Discordance between general and pulmonary pathologists in the diagnosis of interstitial lung disease

Histopathological significance of connective tissue disease-associated interstitial lung disease in transbronchial lung cryobiopsy specimens

Differentiating between idiopathic interstitial pneumonia (IIP) and secondary interstitial pneumonia, particularly connective tissue disease-associated interstitial lung disease (CTD-ILD), can be challenging histopathologically, and there may be discrepancies among pathologists. While surgical lung biopsy has traditionally been considered the gold standard for diagnosing interstitial pneumonia, the usefulness of transbronchial lung cryobiopsy (TBLC) has been reported. If TBLC could effectively distinguish between primary and secondary diseases, it would provide a less invasive option for patients. The aim of this study was to identify specific pathologic findings in TBLC specimens that could assist in distinguishing CTD-ILD from IIP. A total of 93 underwent TBLC at Tenri Hospital between 2018 and 2022. We retrospectively reviewed cases of CTD-ILD exhibiting a nonspecific interstitial pneumonia (NSIP) pattern (CTD-NSIP) and cases of NSIP with an unknown etiology (NSIP-UE), as determined through multidisciplinary discussion. Nineteen patients with CTD-NSIP and 26 patients with NSIP-UE were included in the study for clinicopathological analysis. The CTD-NSIP group had a significantly higher proportion of female patients compared to the NSIP-UE group (79% vs. 31%; p = 0.002). The presence of both fresh and old intraluminal fibrosis within the same TBLC specimen was significantly more frequent in CTD-NSIP group than in the NSIP-UE group (p = 0.023). The presence of an NSIP pattern with co-existing fresh and old intraluminal fibrosis in TBLC specimens raised suspicion for CTD-ILD.

Care Delivery Models and Interstitial Lung Disease: The Role of the Specialized Center

Comprehensive interstitial lung disease (ILD) care delivery models have several key components including diagnosis, treatment, monitoring, coordination with other health care providers, patient support/advocacy, education, and research. ILD is rapidly evolving, and specialized centers with ILD-specific expertise have emerged as ways to care for complex patients. The role of the specialized center in care delivery is multifaceted and aimed at improving patient care and advancing the field of ILD. Widespread access to specialized centers is a barrier to ILD care delivery worldwide. Creative and innovative strategies that leverage technology are needed to bridge gaps in ILD care.

Utility of a Molecular Classifier as a Complement to High-Resolution Computed Tomography to Identify Usual Interstitial Pneumonia

Rationale: Usual interstitial pneumonia (UIP) is the defining morphology of idiopathic pulmonary fibrosis (IPF). Guidelines for IPF diagnosis conditionally recommend surgical lung biopsy for histopathology diagnosis of UIP when radiology and clinical context are not definitive. A "molecular diagnosis of UIP" in transbronchial lung biopsy, the Envisia Genomic Classifier, accurately predicted histopathologic UIP.Objectives: We evaluated the combined accuracy of the Envisia Genomic Classifier and local radiology in the detection of UIP pattern.Methods: Ninety-six patients who had diagnostic lung pathology as well as a transbronchial lung biopsy for molecular testing with Envisia Genomic Classifier were included in this analysis. The classifier results were scored against reference pathology. UIP identified on high-resolution computed tomography (HRCT) as documented by features in local radiologists' reports was compared with histopathology.Measurements and Main Results: In 96 patients, the Envisia Classifier achieved a specificity of 92.1% (confidence interval [CI],78.6-98.3%) and a sensitivity of 60.3% (CI, 46.6-73.0%) for histology-proven UIP pattern. Local radiologists identified UIP in 18 of 53 patients with UIP histopathology, with a sensitivity of 34.0% (CI, 21.5-48.3%) and a specificity of 96.9% (CI, 83.8-100%). In conjunction with HRCT patterns of UIP, the Envisia Classifier results identified 24 additional patients with UIP (sensitivity 79.2%; specificity 90.6%).Conclusions: In 96 patients with suspected interstitial lung disease, the Envisia Genomic Classifier identified UIP regardless of HRCT pattern. These results suggest that recognition of a UIP pattern by the Envisia Genomic Classifier combined with HRCT and clinical factors in a multidisciplinary discussion may assist clinicians in making an interstitial lung disease (especially IPF) diagnosis without the need for a surgical lung biopsy.

