Radiological versus histological diagnosis in UIP and NSIP: survival implications

Acute exacerbation of idiopathic pulmonary fibrosis: usual interstitial pneumonitis vs. possible usual interstitial pneumonitis pattern

Background:

The prognosis of acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is very poor with a high mortality. The aim of this study was to describe the clinical features and survival of patients with AE-IPF with usual pulmonary fibrosis (UIP) and possible UIP (P-UIP) pattern on chest high resolution computed tomography (HRCT).

Methods:

This retrospective study included 107 patients with AE-IPF admitted to Nanjing Drum Tower Hospital from January 2010 to December 2016. The subjects were divided into UIP (n = 86) and P-UIP group (n = 21) based on chest HRCT. Continuous variables were analyzed using Student's t test or Mann-Whitney U test. Categorical variables were analyzed using χ² test. Log-rank test was used for the survival analysis. Cox proportional models evaluated the risk factors for AE occurrence and survival.

Results:

The male, older patients, previous N-acetylcysteine use, elevated white blood cell (WBC) counts, and microbiology infection were more common in the UIP group than the P-UIP group (χ² = 13.567, P < 0.001; z = −2.936, P = 0.003; χ² = 5.901, P = 0.015; t = 2.048, P = 0.043; χ² = 10.297, P = 0.036, respectively). The percentage of AE with UIP pattern in idiopathic interstitial pneumonia (IIP) was significantly higher than P-UIP pattern (χ² = 40.011, P < 0.001). Smoking was the risk factor for AE within 6 months after IPF diagnosis in the UIP group. The cumulative proportion survival of 30-days was significantly higher in the UIP group compared with the P-UIP group (χ² = 5.489, P = 0.019) despite of the similar overall survival in the two groups. Multivariate Cox regression analysis indicated WBC count, partial pressure of oxygen in artery (PaO₂)/fractional concentration of inspired oxygen (FiO₂), and computed tomography (CT) score were the independent predictors for survival in the UIP group (hazard ratio [HR]: 1.070, 95% confidential interval [CI]: 1.027–1.114, P = 0.001; HR: 0.992, 95% CI: 0.986–0.997, P = 0.002; and HR: 1.649, 95% CI: 1.253–2.171, P < 0.001, respectively).

Conclusions:

AE occurrence of UIP patients in IIP was significantly more than P-UIP cases. The short-term survival was better in the UIP group despite of the similar overall survival in the two groups. WBC count, PaO₂/FiO₂, and CT score were the independent predictors for survival in UIP subjects.

Progression of fibrosing interstitial lung disease

Fibrotic interstitial lung diseases (ILDs) are often challenging to diagnose and classify, but an accurate diagnosis has significant implications for both treatment and prognosis. A subset of patients with fibrotic ILD experience progressive deterioration in lung function, physical performance, and quality of life. Several risk factors for ILD progression have been reported, such as male sex, older age, lower baseline pulmonary function, and a radiological or pathological pattern of usual interstitial pneumonia. Morphological similarities, common underlying pathobiologic mechanisms, and the consistently progressive worsening of these patients support the concept of a progressive fibrosing (PF)-ILD phenotype that can be applied to a variety of ILD subtypes. The conventional approach has been to use antifibrotic medications in patients with idiopathic pulmonary fibrosis (IPF) and immunosuppressive medications in patients with other fibrotic ILD subtypes; however, recent clinical trials have suggested a favourable treatment response to antifibrotic therapy in a wider variety of fibrotic ILDs. This review summarizes the literature on the evaluation and management of patients with PF-ILD, and discusses questions relevant to applying recent clinicial trial findings to real-world practice.

Tissue Continues to Be the Issue: Role of Histopathology in the Context of Recent Updates in the Radiologic Classification of Interstitial Lung Diseases

CONTEXT.—

High-resolution computed tomography (HRCT) imaging has an increasingly important role in clinical decision-making in patients with interstitial lung diseases. The recent Fleischner Society white paper on the diagnostic criteria for idiopathic pulmonary fibrosis highlights the advances in our understanding of HRCT imaging in interstitial lung diseases.

OBJECTIVE.—

To discuss the evidence and recommendations outlined in the white paper as it pertains to the radiologic diagnosis of interstitial lung disease, specifically highlighting the current limitations of HRCT in confidently predicting histopathologic findings.

DATA SOURCES.—

The recent Fleischner Society white paper and other studies pertaining to the role of HRCT in predicting histopathology in interstitial lung diseases are reviewed.

CONCLUSIONS.—

High-resolution computed tomography is highly predictive of a usual interstitial pneumonia (UIP) pattern on histopathology when the HRCT shows a typical UIP pattern on a "confident" read by the radiologist. A probable UIP pattern is also very predictive of a UIP pattern on histopathology, and histopathologic confirmation is not needed for most patients demonstrating this pattern in the appropriate clinical setting. A UIP pattern may be seen in a substantial proportion of patients with an "indeterminate UIP" pattern on HRCT and in many patients for whom the HRCT suggests an alternative diagnosis; histopathologic confirmation should be considered in patients demonstrating these patterns whenever feasible.

Retrospective immunohistological study of autopsied lungs in patients with acute exacerbation of interstitial pneumonia managed with extracorporeal membrane oxygenation

Background

Acute exacerbation of interstitial pneumonia (AE-IP) is a life-threatening pulmonary condition that involves various pathogeneses. In patients with AE-IP who need mechanical ventilation with high driving pressure and oxygen concentration, veno-venous extracorporeal membrane oxygenation (V-V ECMO) may diminish alveolar epithelial damage by decreasing ventilator settings. The pathophysiological benefit of this therapeutic option is not well investigated.

Methods

We retrospectively collected 15 autopsied patients with AE-IP who were treated with mechanical ventilation in the intensive care unit (ICU) at Hiroshima University Hospital (Hiroshima, Japan) between 2010 and 2016. The patients were grouped by whether they were managed with mechanical ventilation only (the ventilator group, n=6) or with mechanical ventilation and V-V ECMO (the ECMO group, n=9).

