Connective tissue disease-associated interstitial pneumonia and idiopathic interstitial pneumonia: similarity and difference

The phenotype of mixed connective tissue disease patients having associated interstitial lung disease

OBJECTIVE

We aimed to compare two matched populations of patients with MTCD with and without associated ILD and to identify predictive factors for ILD progression and severity.

METHODS

This international multicenter retrospective study (14 tertiary hospitals), included MCTD patients who fulfilled at least one historical MCTD classification criteria. ILD was defined by the presence of typical chest high-resolution computed tomography (HRCT) abnormalities. Factors associated with ILD were assessed at baseline. Long-term progressive ILD was assessed in MCTD-ILD patients with multiple forced vital capacity (FVC) measurements.

RESULTS

300 patients with MCTD were included. Mean age at diagnosis was 39.7 ± 15.4 years and 191 (63.7%) were women. Mean follow-up was 7.8 ± 5.5 years. At baseline, we identified several factors associated with ILD presence: older age (p = 0.01), skin thickening (p = 0.03), upper gastro-intestinal (GI) symptoms (p<0.001), FVC <80% (p<0.0001), diffusing capacity for carbon monoxide <80% (p<0.0001), anti-topoisomerase antibodies (p = 0.01), SSA/Ro antibodies (p = 0.02), cryoglobulinemia (p = 0.04) and elevated C-reactive protein (p<0.001). Patients with MTCD-ILD were more likely to be treated with synthetic immunosuppressant agents (p<0.001) in particular mycophenolate mofetil (p = 0.03). Digital ulcers (DU) were identified as a risk factor for FVC decline >10%. During follow-up mortality was higher in the MTCD-ILD group (p<0.001).

CONCLUSION

In this large international cohort of patients with MTCD, we identified different factors associated with ILD. Our findings also provide evidence that MCTD-ILD patients have increased mortality and that DU are associated with progressive lung disease.

Non-contrast computed tomography-based radiomics for staging of connective tissue disease-associated interstitial lung disease

Rationale and introduction

It is of significance to assess the severity and predict the mortality of patients with connective tissue disease-associated interstitial lung disease (CTD-ILD). In this double-center retrospective study, we developed and validated a radiomics nomogram for clinical management by using the ILD-GAP (gender, age, and pulmonary physiology) index system.

Materials and methods

Patients with CTD-ILD were staged using the ILD-GAP index system. A clinical factor model was built by demographics and CT features, and a radiomics signature was developed using radiomics features extracted from CT images. Combined with the radiomics signature and independent clinical factors, a radiomics nomogram was constructed and evaluated by the area under the curve (AUC) from receiver operating characteristic (ROC) analyses. The models were externally validated in dataset 2 to evaluate the model generalization ability using ROC analysis.

Results

A total of 245 patients from two clinical centers (dataset 1, n = 202; dataset 2, n = 43) were screened. Pack-years of smoking, traction bronchiectasis, and nine radiomics features were used to build the radiomics nomogram, which showed favorable calibration and discrimination in the training cohort {AUC, 0.887 [95% confidence interval (CI): 0.827-0.940]}, the internal validation cohort [AUC, 0.885 (95% CI: 0.816-0.922)], and the external validation cohort [AUC, 0.85 (95% CI: 0.720-0.919)]. Decision curve analysis demonstrated that the nomogram outperformed the clinical factor model and radiomics signature in terms of clinical usefulness.

Conclusion

The CT-based radiomics nomogram showed favorable efficacy in predicting individual ILD-GAP stages.

A computed tomography-based radiomics nomogram for predicting overall survival in patients with connective tissue disease-associated interstitial lung disease

OBJECTIVES

Accurate prognostic prediction is beneficial for the management of patients with connective tissue disease-associated interstitial lung disease (CTD-ILD). The purpose of the present study was to develop and validate a nomogram using clinical features and computed tomography (CT) based radiomics features to predict overall survival (OS) in patients with CTD-ILD, and to assess the incremental prognostic value the radiomics might add to clinical risk factors.