Histologic factors associated with nintedanib efficacy in patients with idiopathic pulmonary fibrosis

Background

Histopathologic factors predictive of nintedanib efficacy in idiopathic pulmonary fibrosis have not been studied. We aimed to describe the characteristics, focusing on histopathology, of idiopathic pulmonary fibrosis patients who did and did not respond to nintedanib.

Methods

This study retrospectively examined the clinicoradiopathologic features of 40 consecutive patients with surgical lung biopsy-confirmed idiopathic pulmonary fibrosis treated with nintedanib. Additionally, we compared the histopathologic scoring of 21 microscopic features between patients with functional or radiological progression and those with non-progression during 12 months of treatment.

Results

The histopathologic evaluation showed edematous changes in the interlobular septum as the only histologic finding observed more frequently in patients with both functional and radiological progression than in those without (58% vs. 14%, P = 0.007 and 50% vs. 0%, P = 0.003, respectively). Regarding per-year change, patients with edematous changes in the interlobular septum showed greater progression in median changes in spared area (-12%, interquartile range: [-25%–-5%], vs. -3% [-7%–0%], P = 0.004) and reticular shadow (7% [3%–13%], vs. 0% [0%–5%], P = 0.041) on computed tomography. Functional and radiological progression-free survival were shorter in patients with edematous changes in the interlobular septum than in those without (6.6 months, 95% confidence interval: [5.9–25.3], vs. event <50%, [12.1–Not available], P = 0.0009, and 6.1 months, [5.2–6.6] vs. 14.5 months [7.8–not available], P<0.0001).

Conclusions

Edematous changes in the interlobular septum may indicate poor nintedanib efficacy in idiopathic pulmonary fibrosis. Further studies are needed to validate these findings and address the mechanism behind ECIS.

Transbronchial Cryobiopsy in Interstitial Lung Diseases: State-of-the-Art Review for the Interventional Pulmonologist

Interstitial lung diseases are a heterogenous group of disorders that are often difficult to diagnose precisely. Clinical, laboratory, radiographic, and histologic information may be needed to arrive at the correct diagnosis. The multidisciplinary discussion has been proven to be useful in this patient group. Transbronchial cryobiopsy has become a popular method for obtaining tissue samples. Over the course of the last decade, there has been a significant amount of research assessing the feasibility, safety, and diagnostic endpoints of transbronchial cryobiopsy in patients with interstitial lung disease. Data continues to mount to support its use, which has been reflected in guidelines and expert panel reports. Patient selection, procedural performance, and appropriate specimen handling are critical factors for success. A coordinated approach by pulmonologists with expertise in interstitial lung diseases, interventional pulmonologists, and thoracic pathologists is essential. In this evidence-based narrative review, we address transbronchial cryobiopsies from these three distinct perspectives. In addition, the current literature was used to address nine common procedural questions.

Morphologic Aspects of Interstitial Pneumonia With Autoimmune Features

Context.—

Interstitial lung disease, a common complication observed in several connective tissue diseases, causes significant morbidity and mortality. Similar to individuals with connective tissue diseases, a significant subgroup of patients with clinical and serologic characteristics suggestive of autoimmunity but without confirmed specific connective tissue disease presents with associated interstitial lung disease. These patients have been classified using different controversial nomenclatures, such as undifferentiated connective tissue disease–associated interstitial lung disease, lung-dominant connective tissue disease, and autoimmune featured interstitial lung disease. The need for a better understanding and standardization of this entity, interstitial lung disease with autoimmune features, and the need for an adequate management protocol for patients resulted in the introduction of a new terminology in 2015: interstitial pneumonia with autoimmune features. This new classification requires a better comprehension of its diagnostic impact and the influence of its morphologic aspects on the prognosis of patients.

Objective.—

To review the diagnostic criteria for interstitial pneumonia with autoimmune features, with an emphasis on morphologic aspects.

Data Sources.—

The review is based on the available literature, and on pathologic, radiologic, and clinical experience.

Conclusions.—

The interstitial pneumonia with autoimmune features classification seems to identify a distinct subgroup of patients with different prognoses. Studies show that nonspecific interstitial pneumonia and usual interstitial pneumonia are the most prevalent morphologic patterns and show discrepant results on the impact of the usual interstitial pneumonia pattern on survival. Prospective investigations are necessary to better define this subgroup and to determine the prognosis and appropriate clinical management of these patients.

