Computed tomographic features of idiopathic fibrosing interstitial pneumonia: comparison with pulmonary fibrosis related to collagen vascular disease

Interstitial Lung Disease Associated with Systemic Sclerosis

Systemic sclerosis (SSc) is a rare autoimmune disease characterized by a tripod combining vasculopathy, fibrosis, and immune-mediated inflammatory processes. The prevalence of interstitial lung disease (ILD) in SSc varies according to the methods used to detect it, ranging from 25 to 95%. The fibrotic and vascular pulmonary manifestations of SSc, particularly ILD, are the main causes of morbidity and mortality, contributing to 35% of deaths. Although early trials were conducted with cyclophosphamide, more recent randomized controlled trials have been performed to assess the efficacy and tolerability of several medications, mostly mycophenolate, rituximab, tocilizumab, and nintedanib. Although many uncertainties remain, expert consensus is emerging to optimize the therapeutic management and to provide clinicians with evidence-based clinical practice guidelines for patients with SSc-ILD. This article provides an overview, in the light of the latest advances, of the available evidence for the diagnosis and management of SSc-ILD.

Diagnosis and Pharmacologic Management of Fibrotic Interstitial Lung Disease

Interstitial lung disease is an umbrella term that encompasses a spectrum of parenchymal lung pathologies affecting the gas exchanging part of the lung. While many of these disease entities are not fibrotic in nature, a number can lead to pulmonary fibrosis which may or may not progress over time. Idiopathic pulmonary fibrosis is the prototypical, progressive fibrotic interstitial lung disease, which can lead to worsening hypoxemic respiratory failure and mortality within a number of years from the time of diagnosis. The importance of an accurate and timely diagnosis of interstitial lung diseases, which is needed to inform prognosis and guide clinical management, cannot be overemphasized. Developing a consensus diagnosis requires the incorporation of a variety of factors by a multidisciplinary team, which then may or may not determine a need for tissue sampling. Clinical management can be challenging given the heterogeneity of disease behavior and the paucity of controlled trials to guide decision making. This review addresses current paradigms and recent updates in the diagnosis and pharmacologic management of these fibrotic interstitial lung diseases.

The ER Stress/UPR Axis in Chronic Obstructive Pulmonary Disease and Idiopathic Pulmonary Fibrosis

Cellular protein homeostasis in the lungs is constantly disrupted by recurrent exposure to various external and internal stressors, which may cause considerable protein secretion pressure on the endoplasmic reticulum (ER), resulting in the survival and differentiation of these cell types to meet the increased functional demands. Cells are able to induce a highly conserved adaptive mechanism, known as the unfolded protein response (UPR), to manage such stresses. UPR dysregulation and ER stress are involved in numerous human illnesses, such as metabolic syndrome, fibrotic diseases, and neurodegeneration, and cancer. Therefore, effective and specific compounds targeting the UPR pathway are being considered as potential therapies. This review focuses on the impact of both external and internal stressors on the ER in idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) and discusses the role of the UPR signaling pathway activation in the control of cellular damage and specifically highlights the potential involvement of non-coding RNAs in COPD. Summaries of pathogenic mechanisms associated with the ER stress/UPR axis contributing to IPF and COPD, and promising pharmacological intervention strategies, are also presented.

Evaluation and management of Idiopathic Pulmonary Fibrosis

Idiopathic Pulmonary Fibrosis (IPF) is a most common progressive interstitial lung disease (ILD) of unknown etiology, although majority of patients are elderly male smokers. The main pathogenesis is aberrant recovery of epithelial injury and collagen deposition. Fibrotic nonspecific interstitial pneumonia, connective tissue disease (CTD) especially rheumatoid arthritis (RA) associated ILD, and chronic hypersensitivity pneumonia(CHP) are important differential diagnosis. Main symptoms are non-productive cough and progressive exertional dyspnea. Crucial physical findings are scalene muscle hypertrophy, bibasilar fine crackles, and finger clubbing. The serum markers such as lactate dehydrogenase (LDH) and Krebs von den Lungen-6 (KL-6) are sensitive for ILD detection and activity. Both pulmonary function test (PFT) and the 6-minute walk test (6MWT) are useful tool for evaluation of disease progression of IPF. Serial changes of forced vital capacity (FVC) and 6MWT distance predict mortality in IPF effectively. Recently published international IPF guidelines highlight the importance of chest high resolution computed tomography (HRCT) findings such as honeycombing, traction bronchiectasis (TBE), and sub-pleural reticular opacity. IPF is chronic and progressive; therefore, tracking disease behavior is crucial. Unifying clinical, physiological, and imaging information over time is useful. With regard to its management, two anti-fibrotic drugs such as pirfenidone and nintedanib have been available. These drugs can slow the decline of FVC and prevent acute exacerbation (AE). In this review, I outline the clinical characteristics of IPF, physiological, imaging, pathological findings and review diagnosis process and management.

