Organizing pneumonia/non-specific interstitial pneumonia overlap is associated with unfavorable lung disease progression

HRCT findings predict 1-year mortality in patients with acute exacerbation of idiopathic inflammatory myopathies-associated interstitial lung disease

Background

Acute exacerbation of idiopathic inflammatory myopathies-associated interstitial lung disease (AE-IIM-ILD) is a significant event associated with increased morbidity and mortality. However, few studies investigated the potential prognostic factors contributing to mortality in patients who experience AE-IIM-ILD.

Objectives

The purpose of our study was to comprehensively investigate whether high-resolution computed tomography (HRCT) findings predict the 1-year mortality in patients who experience AE-IIM-ILD.

Methods

A cohort of 69 patients with AE-IIM-ILD was retrospectively created. The cohort was 79.7 % female, with a mean age of 50.7. Several HRCT features, including total interstitial lung disease extent (TIDE), distribution patterns, and radiologic ILD patterns, were assessed. A directed acyclic graph (DAG) was used to evaluate the statistical relationship between variables. The Cox regression method was performed to identify potential prognostic factors associated with mortality.

Results

The HRCT findings significantly associated with AE-IIM-ILD mortality include TIDE (HR per 10%-increase, 1.64; 95%CI, 1.29-2.1, p < 0.001; model 1: C-index, 0.785), diffuse distribution pattern (HR, 3.75, 95%CI, 1.5-9.38, p = 0.005; model 2: C-index, 0.737), and radiologic diffuse alveolar damage (DAD) pattern (HR, 6.37, 95 % CI, 0.81-50.21, p = 0.079; model 3: C-index, 0.735). TIDE greater than 58.33 %, diffuse distribution pattern, and radiologic DAD pattern correlate with poor prognosis. The 90-day, 180-day, and 1-year survival rates of patients who experience AE-IIM-ILD were 75.3 %, 66.3 %, and 63.3 %, respectively.

Conclusion

HRCT findings, including TIDE, distribution pattern, and radiological pattern, are predictive of 1-year mortality in patients who experience AE-IIM-ILD.

Imaging of the Spectrum of Acute Lung Injury

Organizing pneumonia, acute fibrinous and organizing pneumonia, and diffuse alveolar damage, represent multi-compartment patterns of lung injury. The initial region of injury in all remains the same and is centered on the fused basement membrane (BM) between the capillary endothelium and type I pneumocyte. Injury leads to cellular death, BM denudation, increased cellular permeability, and BM structural damage, which leads to exudation, organization, and attempts at repair. When acute lung injury does lead to fibrosis, in some instances it can lead to histologic and/or radiologic usual interstitial pneumonia or nonspecific interstital pneumonia patterns suggesting that lung injury is the primary mechanism for the development of fibrosis.

Relationship between idiopathic interstitial pneumonias (IIPs) and connective tissue disease-related interstitial lung disease (CTD-ILD): A narrative review

While idiopathic interstitial pneumonia (IIP) centering on idiopathic pulmonary fibrosis (IPF) is the most prevalent interstitial lung disease (ILD), especially in the older adult population, connective tissue disease (CTD)-related ILD is the second most prevalent ILD. The pathogenesis of IPF is primarily fibrosis, whereas that of other ILDs, particularly CTD-ILD, is mainly inflammation. Therefore, a precise diagnosis is crucial for selecting appropriate treatments, such as antifibrotic or immunosuppressive agents. In addition, some patients with IIP have CTD-related features, such as arthritis and skin eruption, but do not meet the criteria for any CTD, this is referred to as interstitial pneumonia with autoimmune features (IPAF). IPAF is closely associated with idiopathic nonspecific interstitial pneumonia (iNSIP) and cryptogenic organizing pneumonia (COP). Furthermore, patients with iNSIP or those with NSIP with OP overlap frequently develop polymyositis/dermatomyositis after the diagnosis of IIP. Acute exacerbation of ILD, the most common cause of death, occurs more frequently in patients with IPF than in those with other ILDs. Although acute exacerbation of CTD-ILD occurs at a low rate of incidence, patients with rheumatoid arthritis, microscopic polyangiitis, or systemic sclerosis experience more acute exacerbation of CTD-ILD than those with other CTD. In this review, the features of each IIP, focusing on CTD-related signatures, are summarized, and the pathogenesis and appropriate treatments to improve the prognoses of patients with various ILDs are discussed.