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.

Interobserver Agreement of Usual Interstitial Pneumonia Diagnosis Correlated With Patient Outcome

CONTEXT

- The histopathologic criteria for idiopathic pulmonary fibrosis were revised in the American Thoracic Society/European Respiratory Society/Japan Respiratory Society/Latin American Thoracic Association guidelines in 2011. However, the evidence of diagnosis based on the guidelines needs further investigation.

OBJECTIVE

- To examine whether the revised histopathologic criteria for idiopathic pulmonary fibrosis improved interobserver agreement among pathologists and the predicted prognosis in patients with interstitial pneumonia.

DESIGN

- Twenty, consecutive, surgical lung-biopsy specimens from cases of interstitial pneumonia were examined for histologic patterns by 11 pathologists without knowledge of clinical and radiologic data. Diagnosis was based on American Thoracic Society/European Respiratory Society guidelines of 2002 and 2011. Pathologists were grouped by cluster analysis, and interobserver agreement and association to the patient prognosis were compared with the diagnoses for each cluster.

RESULTS

- The generalized κ coefficient of diagnosis for all pathologists was 0.23. If the diagnoses were divided into 2 groups: usual interstitial pneumonia (UIP)/probable UIP (the UIP group) or possible/not UIP (the non-UIP group), according to the 2011 guidelines, the κ improved to 0.37. The pathologists were subdivided into 2 clusters in which 1 showed an association between UIP group diagnosis and patient prognosis (P < .05).

CONCLUSIONS

- Agreement about pathologic diagnosis of interstitial pneumonia is low; however, results after division into UIP and non-UIP groups provided favorable agreement. The cluster analysis revealed 1 of the 2 clusters providing high interobserver agreement and prediction of patient prognosis.

Usual interstitial pneumonia end-stage features from explants with radiologic and pathological correlations

Idiopathic pulmonary fibrosis (IPF) is the most frequent and severe idiopathic interstitial pneumonia, with typical high-resolution computed tomography (HRCT) features and histologic pattern of usual interstitial pneumonia (UIP); its main differential diagnosis is fibrotic nonspecific interstitial pneumonia (F-NSIP). Usual interstitial pneumonia was mainly described from lung biopsies, and little is known on explants. Twenty-two UIP/IPF explants were analyzed histologically and compared with previous open lung biopsies (OLBs; n = 11) and HRCT (n = 19), when available. Temporospatial heterogeneity and subpleural and paraseptal fibrosis were similarly found in UIP/IPF explants and OLB (91%-95%). Fibroblastic foci were found in 82% of OLBs and 100% of explants, with a higher mean score in explants (P = .023). Honeycombing was present in 64% of OLBs and 95% of explants, with a higher mean score in explants (P = .005). Almost 60% of UIP/IPF explants showed NSIP areas and 41% peribronchiolar fibrosis; inflammation, bronchiolar metaplasia, and vascular changes were more frequent in UIP/IPF explants; and Desquamative Interstitial Pneumonia (DIP)-like areas were not common (18%-27%). Numerous large airspace enlargements with fibrosis were frequent in UIP/IPF explants (59%). On HRCT, honeycombing was observed in 95% of the cases and ground-glass opacities in 53%, correlating with NSIP areas or acute exacerbation at histology. Six patients had combined IPF and emphysema. Lesions were more severe in UIP/IPF explants, reflecting the worsening of the disease. Usual interstitial pneumonia/IPF explants more frequently presented with confounding lesions such as NSIP areas, peribronchiolar fibrosis, and airspace enlargements with fibrosis sometimes associated with emphysema.

Idiopathic pulmonary fibrosis: an update

Idiopathic pulmonary fibrosis (IPF) is the most common and lethal form of idiopathic interstitial pneumonia. The disease, which occurs primarily in middle-aged and older adults, is thought to arise following an aberrant reparative response to alveolar epithelial cell injury characterized by secretion of excessive amounts of extracellular matrix components, resulting in scarring of the lung, architectural distortion, and irreversible loss of function. A complex interplay between environmental and host factors is thought to contribute to the development of the disease, although the cause of IPF remains elusive and its pathogenesis incompletely understood. Over the last decade, disease definition and diagnostic criteria have evolved significantly, and this has facilitated the design of a number of high-quality clinical trials evaluating novel therapeutic agents for IPF. This massive effort of the medical and industry community has led to the identification of two compounds (pirfenidone and nintedanib) able to reduce functional decline and disease progression. These promising results notwithstanding, IPF remains a major cause of morbidity and mortality and a largely unmet medical need. A real cure for this devastating disease has yet to emerge and will likely consist of a combination of drugs targeting the plethora of pathways potentially involved in disease pathogenesis.