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.

Cyclophosphamide for connective tissue disease-associated interstitial lung disease

BACKGROUND

Approximately one-third of individuals with interstitial lung disease (ILD) have associated connective tissue disease (CTD). The connective tissue disorders most commonly associated with ILD include scleroderma/systemic sclerosis (SSc), rheumatoid arthritis, polymyositis/dermatomyositis, and Sjögren's syndrome. Although many people with CTD-ILD do not develop progressive lung disease, a significant proportion do progress, leading to reduced physical function, decreased quality of life, and death. ILD is now the major cause of death amongst individuals with systemic sclerosis.Cyclophosphamide is a highly potent immunosuppressant that has demonstrated efficacy in inducing and maintaining remission in autoimmune and inflammatory illnesses. However this comes with potential toxicities, including nausea, haemorrhagic cystitis, bladder cancer, bone marrow suppression, increased risk of opportunistic infections, and haematological and solid organ malignancies.Decision-making in the treatment of individuals with CTD-ILD is difficult; the clinician needs to identify those who will develop progressive disease, and to weigh up the balance between a high level of need for therapy in a severely unwell patient population against the potential for adverse effects from highly toxic therapy, for which only relatively limited data on efficacy can be found. Similarly, it is not clear whether histological subtype, disease duration, or disease extent can be used to predict treatment responsiveness.

OBJECTIVES

To assess the efficacy and adverse effects of cyclophosphamide in the treatment of individuals with CTD-ILD.

SEARCH METHODS

We performed searches on CENTRAL, MEDLINE, Embase, CINAHL, and Web of Science up to May 2017. We handsearched review articles, clinical trial registries, and reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised controlled parallel-group trials that compared cyclophosphamide in any form, used individually or concomitantly with other immunomodulating therapies, versus non-cyclophosphamide-containing therapies for at least six months, with follow-up of at least 12 months from the start of treatment.

DATA COLLECTION AND ANALYSIS

We imported studies identified by the search into a reference manager database. We retrieved the full-text versions of relevant studies, and two review authors independently extracted data. Primary outcomes were change in lung function (change in forced vital capacity (FVC) % predicted and diffusing capacity of the lung for carbon monoxide (DLCO) % predicted), adverse events, and health-related quality of life measures. Secondary outcomes included all-cause mortality, dyspnoea, cough, and functional exercise testing. When appropriate, we performed meta-analyses and subgroup analyses by severity of lung function, connective tissue disease diagnosis, and radiological pattern of fibrosis. We assessed the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach and created 'Summary of findings' tables.

MAIN RESULTS

We included in the analysis four trials with 495 participants (most with systemic sclerosis). We formed two separate comparisons: cyclophosphamide versus placebo (two trials, 195 participants) and cyclophosphamide versus mycophenolate (two trials, 300 participants). We found evidence to be of low quality, as dropout rates were high in the intervention groups, and as we noted a wide confidence interval around the effect with small differences, which affected the precision of results.The data demonstrates significant improvement in lung function with cyclophosphamide compared with placebo (post-treatment FVC % mean difference (MD) 2.83, 95% confidence interval (CI) 0.80 to 4.87; P = 0.006) but no significant difference in post-treatment DLCO (% MD -1.68, 95% CI -4.37 to 1.02; P = 0.22; two trials, 182 participants).Risk of adverse effects was increased in the cyclophosphamide treatment groups compared with the placebo groups, in particular, haematuria, leukopenia, and nausea, leading to a higher rate of withdrawal from cyclophosphamide treatment. The data demonstrates statistically significant improvement in one-measure of quality of life in one trial favouring cyclophosphamide over placebo and clinically and statistically significant improvement in breathlessness in one trial favouring cyclophosphamide compared with placebo, with no significant impact on mortality.Trialists reported no significant impact on lung function when cyclophosphamide was used compared with mycophenolate at 12 months (FVC % MD -0.82, 95% CI -3.95 to 2.31; P = 0.61; two trials, 149 participants; DLCO % MD -1.41, 95% CI -10.40 to 7.58; P = 0.76; two trials, 149 participants).Risk of side effects was increased with cyclophosphamide versus mycophenolate, in particular, leukopenia and thrombocytopenia.The data demonstrates no significant impact on health-related quality of life, all-cause mortality, dyspnoea, or cough severity in the cyclophosphamide group compared with the mycophenolate group. No trials reported outcomes associated with functional exercise tests.We performed subgroup analysis to determine whether severity of lung function, connective tissue disease diagnosis, or radiological pattern had any impact on outcomes. One trial reported that cyclophosphamide protected against decreased FVC in individuals with worse fibrosis scores, and also showed that cyclophosphamide may be more effective in those with worse lung function. No association could be made between connective tissue disease diagnosis and outcomes.

