Organizing diffuse alveolar damage associated with progressive systemic sclerosis

Feasibility and Outcomes of a Standardized Management Protocol for Acute Exacerbation of Interstitial Lung Disease

BACKGROUND AND OBJECTIVE

Despite the high mortality of acute exacerbations of interstitial lung disease (AE-ILD), there is minimal evidence to guide management decisions. We aimed to assess the feasibility and outcomes of a standardized management protocol for AE-ILD.

METHODS

We performed a retrospective cohort study of patients with AE-ILD admitted to hospital between January 2015 and August 2019. Patients were managed with a standardized protocol including chest computed tomography (CT) at diagnosis, pulse corticosteroid treatment, and a follow-up CT 7 days after corticosteroid pulse. The association between idiopathic pulmonary fibrosis (IPF) versus non-IPF diagnosis and transplant-free survival within 1-year of AE-ILD was assessed using adjusted Cox proportional hazards regression survival analysis. Associations with CT chest improvement 7 days after corticosteroid pulse were secondarily assessed.

RESULTS

89 patients with AE-ILD were identified. 1-year transplant-free and overall survival were 20.2 and 51.7%, respectively. Protocol adherence to pulse corticosteroids was high (95.5%). A diagnosis of IPF was associated with higher risk of death or transplant at 1-year versus a non-IPF diagnosis [hazard ratio (HR) 2.23, 95% CI 1.19-4.17, p = 0.012]. There were no significant associations with 7-day CT improvement; however, CT improvement was associated with higher transplant-free survival (p = 0.02) and a lower risk of in-hospital mortality (χ² = 7.06, p = 0.01) on unadjusted analysis.

CONCLUSIONS

IPF is associated with a higher risk of death or transplant at 1-year as compared to a non-IPF diagnosis in patients with AE-ILD managed using a standardized protocol. Improvement on CT chest 7 days after corticosteroid pulse is associated with better survival.

Interstitial lung disease pathology in systemic sclerosis

Interstitial lung disease is a relatively frequent manifestation of systemic sclerosis with approximately one-third of patients developing clinical restrictive lung disease. Fibrotic nonspecific interstitial pneumonia is the most common cause of diffuse parenchymal lung disease in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD), followed by usual interstitial pneumonia (UIP). Radiographic pleuroparenchymal fibroelastosis-like changes may accompany other forms of interstitial lung disease, most commonly UIP. In an appropriate clinical setting with supportive high-resolution computed tomography findings, lung biopsy is not needed to confirm the presence of interstitial lung disease and surgical lung biopsies are often reserved for atypical presentations. In this review, we discuss the histological findings that define the most common patterns of SSc-ILD and outline other findings sometimes encountered in lung biopsies obtained from systemic sclerosis patients, including pulmonary vascular changes, aspiration, chronic pleuritis, and diffuse alveolar damage.

Clinical, Serological, and Histopathological Similarities Between Severe COVID-19 and Acute Exacerbation of Connective Tissue Disease-Associated Interstitial Lung Disease (CTD-ILD)

Background and Objectives

Understanding the pathophysiology of respiratory failure in coronavirus disease 2019 (COVID-19) is indispensable for development of therapeutic strategies. Since we observed similarities between COVID-19 and interstitial lung disease in connective tissue disease (CTD-ILD), we investigated features of autoimmunity in SARS-CoV-2-associated respiratory failure.

Methods

We prospectively enrolled 22 patients with RT-PCR-confirmed SARS-CoV-2 infection and 10 patients with non-COVID-19-associated pneumonia. Full laboratory testing was performed including autoantibody (AAB; ANA/ENA) screening using indirect immunofluorescence and immunoblot. Fifteen COVID-19 patients underwent high-resolution computed tomography. Transbronchial biopsies/autopsy tissue samples for histopathology and ultrastructural analyses were obtained from 4/3 cases, respectively.