Results

The median age of the ventilator and ECMO group patients were similar (65 and 64 years, respectively). The severity score APACHE II in the ECMO group (35.0) is significantly higher than that of ventilator group (14.5) (P=0.006). Ventilator days were significantly shorter in the ventilator group (17.5 days) than in the ECMO group (30.0 days) (P=0.04). Compared with the ECMO group, the ventilator group had a stronger Masson-trichrome stain grade (4 vs. 6, P=0.04) and higher immunoreactivity grades for Krebs von den Lungen-6 (4 vs. 6, P=0.04) and IL-8 (3 vs. 6, P=0.02). Between the ventilator and ECMO groups, the immunoreactivity grades of angiopoietin 2 (4 vs. 1, P=0.08) and receptor for advanced glycation end products (2 vs. 1, P=0.52) did not differ.

Conclusions

The lungs of mechanically ventilated AE-IP patients treated with V-V ECMO had decreased fibrosis, endothelial injury, and inflammation. This finding suggests the lung-protective efficacy of adjunctive V-V ECMO therapy.

Usual interstitial pneumonia in ANCA-associated vasculitis: A poor prognostic factor

BACKGROUND

Progressive fibrosing interstitial lung disease (ILD) is rarely associated with antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV). This study focused on the outcomes of ILD patients with associated AAV (AAV-ILD).

METHODS

AAV-ILD (cases: microscopic polyangiitis (MPA) or granulomatosis with polyangiitis (GPA) with ILD) were compared to AAV patients without ILD (controls). ILD was defined as a usual interstitial pneumonia (UIP) or non-specific interstitial pneumonia (NSIP) pattern. Two controls were matched to each case for age (>or ≤65 years), ANCA status (PR3-or MPO-positive) and creatininemia (≥or <150 μmol/L).

RESULTS

Sixty-two cases (89% MPO-ANCA+) were included. Median age at AAV diagnosis was 66 years. ILD (63% UIP), was diagnosed before (52%) or simultaneously (39%) with AAV. Cases versus 124 controls less frequently had systemic vasculitis symptoms. One-, 3- and 5-year overall survival rates, respectively, were: 96.7%, 80% and 66% for cases versus 93.5%, 89.6% and 83.8% for controls (p = 0.008). Multivariate analyses retained age >65 years (hazard ratio (HR) 4.54; p < 0.001), alveolar haemorrhage (HR 2.25; p = 0.019) and UIP (HR 2.73; p = 0.002), but not immunosuppressant use, as factors independently associated with shorter survival.

CONCLUSION

For AAV-ILD patients, only UIP was associated with poorer prognosis. Immunosuppressants did not improve the AAV-ILD prognosis. But in analogy to idiopathic pulmonary fibrosis, anti-fibrosing agents might be useful and should be assessed in AAV-ILD patients with a UIP pattern.

Assessment of interstitial lung disease among black rheumatoid arthritis patients

BACKGROUND

Conflicting reports exist regarding the racial and the gender distribution of rheumatoid arthritis-related interstitial lung disease (RA-ILD). In a major population study of predominately Whites, RA-ILD was reported mainly among smoker middle-aged men. However, recent data suggest that the disease is that of elderly women. Our study aimed to assess the prevalence and identify the gender differences and clinical characteristics of RA-ILD in a predominantly Black population.

METHODS

Cross-sectional analysis of data obtained from the records of 1142 patients with RA diagnosis by ICD codes of which 503 cases met the inclusion criteria for the study. Eighty-six patients had chronic respiratory symptoms of cough and dyspnea and were further assessed by our multidisciplinary group of investigators. Thirty-two subjects with an established diagnosis of rheumatoid arthritis met the diagnostic criteria for interstitial lung disease.

RESULTS

Of the 32 patients with RA-ILD, mean age was 62.6 ± 2.2 (± SEM), 93.7% were females, and 89% Blacks with a BMI = 29.2 (Kg/m²). Usual interstitial pneumonia (UIP) was found in 24/32 (75%) of the cases. Seventy-two percent of the RA-ILD patient had seropositive RA. Smoking history was reported in 31.3% of the cohort, gastroesophageal reflux disease (GERD) in 32.3%, and cardiovascular disease (CVD) risk factors in 65.6%.

CONCLUSION

Our study indicates RA-ILD among Blacks is predominantly a disease of elderly females with higher rates of GERD and CVD risk factors. Further studies are needed to identify the pathogenetic differences accounting for the gender distribution of RA-ILD among Black and White populations.Key Points• First study to assess ILD among predominantly Black RA patients.• The prevalence of RA-associated ILD was 6.36%, affecting mostly women in their sixth decade with seropositive disease.• COPD was the most common airway disease among non-RA-ILD Black population.• GERD was found in approximately one-third of patients with RA-associated ILD versus one-fifth of those RA patients without any lung disease.

Prediction of idiopathic pulmonary fibrosis progression using early quantitative changes on CT imaging for a short term of clinical 18-24-month follow-ups

OBJECTIVE

High-resolution computed tomography (HRCT) plays an indispensable role in the diagnosis of idiopathic pulmonary fibrosis (IPF). Due to unpredictability in progression and the short median survival of 2-5 years, it is critical to delineate the patients with rapid progression. The aim is to evaluate the predictability of IPF progression using the early quantitative changes.

METHODS

Automated texture-based quantitative lung fibrosis (QLF) was calculated from the anonymized HRCT. Two datasets were collected retrospectively: (1) a pilot study of 35 subjects with three sequential scans (baseline and 6 and 12 months) to obtain a threshold, where visual assessments were stable at 6 months but worsened at 12 months; (2) 157 independent subjects to test the threshold. Landmark Cox regressions were used to compare the progression-free survival (PFS) defined by pulmonary function using the threshold from the early changes in QLF. C-indexes were reported as estimations of the concordance of prediction.

RESULTS

A threshold of 4% QLF change at 6 months corresponded to the mean change that worsened on HRCT visually at 12 months from the pilot study. Using the threshold, significant differences were found in the independent dataset (hazard ratio (HZ) = 5.92, p = 0.001 by Cox model, C-index = 0.71 at the most severe lobe; and HZ = 3.22, p = 0.012, C-index = 0.68 in the whole lung). Median PFS was 11.9 months for subjects with ≥ 4% changes, whereas median PFS was greater than 18 months for subjects with < 4% changes at the most severe lobe.