Multidisciplinary Approach to the Diagnosis of Idiopathic Interstitial Pneumonias: Focus on the Pathologist's Key Role

Idiopathic Interstitial Pneumonias (IIPs) are a heterogeneous group of the broader category of Interstitial Lung Diseases (ILDs), pathologically characterized by the distortion of lung parenchyma by interstitial inflammation and/or fibrosis. The American Thoracic Society (ATS)/European Respiratory Society (ERS) international multidisciplinary consensus classification of the IIPs was published in 2002 and then updated in 2013, with the authors emphasizing the need for a multidisciplinary approach to the diagnosis of IIPs. The histological evaluation of IIPs is challenging, and different types of IIPs are classically associated with specific histopathological patterns. However, morphological overlaps can be observed, and the same histopathological features can be seen in totally different clinical settings. Therefore, the pathologist's aim is to recognize the pathologic-morphologic pattern of disease in this clinical setting, and only after multi-disciplinary evaluation, if there is concordance between clinical and radiological findings, a definitive diagnosis of specific IIP can be established, allowing the optimal clinical-therapeutic management of the patient.

Clinical features of relapsed connective tissue disease-associated organizing pneumonia

BACKGROUND

Organizing pneumonia (OP) is recognized as a nonspecific lung injury response characterized histopathologically by the presence of intra-alveolar buds of granulation tissue. Most OP patients show excellent responses to corticosteroids, but relapse is frequently seen when corticosteroids are tapered or discontinued. Although several factors associated with relapse have been reported in cryptogenic OP (COP), the clinical features and risk factors associated with relapse in connective tissue disease-associated OP (CTD-OP) have yet to be fully understood.

METHODS

We retrospectively reviewed data on 47 CTD-OP patients. We investigated the frequency of relapse and compared the clinical data between CTD-OP with and without relapse to clarify the risk factors for relapse.

RESULTS

Eleven (23.4%) CTD-OP patients had relapses of OP during the study. In the multivariate analysis, no CTD treatment at OP diagnosis [O.R. 11.920, p = 0.012] and partial remission after steroid treatment [O.R. 35.944, p = 0.045] were independent risk factors for relapse. Among rheumatoid arthritis-associated OP (RA-OP) patients, partial remission after steroid treatment [O.R. 16.151, p = 0.047] and age at OP diagnosis [O.R. 0.899, p = 0.045] were independent risk factors for relapse. Most of the relapsed OP patients who were on no medication at OP diagnosis later developed CTD.

CONCLUSION

CTD-OP patients with residual disease on HRCT after treatment and who had OP diagnosis preceding CTD diagnosis were more likely to have an OP relapse. During the clinical course of relapsed OP patients, it is necessary to pay attention to the onset of CTD.

Variable radiographic and histologic presentations of amiodarone-related interstitial lung disease and the importance of avoiding re-exposure

Amiodarone is a commonly used antiarrhythmic agent but exhibits potential pulmonary toxicity. In this case series, we describe the clinical, radiographic, and histologic manifestations of three patients who developed interstitial lung disease (ILD) following amiodarone treatment for variable lengths of time with different dosages. The presentations on computed tomographic images and in pulmonary pathology differed among the three patients. All three had immediate discontinuation of amiodarone and received treatment with systemic corticosteroids. One patient eventually died from ventilator-associated pneumonia after an initial improvement. The other two patients recovered well but later experienced ILD recurrence following brief re-exposure to amiodarone. Through this case series, we aim to demonstrate the variable features of amiodarone-related ILD, and highlight the importance of timely amiodarone cessation and avoiding re-exposure to prevent the progression and recurrence of ILD.