Diagnostic approach to interstitial pneumonias in a single centre: report on 88 cases

Background

Interstitial pneumonias (IP) cover a broad spectrum of diseases. Open lung biopsies reveal histological patterns and suggest possible diagnoses. Complete clinical records are necessary for final diagnoses. Especially idiopathic interstitial pneumonias (IIP) according to the ATS/ERS classification can only be diagnosed under these predictions. The aim of this study was to compare the results of histological evaluations with the final diagnosis after interdisciplinary case evaluation.

Patients and methods

88 patients with interstitial pneumonia that underwent open lung biopsies were investigated. Histology and clinical records were available for review. Diagnosis was made in three steps: first on the sole basis of histology, second with clinical information given initially and third, on the basis of an interdisciplinary case evaluation.

Results

63 patients (72%) were diagnosed as idiopathic interstitial pneumonias according to ATS/ERS criteria. Further 10 (11%) cases of hypersensitivity pneumonitis, 7 (8%) Langerhans cell histiocytosis and 8 (9%) interstitial pneumonias of other known causes or associations were detected. Histological patterns alone agreed with the final diagnosis in 67%. In 82% histology and clinical information given to the pathologist could provide correct diagnosis. In the rest of cases, especially in non idiopathic interstitial pneumonias, an interdisciplinary case evaluation was needed.

Conclusions

Diagnosis of interstitial pneumonias by open lung biopsies needs sufficient clinical information. Because of the overlap of histological patterns, an interdisciplinary case evaluation that includes at least one clinical expert and one pathologist with excellent expertise and the follow-up of the patients is necessary to find correct diagnosis in all cases.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5031706258025129

Integrating pathology and radiology disciplines: an emerging opportunity?

Pathology and radiology form the core of cancer diagnosis, yet the workflows of both specialties remain ad hoc and occur in separate "silos," with no direct linkage between their case accessioning and/or reporting systems, even when both departments belong to the same host institution. Because both radiologists' and pathologists' data are essential to making correct diagnoses and appropriate patient management and treatment decisions, this isolation of radiology and pathology workflows can be detrimental to the quality and outcomes of patient care. These detrimental effects underscore the need for pathology and radiology workflow integration and for systems that facilitate the synthesis of all data produced by both specialties. With the enormous technological advances currently occurring in both fields, the opportunity has emerged to develop an integrated diagnostic reporting system that supports both specialties and, therefore, improves the overall quality of patient care.

Diagnostic accuracy of computed tomography and histopathology in the diagnosis of usual interstitial pneumonia

BACKGROUND

The relative clinical benefit of histopathology and computed tomography (CT) in patients with idiopathic interstitial pneumonia (IIP) is under debate.

PURPOSE

To analyze thin-section CT features and histopathologic findings in patients with usual interstitial pneumonia (UIP) in the clinical context of idiopathic pulmonary fibrosis (IPF), and to evaluate and compare diagnostic accuracy of the two methods among patients with an appropriate spectrum of IIP.

MATERIAL AND METHODS

The study included 91 patients (49 men; mean age 53.2 years; median follow-up 7.2 years) with clinically suspected interstitial lung disease. All underwent surgical lung biopsy and thin-section CT. Two independent readers retrospectively assessed the CT images for the extent and pattern of abnormality and made a first-choice diagnosis. Two pathologists retrospectively assessed the histopathologic slides. In 64 patients with IIP, a retrospective composite reference standard identified 41 patients with UIP. CT characteristics of UIP and IIPs other than UIP were compared with univariate and multivariate analyses.

RESULTS

There was good agreement between the readers for the correct first-choice CT diagnosis of UIP (κ = 0.79). The sensitivity, specificity, and positive predictive value of the CT diagnosis of UIP were 63%, 96%, and 96%, respectively. The sensitivity, specificity, and positive predictive value of the histological diagnosis of UIP were 73%, 74%, and 83%, respectively. The CT feature that best differentiated UIP from IIPs other than UIP was the extent of reticular pattern (odds ratio, 5.1).