Results

Thirteen (59.1%) patients developed acute respiratory distress syndrome (ARDS), and five patients (22.7%) died from the disease. ANA titers ≥1:320 and/or positive ENA immunoblots were detected in 11/13 (84.6%) COVID-19 patients with ARDS, in 1/9 (11.1%) COVID-19 patients without ARDS (p = 0.002) and in 4/10 (40%) patients with non-COVID-19-associated pneumonias (p = 0.039). Detection of AABs was significantly associated with a need for intensive care treatment (83.3 vs. 10%; p = 0.002) and occurrence of severe complications (75 vs. 20%, p = 0.03). Radiological and histopathological findings were highly heterogeneous including patterns reminiscent of exacerbating CTD-ILD, while ultrastructural analyses revealed interstitial thickening, fibroblast activation, and deposition of collagen fibrils.

Conclusions

We are the first to report overlapping clinical, serological, and imaging features between severe COVID-19 and acute exacerbation of CTD-ILD. Our findings indicate that autoimmune mechanisms determine both clinical course and long-term sequelae after SARS-CoV-2 infection, and the presence of autoantibodies might predict adverse clinical course in COVID-19 patients.

Acute Lung Injury

A wide variety of insults can produce acute lung damage, inclusive of those that injure the lungs directly. The clinical syndrome of acute onset respiratory distress, dyspnea, and bilateral infiltrates is referred to as acute respiratory distress syndrome. The histologic counterpart of acute respiratory distress syndrome is diffuse alveolar damage, classically characterized by hyaline membranes. Other histologic features of acute lung injury include intraalveolar fibrin, organization, interstitial edema, and reactive pneumocytes. Diffuse alveolar damage and other histologic features of acute lung injury are nonspecific as to etiology, and once identified require the pathologist to search the biopsy for further features that may help identify a specific etiology. This chapter reviews the temporal sequence of acute lung injury and explores the large variety of specific etiologic causes with emphasis on helpful histologic features to identify.

Pulmonary involvement in systemic sclerosis

Systemic sclerosis (SSc) is a multi-systemic autoimmune disease that mainly affects the skin, lungs, gastrointestinal tract, heart and kidneys. Pulmonary disease in patients with SSc is strongly associated with mortality. The mechanisms involved into its pathophysiology include the activation of autoimmune cells and hyperplasia of fibroblasts with an increased capacity to produce collagen and diminished collagen breakdown. Although pulmonary biopsy is the gold standard for the diagnosis of interstitial lung disease in SSc, the most commonly used method is high-resolution computed tomography due to its high sensitivity and specificity. Herein, a comprehensive review on the pulmonary involvement in SSc is presented highlighting the radiologic-pathologic correlations.

State-of-the-Art Imaging of the Lung for Connective Tissue Disease (CTD)

Involvement of the respiratory system is common in connective tissue diseases (CTDs), and the resultant lung injury can affect every part of the lung: the pleura, alveoli, interstitium, vasculature, lymphatic tissue, and large and/or small airways. Most of the parenchymal manifestations of CTD are similar to those found in interstitial lung diseases (ILDs), especially idiopathic interstitial pneumonias, and can be classified using the same system. Although there is some overlap, each CTD is associated with a characteristic pattern of pulmonary involvement. For this reason, thin-section CT as well as pulmonary function tests and serum markers are utilized for diagnosis, disease severity assessment, and therapeutic efficacy evaluation of ILD associated with CTD. In addition, newly developed pulmonary magnetic resonance imaging (MRI) procedures have been recommended as useful alternative imaging options for patients with CTD. This review article will (1) address radiological findings for chest radiography and conventional or thin-section CT currently used for six major types of CTD, rheumatoid arthritis, scleroderma (progressive systemic sclerosis), polymyositis/dermatomyositis, systemic lupus erythematosus, Sjögren syndrome and mixed connective tissue disease; (2) briefly deal with radiation dose reduction for thin-section CT examination; and (3) discuss clinically applicable or state-of-the-art MR imaging for CTD patients.