Update on cryptogenic organizing pneumonia

Cryptogenic organizing pneumonia (COP) is a form of idiopathic interstitial pneumonia that results from the pulmonary reaction to various unidentified injuries. Secondary organizing pneumonia is diagnosed when the triggering factor has been identified; it is mainly caused by infections, toxic substance exposure, drugs, connective tissue diseases, malignancies, autoimmune diseases, bone marrow, or organ transplantation, and radiotherapy. There has been an increase in the number of reports of drug-induced organizing pneumonia (OP). New biological therapies, interferon, monoclonal antibodies, anti-interleukin antibodies, and PD1/PDL-1 inhibitors may induce this specific pulmonary reaction. The classical form of COP is usually subacute and does not manifest as severe disease. Patients maintain sufficient respiratory function, and treatment with steroids is usually effective. Several specific forms of OP (e.g., the cicatricial variant or acute fibrinous type) have distinct clinical and histological features, require higher doses of immunosuppressive drugs, and have a worse prognosis. In the era of administering steroid-sparing therapies for the treatment of interstitial lung diseases, connective tissue dases, and other conditions, it is important to emphasize this type of therapy for patients with COP.

Organizing pneumonia

Organizing pneumonia is a nonspecific pathologic pattern of response to lung damage. It can be idiopathic, or it can occur secondary to various medical processes, most commonly infections, connective tissue disease, and pharmacological toxicity. Although there is no strict definition of the pattern of organising pneumonia as in other idiopathic interstitial pneumonias, the characteristic pattern of this disease could be considered to include patchy consolidations and ground-glass opacities in the peribronchial and subpleural areas of both lungs. Moreover, studies of the course of the disease show that these lesions respond to treatment with corticoids, migrate with or without treatment, and tend to recur when treatment is decreased or withdrawn. Other manifestations of organising pneumonia include nodules of different sizes and shapes, solitary masses, nodules with the reverse halo sign, a perilobular pattern, and parenchymal bands.

Nonspecific interstitial pneumonia revealing an antisynthetase syndrome

One of the most common interstitial lung diseases in antisynthetase syndrome is nonspecific interstitial pneumonia (NSIP). A 49-year-old woman presented with slow progression exertional dyspnea, myalgia, and arthralgia. The radiological findings indicated an NSIP pattern. Autoantibodies were found to be positive, but no lung biopsy was performed. Even though corticosteroid therapy significantly improved the patient's dyspnea, the patient developed mechanic's hands, the anti-synthetase antibody (PL12) became positive, and creatine phosphokinase (CPK) levels increased. As a result, the antisynthetase syndrome was established. The patient follow-up after three years revealed an improvement in symptoms under corticosteroid therapy.

Algorithmic Approach to the Diagnosis of Organizing Pneumonia: A Correlation of Clinical, Radiologic, and Pathologic Features

Organizing pneumonia (OP), characterized histopathologically by patchy filling of alveoli and bronchioles by loose plugs of connective tissue, may be seen in a variety of conditions. These include but are not limited to after an infection, drug reactions, radiation therapy, and collagen vascular diseases. When a specific cause is responsible for this entity, it is referred to as "secondary OP." When an extensive search fails to reveal a cause, it is referred to as "cryptogenic OP" (previously called "bronchiolitis obliterans with OP"), which is a clinical, radiologic, and pathologic entity classified as an interstitial lung disease. The clinical presentation of OP often mimics that of other disorders, such as infection and cancer, which can result in a delay in diagnosis and inappropriate management of the underlying disease. The radiographic presentation of OP is polymorphous but often has subpleural consolidations with air bronchograms or solitary or multiple nodules, which can wax and wane. Diagnosis of OP sometimes requires histopathologic confirmation and exclusion of other possible causes. Treatment usually requires a prolonged steroid course, and disease relapse is common. The aim of this article is to summarize the clinical, radiographic, and histologic presentations of this disease and to provide a practical diagnostic algorithmic approach incorporating clinical history and characteristic imaging patterns.

Demystifying idiopathic interstitial pneumonia: time for more etiology-focused nomenclature in interstitial lung disease

INTRODUCTION

A major focus of interstitial lung disease (ILD) has centered on disorders termed idiopathic interstitial pneumonias (IIPs) which include, among others, idiopathic pulmonary fibrosis, idiopathic nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, and respiratory bronchiolitis-interstitial lung disease.