CONCLUSION

Early structural changes on HRCT using a quantitative score can predict progression in lung function.

KEY POINTS

• Changes on HRCT using quantitative texture-based scores can play a pivotal role for providing information and an aid tool for timely management decision for patients with IPF. • Quantitative changes on HRCT of 4% or more, which matched 6-month prior changes with visual assessment of worsening, can play a pivotal role for providing prediction of clinical progression by 3-5 folds higher in the next incidence, compared with those of subjects with less than 4% changes. • Early structural changes of 4% or more in a paired HRCT scans derived by quantitative scores can predict the progression in lung function in 1-2 years in subjects with IPF, which is critical information for timely management decision for subjects with IPF where the median survival is 2 to 5 years.

Interstitial pneumonia with autoimmune features show better survival and less exacerbations compared to idiopathic pulmonary fibrosis

BACKGROUND

Patients with interstitial lung disease (ILD) who show features related to autoimmunity without meeting criteria for a defined connective tissue disease are categorized as interstitial pneumonia with autoimmune features (IPAF). The present study compared clinical characteristics and clinical outcomes of patients with IPAF to patients with connective tissue disease related-interstitial lung disease (CTD-ILD) and patients with idiopathic pulmonary fibrosis (IPF).

METHODS

ILD patients who were consecutively enrolled in a single institution ILD cohort between 2008 and 2015 were evaluated for the study. Clinical data had been prospectively collected, while radiologic imaging and pathologic findings were re-reviewed for the present study.

RESULTS

Out of 305 patients with ILD, 54 (17.7%) patients met the classification of IPAF, 175 (57.4%) patients had IPF, and 76 (24.9%) patients were diagnosed with CTD-ILD. Compared to IPF, incidences of acute exacerbations in 1,3 and 5 years were significantly less in the IPAF group (p = 0.022, p = 0.026 and p = 0.007, respectively). From multivariate analysis for mortality, age (p = 0.034, HR 1.022, 95% CI: 1.002-1.044), FVC (p < 0.001, HR 0.970, 95% CI: 0.955-0.984), ILD exacerbation (p = 0.001, HR 2.074, 95% CI: 1.366-3.148), and ILD type (p = 0.047, HR 0.436, 95% CI: 0.192-0.984 (IPAF vs IPF), respectively) showed significant association.

CONCLUSIONS

Compared to the other ILD groups, IPAF showed distinct clinical characteristics. The IPAF group showed better survival and less episodes of exacerbation when compared to the IPF group.

Predicting Outcome in Idiopathic Pulmonary Fibrosis: Addition of Fibrotic Score at Thin-Section CT of the Chest to Gender, Age, and Physiology Score Improves the Prediction Model

Purpose

To assess the impact of adding thin-section CT-derived semiquantitative fibrotic score to gender, age, and physiology (GAP) model for predicting survival in idiopathic pulmonary fibrosis (IPF).

Materials and Methods

In this retrospective study of 194 patients with IPF, primary outcome was transplant-free survival. Two thoracic radiologists visually estimated the percentage of reticulation and honeycombing at baseline thin-section CT, which were added to give fibrotic score. For analysis, fibrotic score cutoff (x) determined by using receiver operating characteristic analysis categorized patients into group A (<x) and group B (≥x). Another categorization based on GAP score created group 1 (score 0-3) and group 2 (score >3). Combining the above categories gave four groups (A1, A2, B1, B2). Kaplan-Meier survival analysis was performed with comparison statistics (log-rank test), and hazard ratios were calculated by using the Cox model.

Results

The study patients included 141 men (72.7%), with average age of 66.1 years ± 9.1 (standard deviation). Eighty-four patients (43.3%) has stage I disease with a median follow up of 3.3 years. The interobserver agreement for thin-section CT fibrotic score was substantial (83.3%; κ = 0.64). The optimal cutoff for fibrotic score was 25% (x), with area under the curve of 0.654 (95% confidence interval [CI]: 0.569, 0.74). Survival for group A1 was significantly better than in the other three groups (P < .001). The hazard ratios for respective groups were as follows: B1 was 4.03 (95% CI: 2.02, 8.07), A2 was 4.10 (95% CI: 1.89, 8.87), and B2 was 5.62 (95% CI: 2.86, 11.06) (P < .001 for all). Within the group with GAP score less than or equal to 3 (A1, B1), participants with higher fibrotic score (B1) had four times the increased risk of death or transplantation (P < .001).

Conclusion

Incorporating semiquantitative fibrotic score from thin-section CT to GAP score provides an improved prediction model for survival in idiopathic pulmonary fibrosis.© RSNA, 2019See also the commentary by Chung in this issue.

Differential diagnoses of fibrosing lung diseases

OBJECTIVES

To describe the challenges inherent in diagnosing fibrosing lung diseases (FLD) on CT imaging and methodologies by which the diagnostic process may be simplified.

METHODS

Extensive searches in online scientific databases were performed to provide relevant and contemporary evidence that describe the current state of knowledge related to FLD diagnosis. This includes descriptions of the utility of a working diagnosis for an individual case discussed in a multidisciplinary team (MDT) setting and challenges associated with the lack of consensus guidelines for diagnosing chronic hypersensitivity pneumonitis.

RESULTS

As well as describing imaging features that indicate the presence of a fibrosing lung disease, those CT characteristics that nuance a diagnosis of the various FLDs are considered. The review also explains the essential information that a radiologist needs to convey to an MDT when reading a CT scan. Lastly, we provide some insights as to the future directions the field make take in the upcoming years.

CONCLUSIONS

This review outlines the current state of FLD diagnosis and emphasizes areas where knowledge is limited, and more evidence is required. Fundamentally, however, it provides a guide for radiologists when tackling CT imaging in a patient with FLD.

ADVANCES IN KNOWLEDGE

This review encompasses advice from recent guideline statements and evidence from the latest studies in FLD to provide an up-to-date manual for radiologists to aid the diagnosis of FLD on CT imaging in an MDT setting.