AUTHORS' CONCLUSIONS

This review, which is based on studies of varying methodological quality, demonstrates that overall, in this population, small benefit may be derived from the use of cyclophosphamide in terms of mean difference in % FVC when compared with placebo, but not of the difference in % DLCO, or when compared with mycophenolate. Modest clinical improvement in dyspnoea may be noted with the use of cyclophosphamide. Clinical practice guidelines should advise clinicians to consider individual patient characteristics and to expect only modest benefit at best in preserving FVC. Clinicians should carefully monitor for adverse effects during treatment and in the years thereafter.Further studies are required to examine the use of cyclophosphamide; they should be adequately powered to compare outcomes within different subgroups, specifically, stratified for extent of pulmonary infiltrates on high-resolution computed tomography (HRCT) and skin involvement in SSc. Studies on other forms of connective tissue disease are needed. Researchers may consider comparing cyclophosphamide (a potent immunosuppressant) versus antifibrotic agents, or comparing both versus placebo, in particular, for those with evidence of rapidly progressive fibrotic disease, who may benefit the most.

Interstitial Pneumonia with Autoimmune Features: Overview of proposed criteria and recent cohort characterization

The accurate diagnosis of interstitial lung disease (ILD) is essential for optimal prognostication and management. While connective tissue disease (CTD) is among the most common causes of ILD, some patients have features suggestive of autoimmunity without meeting criteria for a specific CTD. To help define and study this disease entity more uniformly, a 2015 research statement proposed consensus-based criteria and coined the term "interstitial pneumonia with autoimmune features" (IPAF). In this review, we summarize and compare previously proposed criteria to characterize these patients, provide an overview of the IPAF criteria and highlight recent investigations aimed at characterizing IPAF cohorts. We then call attention to questions that have arisen with the application of the IPAF criteria and discuss future areas of study.

The Spectrum of Interstitial Lung Disease in Connective Tissue Disease

Interstitial lung disease (ILD) is a common cause of morbidity and mortality in patients with connective tissue disease (CTD). In a minority of patients the ILD may be the presenting (or only) manifestation of an underlying CTD. Diagnosis of CTD-related ILD relies on a multidisciplinary team including pulmonologists, pathologists, radiologists, and rheumatologists, as the imaging and pathologic findings may be indistinguishable from idiopathic interstitial pneumonias. Moreover, many patients with ILD are suspected of having an underlying CTD but do not meet all of the necessary criteria for a specific disorder. This article provides a pattern-based approach to the imaging of CTD-related ILD and also reviews relevant clinical, pathologic, and serologic data that radiologists should be familiar with as part of a multidisciplinary team.

Idiopathic Pulmonary Fibrosis: Diagnosis and Clinical Manifestations

Idiopathic pulmonary fibrosis (IPF) is a parenchymal lung disease characterized by progressive interstitial fibrosis. The clinical course of IPF can be unpredictable and may be punctuated by acute exacerbations. Although much progress is being made in unraveling the mechanisms underlying IPF, effective therapy for improving survival remains elusive. Longitudinal disease profiling, especially in terms of clinical manifestations in a large cohort of patients, should lead to proper management of the patients and development of new treatments for IPF. Appropriate multidisciplinary assessment in ongoing registries is required to achieve this. This review summarizes the current status of the diagnosis and clinical manifestations of IPF.

Connective tissue disease-related interstitial lung disease

Interstitial lung disease (ILD) is commonly present in patients with an underlying connective tissue disease (CTD), particularly those with systemic sclerosis, rheumatoid arthritis, and inflammatory myositis. The clinical spectrum can range from asymptomatic findings on imaging to respiratory failure and death. Distinguishing features in the clinical, radiographic, and histopathologic characteristics of CTD-ILD subsets can predict prognosis and treatment response. Treatment often consists of combinations of immunosuppressive medications, but there is a paucity of guidance in the literature to help clinicians determine appropriate screening and management of CTD-ILD. As such, there is a critical need for studies that can elucidate the natural history of the CTD-ILD, as well as clarify optimal therapies for CTD patients with ILD.

Combined pulmonary fibrosis and emphysema: The many aspects of a cohabitation contract

Combined pulmonary fibrosis and emphysema (CPFE) is a clinical entity characterized by the coexistence of upper lobe emphysema and lower lobe fibrosis. Patients with this condition experience severe dyspnea and impaired gas exchange with preserved lung volumes. The diagnosis of the CPFE syndrome is based on HRCT imaging, showing the coexistence of emphysema and pulmonary fibrosis both in varying extent and locations within the lung parenchyma. Individual genetic background seem to predispose to the development of the disease. The risk of the development of pulmonary hypertension in patients with CPFE is high and related to poor prognosis. CPFE patients also present a high risk of lung cancer. Mortality is significant in patients with CPFE and median survival is reported between 2.1 and 8.5 years. Currently, no specific recommendations are available regarding the management of patients with CPFE. In this review we provide information on the existing knowledge on CPFE regarding the pathophysiology, clinical manifestations, imaging, complications, possible therapeutic interventions and prognosis of the disease.