AREAS COVERED

We review the radiologic and histologic patterns for the nine disorders classified by multidisciplinary approach as IIP, and describe the remarkable amount of published epidemiologic, translational, and molecular studies demonstrating their associations with numerous yet definitive environmental exposures, occupational exposures, pulmonary diseases, systemic diseases, medication toxicities, and genetic variants.

EXPERT OPINION

In the 21st century, these disorders termed IIPs are rarely idiopathic, but rather are well-described radiologic and histologic patterns of lung injury that are associated with a wide array of diverse etiologies. Accordingly, the idiopathic nomenclature is misleading and confusing, and may also promote a lack of inquisitiveness, suggesting the end rather than the beginning of a thorough diagnostic process to identify ILD etiology and initiate patient-centered management. A shift toward more etiology-focused nomenclature will be beneficial to all, including patients hoping for better life quality and disease outcome, general medicine and pulmonary physicians furthering their ILD knowledge, and expert ILD clinicians and researchers who are advancing the ILD field.

Cigarette Smoke Particle-Induced Lung Injury and Iron Homeostasis

It is proposed that the mechanistic basis for non-neoplastic lung injury with cigarette smoking is a disruption of iron homeostasis in cells after exposure to cigarette smoke particle (CSP). Following the complexation and sequestration of intracellular iron by CSP, the host response (eg, inflammation, mucus production, and fibrosis) attempts to reverse a functional metal deficiency. Clinical manifestations of this response can present as respiratory bronchiolitis, desquamative interstitial pneumonitis, pulmonary Langerhans’ cell histiocytosis, asthma, pulmonary hypertension, chronic bronchitis, and pulmonary fibrosis. If the response is unsuccessful, the functional deficiency of iron progresses to irreversible cell death evident in emphysema and bronchiectasis. The subsequent clinical and pathological presentation is a continuum of lung injuries, which overlap and coexist with one another. Designating these non-neoplastic lung injuries after smoking as distinct disease processes fails to recognize shared relationships to each other and ultimately to CSP, as well as the common mechanistic pathway (ie, disruption of iron homeostasis).

GAP Score and CA-153 Associated with One-Year Mortality in Anti-MDA-5 Antibody-Positive Patients: A Real-World Experience

Background. Anti-melanoma differentiation-associated gene 5 (MDA-5) antibody is associated with respiratory failure and death in patients with idiopathic inflammatory myositis (IIM) and interstitial lung disease (ILD). This study aimed to investigate clinical parameters associated with mortality in anti-MDA-5 antibody-positive patients. Methods. We retrospectively reviewed the clinical and laboratory data, and pulmonary function test results in 55 anti-MDA-5 antibody-positive patients. A comparison was made between the survivors and non-survivors at the 12-month follow-up. Results. A total of 13 patients (23.6%) died within 12 months. Non-survivors had higher GAP scores (gender, age, and physiology score for idiopathic pulmonary fibrosis) (1 vs. 6, p < 0.01) and CA-153 (16.4 vs. 72.9, p < 0.01). In addition, rapid progressive ILD, fever, peak ferritin, leukocyte count, lactate dehydrogenase, CT score, intravenous immunoglobulin, mycophenolic acid, CMV infections, pneumocystis pneumonia, and pneumothorax were significantly associated with increased risks of 1-year mortality, while forced vital capacity, forced expiratory volume in one second, and diffusion capacity for carbon monoxide were correlated with decreased risk of 1-year mortality. Conclusions. Our study results suggest that GAP scores and CA-153 could be prognostic factors for 1-year mortality in anti-MDA-5 antibody-positive patients. A prompt pulmonary function test and CA-153 are essential for these patients to guide further management.

Cryptogenic organising pneumonia: current understanding of an enigmatic lung disease

Organising pneumonia (OP) is currently recognised as a nonspecific lung injury response that is associated with a variety of imaging patterns obtained with high-resolution computed tomography (HRCT) of the chest and is characterised histopathologically by the presence of inflammatory cells and a connective tissue matrix within distal airspaces of the lungs. OP is associated with many conditions that include connective tissue disorders, various infections, drug reactions, hypersensitivity pneumonitis and aspiration. When OP cannot be linked to an associated condition and appears to be idiopathic, it is termed cryptogenic organising pneumonia.