Imaging biomarkers and staging in IPF

PURPOSE OF REVIEW

The application of computer-based imaging analysis in patients with idiopathic pulmonary fibrosis is a rapidly developing field. The purpose of this review is to provide insights into the problems associated with visual interpretation of HRCT patterns and describe some of the current technologies used to provide objective quantification of disease on HRCT. Future directions are also discussed.

RECENT FINDINGS

Although there is strong evidence that visual quantification of disease on HRCT in idiopathic pulmonary fibrosis provides prognostic information, this approach is hampered by its subjective nature and interobserver variability. In contrast, computer-based quantification of disease on HRCT provides objective and reproducible data, which may help to predict mortality and time to decline in patients with idiopathic pulmonary fibrosis. The use of these technologies may also help to stratify clinical risk in patients enrolled in drug trials.

SUMMARY

The future of imaging-based biomarker research in idiopathic pulmonary fibrosis is undoubtedly computer-based HRCT evaluation. However, if this field is to continue to innovate, large, well annotated imaging datasets for developing and testing. new computer-based tools are needed as well as prospective trials for biomarker validation.

Idiopathic pulmonary fibrosis: the radiologist's role in making the diagnosis

Radiologists have a critical role in the evaluation and diagnosis of suspected idiopathic pulmonary fibrosis (IPF). Accurate pattern identification on imaging is key in the multidisciplinary diagnostic process and frequently obviates the need for a surgical lung biopsy. In this review, we describe the clinical and imaging features of IPF in the context of recently revised international guidelines; contrast findings in other diseases that may inform differential diagnosis of fibrotic lung disease; and highlight common complications associated with pulmonary fibrosis.

Comparison of anti-aminoacyl-tRNA synthetase antibody-related and idiopathic non-specific interstitial pneumonia

BACKGROUND AND PURPOSE

Patients with anti-aminoacyl-tRNA synthetase (ARS) antibodies frequently experience complications of interstitial pneumonia (ARS-IP), and the computed tomography (CT) of ARS-IP frequently shows nonspecific interstitial pneumonia (NSIP) pattern. The CT pattern of ARS-IP might be different from that of idiopathic IP. However, the clinical differences in patients with ARS-IP and idiopathic IP showing the similar CT patterns have not yet been well studied. The objective of this study was to evaluate the clinical differences between patients with ARS-NSIP and idiopathic NSIP (I-NSIP).

METHODS

Two groups of 34 patients each, with ARS-NSIP and I-NSIP, who visited Hiroshima University Hospital between January 2005 and December 2017, were enrolled. Clinical features and outcomes were retrospectively compared between the two groups.

RESULTS

The ARS-NSIP group included more female patients and significantly younger patients than the I-NSIP group. The percentage of lymphocytes in bronchoalveolar lavage fluid (BALF) was significantly higher, and the CD4/CD8 ratio in BALF was significantly lower in the ARS-NSIP group compared with the I-NSIP group. The proportion of patients with traction bronchiectasis detected by CT was significantly higher in I-NSIP compared with ARS-NSIP. The number of patients who received corticosteroid and/or immunosuppressant therapy was significantly larger in the ARS-NSIP group than in the I-NSIP group. In addition, the patients in the I-NSIP group who underwent the immunosuppressive therapy demonstrated shorter survival than those who underwent no treatment; this tendency was not observed in the ARS-NSIP group. The 10-year survival rate of patients in the ARS-NSIP group was significantly higher than that of patients in the I-NSIP group (91.8% vs. 43.0%; log-rank, p = 0.012). The multivariate survival analysis revealed that positive anti-ARS antibody was an independent favorable prognostic factor in the patients with NSIP (OR, [95% CI]:0.12 [0.02-0.55], p = 0.013).

CONCLUSIONS

Patients with ARS-NSIP had a significantly better prognosis than those with I-NSIP; this may be associated with the sensitivity to immunosuppressive therapies, and the different findings of BALF and HRCT between the two groups.

Quantitative CT-derived vessel metrics in idiopathic pulmonary fibrosis: A structure-function study

BACKGROUND AND OBJECTIVE

This study aimed to investigate whether quantitative lung vessel morphology determined by a new fully automated algorithm is associated with functional indices in idiopathic pulmonary fibrosis (IPF).

METHODS

A total of 152 IPF patients had vessel volume, density, tortuosity and heterogeneity quantified from computed tomography (CT) images by a fully automated algorithm. Separate quantitation of vessel metrics in pulmonary arteries and veins was performed in 106 patients. Results were evaluated against readouts from lung function tests.

RESULTS

Normalized vessel volume expressed as a percentage of total lung volume was moderately correlated with functional indices on univariable linear regression analysis: forced vital capacity (R2 = 0.27, P < 1 × 10-6 ), diffusion capacity for carbon monoxide (DLCO ; R2 = 0.12, P = 3 × 10-5 ), total lung capacity (TLC; R2 = 0.45, P < 1 × 10-6 ) and composite physiologic index (CPI; R2 = 0.28, P < 1 × 10-6 ). Normalized vessel volume was correlated with vessel density but not with vessel heterogeneity. Quantitatively derived vessel metrics (and artery and vein subdivision scores) were not significantly linked with the transfer factor for carbon monoxide (KCO ), and only weakly with DLCO . On multivariable linear regression analysis, normalized vessel volume and vessel heterogeneity were independently linked with DLCO , TLC and CPI indicating that they capture different aspects of lung damage. Artery-vein separation provided no additional information beyond that captured in the whole vasculature.

CONCLUSION

Our study confirms previous observations of links between vessel volume and functional measures of disease severity in IPF using a new vessel quantitation tool. Additionally, the new tool shows independent linkages of normalized vessel volume and vessel heterogeneity with functional indices. Quantitative vessel metrics do not appear to reflect vasculopathic damage in IPF.