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.

Connective Tissue Disease-related Thoracic Disease

Pulmonary involvement is a frequent manifestation of connective tissue disease (CTD)-related thoracic disease. It is important to characterize the underlying pattern when pulmonary involvement occurs in a patient with CTD, and to exclude other causes. A systematic approach, evaluating each compartment of the lung (airway, interstitium, pleura, pulmonary vasculature) may be helpful. In complex cases, a multidisciplinary approach should be considered, potentially including the pulmonologist, rheumatologist, radiologist, pathologist, and sometimes the infectious disease specialist or oncologist. New techniques, such as quantitative computed tomography and MRI, are expected to be helpful for evaluation and management of CTD-associated thoracic disease.

Pleuropulmonary pathology in patients with rheumatic disease

Thoracic manifestations of rheumatic disease (RD) are increasingly recognized as a significant cause of morbidity and mortality worldwide. Rheumatologic underpinnings have been identified in a significant proportion of patients with interstitial lung disease. The 5 RDs most frequently associated with pleuropulmonary disease are (1) rheumatoid arthritis, (2) systemic lupus erythematosus, (3) progressive systemic sclerosis, (4) polymyositis/dermatomyositis, and (5) Sjögren syndrome. The onset of thoracic involvement in these diseases is variable. In some patients, it precedes the systemic disease or is its only manifestation. Moreover, there is a wide spectrum of clinical presentation ranging from subclinical abnormalities to acute respiratory failure. Histopathologically, the hallmark features of thoracic involvement by RD are inflammatory, targeting one or more lung compartments. The reactions range from acute to chronic, with remodeling by fibrosis being a common result. Although the inflammatory findings are often nonspecific, certain reactions or anatomic distributions may favor one RD over another, and occasionally, a distinctive histopathology may be present (eg, rheumatoid nodules). Three diagnostic dilemmas are encountered in patients with RD who develop diffuse lung disease: 1) opportunistic infection in the immunocompromised host, 2) drug toxicity related to the medications used to treat the systemic disease, and 3) manifestations of the patient's known systemic disease in lung and pleura. To confidently address the latter, the 5 major RDs are presented here, with their most common pleuropulmonary pathologic manifestations, accompanied by brief clinical and radiologic correlations.

Systemic sclerosis with hemoptysis and a huge lung cavity

Systemic sclerosis or scleroderma is associated with distal vasculitis, Raynaud's phenomenon, and inflammation of internal organs and the skin. We present on a 58-year-old Thai woman with systemic sclerosis who came to the 10^th Zonal Tuberculosis and Chest Disease Center, Chiang Mai, Thailand in 2009 and presented with hemoptysis and a solitary huge-lung cavity as the predominant clinical manifestations which spontaneously resoluted 2 months later. This case demonstrates a solitary huge-lung cavity with hemoptysis and looked like from non-tuberculous Mycobacterial infections or malignancy with spontaneous resolution of hemoptysis and the lung cavity, which does not need invasive investigations.

Review series: Aspects of interstitial lung disease: connective tissue disease-associated interstitial lung disease: how does it differ from IPF? How should the clinical approach differ?

