Can interstitial pneumonia as the sole presentation of collagen vascular diseases be differentiated from idiopathic interstitial pneumonia?

Imaging of Pulmonary Manifestations of Connective Tissue Disease

The majority of connective tissue diseases (CTDs) are multisystem disorders that are often heterogeneous in their presentation and do not have a single laboratory, histologic, or radiologic feature that is defined as the gold standard to support a specific diagnosis. Given this challenging situation, the diagnosis of CTD is a process that requires the synthesis of multidisciplinary data which may include patient clinical symptoms, serologic evaluation, laboratory testing, and imaging. Pulmonary manifestations of connective tissue disease include interstitial lung disease as well as multicompartmental manifestations. These CT imaging patterns and features of specific diseases will be discussed in this article.

Diagnostic Approach to Interstitial Lung Diseases Associated with Connective Tissue Diseases

Interstitial lung disorders are a group of respiratory diseases characterized by interstitial compartment infiltration, varying degrees of infiltration, and fibrosis, with or without small airway involvement. Although some are idiopathic (e.g., idiopathic pulmonary fibrosis, idiopathic interstitial pneumonias, and sarcoidosis), the great majority have an underlying etiology, such as systemic autoimmune rheumatic disease (SARD, also called Connective Tissue Diseases or CTD), inhalational exposure to organic matter, medications, and rarely, genetic disorders. This review focuses on diagnostic approaches in interstitial lung diseases associated with SARDs. To make an accurate diagnosis, a multidisciplinary, personalized approach is required, with input from various specialties, including pulmonary, rheumatology, radiology, and pathology, to reach a consensus. In a minority of patients, a definitive diagnosis cannot be established. Their clinical presentations and prognosis can be variable even within subsets of SARDs.

Chronic dyspnea with Raynaud's phenomenon and elevated ANA: A diagnosis of systemic sclerosis sine scleroderma

Systemic sclerosis (SSc) should be considered in all patients initially diagnosed with idiopathic interstitial lung disease (ILD), even in the absence of classical scleroderma cutaneous features. Systemic sclerosis sine scleroderma (ssSSc) is a rare subtype of SSc, and the diagnosis requires the absence of characteristic skin thickening but the presence of the three following criteria: (A) Raynaud's phenomenon or the equivalent of abnormal nail fold capillaries, (B) positive antinuclear antibody (ANA), typically with nucleolar or speckled immunofluorescence pattern, and (C) at least one internal organ involvement of ILD, renal dysfunction, esophageal/bowel dysmotility or pulmonary arterial hypertension; in the absence of an alternative rheumatological diagnosis. The radiological and histopathological features of systemic sclerosis sine scleroderma-associated interstitial lung disease (ssSSc-ILD) are commonly those of non-specific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP) that cannot help distinguish between idiopathic interstitial pneumonia, different types of connective tissue diseases, or even different subsets of SSc. Therefore, other than chest imaging, the use of nail fold capillaroscopy, positive serum ANA antibody, echocardiogram, and esophagram are essential, in conjunction with the clinical presentation for facilitating the diagnosis of ssSSc. We present a case of a 58-year-old woman presenting with chronic dyspnea, a positive review of systems for Raynaud's phenomenon, and found to have elevated nucleolar immunofluorescence pattern of ANA with chest imaging consistent with the diagnosis of ssSSc-ILD. The uniqueness of this case is that despite symptomatic alleviation with oral mycophenolate therapy, our patient's restrictive lung disease on pulmonary function tests continued to decline, requiring initiation of oral nintedanib therapy leading to stability and improvement. However, due to the rarity of ssSSc, the use of oral nintedanib for systemic sclerosis-associated ILD has only been formally assessed on patients with diffuse cutaneous systemic sclerosis and limited cutaneous systemic sclerosis.

Functional respiratory impairment and related factors in patients with interstitial pneumonia with autoimmune features (IPAF): Multicenter study from NEREA registry

BACKGROUND

The objective of the present study is to describe the characteristics of interstitial pneumonia with autoimmune features (IPAF) patients, to assess the incidence rate of functional respiratory impairment over time and to evaluate the influence of therapeutic alternatives on the prognosis of these patients.

METHODS

A longitudinal observational multicenter study was performed (NEREA registry). It was carried out by a multidisciplinary team in seven Hospitals of Madrid. Patients were included from IPAF diagnosis.

MAIN OUTCOME

poor prognosis as functional respiratory impairment (relative decline in FVC % defined as ≥ 5% every 6 months). Covariates: therapy, sociodemographic, clinical, radiological patterns, laboratory and functional tests.

STATISTICS

Survival techniques were used to estimate IR per 100 patients-semester with their 95% confidence interval [CI]. The influence of covariates in prognosis were analyzed through cox multivariate regression models (hazard ratio (HR) and [CI]).