MATERIALS & METHODS

Patients from two clinical centers with CTD-ILD were enrolled in the present retrospective study. A radiomics signature, a clinical model and a combined nomogram were developed and assessed in the cohorts. The incremental value of radiomics signature to the clinical independent risk factors in survival prediction was evaluated. The models were externally validated to evaluate the model generalization ability.

RESULTS

A total of 215 patients (mean age, 53 years ± 14 [standard deviation], 45 men) were evaluated. Patients with higher radiomics scores had higher mortality risk than those with lower radiomics scores (Hazard ratio, 12.396; 95% CI, 3.364-45.680; P < 0.001). The combined nomogram showed better predictive capability than the clinical model did with higher C-indices (0.800, 0.738, 0.742 vs. 0.747, 0.631, 0.587 in the training, internal- and external-validation cohort, respectively), time-AUCs and overall net-benefit.

CONCLUSION

The radiomics signature is a potential prognostic biomarker of CTD-ILD and add incremental value to the clinical independent risk factors. The combined nomogram can provide a more accurate estimation of OS than the clinical model for CTD-ILD patients.

CLINICAL RELEVANCE STATEMENT

The developed combined nomogram showed accurate prognostic prediction performance, which is beneficial for the management of CTD-ILD patients. It also proved radiomics could extract prognostic information from CT images.

Clinical and radiological features of lung disorders related to connective-tissue diseases: a pictorial essay

Connective tissue diseases (CTDs) include a spectrum of disorders that affect the connective tissue of the human body; they include autoimmune disorders characterized by immune-mediated chronic inflammation and the development of fibrosis. Lung involvement can be misdiagnosed, since pulmonary alterations preceded osteo-articular manifestations only in 20% of cases and they have no clear clinical findings in the early phases. All pulmonary structures may be interested: pulmonary interstitium, airways, pleura and respiratory muscles. Among these autoimmune disorders, rheumatoid arthritis (RA) is characterized by usual interstitial pneumonia (UIP), pulmonary nodules and airway disease with air-trapping, whereas non-specific interstitial pneumonia (NSIP), pulmonary hypertension and esophageal dilatation are frequently revealed in systemic sclerosis (SSc). NSIP and organizing pneumonia (OP) may be found in patients having polymyositis (PM) and dermatomyositis (DM); in some cases, perilobular consolidations and reverse halo-sign areas may be observed. Systemic lupus erythematosus (SLE) is characterized by serositis, acute lupus pneumonitis and alveolar hemorrhage. In the Sjögren syndrome (SS), the most frequent pattern encountered on HRCT images is represented by NSIP; UIP and lymphocytic interstitial pneumonia (LIP) are reported with a lower frequency. Finally, fibrotic NSIP may be the interstitial disease observed in patients having mixed connective tissue diseases (MCTD). This pictorial review therefore aims to provide clinical features and imaging findings associated with autoimmune CTDs, in order to help radiologists, pneumologists and rheumatologists in their diagnoses and management.

The use of exhaled air analysis in discriminating interstitial lung diseases: a pilot study

BACKGROUND

Fibrotic Interstitial lung diseases (ILD) are a heterogeneous group of chronic lung diseases characterized by diverse degrees of lung inflammation and remodeling. They include idiopathic ILD such as idiopathic pulmonary fibrosis (IPF), and ILD secondary to chronic inflammatory diseases such as connective tissue disease (CTD). Precise differential diagnosis of ILD is critical since anti-inflammatory and immunosuppressive drugs, which are beneficial in inflammatory ILD, are detrimental in IPF. However, differential diagnosis of ILD is still difficult and often requires an invasive lung biopsy. The primary aim of this study is to identify volatile organic compounds (VOCs) patterns in exhaled air to non-invasively discriminate IPF and CTD-ILD. As secondary aim, the association between the IPF and CTD-ILD discriminating VOC patterns and functional impairment is investigated.