Comparison of clinical courses and mortality of connective tissue disease-associated interstitial pneumonias and chronic fibrosing idiopathic interstitial pneumonias

Interstitial lung disease (ILD) is a common pulmonary manifestation of connective tissue diseases (CTD). Prognostic effect of radiological usual interstitial pneumonia (UIP) pattern in CTD-associated interstitial lung disease (CTD-ILD) is unknown. This study aimed to investigate the disease progression and mortality of patients with CTD-ILD and idiopathic interstitial pneumonias (IIP) including idiopathic pulmonary fibrosis (IPF) and idiopathic nonspecific interstitial pneumonia and the prognostic impact of the radiological UIP pattern on both disease groups. The medical records of 91 patients (55 with CTD-ILD and 36 with IIP) diagnosed with ILD at pulmonary medicine department, Faculty of Medicine, Gazi University from 2004 to 2014 were retrospectively reviewed. Patients included whose baseline high-resolution computed tomography (HRCT) scans showed either a UIP or non-UIP pattern. While 67.3% (n = 37) of CTD-ILD patients possessed UIP pattern, 38.9% (n = 14) of IIP patients had UIP pattern in HRCT. Respiratory functions including the forced expiratory volume in the first second (FEV₁ ), functional vital capacity (FVC), and transfer coefficient for carbon monoxide (diffusing capacity of the lung for carbon monoxide [DLCO]) of IIP group at the time of diagnosis were significantly lower than CTD-ILD group (P = .007, P = .002, and P = .019, respectively). There was no significant survival difference between CTD-ILD and IIP by using the log-rank test (P = .76). Multivariate analysis revealed that UIP pattern in HRCT (Hazard ratio: 1.85; 95% Confidence interval = 1.14-3; P = .013), annual FVC (Hazard ratio: 0.521; 95% Confidence interval = 0.32-0.84; P = .007), and annual DLCO declines (Hazard ratio: 0.943; 95% Confidence interval = 0.897-0.991; P = .02) were independent risk factors for mortality in both CTD-ILD and IIP groups. We found that UIP pattern in HRCT and annual losses in respiratory functions were the main determinants of prognosis of ILDs either idiopathic or CTD-associated.

Bronchoscopic lung cryobiopsy: An Indian association for bronchology position statement

BACKGROUND

Bronchoscopic lung cryobiopsy (BLC) is a novel technique for obtaining lung tissue for the diagnosis of diffuse parenchymal lung diseases. The procedure is performed using several different variations of technique, resulting in an inconsistent diagnostic yield and a variable risk of complications. There is an unmet need for standardization of the technical aspects of BLC.

METHODOLOGY

This is a position statement framed by a group comprising experts from the fields of pulmonary medicine, thoracic surgery, pathology, and radiology under the aegis of the Indian Association for Bronchology. Sixteen questions on various technical aspects of BLC were framed. A literature search was conducted using PubMed and EMBASE databases. The expert group discussed the available evidence relevant to each question through e-mail and a face-to-face meeting, and arrived at a consensus.

RESULTS

The experts agreed that patients should be carefully selected for BLC after weighing the risks and benefits of the procedure. Where appropriate, consideration should be given to perform alternate procedures such as conventional transbronchial biopsy or subject the patient directly to a surgical lung biopsy. The procedure is best performed after placement of an artificial airway under sedation/general anesthesia. Fluoroscopic guidance and occlusion balloon should be utilized for positioning the cryoprobe to reduce the risk of pneumothorax and bleeding, respectively. At least four tissue specimens (with at least two of adequate size, i.e., ≥5 mm) should be obtained during the procedure from different lobes or different segments of a lobe. The histopathological findings of BLC should be interpreted by an experienced pulmonary pathologist. The final diagnosis should be made after a multidisciplinary discussion. Finally, there is a need for structured training for performing BLC.

CONCLUSION

This position statement is an attempt to provide practical recommendations for the performance of BLC in DPLDs.

The place of high-resolution computed tomography imaging in the investigation of interstitial lung disease

INTRODUCTION

High-resolution computed tomography (HRCT) has revolutionized the diagnosis, prognosis and in some cases the prediction of therapeutic response in interstitial lung disease (ILD). HRCT represents an essential second step to a patient's clinical history, before considering any other investigation, including lung biopsy. Areas covered: This review describes the current place of HRCT in the diagnosis, prognosis and monitoring of ILD. It also lists some perspectives for the near future. Expert commentary: Since the 1980s, HRCT and its interpretation have improved, the diagnosis value of patterns, and the integration of bio-clinical elements to HRCT have been better standardized. The interobserver agreement has been investigated, allowing a better use of some limits in the interpretation of various signs. It not only takes into account one particular predominant sign, but the combination of patterns and the distribution of findings. Thanks to HRCT, the range of diagnoses and their probability are more accurately identified. The contribution of HRCT has been optimized during the multidisciplinary discussion that a difficult diagnosis calls for. HRCT quantification of the extent of diffuse lung disease becomes possible and is linked to prognosis. In the future, artificial intelligence may significantly modify the practice of radiology.

Interstitial Pneumonia With Autoimmune Features: An Emerging Challenge at the Intersection of Rheumatology and Pulmonology

Interstitial lung disease (ILD) remains a cause of significant morbidity and mortality in patients with connective tissue disease (CTD)-associated ILD. While some patients meet clear classification criteria for a systemic rheumatic disease, a subset of patients do not meet classification criteria but still benefit from immunosuppressive therapy. In 2015, the American Thoracic Society and European Respiratory Society described classification criteria for interstitial pneumonia with autoimmune features (IPAF) to identify patients with lung-predominant CTD who lack sufficient features of a systemic rheumatic disease to meet classification criteria. Although these criteria are imperfect, they are an important attempt to classify the patient with undifferentiated disease for future study. Rheumatologists play a key role in the evaluation of potential IPAF in patients, especially as many patients with a myositis-spectrum disease (e.g., non-Jo-1 antisynthetase syndrome, anti-melanoma differentiation-associated protein 5 antibody inflammatory myositis, or anti-PM/Scl antibody-associated inflammatory myositis) would be classified under IPAF using the currently available criteria for inflammatory myositis, and would therefore benefit from rheumatologic comanagement. The aim of this review was to describe the historical context that led to the development of these criteria and to discuss the limitations of the current criteria, diagnostic challenges, treatment options, and strategies for disease monitoring.