RESULTS

79 IPAF were included, with a mean and a maximum follow-up of 3.17 and 12 years respectively. Along the study, 77.2% received treatment (52 glucocorticoids, 25 mycophenolate, 21 azathioprine, 15 rituximab and 11 antifibrotics). IR was 23.9 [19.9-28.8], and 50% of IPAF developed functional respiratory impairment after 16 months from its diagnosis. Multivariate analysis: usual interstitial pneumonia (UIP) had poorer prognosis compared to non-specific interstitial pneumonia (NSIP) (p = 0.001). In NSIP, positive ANA, increased the risk of poor prognosis. In UIP, glucocorticoids (HR: 0.53 [0.34-0.83]), age (HR: 1.04 [1.01-1.07]), and Ro-antibodies (HR: 0.36 [0.19-0.65]) influenced the prognosis.

CONCLUSIONS

IPAF have functional impairment during the first years of disease. Factors predicting deterioration differ between radiographic patterns. Our real-life study suggests the potential benefit of particular therapies in IPAF.

Connective tissue disease-related interstitial lung disease (CTD-ILD) and interstitial lung abnormality (ILA): Evolving concept of CT findings, pathology and management

Connective tissue diseases (CTDs) demonstrating features of interstitial lung disease (ILD) include systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), dermatomyositis (DM) and polymyositis (PM), ankylosing spondylitis (AS), Sjogren syndrome (SS), and mixed connective tissue disease (MCTD). On histopathology of lung biopsy in CTD-related ILDs (CTD-ILDs), multi-compartment involvement is an important clue, and when present, should bring CTD to the top of the list of etiologic differential diagnoses. Diverse histologic patterns including nonspecific interstitial pneumonia (NSIP), usual interstitial pneumonia (UIP), organizing pneumonia, apical fibrosis, diffuse alveolar damage, and lymphoid interstitial pneumonia can be seen on histology in patients with CTD-ILDs. Although proportions of ILDs vary, the NSIP pattern accounts for a large proportion, especially in SSc, DM and/or PM and MCTD, followed by the UIP pattern. In RA patients, interstitial lung abnormality (ILA) is reported to occur in approximately 20–60% of individuals of which 35–45% will have progression of the CT abnormality. Subpleural distribution and greater baseline ILA involvement are risk factors associated with disease progression. Asymptomatic CTD-ILDs or ILA patients with normal lung function and without evidence of disease progression can be followed without treatment. Immunosuppressive or antifibrotic agents for symptomatic and/or fibrosing CTD-ILDs can be used in patients who require treatment.

Interstitial pneumonia with autoimmune features: from research classification to diagnosis

PURPOSE OF REVIEW

The term interstitial pneumonia with autoimmune features (IPAF) was first proposed by an international task force in 2015 as a research classification to standardise nomenclature regarding patients with idiopathic interstitial pneumonia and features of connective tissue disease. However, how the use of this term and its proposed definition translates to clinical practice remains uncertain. This review will provide a comprehensive overview of studies of IPAF cohorts to date, discuss the consideration of IPAF as a distinct diagnostic entity and outline a suggested approach to patient management.

RECENT FINDINGS

Considerable heterogeneity exists between published IPAF cohorts, with some cohorts exhibiting similarities to those with connective tissue disease-associated interstitial lung disease (CTD-ILD), and others more similar to idiopathic interstitial pneumonias including idiopathic pulmonary fibrosis (IPF). Little data exist to inform the management of patients who fulfil the IPAF criteria. Preliminary data supports pragmatic management of these patients as having a working clinical diagnosis of either idiopathic interstitial pneumonia or CTD-ILD. Future research studies into this approach are required.

SUMMARY

The term IPAF, and its definition, have been of fundamental benefit to facilitating research in this diverse patient group. However, to date, there remain many unanswered questions regarding their natural histories and response to treatment.

Unclassifiable, or simply unclassified interstitial lung disease?

PURPOSE OF REVIEW

Unclassifiable interstitial lung disease (ILD) comprises a subset of ILDs which cannot be classified according to the current diagnostic framework. This is a likely a heterogeneous group of diseases rather than a single entity and it is poorly defined and hence problematic for prognosis and therapy.

RECENT FINDINGS

With increased treatment options for progressive fibrosing ILD it is increasingly relevant to correctly categorise ILD.

SUMMARY

This review article will summarise the definition and reasons for a diagnosis of unclassifiable ILD, the current management options and possible future approaches to improve diagnosis and differentiation within this broad subset. Finally, we will describe the implications of the labelling of unclassifiable ILD in clinical practice and research and whether the term 'unclassified' should be used, implying a less definitive diagnosis.