CONCLUSION

Surgical lung biopsy may not be warranted in patients with thin-section CT diagnosis of UIP.

One hundred consecutive granulomas in a pulmonary pathology consultation practice

Lung biopsies showing granulomatous disease are commonly sent for expert pathology consultation. On the basis of features we and others have identified, an algorithmic approach to diagnosis of these cases was developed. We hypothesized that applying this approach would increase the likelihood of rendering a more specific diagnosis, or by rendering either a narrower or broader differential diagnosis, offer a more clinically useful diagnosis. One hundred consecutive lung biopsies from patients with granulomatous and giant cell reactions were retrieved from our consultation files. Cases were categorized into those in which a confident diagnosis was made at sign out, ones in which a specific diagnosis was strongly favored, and those in which a differential diagnosis was suggested. One year later follow-up information was obtained and consultation diagnoses were compared with clinical diagnoses to determine the reliability of the approach. A confident diagnosis was rendered in 27 cases, a specific diagnosis was strongly favored in 34, and in 39 a differential diagnosis was provided. Consultant diagnoses were more specific in 47 of 75 (63 %) cases. In 15 cases, the differential diagnosis was expanded. The most common unrecognized diagnosis was aspiration pneumonia and the most common diagnosis omitted from the differential diagnosis by the primary pathologist was hypersensitivity pneumonia. Follow-up in 49% of cases in which it was sought, confirmed the consultant's diagnosis or was inconclusive in 97% of cases. The use of a standardized algorithmic approach to the interpretation of granulomatous disease in lung biopsies yields more specific and clinically useful diagnoses for consideration.

The role of histology in idiopathic pulmonary fibrosis: an update

The diagnosis of idiopathic pulmonary fibrosis (IPF) currently requires an integrated clinical-radiological-pathological approach in which the histology plays a different role from in the past. The first reason for this change is that non-invasive diagnostic procedures, particularly pulmonary function tests and high resolution computed tomography, have become increasingly competitive with biopsy in providing prognostic information. The other reason is a better appreciation of the limitations of histology: sampling error and interobserver variation. In this review we analyze the reasons for this change of perspective, provide an update on the practical role of histology in the diagnosis of IPF and discuss some of its complications.

Treating IPF--all or nothing? A PRO-CON debate

The Idiopathic Pulmonary Fibrosis (IPF) is a progressive fibrotic lung disease with poor prognosis. It is distinct from other idiopathic interstitial pneumonias by its histopathological pattern of usual interstitial pneumonia which is characterized by accumulation of fibroblasts, extracellular matrix and honeycombing. Inflammation is only scarce in true IPF. The use of anti-inflammatory therapy is still part of guidelines for IPF management, although not specifically recommended, because convincing evidence showing beneficial effects of this approach is lacking. This review provides a summary of important arguments PRO and CON using anti-inflammatory and anti-oxidant therapy for patients with IPF in form of a debate with a concluding statement of both positions at the end.

Beyond a consensus classification for idiopathic interstitial pneumonias: progress and controversies

Histopathological classification schemes provide the underpinnings for separating idiopathic interstitial pneumonias into clinically meaningful groups. An interdisciplinary classification system based on a combination of evidence and expert opinion was published in 2002 and set the stage for controversy in several areas, including not only nomenclature but also the role of surgical lung biopsy and pathologists in diagnosis. We provide a brief overview of the clinical and histological features of the idiopathic interstitial pneumonias, and focus on selected topics of interest that have emerged in recent years.

Diagnosis of usual interstitial pneumonia and distinction from other fibrosing interstitial lung diseases

Usual interstitial pneumonia is an almost uniformly fatal form of fibrosing interstitial lung disease. It is the most common idiopathic interstitial pneumonia, and currently, there is no effective therapy. Lung biopsy is often needed for diagnosis, and pathologists must be able to recognize its features and distinguish it from other interstitial lung diseases that have a better prognosis and a more favorable response to therapy. This review is an attempt to clarify the diagnostic pathologic features of usual interstitial pneumonia and to provide guidelines for its distinction from other interstitial lung diseases that enter the differential diagnosis.