[Cryptogenic organizing pneumonia versus secondary organizing pneumonia]

Die organisierende Pneumonie (OP) beschreibt ein histologisches Muster des akuten bzw. subakuten Lungenschadens. Klinisch fallen die Patienten mit Husten, Fieber und Dyspnoe auf. Es wird zwischen der idiopathischen bzw. kryptogen organisierenden (COP) und der sekundären organisierenden Pneumonie (OP) unterschieden. Bei der COP kann weder klinisch/radiologisch noch histologisch eine Ursache bestimmt werden. Sie wird zu den interstitiellen idiopathischen Pneumonien (IIP) gezählt nach Kriterien der American Thoracic Society (ATS) und der European Respiratory Society (ERS). Bei der sekundären organisierenden Pneumonie liegt ein bekannter auslösender Mechanismus vor, wie z. B. infektiöse Erreger, bestimmte Medikamente oder auch Begleiterscheinungen anderer primär pulmonaler Erkrankungen und Erkrankungen anderer Organsysteme. Beiden Formen gemeinsam ist das histologische Bild der intraalveolären Mesenchymknospen. Diese sind Myofibroblastenproliferate, welche sich zopfartig entlang der Alveolarräume verzweigen. Sie werden in der Regel von einem bis mäßigen interstitiellen und alveolären, chronischen und makrophagenreichen Entzündungszellinfiltrat begleitet. Wichtigste Differenzialdiagnose ist die gewöhnliche interstitielle Pneumonie (UIP). Diese zeigt ebenfalls Fibroblastenproliferate, welche allerdings interstitiell liegen. Die korrekte Zuordnung einer IIP als COP mittels klinischer, radiologischer und histologischer Befunderhebung ist essenziell, da die COP im Gegensatz zur UIP sehr gut auf Kortikosteroide anspricht und somit gegenüber der UIP eine exzellente Prognose hat. Der Verlauf sekundärer organisierender Pneumonien hängt von der jeweiligen Grunderkrankung ab. Hier ist es wichtig, dass der Pathologe histologische Begleitcharakteristika einer OP korrekt identifiziert, um Hinweise auf eine mögliche Ursache geben zu können.

[Guide for management of patients with possible respiratory sequelae after a SARS-CoV-2 pneumonia. Support proposals developed by the French-speaking Respiratory Medicine Society. Version of 10 November 2020]

La Société de Pneumologie de Langue Française (SPLF) propose un guide pour la prise en charge thérapeutique des patients ayant d’éventuelles séquelles respiratoires après avoir présenté une pneumonie à SARS-CoV-2 (COVID-19). Les propositions s’appuient sur les données connues des précédentes épidémies, les données préliminaires publiées sur le suivi après COVID-19 et les avis d’experts. Les propositions ont été élaborées par un groupe d’experts puis soumises selon la méthode Delphi à un panel composé de 22 pneumologues. Dix-sept propositions ont été validées, qui vont des examens complémentaires à réaliser après le bilan minimal proposé dans le guide de suivi de la SPLF à la place de la corticothérapie inhalée ou systémique et des médicaments antifibrosants. Ces propositions pourront évoluer dans le temps au fil des connaissances sur le sujet. Ce guide insiste sur l’importance de la discussion multidisciplinaire.

Clinical, radiological, and pathological evaluation of "NSIP with OP overlap" pattern compared with NSIP in patients with idiopathic interstitial pneumonias

BACKGROUND

Nonspecific interstitial pneumonia (NSIP) and organizing pneumonia (OP) are major subtypes of idiopathic interstitial pneumonias (IIPs) and closely related to connective tissue diseases (CTDs). "NSIP with OP overlap" is a controversial finding that has recently appeared in the criteria of interstitial pneumonia with autoimmune features (IPAF). However, details of this controversial entity are not well known.

OBJECTIVE

To determine the frequency of "NSIP with OP overlap" pattern in IIPs and to identify differences from idiopathic NSIP (iNSIP).