Connective tissue disease-related interstitial lung disease (CTD-ILD) and interstitial lung abnormality (ILA): Evolving concept of CT findings, pathology and management

The connective tissue diseases (CTDs) demonstrating features of interstitial lung disease (ILD) include systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), progressive systemic sclerosis (PSS), dermatomyositis (DM) and polymyositis (PM), ankylosing spondylitis (AS), Sjogren's syndrome (SS), and mixed connective tissue disease (MCTD). In RA patients in particular, interstitial lung abnormality (ILA) (of varying degrees; severe vs. mild) is reported to occur in approximately 20-60 % of individuals and CT disease progression occurs in approximately 35-45 % of them. The ILAs have been associated with a spectrum of functional and physiologic decrement. The identification of progressive ILA may enable appropriate surveillance and the commencement of treatment with the goal of improving morbidity and mortality rates of established RA-ILD. Subpleural distribution and higher baseline ILA/ILD extent were risk factors associated with disease progression. At histopathologic analysis, connective tissue disease-related interstitial lung diseases (CTD-ILDs) are diverse and include nonspecific interstitial pneumonia (NSIP), usual interstitial pneumonia (UIP), organizing pneumonia (OP), apical fibrosis, diffuse alveolar damage (DAD), and lymphoid interstitial pneumonia (LIP). Even though proportions of ILDs vary, NSIP pattern accounts for a large proportion, especially in PSS, DM/PM and MCTD, followed by UIP pattern. Evidence has been published that treatment of subclinical CT lung abnormalities showing a tendency to progress to ILD may stabilize the CT alterations. The identification of subclinical lung abnormalities can be appropriate in the management of the disease and CT appears to be the gold standard for the evaluation of lung parenchyma.

Systematic review and meta-analysis of the prognosis and prognostic factors of interstitial pneumonia with autoimmune features

OBJECTIVE

To clarify the prognosis and prognostic factors of interstitial pneumonia with autoimmune features (IPAF) in comparison to idiopathic pulmonary fibrosis (IPF), the most common idiopathic interstitial pneumonia, and connective tissue disease-associated interstitial pneumonia (CTD-IP).

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

Electronic databases such as Medline and Embase were searched from 2015 through 6 September 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Primary studies that comparatively investigated the prognosis or prognostic factors of IPAF were eligible.

DATA EXTRACTION AND ANALYSIS

Two reviewers extracted relevant data and assessed the risk of bias independently. A meta-analysis was conducted using a random-effects model. The quality of presented evidence was assessed by the Grades of Recommendation, Assessment, Development, and Evaluation system.

RESULTS

Out of a total of 656 records retrieved, 12 studies were reviewed. The clinical features of IPAF were diverse between studies, which included a radiological and/or pathological usual interstitial pneumonia (UIP) pattern of between 0% and 73.8%. All studies contained some risk of bias. There was no significant difference of all-cause mortality between IPAF-UIP and IPF in all studies, although the prognosis of IPAF in contrast to IPF or CTD-IP varied between studies depending on the proportion of UIP pattern. Among the potential prognostic factors identified, age was significantly associated with all-cause mortality of IPAF by a pooled analysis of univariate results with a hazard ratio (HR) of 1.06 (95% confidence interval (CI) 1.04 to 1.07). The adjusted effect of age was also significant in all studies. The quality of presented evidence was deemed as very low.

CONCLUSION

There was no significant difference of all-cause mortality between IPAF-UIP and IPF. Age was deemed as a prognostic factor for all-cause mortality of IPAF. The findings should be interpreted cautiously due to the low quality of the presented evidence.

PROSPERO REGISTRATION NUMBER

CRD42018115870.

Current Perspectives On Emerging Biomarkers For Rheumatoid Arthritis-Associated Interstitial Lung Disease

Rheumatoid arthritis (RA) is a common systemic autoimmune disease whose fibro-inflammatory manifestations may affect a number of tissues and organs, including the lungs. In fact, interstitial lung disease (ILD) is a leading cause of mortality among patients with RA. RA-related interstitial lung disease (RA-ILD) most often presents in an injury pattern called usual interstitial pneumonia (UIP), which portends a relatively worse prognosis than other less commonly occurring patterns of RA-ILD, like non-specific interstitial pneumonia (NSIP). Biomarkers from serum or bronchoalveolar lavage fluid could aid in the identification of patients at risk for RA-ILD, the detection of patients most likely to develop the UIP pattern of RA-ILD, and the prediction of disease behaviour over time. Notably, the use of highly sensitive serologic biomarkers, including rheumatoid factor (RF) and antibodies targeting cyclic citrullinated peptides, while somewhat specific for RA joint disease, have only limited utility as biomarkers for RA-ILD. Candidate biomarkers for RA-ILD include these and other autoantibodies as well as certain genes and molecules that hold promise as biomarkers in other forms of ILD. In this manuscript, we summarize the state of knowledge on biomarkers for the development and progression of RA-ILD.