Prognostic determinants among clinical, thin-section CT, and histopathologic findings for fibrotic idiopathic interstitial pneumonias: tertiary hospital study

PURPOSE

To evaluate the utility of clinical, thin-section computed tomography (CT), and histopathologic findings in predicting the prognosis of patients with usual interstitial pneumonia (UIP) or fibrotic nonspecific interstitial pneumonia (NSIP).

MATERIALS AND METHODS

The institutional review board approved this retrospective study, with waiver of informed consent. Included were 108 patients (71 men, 37 women; mean age, 61 years +/- 8 [standard deviation]) with UIP (n = 79; 60 men, 19 women; mean age, 63 years +/- 7.4) and fibrotic NSIP (n = 29; 11 men, 18 women; mean age, 57 years +/- 12.9). Patients underwent pulmonary function tests (PFTs), bronchoalveolar lavage (BAL) fluid analysis, and thin-section CT. Two chest radiologists independently assigned scores for the extent of lung abnormalities detected at CT twice at 3-month intervals. The effect of histopathologic diagnoses and clinical and thin-section CT features on survival was evaluated by using Cox regression analyses.

RESULTS

The 5-year survival rate (mean follow-up, 45 months) of patients with fibrotic NSIP was 76% in contrast to 46% for patients with UIP (P = .006). With multivariate analysis, a high fibrotic score (the extent of reticulation plus honeycombing) (hazard ratio = 1.200, P = .043) and an initial low diffusing capacity of lung for carbon monoxide (Dlco) level (hazard ratio = 0.973, P = .025) were identified as associated with increased death risk.

CONCLUSION

Patients with UIP or fibrotic NSIP who have a high fibrotic score determined at thin-section CT and a low Dlco level appear to have a high death risk.

Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a non-neoplastic pulmonary disease that is characterized by the formation of scar tissue within the lungs in the absence of any known provocation. IPF is a rare disease which affects approximately 5 million persons worldwide. The prevalence is estimated to be slightly greater in men (20.2/100,000) than in women (13.2/100,000). The mean age at presentation is 66 years. IPF initially manifests with symptoms of exercise-induced breathless and dry coughing. Auscultation of the lungs reveals early inspiratory crackles, predominantly located in the lower posterior lung zones upon physical exam. Clubbing is found in approximately 50% of IPF patients. Cor pulmonale develops in association with end-stage disease. In that case, classic signs of right heart failure may be present. Etiology remains incompletely understood. Some environmental factors may be associated with IPF (cigarette smoking, exposure to silica and livestock). IPF is recognized on high-resolution computed tomography by peripheral, subpleural lower lobe reticular opacities in association with subpleural honeycomb changes. IPF is associated with a pathological lesion known as usual interstitial pneumonia (UIP). The UIP pattern consists of normal lung alternating with patches of dense fibrosis, taking the form of collagen sheets. The diagnosis of IPF requires correlation of the clinical setting with radiographic images and a lung biopsy. In the absence of lung biopsy, the diagnosis of IPF can be made by defined clinical criteria that were published in guidelines endorsed by several professional societies. Differential diagnosis includes other idiopathic interstitial pneumonia, connective tissue diseases (systemic sclerosis, polymyositis, rheumatoid arthritis), forme fruste of autoimmune disorders, chronic hypersensitivity pneumonitis and other environmental (sometimes occupational) exposures. IPF is typically progressive and leads to significant disability. The median survival is 2 to 5 years from the time of diagnosis. Medical therapy is ineffective in the treatment of IPF. New molecular therapeutic targets have been identified and several clinical trials are investigating the efficacy of novel medication. Meanwhile, pulmonary transplantation remains a viable option for patients with IPF. It is expected that, during the next decade, considerable progress will be made toward the understanding and treatment of this devastating illness.

Recent advances in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) remains the most common of the idiopathic interstitial pneumonias and portends a poor prognosis. Significant strides have been made in the approach to diagnosis and in the ability to predict outcome in the last few years. Advances in high-resolution CT (HRCT) scanning have allowed an accurate diagnosis obviating the need for surgical biopsy in many patients. Furthermore, HRCT scanning may aid in determining prognosis and identifying disease progression. The appropriate use of the HRCT scan requires a multidisciplinary iterative approach incorporating all available data to reach a final diagnosis. However, there remains great heterogeneity in disease progression. Pulmonary hypertension and acute exacerbations of IPF negatively influence prognosis and are increasingly a target of therapy. There has been an increase in the number of well-designed clinical trials of IPF that have focused on more specific targets. While no cure has yet been found, each trial expands our understanding regarding the natural course of the disease and the impact of targeted therapy. In the interim, lung transplantation, which appears to improve survival in a subset of IPF patients, remains the only intervention. The objective of this article is to review advances in the understanding of IPF and the evidence for the findings outlined above.