Reprint of: Nonspecific interstitial pneumonia: pathologic features and clinical implications

Nonspecific interstitial pneumonia (NSIP) is a form of chronic interstitial pneumonia that should be separated from the other idiopathic interstitial pneumonias, including most importantly, usual interstitial pneumonia (UIP). Diagnosis is predicated on identification of characteristic findings in a surgical lung biopsy in the appropriate clinical and radiological context. Affected patients may have a variety of underlying or associated conditions, although most have a form of idiopathic lung disease associated with a more favorable prognosis than UIP/idiopathic pulmonary fibrosis (IPF). Keys to distinguishing NSIP from UIP include absence of heterogeneous lung involvement, architectural distortion in the form of fibrotic scarring and/or honeycomb change, and fibroblast foci in NSIP.

Predicting Outcomes in Idiopathic Pulmonary Fibrosis Using Automated Computed Tomographic Analysis

RATIONALE

Quantitative computed tomographic (CT) measures of baseline disease severity might identify patients with idiopathic pulmonary fibrosis (IPF) with an increased mortality risk. We evaluated whether quantitative CT variables could act as a cohort enrichment tool in future IPF drug trials.

OBJECTIVES

To determine whether computer-derived CT measures, specifically measures of pulmonary vessel-related structures (VRSs), can better predict functional decline and survival in IPF and reduce requisite sample sizes in drug trial populations.

METHODS

Patients with IPF undergoing volumetric noncontrast CT imaging at the Royal Brompton Hospital, London, and St. Antonius Hospital, Utrecht, were examined to identify pulmonary function measures (including FVC) and visual and computer-derived (CALIPER [Computer-Aided Lung Informatics for Pathology Evaluation and Rating] software) CT features predictive of mortality and FVC decline. The discovery cohort comprised 247 consecutive patients, with validation of results conducted in a separate cohort of 284 patients, all fulfilling drug trial entry criteria.

MEASUREMENTS AND MAIN RESULTS

In the discovery and validation cohorts, CALIPER-derived features, particularly VRS scores, were among the strongest predictors of survival and FVC decline. CALIPER results were accentuated in patients with less extensive disease, outperforming pulmonary function measures. When used as a cohort enrichment tool, a CALIPER VRS score greater than 4.4% of the lung was able to reduce the requisite sample size of an IPF drug trial by 26%.

CONCLUSIONS

Our study has validated a new quantitative CT measure in patients with IPF fulfilling drug trial entry criteria-the VRS score-that outperformed current gold standard measures of outcome. When used for cohort enrichment in an IPF drug trial setting, VRS threshold scores can reduce a required IPF drug trial population size by 25%, thereby limiting prohibitive trial costs. Importantly, VRS scores identify patients in whom antifibrotic medication prolongs life and reduces FVC decline.

Usual Interstitial Pneumonia Can Be Detected in Transbronchial Biopsies Using Machine Learning

RATIONALE

Usual interstitial pneumonia (UIP) is the histopathologic hallmark of idiopathic pulmonary fibrosis. Although UIP can be detected by high-resolution computed tomography of the chest, the results are frequently inconclusive, and pathology from transbronchial biopsy (TBB) has poor sensitivity. Surgical lung biopsy may be necessary for a definitive diagnosis.

OBJECTIVES

To develop a genomic classifier in tissue obtained by TBB that distinguishes UIP from non-UIP, trained against central pathology as the reference standard.

METHODS

Exome enriched RNA sequencing was performed on 283 TBBs from 84 subjects. Machine learning was used to train an algorithm with high rule-in (specificity) performance using specimens from 53 subjects. Performance was evaluated by cross-validation and on an independent test set of specimens from 31 subjects. We explored the feasibility of a single molecular test per subject by combining multiple TBBs from upper and lower lobes. To address whether classifier accuracy depends upon adequate alveolar sampling, we tested for correlation between classifier accuracy and expression of alveolar-specific genes.

RESULTS

The top-performing algorithm distinguishes UIP from non-UIP conditions in single TBB samples with an area under the receiver operator characteristic curve (AUC) of 0.86, with specificity of 86% (confidence interval = 71-95%) and sensitivity of 63% (confidence interval = 51-74%) (31 test subjects). Performance improves to an AUC of 0.92 when three to five TBB samples per subject are combined at the RNA level for testing. Although we observed a wide range of type I and II alveolar-specific gene expression in TBBs, expression of these transcripts did not correlate with classifier accuracy.

CONCLUSIONS

We demonstrate proof of principle that genomic analysis and machine learning improves the utility of TBB for the diagnosis of UIP, with greater sensitivity and specificity than pathology in TBB alone. Combining multiple individual subject samples results in increased test accuracy over single sample testing. This approach requires validation in an independent cohort of subjects before application in the clinic.

Assessing Mortality Models in Systemic Sclerosis-Related Interstitial Lung Disease

PURPOSE

The gender, age, and lung physiology (GAP) model, interstitial lung diseases-GAP (ILD-GAP) model, and the smoking history, age, and diffusion capacity of the lung (SADL) model were compared using a systemic sclerosis-ILD (SSc-ILD) cohort to evaluate which best determined prognosis.

METHODS

The models were applied to a cohort of 179 patients with SSc seen at a tertiary care center within 1 year of ILD diagnosis. Demographics, clinical characteristics, and mortality were recorded. The performance of the models was assessed using standardized mortality ratios (SMR) of observed versus predicted outcomes for calibration and concordance (c)-statistics for discrimination.

RESULTS

SSc-ILD patients with usual interstitial pneumonia (31, 17%) had a higher mortality than those with non-specific interstitial pneumonia (147, 83%) (hazard ratio 2.27; 95%CI 1.03-4.97). All 3 models had comparable discrimination (c = 0.72, 0.72, and 0.71, respectively). Regarding calibration, the ILD-GAP model underestimated mortality (SMR 1.50; 95%CI 1.05-2.14). Calibration was acceptable for SADL (SMR 1.00; 95%CI 0.70-1.44) and GAP (SMR 0.90; 95%CI 0.63-1.29). The SADL model underestimated mortality in Stage I ILD.

CONCLUSIONS

The ILD-GAP model underestimated mortality, and the SADL model underestimated mortality in certain subgroups. However, the GAP model performed well in this cohort, providing the best prognostic information for SSc-ILD.