Imaging of the Thoracic Manifestations of Connective Tissue Disease

Imaging, specifically computed tomography (CT), is a key component in the characterization, management, and follow-up of patients with connective tissue disease (CTD)-related diffuse lung disease. The main role of CT is to help direct treatment by determining the primary pattern of lung injury present. Other roles include follow-up of lung disease over time, evaluation of acute symptoms, and monitoring for treatment complications. Although diagnosis is typically made using clinical and serologic criteria, CT plays an important role when lung disease is the dominant presenting feature. This article delineates the roles of CT in patients with CTD-related lung disease.

Prognostic significance of autoantibodies for idiopathic pulmonary fibrosis: protocol for a systematic review

INTRODUCTION

Idiopathic pulmonary fibrosis(IPF) is chronic fibrosing interstitial pneumonia of unknown aetiology. IPF is diagnosed based on the exclusion of known causes such as connective tissue diseases(CTDs). However, some patients fail to meet defined CTD criteria regardless of an implication of immunological involvement and these cases were described in a variety of terms. The classification criteria of this clinical entity consist of a combination of clinical, serological and morphological findings and it is reported to be distinct from IPF. However, the significance of the sole presence of autoantibodies complicated with IPF is still unknown. Therefore, this systematic review aims to clarify the significance of autoantibodies complicated with IPF.

METHODS AND ANALYSIS

IPF with any autoantibody associated with CTDs is eligible for the review. Primary outcomes are all-cause mortality and pulmonary-cause mortality, while secondary outcomes include a progression of the disease, a deterioration of health-related quality of life and the development of a defined CTD. Primary studies of any type except a case report are included. Two reviewers search four electronic databases such as Medline, EMBASE, Science Citation Index Expanded and Google Scholar from each inception through 1 February 2018 and extract data independently. A risk of bias in individual studies is assessed by the Quality in Prognostic Studies tool. Meta-analysis is sought to be conducted if three or more studies report an outcome for a specific autoantibody with the same statistics. If it is inappropriate to combine data due to substantial heterogeneity, the result is reported qualitatively. Subgroup and sensitivity analyses are considered to identify the source of heterogeneity. The Grades of Recommendation, Assessment, Development and Evaluation method is applied to evaluate the evidence level of the result.

ETHICS AND DISSEMINATION

There is no concerning ethical issue. The result will be sought for publication.

PROSPERO REGISTRATION NUMBER

CRD42017077336.

The interstitial lung disease multidisciplinary meeting: A position statement from the Thoracic Society of Australia and New Zealand and the Lung Foundation Australia

Interstitial lung diseases (ILD) are a diverse group of pulmonary diseases for which accurate diagnosis is critical for optimal treatment outcomes. Diagnosis of ILD can be challenging and a multidisciplinary approach is recommended in international guidelines. The purpose of this position paper is to review the evidence for the use of the multidisciplinary meeting (MDM) in ILD and suggest an approach to its governance and constitution, in an attempt to provide a standard methodology that could be applied across Australia and New Zealand. This position paper is endorsed by the Thoracic Society of Australia and New Zealand (TSANZ) and the Lung Foundation Australia (LFA).

Role of Autoantibodies in the Diagnosis of Connective-Tissue Disease ILD (CTD-ILD) and Interstitial Pneumonia with Autoimmune Features (IPAF)

The diagnosis of interstitial lung disease (ILD) requires meticulous evaluation for an underlying connective tissue disease (CTD), with major implications for prognosis and management. CTD associated ILD (CTD-ILD) occurs most commonly in the context of an established CTD, but can be the first and/or only manifestation of an occult CTD or occur in patients who have features suggestive of an autoimmune process, but not meeting diagnostic criteria for a defined CTD-recently defined as "interstitial pneumonia with autoimmune features" (IPAF). The detection of specific autoantibodies serves a critical role in the diagnosis of CTD-ILD, but there remains a lack of data to guide clinical practice including which autoantibodies should be tested on initial assessment and when or in whom serial testing should be performed. The implications of detecting autoantibodies in patients with IPAF on disease behaviour and management remain unknown. The evaluation of CTD-ILD is challenging due to the heterogeneity of presentations and types of CTD and ILD that may be encountered, and thus it is imperative that immunologic tests are interpreted in conjunction with a detailed rheumatologic history and examination and multidisciplinary collaboration between respiratory physicians, rheumatologists, immunologists, radiologists and pathologists.

Update on Pulmonary Fibrosis: Not All Fibrosis Is Created Equally

CONTEXT

Three distinct patterns of pulmonary fibrosis, including usual interstitial pneumonia, fibrotic nonspecific interstitial pneumonia, and airway-centered fibrosis, can be identified on surgical lung biopsies.