The lung is frequently involved in connective tissue diseases (CTDs), although the frequency of lung manifestations varies according to the type of CTD. Interstitial lung diseases (ILD) are frequently seen in CTDs, particularly systemic sclerosis (SSc), polymyositis/dermatomyositis (PM/DM) and rheumatoid arthritis (RA), accounting for a significant proportion of deaths. A large percentage of patients with CTD-associated ILD has limited and stable disease, not requiring treatment. However, a significant minority has severe and/or progressive disease, necessitating prompt initiation of treatment. CTD-ILD histological patterns include non-specific interstitial pneumonia (NSIP), usual interstitial pneumonia (UIP), organizing pneumonia (OP), diffuse alveolar damage (DAD) and lymphocytic interstitial pneumonia (LIP). NSIP is the most common pattern in all CTDs, except for RA, characterized by a higher frequency of UIP. ILD can present acutely or chronically, with acute presentations being more common in systemic lupus erythematosus and PM/DM. Idiopathic pulmonary fibrosis (IPF) is a progressively worsening ILD characterized by inflammation and fibrosis. The characteristic histological pattern of IPF is UIP. Interestingly, a UIP pattern is associated with a significantly better survival in CTD-related disease compared to the idiopathic variety. Prognosis in IPF is dismal, with a median survival since diagnosis of 2-3 years. No treatment regimen has been shown to improve survival in IPF. By contrast, although there have been only two randomized placebo-controlled trials investigating the effect of immunosuppressive treatment in SSc-associated ILD, clinical experience suggests that immunosuppressive drugs in CTD-related ILDs are capable of benefiting a significant proportion of patients, particularly those with certain histological patterns of disease. This review will essentially focus on CTD-associated ILD and will compare aspects of clinical presentation and management to those of IPF.

Desquamative interstitial pneumonia as the initial manifestation of systemic sclerosis

Interstitial lung disease (ILD) is a frequent pulmonary complication of systemic sclerosis (SSc), and nonspecific interstitial pneumonia is the most commonly recognized pattern of lung injury in these patients. In this report, we describe a never-smoker female presenting with Raynaud phenomenon and ILD that demonstrated desquamative interstitial pneumonia (DIP) on surgical lung biopsy. After 8 months, she was diagnosed with pulmonary hypertension at which time clinical examinations and serologic findings established the diagnosis of SSc. This case report expands the spectrum of patterns of ILD seen in association with SSc to include DIP.

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.

Two distinct clinical types of interstitial lung disease associated with polymyositis-dermatomyositis

Most patients with interstitial lung disease (ILD) associated with collagen vascular diseases (CVD) have a chronic indolent course with a relatively favorable prognosis; however, acute progression has been reported in some polymyositis-dermatomyositis patients. This study evaluated the prevalence, clinical features, and outcome relative to the presentation type of ILD in polymyositis-dermatomyositis (PM-DM). Ninety-nine patients with newly diagnosed polymyositis-dermatomyositis seen at the Asan Medical Center in Korea between January 1990 and December 2004 were enrolled. The clinical, radiological, and pathological findings were retrospectively reviewed. ILD were divided into acute (dyspnea within 1 month before diagnosis) or chronic types. ILD was found on chest radiographs in 33 patients (33.3%), and 11 (33.3%) of these were considered acute. The acute group presented with more severe respiratory symptoms, hypoxemia, and poorer lung function. Patients with an acute presentation had ground glass opacity and consolidation on high-resolution computed tomography (HRCT), in contrast to reticulation and honeycombing in the chronic type. Surgical lung biopsy of one acute-type patient revealed diffuse alveolar damage, whereas biopsies in the chronic type showed usual interstitial pneumonia (UIP) in four cases and nonspecific interstitial pneumonia (NSIP) in another four. Eight acute-type patients (72.7%) died of respiratory failure within 1-2 months despite steroid therapy. The 3-year mortality rate of the chronic-type patients (21.2%) was not statistically significantly different from that of the patients without ILD (10.2%). In polymyositis-dermatomyositis, the acute, severe form of ILD was not infrequent.

Acute exacerbation of interstitial pneumonia other than idiopathic pulmonary fibrosis

BACKGROUND

Acute exacerbation (AE) in idiopathic pulmonary fibrosis (IPF) is increasingly recognized as a relatively common and highly morbid clinical event. However, clinical data on AE in non-IPF interstitial pneumonia are sparse. This study was performed to find the frequency, clinical features, and outcome of AE in non-IPF interstitial pneumonia.

METHODS

Retrospective analysis of 10 patients who satisfied the modified Akira criteria for AE during follow-up of 74 patients with surgical lung biopsy-confirmed idiopathic nonspecific interstitial pneumonia (I-NSIP) and 93 patients with biopsy-confirmed interstitial pneumonia associated with collagen vascular disease (CVD-IP).