Imaging of pulmonary involvement in rheumatic disease

Lung disease commonly occurs in connective tissue diseases (CTD) and is an important cause of morbidity and mortality. Imaging is central to the evaluation of CTD-associated pulmonary complications. In this article, a general discussion of radiologic considerations is followed by a description of the pulmonary appearances in individual CTDs, and the imaging appearances of acute and nonacute pulmonary complications. The contribution of imaging to monitoring disease, evaluating treatment response, and prognostication is reviewed. Finally, we address the role of imaging in the challenging multidisciplinary evaluation of interstitial lung disease where there is an underlying suspicion of an undiagnosed CTD.

American Thoracic Society-European Respiratory Society Classification of the Idiopathic Interstitial Pneumonias: Advances in Knowledge since 2002

In the updated American Thoracic Society-European Respiratory Society classification of the idiopathic interstitial pneumonias (IIPs), the major entities have been preserved and grouped into (a) "chronic fibrosing IIPs" (idiopathic pulmonary fibrosis and idiopathic nonspecific interstitial pneumonia), (b) "smoking-related IIPs" (respiratory bronchiolitis-associated interstitial lung disease and desquamative interstitial pneumonia), (c) "acute or subacute IIPs" (cryptogenic organizing pneumonia and acute interstitial pneumonia), and (d) "rare IIPs" (lymphoid interstitial pneumonia and idiopathic pleuroparenchymal fibroelastosis). Furthermore, it has been acknowledged that a final diagnosis is not always achievable, and the category "unclassifiable IIP" has been proposed. The diagnostic interpretation of the IIPs is often challenging because other diseases with a known etiology (most notably, connective tissue disease and hypersensitivity pneumonitis) may show similar morphologic patterns. Indeed, more emphasis has been given to the integration of clinical, computed tomographic (CT), and pathologic findings for multidisciplinary diagnosis. Typical CT-based morphologic patterns are associated with the IIPs, and radiologists play an important role in diagnosis and characterization. Optimal CT quality and a systematic approach are both pivotal for evaluation of IIP. Interobserver variation for the various patterns encountered in the IIPs is an issue. It is important for radiologists to understand the longitudinal behavior of IIPs at serial CT examinations, especially for providing a framework for cases that are unclassifiable or in which a histologic diagnosis cannot be obtained.

Comorbidities in idiopathic pulmonary fibrosis patients: a systematic literature review

Idiopathic pulmonary fibrosis (IPF) is associated with a fatal prognosis and manifests in patients over 60 years old who may have comorbidities. The prevalence and impact of comorbidities on the clinical course of IPF is unclear.

This systematic literature review examined the prevalence of comorbidities and mortality associated with comorbidities in IPF patients. Relevant observational studies published in English from January 1990 to January 2015 identifiedviaMEDLINE and EMBASE were included; bibliographies of articles were also searched.

Among the 126 studies included, prevalence of pulmonary hypertension (PH) was 3–86%, 6–91% for obstructive sleep apnoea, 3–48% for lung cancer and 6–67% for chronic obstructive pulmonary disease (COPD). Nonrespiratory comorbidities included ischaemic heart disease (IHD) (3–68%) and gastro-oesophageal reflux (GER) (0–94%). Mortality was highest among patients with IPF and lung cancer. Most studies assessed relatively small samples of patients with IPF.

PH, COPD, lung cancer, GER and IHD are significant comorbidities; differences in IPF severity, case definitions and patient characteristics limited the comparability of findings. The identification and prompt treatment of comorbidities may have a clinically significant impact on overall outcome that is meaningful for patients with IPF.

An official European Respiratory Society/American Thoracic Society research statement: interstitial pneumonia with autoimmune features

Many patients with an idiopathic interstitial pneumonia (IIP) have clinical features that suggest an underlying autoimmune process but do not meet established criteria for a connective tissue disease (CTD). Researchers have proposed differing criteria and terms to describe these patients, and lack of consensus over nomenclature and classification limits the ability to conduct prospective studies of a uniform cohort.

The “European Respiratory Society/American Thoracic Society Task Force on Undifferentiated Forms of Connective Tissue Disease-associated Interstitial Lung Disease” was formed to create consensus regarding the nomenclature and classification criteria for patients with IIP and features of autoimmunity.

