). No sex- or race-based differences in proportions of patients treated were found in the Australasian cohort. White race was significantly associated with earlier treatment initiation compared with non-White race across diagnoses in the Canadian cohort, whereas the opposite association was found in the Australasian cohort.
Sex- and race-based differences exist in the initiation of ILD treatment, with variability across different cohorts in different countries. Reasons for these differences need to be further explored in future studies.
Clinical practice guidelines separately describe radiologic patterns of usual interstitial pneumonia (UIP) and fibrotic hypersensitivity pneumonitis (fHP), without direction on whether or how to ...apply these approaches concurrently within a single patient.
How can we integrate guideline-defined radiologic patterns to diagnose interstitial lung disease (ILD) and what are the pitfalls associated with described patterns that require reassessment in future guidelines?
Patients from the Canadian Registry for Pulmonary Fibrosis underwent detailed reevaluation in standardized multidisciplinary discussion. CT scan features were quantified by chest radiologists masked to clinical data, and guideline-defined patterns were assigned. Clinical data then were provided to the radiologist and an ILD clinician, who jointly determined the leading diagnosis.
Clinical-radiologic diagnosis in 1,593 patients was idiopathic pulmonary fibrosis (IPF) in 26%, fHP in 12%, connective tissue disease-associated ILD (CTD-ILD) in 34%, idiopathic pneumonia with autoimmune features in 12%, and unclassifiable ILD in 10%. Typical and probable UIP patterns corresponded to a diagnosis of IPF in 66% and 57% of patients, respectively. Typical fHP pattern corresponded to an fHP clinical diagnosis in 65% of patients, whereas compatible fHP was nonspecific and associated with CTD-ILD or IPAF in 48% of patients. No pattern ruled out CTD-ILD. Gas trapping affecting > 5% of lung parenchyma on expiratory imaging was an important feature broadly separating compatible and typical fHP from other patterns (sensitivity, 0.77; specificity, 0.91).
An integrated approach to guideline-defined UIP and fHP patterns is feasible and supports > 5% gas trapping as an important branch point. Typical or probable UIP and typical fHP patterns have moderate predictive values for a corresponding diagnosis of IPF and fHP, although occasionally confounded by CTD-ILD; compatible fHP is nonspecific.
Hypoxemia in fibrotic interstitial lung disease (ILD) indicates disease progression and is of prognostic significance. The onset of hypoxemia signifies disease progression and predicts mortality in ...fibrotic ILD. Accurately predicting new-onset exertional and resting hypoxemia prompts appropriate patient discussion and timely consideration of home oxygen.
We derived and externally validated a risk prediction tool for both new-onset exertional and new-onset resting hypoxemia.
This study used ILD registries from Canada for the derivation cohort and from Australia and the United States for the validation cohort. New-onset exertional and resting hypoxemia were defined as nadir oxyhemoglobin saturation < 88% during 6-minute-walk tests, resting oxyhemoglobin saturation < 88%, or the initiation of ambulatory or continuous oxygen. Candidate predictors included patient demographics, ILD subtypes, and pulmonary function. Time-varying Cox regression was used to identify the top-performing prediction model according to Akaike information criterion and clinical usability. Model performance was assessed using Harrell's C-index and goodness-of-fit (GoF) likelihood ratio test. A categorized risk prediction tool was developed.
The best-performing prediction model for both new-onset exertional and new-onset resting hypoxemia included age, body mass index, a diagnosis of idiopathic pulmonary fibrosis, and percent predicted forced vital capacity and diffusing capacity of carbon monoxide. The risk prediction tool exhibited good performance for exertional hypoxemia (C-index, 0.70; GoF,
= 0.85) and resting hypoxemia (C-index, 0.77; GoF,
= 0.27) in the derivation cohort, with similar performance in the validation cohort except calibration for resting hypoxemia (GoF,
= 0.001).
This clinically applicable risk prediction tool predicted new-onset exertional and resting hypoxemia at 6 months in the derivation cohort and a diverse validation cohort. Suboptimal GoF in the validation cohort likely reflected overestimation of hypoxemia risk and indicated that the model is not flawed because of underestimation of hypoxemia.
Interstitial pneumonia with autoimmune features (IPAF) has features of connective tissue disease-associated interstitial lung disease (CTD-ILD), but without meeting criteria for a specific CTD. We ...compared baseline characteristics, survival, and response to treatment of IPAF to both CTD-ILD and unclassifiable ILD.
Measurements were extracted from a prospective registry. Baseline features and survival were compared in IPAF against both CTD-ILD and unclassifiable ILD. Linear trajectory of lung function decline (%-predicted forced vital capacity FVC% and diffusion capacity of the lung for carbon monoxide DLCO%) before and after initiation of mycophenolate or azathioprine were compared in IPAF against both CTD-ILD and unclassifiable ILD using linear mixed models.
Compared to CTD-ILD (n = 1240), patients with IPAF (n = 128) were older, more frequently male, and had greater smoking history. Compared to unclassifiable ILD (n = 665), patients with IPAF were younger, more frequently female, and had worse baseline lung function. IPAF had higher mortality compared to CTD-ILD and similar risk of mortality compared to unclassifiable ILD. Mycophenolate initiation was associated with stabilization of FVC% and DLCO% in all ILD subtypes except for FVC% in patients with IPAF, and azathioprine initiation with stabilization of FVC% and DLCO% in all ILD subtypes except for FVC% decline in IPAF and DLCO% decline in CTD-ILD.
Patients with IPAF had worse survival compared to those with CTD-ILD and similar mortality to unclassifiable ILD, with treatment being associated with stabilization in lung function in all three ILDs. It is uncertain whether IPAF should be considered a distinct ILD diagnostic subgroup.