OBJECTIVES

To compare the pathologic definitions, clinical and radiographic presentations, etiologies and differential diagnoses, treatments, and prognoses of usual interstitial pneumonia, fibrotic nonspecific interstitial pneumonia, and airway-centered fibrosis patterns, and to address the challenges and controversies related to pulmonary fibrosis.

DATA SOURCES

Data were derived from published literature and clinical experience.

CONCLUSIONS

Although there may be overlap, identification of the dominant form of fibrosis in a particular case can provide a general category of disease and assist in identifying an etiology.

Nonspecific interstitial pneumonia preceding diagnosis of collagen vascular disease

BACKGROUND

The aim of this study was to evaluate the incidence and clinical features of patients who developed collagen vascular disease (CVD) after an initial diagnosis of idiopathic nonspecific interstitial pneumonia (NSIP).

METHODS

We conducted a retrospective review of 72 consecutive patients with NSIP who were diagnosed by surgical lung biopsy in our institution (idiopathic NSIP, n = 35; CVD-NSIP, n = 37 at initial diagnosis). No patients fulfilled the American College of Rheumatology criteria for a diagnosis with CVD within six months after the diagnosis of idiopathic NSIP.

RESULTS

Of 35 patients initially diagnosed with idiopathic NSIP, six patients (17.1%) developed CVD during the follow-up period (5.5 ± 5.0 years); three patients were diagnosed with dermatomyositis (DM), two patients with overlap syndrome (DM and Sjogren's syndrome), and one patient with rheumatoid arthritis. The mean time until CVD diagnosis was 2.0 years (six months - 3.5 years), and the one-, two- and three-year incidences of CVD development were 3.6%, 15.2% and 20.0%, respectively. There was no significant difference in clinical characteristics and survival among patients with NSIP preceding CVD diagnosis, those with idiopathic NSIP, or those with CVD-NSIP. In addition, at the time of initial diagnosis, there was no significant difference for the fulfillment of previous criteria such as interstitial pneumonia with autoimmune feature (IPAF) between patients with NSIP preceding CVD diagnosis and those with idiopathic NSIP.

CONCLUSIONS

It is difficult to predict CVD occurrence and careful attention is needed to detect the development of CVD in patients with idiopathic NSIP.

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.

Idiopathic non-specific interstitial pneumonia

Non-specific interstitial pneumonia (NSIP) is an interstitial lung disease that may be idiopathic or secondary to connective tissue disease, toxins or numerous other causes. Idiopathic NSIP is a rare diagnosis and requires exclusion of these other possible causes. Patients typically present in mid-adulthood with dyspnoea, cough and often constitutional symptoms including fever and fatigue. The disease has a female predominance, and more than 50% of patients have never smoked. Physical exam features mild hypoxaemia and inspiratory rales. Pulmonary function tests demonstrate restriction and a low diffusing capacity for carbon monoxide. High-resolution computed tomography abnormalities include predominantly lower lobe subpleural reticular changes, traction bronchiectasis and ground-glass opacities; honeycombing is rarely seen. An evaluation of the underlying pathology is necessary for a firm diagnosis. Histologically, alveolar and interstitial mononuclear cell inflammation and fibrosis are seen in a temporally uniform pattern with preserved underlying alveolar architecture. NSIP must be differentiated from other parenchymal lung diseases including idiopathic pulmonary fibrosis and hypersensitivity pneumonitis. A thorough exposure history and assessment for underlying connective tissue diseases are highly important, as positive findings in these categories would likely denote a case of secondary NSIP. A multi-disciplinary discussion that includes pulmonologist(s), radiologist(s) and pathologist(s) assists in reaching a consensus diagnosis and improves diagnostic accuracy. Treatment of idiopathic NSIP, although not well proven, is generally instituted in the form of immunosuppression. Prognosis is favourable compared with idiopathic pulmonary fibrosis, although the diagnosis still carries an attributable mortality. Herein we will summarize the clinical characteristics and management of idiopathic NSIP.

Lung-dominant connective tissue disease among patients with interstitial lung disease: prevalence, functional stability, and common extrathoracic features

OBJECTIVE

To describe the characteristics of a cohort of patients with lung-dominant connective tissue disease (LD-CTD).

METHODS

This was a retrospective study of patients with interstitial lung disease (ILD), positive antinuclear antibody (ANA) results (≥ 1/320), with or without specific autoantibodies, and at least one clinical feature suggestive of connective tissue disease (CTD).