The task force proposes the term “interstitial pneumonia with autoimmune features” (IPAF) and offers classification criteria organised around the presence of a combination of features from three domains: a clinical domain consisting of specific extra-thoracic features, a serologic domain consisting of specific autoantibodies, and a morphologic domain consisting of specific chest imaging, histopathologic or pulmonary physiologic features.

A designation of IPAF should be used to identify individuals with IIP and features suggestive of, but not definitive for, a CTD. With IPAF, a sound platform has been provided from which to launch the requisite future research investigations of a more uniform cohort.

State of the art in the diagnosis and management of interstitial lung disease

The interstitial lung diseases (ILDs) are a diverse group of disorders characterized by a varying combination of inflammation and fibrosis of the pulmonary parenchyma. Treatment and prognosis of ILD typically depend on the underlying ILD subtype, highlighting the importance of accurate classification and diagnosis. Besides a thorough history and clinical examination, the protocol should include a 6-minute walk test, chest radiography, high-resolution computed tomography, biochemical analysis, pulmonary function tests, blood gas analysis, bronchoalveolar lavage, and, when necessary, a lung biopsy. The final diagnosis of ILD entities requires dynamic interaction between clinicians, radiologists and pathologists to reach a clinico-radiologic-pathologic diagnosis, the gold standard no longer being the histology but rather a multidisciplinary approach.

Utility of expiratory thin-section CT for fibrotic interstitial pneumonia

BACKGROUND

Collagen vascular disease-associated interstitial lung disease (CVD-ILD) must be differentiated from idiopathic pulmonary fibrosis (IPF) since prognosis and treatment strategies differ between these two conditions. However, differentiating between CVD-ILD and IPF is often difficult.

PURPOSE

To examine the utility of expiratory high-resolution computed tomography (HRCT) for differentiating between CVD-ILD and IPF.

MATERIAL AND METHODS

Seventy patients were examined with expiratory and inspiratory HRCT with CVD-ILD (n = 36) or IPF (n = 34). Associated diagnoses in patients with CVD-ILD were rheumatoid arthritis (n = 22), Sjögren syndrome (n = 3), scleroderma (n = 2), polymyositis/dermatomyositis (n = 1), and unspecified connective tissue disease (n = 8). Parenchymal abnormalities on inspiratory HRCT and visual extent of air trapping on expiratory HRCT were evaluated, statistical differences in HRCT findings between the two conditions were determined, and air trapping CT scores were correlated with the results of pulmonary function testing.

RESULTS

Air trapping was found in 27 (75%) of 36 cases of CVD-ILD and four (12%) of 34 cases of IPF. Seventeen of the 27 cases for which air trapping was exhibited with CVD-ILD were diagnosed with rheumatoid arthritis. A significant difference in frequency of air trapping was seen between CVD-ILD and IPF (P < 0.0001). Frequency of centrilobular nodules was significantly higher in CVD-ILD than in IPF (P = 0.021). In contrast, frequencies of interlobular interstitial thickening and traction bronchiectasis were significantly higher in IPF than in CVD-ILD (P = 0.005, P = 0.007, respectively). Correlations were seen between visual extent of air trapping and pulmonary function test results such as air trapping index (P = 0.004, r = 0.34), closing volume/vital capacity (P = 0.0002, r = -0.47), and closing capacity/total lung capacity (P < 0.0001, r = -0.51).

CONCLUSION

The presence of air trapping on expiratory HRCT suggests CVD-ILD rather than IPF.

An official American Thoracic Society/European Respiratory Society statement: Update of the international multidisciplinary classification of the idiopathic interstitial pneumonias

BACKGROUND

In 2002 the American Thoracic Society/European Respiratory Society (ATS/ERS) classification of idiopathic interstitial pneumonias (IIPs) defined seven specific entities, and provided standardized terminology and diagnostic criteria. In addition, the historical "gold standard" of histologic diagnosis was replaced by a multidisciplinary approach. Since 2002 many publications have provided new information about IIPs.

PURPOSE

The objective of this statement is to update the 2002 ATS/ERS classification of IIPs.

METHODS

An international multidisciplinary panel was formed and developed key questions that were addressed through a review of the literature published between 2000 and 2011.

RESULTS

Substantial progress has been made in IIPs since the previous classification. Nonspecific interstitial pneumonia is now better defined. Respiratory bronchiolitis-interstitial lung disease is now commonly diagnosed without surgical biopsy. The clinical course of idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia is recognized to be heterogeneous. Acute exacerbation of IIPs is now well defined. A substantial percentage of patients with IIP are difficult to classify, often due to mixed patterns of lung injury. A classification based on observed disease behavior is proposed for patients who are difficult to classify or for entities with heterogeneity in clinical course. A group of rare entities, including pleuroparenchymal fibroelastosis and rare histologic patterns, is introduced. The rapidly evolving field of molecular markers is reviewed with the intent of promoting additional investigations that may help in determining diagnosis, and potentially prognosis and treatment.