Interstitial lung disease (ILD) in connective tissue diseases (CTD) have highly variable morphology. We aimed to identify imaging features and their impact on ILD progression, mortality and ...immunosuppression response.
Patients with CTD-ILD had high-resolution chest computed tomography (HRCT) reviewed by expert radiologists blinded to clinical data for overall imaging pattern (usual interstitial pneumonia UIP; non-specific interstitial pneumonia NSIP; organizing pneumonia OP; fibrotic hypersensitivity pneumonitis fHP; and other). Transplant-free survival and change in percent-predicted forced vital capacity (FVC) were compared using Cox and linear mixed effects models adjusted for age, sex, smoking, and baseline FVC. FVC decline after immunosuppression was compared with pre-treatment.
Of 645 CTD-ILD patients, the frequent CTDs were systemic sclerosis (n = 215), rheumatoid arthritis (n = 127), and inflammatory myopathies (n = 100). NSIP was the most common pattern (54%), followed by UIP (20%), fHP (9%), and OP (5%). Compared with UIP, FVC decline was slower for NSIP (1.1%/year, 95%CI 0.2, 1.9) and OP (3.5%/year, 95%CI 2.0, 4.9), and mortality was lower for NSIP (HR 0.65, 95%CI 0.45, 0.93) and OP (HR 0.18, 95%CI 0.05, 0.57), but higher in fHP (HR 1.58, 95%CI 1.01, 2.40). The extent of fibrosis also predicted FVC decline and mortality. After immunosuppression, FVC decline was slower compared with pre-treatment in NSIP (by 2.1%/year, 95%CI 1.4, 2.8), with no change for UIP or fHP.
Multiple radiologic patterns are possible in CTD-ILD, including a fHP pattern. NSIP and OP were associated with better outcomes and response to immunosuppression, while fHP had worse survival compared with UIP.
Patients with fibrotic hypersensitivity pneumonitis (fHP) are frequently treated with immunosuppression to slow lung function decline; however, the impact of this treatment has not been studied ...across different types of antigen exposure.
In patients with fHP, do disease outcomes and response to treatment vary by antigen type?.
A multicenter interstitial lung disease database (Canadian Registry for Pulmonary Fibrosis) was used to identify patients with fHP. The causative antigen was categorized as avian, mold, unknown, or other. Treatment was defined as mycophenolate ≥ 1,000 mg/d or azathioprine ≥ 75 mg/d for ≥ 30 days. Statistical analysis included t tests, χ
tests, and one-way analysis of variance. Unadjusted and adjusted competing risks and Cox proportional hazards models were used to assess survival.
A total of 344 patients were identified with the following causative antigens: avian (n = 93; 27%), mold (n = 88; 26%), other (n = 15; 4%), and unknown (n = 148; 43%). Patient characteristics and lung function were similar among antigen groups with a mean FVC % predicted of 75 ± 20. The percent of patients treated with immunosuppression was similar between antigens with 58% of patients treated. There was no change in lung function or symptom scores with the initiation of immunosuppression in the full cohort. Immunosuppression was not associated with a change in survival for patients with avian or mold antigen (avian: hazard ratio, 0.41; 95% CI, 0.11-1.59; P = .20; mold: hazard ratio, 1.13; 95% CI, 0.26-4.97; P = .88). For patients with unknown causative antigen, survival was worse when treated with immunosuppression (hazard ratio, 2.65; 95% CI, 1.01-6.92; P = .047).
Response to immunosuppression varies by antigen type in patients with fHP. Additional studies are needed to test the role of immunosuppression in fHP, and particularly in those with an unknown antigen.
Finding biomarkers of human neurological diseases is one of the most pressing goals of modern medicine. Most neurological disorders are recognized too late because of the lack of biomarkers that can ...identify early pathological processes in the living brain. Late diagnosis leads to late therapy and poor prognosis. Therefore, during the past decade, a major endeavor of clinical investigations in neurology has been the search for diagnostic and prognostic biomarkers of brain disease. Recently, a new field of metabolomics has emerged, aiming to investigate metabolites within the cell/tissue/ organism as possible biomarkers. Similarly to other "omics" fields, metabolomics offers substantial information about the status of the organism at a given time point. However, metabolomics also provides functional insight into the biochemical status of a tissue, which results from the environmental effects on its genome background. Recently, we have adopted metabolomics techniques to develop an approach that combines both in vitro analysis of cellular samples and in vivo analysis of the mammalian brain. Using proton magnetic resonance spectroscopy, we have discovered a metabolic biomarker of neural stem/progenitor cells (NPCs) that allows the analysis of these cells in the live human brain. We have developed signal-processing algorithms that can detect metabolites present at very low concentration in the live human brain and can indicate possible pathways impaired in specific diseases. Herein, we present our strategy for both cellular and systems metabolomics, based on an integrative processing of the spectroscopy data that uses analytical tools from both metabolomic and spectroscopy fields. As an example of biomarker discovery using our approach, we present new data and discuss our previous findings on the NPC biomarker. Our studies link systems and cellular neuroscience through the functions of specific metabolites. Therefore, they provide a functional insight into the brain, which might eventually lead to discoveries of clinically useful biomarkers of the disease.
Longitudinal monitoring of patients with fibrotic interstitial lung disease (ILD) is essential to identifying disease progression and guiding management decisions. There are no evidence-based ...clinical practice guidelines to inform decision-making for the appropriate components and frequency of monitoring patients with fibrotic ILD. This position statement summarizes the key components of long-term monitoring of fibrotic ILD, including the appropriate frequency of monitoring, specific symptoms and comorbidities to consider, and the objective testing that should be routinely performed. Key messages based on scientific literature review and consensus from a panel of ILD experts are provided to guide clinical practice.