METHODS

In 524 patients with interstitial pneumonia from 39 institutes who underwent surgical lung biopsy, 444 were diagnosed as IIPs by a multidisciplinary discussion meeting via a cloud-based integrated database. Among these patients, 44 (9.9%) who had iNSIP and 21 (4.7%) with histopathologically-defined "NSIP with OP overlap" pattern (a pathological NSIP and OP pattern, but without a UIP pattern) were retrospectively studied.

RESULTS

Patients with "NSIP with OP overlap" pattern showed a significantly greater extent of consolidation (p < 0.001), more subpleural ground glass attenuation (p = 0.036), and more peripheral + bronchovascular distribution (p = 0.009) on high-resolution computed tomography than those with iNSIP. The incidences of newly-developed CTDs during follow-up was similar between the groups and polymyositis/dermatomyositis was the most frequent CTD in both groups. Nearly half of the patients fulfilled IPAF criteria, but no significant difference was found between iNSIP and "NSIP with OP overlap" pattern (47.7% vs. 42.9, p = 0.712). The incidence of acute exacerbation and the survival rates were similar between the groups.

CONCLUSIONS

The incidence of "NSIP with OP overlap" pattern is 4.7% in IIPs. The frequency of newly-developed CTDs during follow-up, mainly polymyositis/dermatomyositis, the frequency of acute exacerbation, and the survival rate in "NSIP with OP overlap" pattern are similar to those of iNSIP.

Cicatricial organizing pneumonia: a clinicopathologic and radiologic study on a cohort diagnosed by surgical lung biopsy at a single institution

Cicatricial organizing pneumonia (CiOP) refers to intraluminal collagen deposition in a background of otherwise classic appearing organizing pneumonia (OP), sometimes with formation of peculiar fibrous nodules or densely fibrotic linear bands. Dendriform ossification has been also described in CiOP cases. This study is to evaluate the clinicopathologic and radiologic characteristics of CiOP identified in a cohort of OP cases diagnosed by surgical lung biopsy at a single institution. Electronic search was performed to find surgical lung biopsy cases with OP as the main histopathologic diagnosis during a 9-year period (2005-2013). The presence of mature collagen deposition in intraluminal plugs of OP (Masson bodies), linear fibrous bands, and ossification in association with OP was evaluated. Pertinent clinical information was obtained from medical records, and available chest computed tomography (CT) scans were reviewed by a chest radiologist. A total of 56 cases met the study criteria. Thirty-two of 56 cases (57.1%) showed at least 10% of cicatricial element within Masson bodies, 9 of which revealed cicatricial elements comprising 50% or higher proportion of OP. All 9 cases with CiOP as the major component (≥50%) revealed some areas of linear fibrous bands. Five of these 9 cases had intraluminal ossification, with features suggestive of dendriform ossification. Twenty of 32 cases with the cicatricial component had postoperative follow-up CT scans ranging from 0.4 to 171 months (median = 44) after the biopsy; 18 of these 20 cases showed stable finding or resolution of radiologic densities. Six of 9 patients with CiOP with major cicatricial change (≥50%) were alive and well at the time of clinical follow-up (median = 47 months; range = 12-125). In summary, minor cicatricial changes involving Masson bodies were seen in more than half of our OP cases, and patients with CiOP seem to follow an indolent and favorable course on radiologic and clinical follow-up, even in those with major cicatricial changes (≥50%) that were often accompanied by linear fibrous bands and/or intraluminal ossification.

Interstitial Lung Disease and Pulmonary Fibrosis: A Practical Approach for General Medicine Physicians with Focus on the Medical History