CONCLUSIONS

This update is a supplement to the previous 2002 IIP classification document. It outlines advances in the past decade and potential areas for future investigation.

Usual interstitial pneumonia-pattern fibrosis in surgical lung biopsies. Clinical, radiological and histopathological clues to aetiology

Pulmonary fibrosis in surgical lung biopsies is said to have a 'usual interstitial pneumonia-pattern' (UIP-pattern) of disease when scarring of the parenchyma is present in a patchy, 'temporally heterogeneous' distribution. These biopsies are one of the more common non-neoplastic specimens surgical pathologists encounter and often pose a number of challenges. UIP is the expected histopathological pattern in patients with clinical idiopathic pulmonary fibrosis (IPF), but the UIP-pattern can be seen in other conditions on occasion. Most important among these are the rheumatic interstitial lung diseases (RILD) and chronic hypersensitivity pneumonitis (CHrHP). Because theses entities have different mechanisms of injury, approach to therapy, and expected clinical progression, it is imperative for the surgical pathologist to correctly classify them. Taken in isolation, the UIP-pattern seen in patients with IPF may appear to overlap with that of RILD and CHrHP, at least when using the broadest definition of this term (patchy fibrosis). However, important distinguishing features are nearly always present in our experience, and the addition of a multidisciplinary approach will often resolve the critical differences between these diseases. In this manuscript, we review the distinguishing clinical, radiologic and histopathological features of UIP of IPF, RILD and CHrHP, based, in part, on the existing literature, but also lessons learned from a busy lung biopsy consultation practice.

Idiopathic pulmonary fibrosis complicated by acute thromboembolic disease: chest X-ray, HRCT and multi-detector row CT angiographic findings

Idiopathic pulmonary fibrosis (IPF) is a chronic diffuse interstitial disease characterized by a predominant reticular pattern of involvement of the lung parenchyma which can be well documented by High Resolution Computed Tomography (HRCT). While almost half of the patients with IPF may develop pulmonary arterial hypertension, the occurrence of superimposed acute thrombo-embolic disease is rare.We describe a case of an 87 yrs old female who was found to have IPF complicated by acute pulmonary thrombo-embolism during the clinical and radiological investigation of a rapidly worsening dyspnea. While chest x-ray findings were initially considered consistent with a congestive heart failure, a bed side echocardiography revealed findings suggestive of pulmonary arterial hypertension and right ventricular failure with enlargement of both right cavities and associated valvular regurgitations. An acute thrombo-embolic disease was initially ruled out by a perfusion lung scintigraphy and subsequently confirmed by contrast-enhanced multi-detector CT which showed an embolus at the emergency of the right inter-lobar artery with associated signs of chronic pulmonary hypertension. However, unenhanced scans performed with both conventional and high resolution techniques also depicted a reticular pattern of involvement of lung parenchyma considered suggestive of IPF despite a atypical upper lobe predominance. IPF was later confirmed by further clinical, serological and instrumental follow-up.

Combined pulmonary fibrosis and emphysema in connective tissue disease

PURPOSE OF REVIEW

This review discusses combined pulmonary fibrosis and emphysema (CPFE) in the setting of connective tissue disease.

RECENT FINDINGS

CPFE is a recently identified syndrome in smokers or ex-smokers characterized by dyspnea often severe, preserved lung volumes, severely impaired gas exchanges, and an increased risk of pulmonary hypertension associated with a dismal prognosis, and possibly lung cancer. It may be encountered in the setting of connective tissue diseases, especially rheumatoid arthritis and systemic sclerosis, with generally similar features as 'idiopathic' (tobacco-related) CPFE. The diagnosis is based on the presence of both emphysema predominating in the upper lobes and frequently paraseptal, and interstitial abnormalities suggesting pulmonary fibrosis in the lower lung zones with velcro crackles at auscultation. Pathologic radiological correlations are difficult owing to various pathology and difficulties in identifying honeycombing at chest high-resolution computed tomography in the setting of coexistent emphysema. Tobacco smoking is associated with an increased risk of developing most of the individual components of the syndrome (i.e. emphysema, pulmonary fibrosis, pulmonary hypertension, rheumatoid arthritis, and pulmonary fibrosis among patients with rheumatoid arthritis). CPFE impacts modalities of follow-up for pulmonary function and detection of pulmonary hypertension especially in systemic sclerosis.

SUMMARY

The syndrome of CPFE is a distinct pulmonary manifestation in the spectrum of lung diseases associated with connective tissue diseases, especially in smokers or ex-smokers.