METHODS

Fifty-three IPF patients, 53 CTD-ILD patients and 51 controls donated exhaled air, which was analyzed for its VOC content using gas chromatograph- time of flight- mass spectrometry.

RESULTS

By applying multivariate analysis, a discriminative profile of 34 VOCs was observed to discriminate between IPF patients and healthy controls whereas 11 VOCs were able to distinguish between CTD-ILD patients and healthy controls. The separation between IPF and CTD-ILD could be made using 16 discriminating VOCs, that also displayed a significant correlation with total lung capacity and the 6 min' walk distance.

CONCLUSIONS

This study reports for the first time that specific VOC profiles can be found to differentiate IPF and CTD-ILD from both healthy controls and each other. Moreover, an ILD-specific VOC profile was strongly correlated with functional parameters. Future research applying larger cohorts of patients suffering from a larger variety of ILDs should confirm the potential use of breathomics to facilitate fast, non-invasive and proper differential diagnosis of specific ILDs in the future as first step towards personalized medicine for these complex diseases.

Interstitial Lung Disease in Connective Tissue Disease: A Common Lesion With Heterogeneous Mechanisms and Treatment Considerations

Connective tissue disease (CTD) related interstitial lung disease (CTD-ILD) is one of the leading causes of morbidity and mortality of CTD. Clinically, CTD-ILD is highly heterogenous and involves rheumatic immunity and multiple manifestations of respiratory complications affecting the airways, vessels, lung parenchyma, pleura, and respiratory muscles. The major pathological features of CTD are chronic inflammation of blood vessels and connective tissues, which can affect any organ leading to multi-system damage. The human lung is particularly vulnerable to such damage because anatomically it is abundant with collagen and blood vessels. The complex etiology of CTD-ILD includes genetic risks, epigenetic changes, and dysregulated immunity, which interact leading to disease under various ill-defined environmental triggers. CTD-ILD exhibits a broad spectra of clinical manifestations: from asymptomatic to severe dyspnea; from single-organ respiratory system involvement to multi-organ involvement. The disease course is also featured by remissions and relapses. It can range from stability or slow progression over several years to rapid deterioration. It can also present clinically as highly progressive from the initial onset of disease. Currently, the diagnosis of CTD-ILD is primarily based on distinct pathology subtype(s), imaging, as well as related CTD and autoantibodies profiles. Meticulous comprehensive clinical and laboratory assessment to improve the diagnostic process and management strategies are much needed. In this review, we focus on examining the pathogenesis of CTD-ILD with respect to genetics, environmental factors, and immunological factors. We also discuss the current state of knowledge and elaborate on the clinical characteristics of CTD-ILD, distinct pathohistological subtypes, imaging features, and related autoantibodies. Furthermore, we comment on the identification of high-risk patients and address how to stratify patients for precision medicine management approaches.

Interstitial Lung Disease Associated with Connective Tissue Diseases

Pulmonary manifestations of connective tissue diseases (CTD) carry high morbidity and potential mortality, and the most serious pulmonary type is interstitial lung disease (ILD). Identifying and promptly intervening CTD-ILD with immune suppressor therapy will change the natural course of the disease resulting in survival improvement. Compared to idiopathic pulmonary fibrosis, the most common presentation of idiopathic interstitial pneumonia (IIP), CTD-ILD carries a better prognosis due to the response to immune suppressor therapy. Nonspecific interstitial pneumonia (NSIP) is the most common type of CTD-ILD that is different from the fibrotic classical presentation of IPF, known as usual interstitial pneumonia (UIP). An exception is rheumatoid arthritis that presents more frequently with UIP type. Occasionally, IPF may not have typical radiographic features of UIP, and a full assessment to differentiate IPF from CTD-ILD is necessary, including the intervention of a multidisciplinary team and the histopathology. Interstitial pneumonia with autoimmune features (IPAF) shows promising advantages to identify patients with ILD who have some features of a CTD without a defined autoimmune disease and who may benefit from immune suppressors. A composition of clinical, serological, and morphologic features in patients presenting with ILD will fulfill criteria for IPAF. In summary, the early recognition and treatment of CTD-ILD, differentiation from IPF-UIP, and identification of patients with IPAF fulfill the assessment by the clinician for an optimal care.