RESULTS

Of the 1,998 patients screened, 52 initially met the criteria for a diagnosis of LD-CTD: 37% were male; the mean age at diagnosis was 56 years; and the median follow-up period was 48 months. During follow-up, 8 patients met the criteria for a definitive diagnosis of a CTD. The remaining 44 patients comprised the LD-CTD group, in which the most prevalent extrathoracic features were arthralgia, gastroesophageal reflux disease, and Raynaud's phenomenon. The most prevalent autoantibodies in this group were ANA (89%) and anti-SSA (anti-Ro, 27%). The mean baseline and final FVC was 69.5% and 74.0% of the predicted values, respectively (p > 0.05). Nonspecific interstitial pneumonia and usual interstitial pneumonia patterns were found in 45% and 9% of HRCT scans, respectively; 36% of the scans were unclassifiable. A similar prevalence was noted in histological samples. Diffuse esophageal dilatation was identified in 52% of HRCT scans. Nailfold capillaroscopy was performed in 22 patients; 17 showed a scleroderma pattern.

CONCLUSIONS

In our LD-CTD group, there was predominance of females and the patients showed mild spirometric abnormalities at diagnosis, with differing underlying ILD patterns that were mostly unclassifiable on HRCT and by histology. We found functional stability on follow-up. Esophageal dilatation on HRCT and scleroderma pattern on nailfold capillaroscopy were frequent findings and might come to serve as diagnostic criteria.

Interpretation of autoantibody positivity in interstitial lung disease and lung-dominant connective tissue disease

The initial evaluation of patients with interstitial lung disease (ILD) primarily involves a comprehensive, active search for the cause. Autoantibody assays, which can suggest the presence of a rheumatic disease, are routinely performed at various referral centers. When interstitial lung involvement is the condition that allows the definitive diagnosis of connective tissue disease and the classical criteria are met, there is little debate. However, there is still debate regarding the significance, relevance, specificity, and pathophysiological role of autoimmunity in patients with predominant pulmonary involvement and only mild symptoms or formes frustes of connective tissue disease. The purpose of this article was to review the current knowledge of autoantibody positivity and to discuss its possible interpretations in patients with ILD and without clear etiologic associations, as well as to enhance the understanding of the natural history of an allegedly new disease and to describe the possible prognostic implications. We also discuss the proposition of a new term to be used in the classification of ILDs: lung-dominant connective tissue disease.

Usual interstitial pneumonia preceding collagen vascular disease: a retrospective case control study of patients initially diagnosed with idiopathic pulmonary fibrosis

Background

The aim of this study was to evaluate the cumulative incidence and the predictive factors for collagen vascular disease (CVD) in patients initially diagnosed with idiopathic pulmonary fibrosis (IPF), and to examine the features of patients who then developed CVD.

Methods

This was a retrospective review of 111 consecutive patients with IPF diagnosed at our institution. None of the patients fulfilled any of the CVD criteria from the American College of Rheumatology (ACR) within 6 months or more after the diagnosis of IPF.

Results

Ten patients (9.0%) developed CVD during the follow-up period: four had rheumatoid arthritis (RA); four had microscopic polyangiitis (MPA); one had systemic sclerosis (SSc); and one had SSc and Sjogren’s syndrome (SjS). The mean time until CVD diagnosis was 3.9 years. The cumulative incidences of CVD at 1, 5, and 10 years were 0.91%, 9.85%, and 15.5%, respectively. Patients who developed CVD were significantly younger, more likely to be women and had a better prognosis than those with IPF. Cox proportional hazards regression analysis showed that female sex and the presence of lymphoid aggregates with germinal centers were significantly associated with the occurrence of CVD in patients initially diagnosed with IPF.

Conclusions

CVD is an important underlying condition in IPF, and shows better prognosis. The possibility of the development of CVD should remain a consideration in the follow-up of IPF.

BPIFB1 is a lung-specific autoantigen associated with interstitial lung disease

Interstitial lung disease (ILD) is a complex and heterogeneous disorder that is often associated with autoimmune syndromes. Despite the connection between ILD and autoimmunity, it remains unclear whether ILD can develop from an autoimmune response that specifically targets the lung parenchyma. We examined a severe form of autoimmune disease, autoimmune polyglandular syndrome type 1 (APS1), and established a strong link between an autoimmune response to the lung-specific protein BPIFB1 (bactericidal/permeability-increasing fold-containing B1) and clinical ILD. Screening of a large cohort of APS1 patients revealed autoantibodies to BPIFB1 in 9.6% of APS1 subjects overall and in 100% of APS1 subjects with ILD. Further investigation of ILD outside the APS1 disorder revealed BPIFB1 autoantibodies present in 14.6% of patients with connective tissue disease-associated ILD and in 12.0% of patients with idiopathic ILD. The animal model for APS1, Aire⁻/⁻ mice, harbors autoantibodies to a similar lung antigen (BPIFB9); these autoantibodies are a marker for ILD. We found that a defect in thymic tolerance was responsible for the production of BPIFB9 autoantibodies and the development of ILD. We also found that immunoreactivity targeting BPIFB1 independent of a defect in Aire also led to ILD, consistent with our discovery of BPIFB1 autoantibodies in non-APS1 patients. Overall, our results demonstrate that autoimmunity targeting the lung-specific antigen BPIFB1 may contribute to the pathogenesis of ILD in patients with APS1 and in subsets of patients with non-APS1 ILD, demonstrating the role of lung-specific autoimmunity in the genesis of ILD.