Diffuse alveolar hemorrhage in coumarin users: a fibrosing interstitial pneumonia trigger?

BACKGROUND

Fibrosing interstitial pneumonias (IPs) include idiopathic pulmonary fibrosis (IPF) and nonspecific interstitial pneumonia (NSIP). It has been suggested that oxidative damage plays a role in the pathophysiology of idiopathic interstitial pneumonias. Diffuse alveolar hemorrhage (DAH) can cause oxidative stress. Accordingly, we hypothesized that episodes of DAH might trigger fibrosing IP development.

METHODS

Patients using coumarins with confirmed DAH were retrospectively gathered during a 9 year period and reviewed for the development of IPF or fibrosing NSIP.

RESULTS

A total of 65 patients with DAH could finally be included, 31 (48 %) of whom subsequently developed a fibrosing IP. The majority of these 31 patients developed the fibrosing IP within 3 years after DAH confirmation. A total of 41 (63 %) patients died within 3.0 ± 0.9 (range 1.3-4.7) years after the DAH diagnosis had been confirmed. Twenty-two of the deceased (54 %) had finally developed fibrosing IP.

CONCLUSIONS

Almost half of the patients with established episodes of DAH developed fibrosing IP; therefore it seems that DAH might be a trigger for the development of fibrosing IP. This observation warrants prospective studies to further evaluate the clinical impact of these findings.

Connective Tissue Disease-associated Interstitial Lung Disease: A review

Interstitial lung disease (ILD) is commonly encountered in patients with connective tissue diseases (CTD). Besides the lung parenchyma, the airways, pulmonary vasculature and structures of the chest wall may all be involved, depending on the type of CTD. As a result of this so-called multi-compartment involvement, airflow limitation, pulmonary hypertension, vasculitis and extrapulmonary restriction can occur alongside fibro-inflammatory parenchymal abnormalities in CTD. Rheumatoid arthritis (RA), systemic sclerosis (SSc), poly-/dermatomyositis (PM/DM), Sjögren's syndrome (SjS), systemic lupus erythematosus (SLE), and undifferentiated (UCTD) as well as mixed connective tissue disease (MCTD) can all be associated with the development of ILD. Non-specific interstitial pneumonia (NSIP) is the most commonly observed histopathological pattern in CTD-ILD, but other patterns including usual interstitial pneumonia (UIP), organizing pneumonia (OP), diffuse alveolar damage (DAD) and lymphocytic interstitial pneumonia (LIP) may occur. Although the majority of patients with CTD-ILD experience stable or slowly advancing ILD, a small yet significant group exhibits a more severe and progressive course. Randomized placebo-controlled trials evaluating the efficacy of immunomodulatory treatments have been conducted only in SSc-associated ILD. However, clinical experience suggests that a handful of immunosuppressive medications are potentially effective in a sizeable portion of patients with ILD caused by other CTDs. In this manuscript, we review the clinical characteristics and management of the most common CTD-ILDs.

Idiopathic Interstitial Pneumonias

The idiopathic interstitial pneumonias are a distinct group of clinicopathologic entities. High-resolution computed tomography (HRCT) plays a critical role in the evaluation and management of patients. In the appropriate clinical setting, characteristic HRCT findings may be diagnostic, obviating the need for open lung biopsy. In more challenging or complicated cases, consensus among the clinician, radiologist, and pathologist may be required. This chapter describes and depicts the characteristic HRCT features of usual interstitial pneumonia, nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, respiratory bronchiolitis, respiratory bronchiolitis associated interstitial lung disease, desquamative interstitial pneumonia, and lymphoid interstitial pneumonia.

Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a specific clinicopathologic ­syndrome presenting in older adults with the predominant features: dyspnea, dry cough, restrictive defect on pulmonary function tests (PFTs), hypoxemia, characteristic abnormalities on high-resolution thin section computed tomographic (HRCT) scans, usual interstitial pneumonitis (UIP) pattern on lung biopsy. Surgical lung biopsy is the gold standard of diagnosis, but the diagnosis can be established in some cases by HRCT, provided the clinical features are consistent. The cause of IPF is unknown. However, IPF is more common in adults >60 years old, smokers (current or ex), and patients with specific occupational or noxious exposures. Familial IPF, associated with several distinct genetic mutations, accounts for 1.5–3% of cases. Unfortunately, the prognosis is poor, and most patients die of respiratory failure within 3–6 years of diagnosis. However, the course is highly variable. In some patients, the disease is fulminant, progressing to lethal respiratory failure within months, whereas the course may be indolent, spanning >5 years in some patients. Therapy has not been proven to alter the course of the disease or influence mortality, but recent studies with pirfenidone and tyrosine kinase inhibitors are promising. Lung transplantation is the best therapeutic option, but is limited to selected patients with severe, life-threatening disease and no contraindications to transplant.