Evaluation of rheumatoid arthritis and connective tissue disease-related interstitial lung disease with pulmonary physiologic test, HRCT, and patient-based measures of dyspnea and functional disability

OBJECTIVES

We aim to investigate the relationship between pulmonary function and imaging parameters with symptom-related patient-reported outcome measures (PROs).

METHOD

We included 65 patients of rheumatoid arthritis (RA) and connective tissue disease (CTD) with and without interstitial lung disease (ILD) into this cross-sectional study. We evaluated the relationship between FVC, DLco, and PROs and compared to HRCT findings. PROs included visual analogue scale for breathing, modified Borg scale, medical research council dyspnea scale, St. George's respiratory questionnaire (SGRQ), Leicester cough questionnaire, and Short Form 36 quality of life (SF-36 QoL).

RESULTS

The mean age was 57.4 ± 9.7 and 61.9% (39/65) of patients had an established ILD. In RA-ILD group, SGRQ score was higher (p < 0.001) and SF-36 physical functioning score was lower (p = 0.02) than CTD-ILD group. In RA group, there was a significant correlation between FVC and SF-36 role functioning/physical score (r = 0.724, p = 0.012). In CTD group, SF-36 general health score was correlated with both FVC (r = 0.441, p = 0.045) and DLco (r = 0.485, p = 0.035), and also SF-36 physical functioning score was correlated with FVC (r = 0.441, p = 0.040). PROs were found to be similar between ILD and non-ILD patients. SF-36 QoL total and SGRQ outcomes were worse in non-ILD group.

CONCLUSIONS

We concluded that PROs could be used to evaluate health-related quality of life (HRQoL) in RA- or CTD-related ILD. The physical health determinants of HRQoL are measurably worse in RA-ILD patients than in CTD patients. But, PROs may not be very helpful in differentiating patients with cough and/or shortness of breath due to ILD or non-ILD causes in RA/CTD.

KEY POINTS

• HRQoL may be affected differently among specific subtypes of ILD. • PROs can be used to evaluate dyspnea and function of patients with RA- or CTD-related ILD but are not distinguished from patients with cough and/or shortness of breath due to non-ILD causes in RA/CTD.

Histologic features suggesting connective tissue disease in idiopathic pulmonary fibrosis

Some patients with idiopathic pulmonary fibrosis (IPF) have histopathologic features suggesting connective tissue disease (CTD); however, their clinical course and prognosis remain unclear. Thus, we aimed to investigate the clinical course and prognosis of these patients with histologic autoimmune features. Among 114 patients with biopsy-proven IPF, the histologic features were semi-quantitatively graded, and CTD scores (range: 0-9) were calculated as the sum of each score of plasma cell infiltration, lymphoid aggregates, and germinal centres. Patients with high CTD scores (≥ 4) were classified into the interstitial pneumonia with histologic autoimmune features (IP-hAF) group. The mean age of the patients was 60.0 years; 74.6% were men, 69.3% were ever-smokers, and 35.1% had IP-hAF. During follow-up, the IP-hAF group showed slower decline in lung function, and better prognosis (median survival, 48.7 vs. 40.4 months; p = 0.015) than the no-IP-hAF group. On multivariate Cox analysis, IP-hAF was an independent prognostic factor (hazard ratio, 0.522; p = 0.016), along with the lower diffusing capacity for carbon monoxide, higher scores of reticulation and honeycombing, and usual interstitial pneumonia pattern on high-resolution computed tomography. Patients with IPF having histologic autoimmune features show distinct clinical characteristics and better outcome than those without histologic autoimmune features.