Diagnostic Ability of a Dynamic Multidisciplinary Discussion in Interstitial Lung Diseases: A Retrospective Observational Study of 938 Cases

BACKGROUND

The advice of a dynamic multidisciplinary discussion (MDD) is believed to be important in the diagnosis of interstitial lung diseases (ILDs). However, to what extent MDD diagnoses differ from the preliminary diagnoses before formal workup and MDD (preMDD diagnoses) is still insufficiently studied.

METHODS

We compared preMDD and MDD diagnoses in patients discussed at the Leuven University Hospitals MDDs between January 2005 and December 2015.

RESULTS

Of 938 consecutive patients discussed in an MDD, 755 (80.5%) received a specific diagnosis. From the 183 patients with unclassifiable ILD, 150 patients (16.0%) received suggestions concerning further investigations to establish a definite diagnosis. In 191 patients (41.9% of patients with a preMDD diagnosis), the MDD changed the diagnosis. In 384 patients (79.5% of patients without preMDD diagnosis), MDD provided a diagnosis when the referring physician did not. MDD diagnosis showed a trend toward better prognostic discrimination between idiopathic pulmonary fibrosis and other ILDs compared with preMDD diagnosis (Harrell C-index, 0.666 vs 0.631; P = .08), which was particularly clear in patients with discordant MDD and preMDD diagnoses (hazard ratio, 2.68 vs 0.84; P = .012 vs .768).

CONCLUSIONS

The MDD provided a definite diagnosis in 80.5% of presented cases, suggesting further investigations in almost all others. Given the high number of patients without preMDD diagnosis, the rate of change in preMDD diagnoses (41.9% of patients with a preMDD diagnosis) probably is an underestimation. The better prognostic discrimination among ILDs by using MDD indicates the added value of MDD in ILD.

Factors affecting treatment outcome in patients with idiopathic nonspecific interstitial pneumonia: a nationwide cohort study

Background

The effects of corticosteroid-based therapy in patients with idiopathic nonspecific interstitial pneumonia (iNSIP), and factors affecting treatment outcome, are not fully understood. We aimed to investigate the long-term treatment response and factors affecting the treatment outcome in iNSIP patients from a multi-center study in Korea.

Methods

The Korean interstitial lung disease (ILD) Study Group surveyed ILD patients from 2003 to 2007. Patients were divided into two groups to compare the treatment response: response group (forced vital capacity (FVC) improves ≥10% after 1 year) and non-response group (FVC <10%). Factors affecting treatment response were evaluated by multivariate logistic regression analysis.

Results

A total of 261 patients with iNSIP were enrolled, and 95 patients were followed-up for more than 1 year. Corticosteroid treatment was performed in 86 patients. The treatment group showed a significant improvement in lung function after 1-year: FVC, 10.0%; forced expiratory volume (FEV₁), 9.8%; diffusing capacity of the lung for carbon monoxide (DLco), 8.4% (p < 0.001). Sero-negative anti-nuclear antibody (ANA) was significantly related with lung function improvement. Sero-positivity ANA was significantly lower in the response group (p = 0.013), compared to that in the non-response group. A shorter duration of respiratory symptoms at diagnosis was significantly associated with a good response to treatment (p = 0.018).

Conclusion

Treatment with corticosteroids and/or immunosuppressants improved lung function in iNSIP patients, which was more pronounced in sero-negative ANA and shorter symptom duration patients. These findings suggest that early treatment should be considered in iNSIP patients, even in an early disease stage.

Electronic supplementary material

The online version of this article (10.1186/s12931-017-0686-7) contains supplementary material, which is available to authorized users.

Management of the Rheumatoid Arthritis Patient with Interstitial Lung Disease

The treatment of rheumatoid arthritis (RA) has undergone considerable changes over the last 15–20 years. With an expansion in the armamentarium of therapies available for RA comes a wider choice in selecting the best treatment in terms of comparative safety in the presence of comorbidities. Clinicians frequently encounter patients with RA-associated interstitial lung disease with uncontrolled joint disease and have to make decisions about the safest treatments in this context with the eventual goal of joint remission. In this chapter, available evidence is reviewed on the comparative pulmonary safety of non-biologic disease-modifying antirheumatic drugs (nbDMARDs), biologic DMARDs, biosimilars and targeted synthetic DMARDs in RA-ILD. In addition, the potential role for additional immunosuppression in RA-ILD is reviewed as well as overarching recommendations proposed for patient assessment to guide treatment decisions and management.

Pathology and radiology correlation of idiopathic interstitial pneumonias

By nature, idiopathic interstitial pneumonias have been diagnosed in a multidisciplinary manner. As classifications have been subject to significant refinement over the last decade, the importance of correlating clinical, radiologic, and pathologic information to arrive at a diagnosis, which will predict prognosis in any given patient, has become increasingly recognized. In 2013, the American Thoracic Society and European Respiratory Society updated the idiopathic interstitial pneumonias classification scheme, addressing the most recent updates in the field. The purpose of this review is to highlight the correlations between radiologic and pathologic findings in idiopathic interstitial pneumonias while using updated classification schemes and naming conventions.

Usual interstitial pneumonia: typical, possible, and "inconsistent" patterns

Idiopathic pulmonary fibrosis is a severe and progressive chronic fibrosing interstitial lung disease, a definitive diagnosis being established by specific combinations of clinical, radiological, and pathological findings. According to current international guidelines, HRCT plays a key role in establishing a diagnosis of usual interstitial pneumonia (UIP). Current guidelines describe three UIP patterns based on HRCT findings: a typical UIP pattern; a pattern designated “possible UIP”; and a pattern designated “inconsistent with UIP”, each pattern having important diagnostic implications. A typical UIP pattern on HRCT is highly accurate for the presence of histopathological UIP, being currently considered to be diagnostic of UIP. The remaining patterns require further diagnostic investigation. Other known causes of a UIP pattern include drug-induced interstitial lung disease, chronic hypersensitivity pneumonitis, occupational diseases (e.g., asbestosis), and connective tissue diseases, all of which should be included in the clinical differential diagnosis. Given the importance of CT studies in establishing a diagnosis and the possibility of interobserver variability, the objective of this pictorial essay was to illustrate all three UIP patterns on HRCT.