[Radiological diagnostic approach to idiopathic interstitial pneumonias: findings in high resolution computed tomography]

A review is presented on the histological and radiological findings in idiopathic interstitial pneumonias, which are included among the diffuse parenchymal lung diseases. Although they may affect other compartments, the lung interstitium is the initial substrate of the parenchymal lesion due to different patterns of inflammation and fibrosis. The current classification, proposed in 2002 as an international multidisciplinary consensus document promoted by the American Thoracic Society and the European Respiratory Society, includes 7 conditions. Based on histological criteria, each histological pattern is associated with an image pattern. They are a group of conditions of unknown origin with common characteristics and differential features that enable them to be individualised as diseases with a different prognosis and treatment. They are rare as idiopathic forms, but share a morphological substrate with other more common diseases of unknown cause, which means they have to be excluded to reach a definitive diagnosis. For this reason it is important that the radiologist is familiar with their characteristic imaging findings.

An official ATS/ERS/JRS/ALAT statement: idiopathic pulmonary fibrosis: evidence-based guidelines for diagnosis and management

This document is an international evidence-based guideline on the diagnosis and management of idiopathic pulmonary fibrosis, and is a collaborative effort of the American Thoracic Society, the European Respiratory Society, the Japanese Respiratory Society, and the Latin American Thoracic Association. It represents the current state of knowledge regarding idiopathic pulmonary fibrosis (IPF), and contains sections on definition and epidemiology, risk factors, diagnosis, natural history, staging and prognosis, treatment, and monitoring disease course. For the diagnosis and treatment sections, pragmatic GRADE evidence-based methodology was applied in a question-based format. For each diagnosis and treatment question, the committee graded the quality of the evidence available (high, moderate, low, or very low), and made a recommendation (yes or no, strong or weak). Recommendations were based on majority vote. It is emphasized that clinicians must spend adequate time with patients to discuss patients' values and preferences and decide on the appropriate course of action.

Combined pulmonary fibrosis and emphysema syndrome in connective tissue disease

OBJECTIVE

Connective tissue diseases (CTDs) are associated with several interstitial lung diseases. The aim of this study was to describe the recently individualized syndrome of combined pulmonary fibrosis and emphysema (CPFE) in a population of patients with CTD.

METHODS

In this multicenter study, we retrospectively investigated data from patients with CTD who also have CPFE. The demographic characteristics of the patients, the results of pulmonary function testing, high-resolution computed tomography, lung biopsy, and treatment, and the outcomes of the patients were analyzed.

RESULTS

Data from 34 patients with CTD who were followed up for a mean±SD duration of 8.3±7.0 years were analyzed. Eighteen of the patients had rheumatoid arthritis (RA), 10 had systemic sclerosis (SSc), 4 had mixed or overlap CTD, and 2 had other CTDs. The mean±SD age of the patients was 57±11 years, 23 were men, and 30 were current or former smokers. High-resolution computed tomography revealed emphysema of the upper lung zones and pulmonary fibrosis of the lower zones in all patients, and all patients exhibited dyspnea during exercise. Moderately impaired pulmonary function test results and markedly reduced carbon monoxide transfer capacity were observed. Five patients with SSc exhibited pulmonary hypertension. Four patients died during followup. Patients with CTD and CPFE were significantly younger than an historical control group of patients with idiopathic CPFE and more frequently were female. In addition, patients with CTD and CPFE had higher lung volumes, lower diffusion capacity, higher pulmonary pressures, and more frequently were male than those with CTD and lung fibrosis without emphysema.

CONCLUSION

CPFE warrants inclusion as a novel, distinct pulmonary manifestation within the spectrum of CTD-associated lung diseases in smokers or former smokers, especially in patients with RA or SSc.

Lung disease related to collagen vascular disease

Collagen vascular disease is one of the most common causes of chronic infiltrative lung disease. Patterns of lung injury from collagen vascular disease include nonspecific interstitial pneumonia (NSIP), usual interstitial pneumonia, organizing pneumonia, bronchiectasis, obliterative bronchiolitis, and pulmonary arterial hypertension. The prevalence of each entity varies according to the specific disease entity. NSIP and pulmonary hypertension are common in scleroderma, whereas usual interstitial pneumonia, bronchiectasis, and obliterative bronchiolitis are commonly found in rheumatoid arthritis. In systemic lupus erythematosus, pleural effusions and pulmonary hemorrhage are the salient features. In polymyositis, a combination of organizing pneumonia and NSIP is characteristic. Sjögren syndrome is characterized by bronchiectasis and lymphoid interstitial pneumonia, often associated with thin-walled cysts. Ankylosing spondylitis is associated with upper lobe fibrosis, and may be complicated by mycetoma.