Clinical significance of serum autoantibodies in idiopathic interstitial pneumonia

Although autoantibodies are routinely screened in patients with idiopathic interstitial pneumonia, there are no reliable data on their clinical usefulness. The aim of this study was to investigate the prognostic value of autoantibodies for predicting the development of new connective tissue disease in these patients and also mortality. We conducted retrospective analysis of the baseline, and follow-up data for 688 patients with idiopathic interstitial pneumonia (526 with idiopathic pulmonary fibrosis, 85 with nonspecific interstitial pneumonia, and 77 with cryptogenic organizing pneumonia) at one single tertiary referral center. The median follow-up period was 33.6 months. Antinuclear antibody was positive in 34.5% of all subjects, rheumatoid factor in 13.2%, and other specific autoantibodies were positive between 0.7%-6.8% of the cases. No significant difference in patient survival was found between the autoantibody-positive and -negative groups. However, the presence of autoantibodies, especially antinuclear antibody with a titer higher than 1:320, was a significant predictor for the future development of new connective tissue diseases (relative risk, 6.4), although the incidence was low (3.8% of all subjects during follow-up). In conclusion, autoantibodies are significant predictors for new connective tissue disease development, although they have no prognostic value.

Successful treatment with tacrolimus in a case of lung-dominant connective tissue disease

A 49-year-old man with dyspnea was found to have reticular opacities and ground-glass attenuation with traction bronchiectasis or bronchiolectasis on computed tomography. The patient met the criteria for lung-dominant connective tissue disease (LD-CTD) and histopathologically exhibited a chronic fibrotic interstitial pneumonia illustrating framework of a usual interstitial pneumonia-like pattern. Due to worsening of the disease, therapy was initiated with corticosteroids in combination with cyclosporine A. However, treatment with these drugs was ineffective. Pirfenidone and intravenous cyclophosphamide therapy also proved ineffective. The cyclosporine A was therefore switched to tacrolimus, and the patient's disease improved, allowing for a reduction in the dose of the corticosteroids. Our experience in this case suggests that treatment with tacrolimus might be useful for treating refractory LD-CTD even when histopathologically chronic fibrotic interstitial pneumonia is evident.

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.

Connective tissue disease-associated interstitial lung disease: a call for clarification

This commentary highlights the present dilemmas surrounding the classification of a patient with interstitial pneumonia who has clinical features suggesting an associated connective tissue disease but the features fall short of a clear diagnosis of connective tissue disease-associated interstitial lung disease under the current rheumatologic classification systems. This commentary illustrates what we perceive to be the limitations in the present approach to the classification of this group of patients and discusses problems with redefining the diagnosis of undifferentiated connective tissue disease to encompass patients with interstitial pneumonia. Finally, we advocate not only for a multidisciplinary approach to evaluation, but also disease classification and offer a proposal to define them as a distinct phenotype--lung-dominant CTD--for which prognostic, therapeutic, and pathobiologic implications can be tested in future, hopefully multiinstitutional, studies.

Idiopathic nonspecific interstitial pneumonia: report of an American Thoracic Society project

RATIONALE

The 2002 American Thoracic Society/European Respiratory Society classification of idiopathic interstitial pneumonias identified nonspecific interstitial pneumonia (NSIP) as a provisional diagnosis. Concern was expressed that NSIP was a "wastebasket" category, difficult to distinguish from other idiopathic interstitial pneumonias.

OBJECTIVES

The following questions were addressed: (1) Is idiopathic NSIP a distinct entity? 2) If so, what are its clinical, radiologic and pathologic characteristics? (3) What is the role of radiology and pathology in establishing the diagnosis? (4) To make a diagnosis of idiopathic NSIP, what other disorders need to be excluded and how should this be done?

METHODS

Investigators who had previously reported cases of idiopathic NSIP were invited to submit cases for review (n = 305). After initial review, cases with complete clinical, radiologic, and pathologic information (n = 193) were reviewed in a series of workshops.

MEASUREMENTS AND MAIN RESULTS

Sixty-seven cases were identified as NSIP. Mean age was 52 years, 67% were women, 69% were never-smokers, and 46% were from Asian countries. The most common symptoms were dyspnea (96%) and cough (87%); 69% had restriction. By high-resolution computed tomography, the lower lung zones were predominantly involved in 92% of cases; 46% had a peripheral distribution; 47% were diffuse. Most showed a reticular pattern (87%) with traction bronchiectasis (82%) and volume loss (77%). Lung biopsies showed uniform thickening of alveolar walls with a spectrum of cellular to fibrosing patterns. Five-year survival was 82.3%.