CT Features of the Usual Interstitial Pneumonia Pattern: Differentiating Connective Tissue Disease-Associated Interstitial Lung Disease From Idiopathic Pulmonary Fibrosis

OBJECTIVE

A substantial proportion of cases of usual interstitial pneumonia (UIP) are due to connective tissue disease (CTD)-associated interstitial lung disease (ILD). The purpose of this study was to determine whether specific CT findings can help differentiate a UIP pattern of CTD-ILD from a UIP pattern of idiopathic pulmonary fibrosis (IPF) and whether these signs are associated with survival.

MATERIALS AND METHODS

Adults visiting an ILD clinic from 2006 to 2015 enrolled in a research registry with a multidisciplinary diagnosis of CTD-ILD or IPF and a UIP pattern at high-resolution CT were included in the study. In these subjects with CT findings of UIP due to either IPF or CTD-ILD, three CT findings anecdotally associated with CTD-ILD were assessed for diagnostic accuracy: the "straight-edge" sign, the "exuberant honeycombing" sign, and the "anterior upper lobe" sign. Survival assessments were performed with univariate and multivariable techniques.

RESULTS

The subjects included 63 patients who had CTD-ILD and 133 patients who had IPF with a UIP pattern at CT. All three CT signs were significantly more common in subjects with CTD-ILD than those with IPF (prevalence, 22.2-25.4% for CTD-ILD, 6.0-12.8% for IPF; p = 0.028 to < 0.001). The highest specificity (94.0%) and sensitivity (25.4%) were seen for the straight-edge sign. No CT sign was associated with survival in multivariable analysis.

CONCLUSION

Although UIP is usually associated with IPF, the index of suspicion for CTD-ILD should be raised in the care of patients with any of the three CT signs. A thorough workup for CTD-ILD should be pursued, including referral to the rheumatology department.

Cardiopulmonary Manifestations of Collagen Vascular Diseases

PURPOSE OF REVIEW

The study aimed to illustrate the cardiopulmonary findings of the following collagen vascular diseases on cross-sectional imaging: rheumatoid arthritis, scleroderma (progressive systemic sclerosis), systemic lupus erythematosus, the inflammatory myopathies (polymyositis/dermatomyositis), and Sjögren's syndrome.

RECENT FINDINGS

Although collagen vascular diseases can affect any part of the body, interstitial lung disease and pulmonary hypertension are the two most important cardiopulmonary complications and are responsible for the majority of morbidity and mortality in this patient population. Interstitial pneumonia with autoimmune features (IPAF) is a newly described entity that encompasses interstitial lung disease in patients with clinical, serologic, or morphologic features suggestive of but not diagnostic of collagen vascular disease; these patients are thought to have better outcomes than idiopathic interstitial pneumonias. Interstitial lung disease and pulmonary hypertension determine the prognosis in collagen vascular disease patients. IPAF is a new term to label patients with possible collagen vascular disease-related interstitial lung disease. Collagen vascular disease patients are at increased risk for various malignancies.

Possible UIP pattern on high-resolution computed tomography is associated with better survival than definite UIP in IPF patients

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing lung disease of unknown etiology. Inter-society consensus guidelines on IPF diagnosis and management outline radiologic patterns including definite usual interstitial pneumonia (UIP), possible UIP, and inconsistent with UIP. We evaluate these diagnostic categories as prognostic markers among patients with IPF.

METHODS

Included subjects had biopsy-proven UIP, a multidisciplinary team diagnosis of IPF, and a baseline high-resolution computed tomography (HRCT). Thoracic radiologists assigned the radiologic pattern and documented the presence and extent of specific radiologic findings. The outcome of interest was lung transplant-free survival.

RESULTS

IPF patients with a possible UIP pattern on HRCT had significantly longer Kaplan-Meier event-free survival compared to those with definite UIP pattern (5.21 and 3.57 years, respectively, p = 0.002). In a multivariable Cox proportional hazards model adjusted for baseline age, gender, %-predicted FVC, and %-predicted DLCO via the GAP Stage, extent of fibrosis (via the traction bronchiectasis score) and ever-smoker status, possible UIP pattern on HRCT (versus definite UIP) was associated with reduced hazard of death or lung transplant (HR = 0.42, CI 95% 0.23-0.78, p = 0.006).

CONCLUSIONS

Radiologic diagnosis categories outlined by inter-society consensus guidelines is a widely-reported and potentially useful prognostic marker in IPF patients, with possible UIP pattern on HRCT associated with a favorable prognosis compared to definite UIP pattern, after adjusting for relevant covariates.

Diagnosis of Idiopathic Pulmonary Fibrosis "Pragmatic Challenges in Clinical Practice"

The past few years have signaled a major breakthrough on the management of idiopathic pulmonary fibrosis (IPF). Finally, we have drugs in our arsenal able to slow down the inexorable disease natural course. On the other hand, the latter evidence has increased the responsibility for a timely and accurate diagnosis. Establishment of IPF diagnosis directly affects the choice of appropriate treatment. The current diagnostic guidelines represent a major step forward providing an evidence-based road map; yet, clinicians are encountering major diagnostic dilemmas that inevitably affect therapeutic decisions. This review article aims to summarize the current state of knowledge on the diagnostic procedure of IPF based on the current guidelines and discuss pragmatic difficulties and challenges encountered by clinicians with regards to their applicability in the everyday clinical practice.

Evaluating disease severity in idiopathic pulmonary fibrosis

Accurate assessment of idiopathic pulmonary fibrosis (IPF) disease severity is integral to the care provided to patients with IPF. However, to date, there are no generally accepted or validated staging systems. There is an abundance of data on using information acquired from physiological, radiological and pathological parameters, in isolation or in combination, to assess disease severity in IPF. Recently, there has been interest in using serum biomarkers and computed tomography-derived quantitative lung fibrosis measures to stage disease severity in IPF. This review will focus on the suggested methods for staging IPF, at baseline and on serial assessment, their strengths and limitations, as well as future developments.