RESULTS

AE occurred in six patients with I-NSIP (1-year frequency, 4.2%) and in four patients with CVD-IP (rheumatoid arthritis [RA], n = 3; scleroderma, n = 1), with 1-year frequency of 3.3%. Median age was 58 years (range, 47 to 75); six patients were female. AE occurred in two patients immediately after surgical biopsy. Median duration of acute symptom before hospital admission was 10 days (range, 1 to 30). Median ratio of Pao(2) to the fraction of inspired oxygen (Fio(2)) was 172 (range, 107 to 273), and Pao(2)/Fio(2) ratio was < 200 in six patients. Surgical lung biopsy performed at the time of AE in two patients revealed diffuse alveolar damage superimposed on nonspecific interstitial pneumonia pattern. Four patients with I-NSIP survived to discharge and were followed up for 24 months (range, 6 to 121).

CONCLUSION

AE occurred in the patients with I-NSIP with apparently better prognosis. In patients with CVD-IP, AE occurred mostly with RA-usual interstitial pneumonia in our small series with poor outcome.

Diffuse alveolar damage: uncommon manifestation of pulmonary involvement in patients with connective tissue diseases

BACKGROUND

Diffuse alveolar damage (DAD) is a relatively common finding on surgical lung biopsy and can result from a variety of causes.

METHODS

We studied nine consecutive patients with connective tissue disease (CTD) and DAD diagnosed on surgical lung biopsy to examine this association and clinical implications.

RESULTS

The median age was 63 years (range, 35 to 76 years), and seven of the patients were women (78%). Underlying CTDs included rheumatoid arthritis in five patients, polymyositis in two patients, and one patient each with systemic sclerosis and mixed CTD. In seven patients (78%), CTD had been diagnosed before the onset of DAD; six of these patients had a preexisting interstitial lung disease (ILD) related to their CTD. DAD was the presenting manifestation leading to a new CTD diagnosis in two patients (22%). CT of the chest revealed ground-glass opacities and/or consolidation bilaterally with or without honeycombing. In all patients, surgical lung biopsy revealed DAD for which no cause could be identified other than the underlying CTD. Seven patients (78%) were receiving mechanical ventilatory support at the time of the surgical lung biopsy. Four patients (44%) survived to hospital discharge and included one patient with preexisting ILD and all three patients without chronic ILD.

CONCLUSION

We conclude that DAD can complicate the clinical course of patients with CTD-related chronic ILD, or can occasionally occur as a presenting manifestation of CTDs. When DAD occurs in patients with CTDs, the outcome appears to be worse for those with preexisting chronic ILD compared to those without ILD.

Interstitial lung diseases associated with collagen vascular diseases: radiologic and histopathologic findings

Collagen vascular diseases that demonstrate features of interstitial lung disease include systemic lupus erythematosus, rheumatoid arthritis, progressive systemic sclerosis, dermatomyositis and polymyositis, ankylosing spondylitis, Sjögren syndrome, and mixed connective tissue disease. At histopathologic analysis, interstitial lung diseases associated with collagen vascular diseases are diverse and include nonspecific interstitial pneumonia, usual interstitial pneumonia, bronchiolitis obliterans organizing pneumonia (BOOP), apical fibrosis, diffuse alveolar damage, and lymphocytic interstitial pneumonia. Although proportions of interstitial pneumonias vary, nonspecific interstitial pneumonia accounts for a large proportion, especially in progressive systemic sclerosis, dermatomyositis and polymyositis, and mixed connective tissue disease. The more favorable prognosis in interstitial pneumonia associated with collagen vascular diseases than in idiopathic interstitial pneumonias may be explained by the larger proportion of nonspecific interstitial pneumonia than of usual interstitial pneumonia. High-resolution computed tomography seems to help characterize and determine the extent of interstitial lung disease in collagen vascular diseases.