CONCLUSIONS

Idiopathic NSIP is a distinct clinical entity that occurs mostly in middle-aged women who are never-smokers. The prognosis of NSIP is very good.

Collagen Vascular Diseases and Disorders of Connective Tissue

The collagen vascular diseases, also referred to as connective tissue diseases, are a diverse group of systemic inflammatory disorders thought to be immunologically mediated. The concept of collagen vascular disease began to take shape in the 1930s, when it was recognized that rheumatic fever and rheumatoid arthritis can affect connective tissues throughout the body.1,2 During the following decade, as conditions such as systemic lupus erythematosus (SLE) and scleroderma came to be viewed as systemic diseases of connective tissue, the terms diffuse connective disease and diffuse collagen disease were proposed.3,4 During the same period, the designation of diffuse vascular disease was proposed for diseases such as scleroderma, polymyositis, SLE, and polyarteritis nodosa, which featured widespread vascular involvement.5 With the realization that many of these entities can exhibit both systemic connective tissue manifestations and vascular abnormalities, the unifying designation of collagen vascular disease was introduced.6

Autoantibody to alanyl-tRNA synthetase in patients with idiopathic pulmonary fibrosis

BACKGROUND AND OBJECTIVES

The pathogenesis of IPF is unknown and it is hypothesized that immunological responses are involved. The purpose of this study was to detect autoantibodies in IPF patients and to identify the relevant antigens.

METHODS

Sera from 37 healthy subjects and 22 IPF patients who had no clinical symptoms of collagen vascular disease were examined for immunostaining of A549 human type II cells and human lung tissue. Immunoprecipitation and proteome analysis were performed to identify the antigen.

RESULTS

Fifty per cent of the patient sera and none of the control sera exhibited positive staining. Sera from 10 of the 22 IPF patients showed positive immunohistochemistry and immunoprecipitated a 110-kDa protein from the A549 cell lysate. Sera from only two of 41 patients with collagen vascular disease showed positive immunoreactivity. Proteome analysis using tandem mass spectrometry revealed that the protein was alanyl-tRNA synthetase. Transfection of cDNA of this enzyme into CHO-K1 cells conferred positive staining on these cells with the patients' IgG. The 135-kDa fusion protein consisting of 108-kDa enzyme protein and 27-kDa YFP from the cell lysate of the transfected cells was immunoprecipitated by the patient IgG. In addition, sera from IPF patients significantly inhibited the enzyme activity of alanyl-tRNA synthetase.

CONCLUSION

A significant number of IPF patients possess circulating autoantibodies against alanyl-tRNA synthetase, suggesting the involvement of an autoimmune background in the pathogenesis of IPF.

Unique Characteristics of Systemic Sclerosis Sine Scleroderma-Associated Interstitial Lung Disease

STUDY OBJECTIVES

To describe the characteristics of systemic sclerosis sine scleroderma (ssSSc)-associated interstitial lung disease (ILD) presenting as idiopathic interstitial pneumonia (IIP).

DESIGN

Retrospective review of six patients with ssSSc-associated ILD diagnosed after referral for evaluation of IIP.

MEASUREMENT AND RESULTS

All patients were white, their mean age was 56 years (range, 37 to 86), and gender was evenly divided. Sclerodactyly, skin thickening, and digital edema were absent in all patients. All patients had scattered telangiectasia, and four patients had Raynaud phenomenon with abnormal nailfold capillaroscopy findings. All described gastroesophageal reflux, and three patients had esophageal dysmotility by esophagography. All had restrictive pulmonary physiology and a reduced diffusion capacity. High-resolution CT revealed nonspecific interstitial pneumonia (NSIP) or usual interstitial pneumonia (UIP) radiographic patterns. Of the three patients who underwent surgical lung biopsy, two patients had NSIP and one patient had UIP pathologic patterns. Five patients had asymptomatic pericardial effusions and elevated pulmonary artery pressures by echocardiography. All patients had nucleolar-staining anti-nuclear antibodies (ANAs), and one patient was anti-Scl-70 positive. All five anti-Scl-70-negative patients were anti-Th/To positive, and the anti-Scl-70-positive patient was anti-Th/To negative.

CONCLUSIONS

In the presentation of an IIP, the presence of a nucleolar-staining ANA, telangiectasia, Raynaud phenomenon with abnormal capillaroscopy findings, gastroesophageal reflux, or pericardial disease suggests underlying systemic sclerosis. These findings should aid clinicians in the evaluation and treatment of patients with otherwise undefined ILD.