Interstitial lung disease (ILD) and pulmonary fibrosis comprise a wide array of inflammatory and fibrotic lung diseases which are often confusing to general medicine and pulmonary physicians alike. In addition to the myriad of clinical and radiologic nomenclature used in ILD, histopathologic descriptors may be particularly confusing, and are often extrapolated to radiologic imaging patterns which may further add to the confusion. We propose that rather than focusing on precise histologic findings, focus should be on identifying an accurate etiology of ILD through a comprehensive and detailed medical history. Histopathologic patterns from lung biopsy should not be dismissed, but are often nonspecific, and overall treatment strategy and prognosis are likely to be determined more by the specific etiology of ILD rather than any particular histologic pattern. In this review, we outline a practical approach to common ILDs, highlight important aspects in obtaining an exposure history, clarify terminology and nomenclature, and discuss six common subgroups of ILD likely to be encountered by general medicine physicians in the inpatient or outpatient setting: Smoking-related, hypersensitivity pneumonitis, connective tissue disease-related, occupation-related, medication-induced, and idiopathic pulmonary fibrosis. Accurate diagnosis of these forms of ILD does require supplementing the medical history with results of the physical examination, autoimmune serologic testing, and chest radiographic imaging, but the importance of a comprehensive environmental, avocational, occupational, and medication-use history cannot be overstated and is likely the single most important factor responsible for achieving the best possible outcomes for patients.

Expanded acceptance of acute exacerbation of nonspecific interstitial pneumonia, including 7 additional cases with detailed clinical pathologic correlation

Acute exacerbation is uncommonly diagnosed in patients with nonspecific interstitial pneumonia (NSIP) and its pathologic features have received relatively little attention compared to idiopathic pulmonary fibrosis. We retrospectively studied 14 consecutive cases of histopathologically proven NSIP by surgical lung biopsy. The diagnosis of acute exacerbation was confirmed clinically. We analyzed whether four reported pathologic features, including organizing pneumonia lesion, alveolar hemorrhage, many fibroblastic foci, and focal hyaline membranes were present and suggestive of acute exacerbation of NSIP or not. Acute exacerbation in patients with NSIP was diagnosed in 8 cases, while the remaining 6 cases were diagnosed as clinically stable. Seven cases of organizing pneumonia lesion, 7 of alveolar hemorrhage, 6 of many fibroblastic foci, and 3 of focal hyaline membranes were identified as the main pathologic components in patients with acute exacerbation. Organizing pneumonia lesion and many fibroblastic foci were identified in 2 and 3 stable cases, respectively. Having more than two components was significantly associated with acute exacerbation. Evaluation of lung biopsies with NSIP for organizing pneumonia lesions, alveolar hemorrhage, many fibroblastic foci, and focal hyaline membranes may be useful to predict the possibility of acute exacerbation.

Interstitial Pneumonia With Autoimmune Features: Value of Histopathology

CONTEXT

- Patients with idiopathic interstitial pneumonia may display evidence of autoimmunity without meeting criteria for a defined connective tissue disease. A recent European Respiratory Society/American Thoracic Society statement proposed research criteria for interstitial pneumonia with autoimmune features (IPAF), which includes findings from the clinical, serologic, and morphologic domains.

OBJECTIVES

- To investigate the importance of histopathologic criteria within the morphologic domain and to report our methodology for identifying these features.

DESIGN

- Patients with idiopathic interstitial pneumonia at the University of Chicago who underwent surgical lung biopsy or lung transplantation were assessed for IPAF histopathologic features, using the initial pathology interpretation in the electronic records. A focused rereview of available slides by a pulmonary pathologist was then performed for patients who failed to meet IPAF criteria on initial pathology assessment.

RESULTS

- Of 422 patients with idiopathic interstitial pneumonia, 176 (41.7%) underwent surgical lung biopsy or lung transplant. Forty-six of those 176 patients (26.1%) met IPAF criteria by initial pathology interpretation and a positive clinical or serologic feature. Of the remaining 130 patients, 73 (56.2%) met either the clinical or serologic domains without meeting the morphologic domain, whereas 36 (27.7%) had slides available for pathology rereview. This rereview demonstrated nonspecific interstitial pneumonia in 8 of 36 patients (22.2%) and lymphoplasmacytic infiltrates in 6 of 36 patients (16.7%), resulting in an additional 7 of 36 patients (19.4%) with idiopathic interstitial pneumonia that met the IPAF criteria. In IPAF, pulmonary vasculopathy was the most prevalent finding (45 of 84; 53.6%) and predicted increased mortality (hazard ratio, 2.5; P = .04).

CONCLUSIONS

- Using a methodological approach to identifying IPAF pathology, we demonstrate a significant increase in the number of patients meeting IPAF criteria because of focused pathologic review and highlight the prognostic value of the IPAF pathologic findings.