Is there a uniform approach to the management of diffuse parenchymal lung disease (DPLD) in the UK? A national benchmarking exercise

Background

Benchmarking is the comparison of a process to the work or results of others. We conducted a national benchmarking exercise to determine how UK pulmonologists manage common clinical scenarios in diffuse parenchymal lung disease (DPLD), and to determine current use and availability of investigative resources. We compared management decisions to existing international guidelines.

Methods

Consultant members of the British Thoracic Society were mailed a questionnaire seeking their views on the management of three common scenarios in DPLD. They were asked to choose from various management options for each case. Information was also obtained from the respondents on time served as a consultant, type of institution in which they worked and the availability of a local radiologist and histopathologist with an interest/expertise in thoracic medicine.

Results

370 out of 689 consultants replied (54% response rate). There were many differences in the approach to the management of all three cases. Given a scenario of relapsing pulmonary sarcoidosis in a lady with multiple co-morbidities, half of respondents would institute treatment with a variety of immunosuppressants while a half would simply observe. 42% would refer a 57-year old lady with new onset DPLD for a surgical lung biopsy, while a similar number would not. 80% would have referred her for transplantation, but a fifth would not. 50% of consultants from district general hospitals would have opted for a surgical biopsy compared to 24% from cardiothoracic centres: this may reflect greater availability of a radiologist with special interest in thoracic imaging in cardiothoracic centres, obviating the need for tissue diagnosis. Faced with an elderly male with high resolution CT thorax (HRCT) evidence of usual interstitial pneumonia (UIP), three quarters would observe, while a quarter would start immunosuppressants. 11% would refer for a surgical biopsy. 14% of UK pulmonologists responding to the survey revealed they had no access to a radiologist with an interest in thoracic radiology.

Conclusion

From our survey, it appears there is a lack of consensus in the management of DPLD. This may reflect lack of evidence, lack of resources or a failure to implement current guidelines.

Clinical review: Idiopathic pulmonary fibrosis—Past, present and future

Idiopathic pulmonary fibrosis (IPF) is an important, and devastating, interstitial lung disease. It has a median mortality of only 3 years, worse than many cancers, and its incidence continues to rise. In this article, an overview of key developments in our understanding and clinical management of IPF will be provided.

The distance-saturation product predicts mortality in idiopathic pulmonary fibrosis

INTRODUCTION

The 6-min walk test (6MWT) has prognostic value in various pulmonary disorders including idiopathic pulmonary fibrosis (IPF). We determined the individual prognostic accuracy of distance walked and oxygen saturation during the 6MWT in patients with IPF. We defined a new composite index, the distance-saturation product (DSP), which is the product of distance walked and lowest oxygen saturation during the 6-min walk test. We compared the performance of the DSP to the individual 6MWT parameters in predicting mortality.

METHODS

We evaluated pulmonary function tests, 6-min walk parameters and the DSP between survivors and non-survivors. The ability of each measure to discriminate outcomes was determined by receiver operator curves.

RESULTS

81 patients (48 survivors, 33 non-survivors) were included. Pulmonary function tests were similar and did not correlate with survival. Desaturation was greater (89.4% versus 83.7%, P<0.001) and distance walked was lower (406.9 versus 181.3m, P = 0.005) in non-survivors. The DSP was significantly lower among non-survivors (364.8 versus 153.5m%, P < 0.001) and predicted mortality more accurately than either individual 6MWT component (P = 0.035 versus desaturation, P=0.040 versus distance). A DSP <200 m% was associated with a seven-fold greater risk of 12-month mortality and an 18.0% shorter median survival compared with a DSP > 200 m% (P < 0.001).

DISCUSSION

Each component of the 6-min walk independently predicted mortality in IPF with greater accuracy than spirometry. However, a composite of both parameters, the DSP, provides slightly greater accuracy and represents a novel measure for assessing survival in patients with IPF.