Diagnosis and management of connective tissue disease-associated interstitial lung disease in Australia and New Zealand: A position statement from the Thoracic Society of Australia and New Zealand

Pulmonary complications in CTD are common and can involve the interstitium, airways, pleura and pulmonary vasculature. ILD can occur in all CTD (CTD-ILD), and may vary from limited, non-progressive lung involvement, to fulminant, life-threatening disease. Given the potential for major adverse outcomes in CTD-ILD, accurate diagnosis, assessment and careful consideration of therapeutic intervention are a priority. Limited data are available to guide management decisions in CTD-ILD. Autoimmune-mediated pulmonary inflammation is considered a key pathobiological pathway in these disorders, and immunosuppressive therapy is generally regarded the cornerstone of treatment for severe and/or progressive CTD-ILD. However, the natural history of CTD-ILD in individual patients can be difficult to predict, and deciding who to treat, when and with what agent can be challenging. Establishing realistic therapeutic goals from both the patient and clinician perspective requires considerable expertise. The document aims to provide a framework for clinicians to aid in the assessment and management of ILD in the major CTD. A suggested approach to diagnosis and monitoring of CTD-ILD and, where available, evidence-based, disease-specific approaches to treatment have been provided.

Multimodality imaging in connective tissue disease-related interstitial lung disease

Interstitial lung disease is a well-recognised manifestation and a major cause of morbidity and mortality in patients with connective tissue diseases. Interstitial lung disease may arise in the context of an established connective tissue disease or be the initial manifestation of an otherwise occult autoimmune disorder. Early detection and characterisation are paramount for adequate patient management and require a multidisciplinary approach, in which imaging plays a vital role. Computed tomography is currently the imaging method of choice; however, other imaging techniques have recently been investigated, namely ultrasound, magnetic resonance imaging, and positron-emission tomography, with promising results. The aim of this review is to describe the imaging findings of connective tissue disease-related interstitial lung disease and explain the role of each imaging technique in diagnosis and disease characterisation.

Connective tissue disease--associated interstitial lung disease: an underreported cause of interstitial lung disease in Sub-Saharan Africa

Interstitial lung disease (ILD) occurs in 15% of connective tissue disease (CTD) patients causing considerable morbidity and mortality. Data is scarce regarding its clinical characteristics and outcomes in Africa. We aim to study the frequency, clinico-radiological characteristics, and treatment outcomes of African CTD-ILD patients. A retrospective cross-sectional study of ILD among 318 CTD patients diagnosed using relevant ACR criteria at the rheumatology unit of Lagos State University Teaching Hospital (LASUTH), Lagos from 2012 to 2019. Socio-demographics, clinical features, radiological findings, and treatment outcomes were documented. Data was analyzed using SPSS version 21 with p < 0.05. The LASUTH ethics committee approved the study. Interstitial lung disease occurred in 31 (9.7%) of 318 CTD cases. Their mean age was 38.8 ± 13.3 years, range 19-68 years with 28 (90.3%) females. Proportions of CTD-ILD were Sjogren's syndrome (50%), UCTD (50%), systemic sclerosis (46.7%), MCTD (33.3%), PM/DM (25%), SLE (6.5%), and RA (2.6%). Commonest presentations were cough (93.5%) and bibasal inspiratory crackles (83.9%) with a restrictive pattern in 83.9%. Antinuclear antibody occurred in 100% and anti-ENA in 67.7%. Traction bronchiectasis (89.7%) and ground glass opacities (96.6%) were frequent HRCT findings. Treatments included pulse-dose prednisolone, cyclophosphamide, mycophenolate mofetil, pirfenidone, and rituximab. Outcomes were ambulatory oxygen therapy (12.9%) and mortality (16.1%) with 9.7% lost to follow-up. CTD-ILD is a female predominant disease occurring in 9.7% of CTD patients mostly those with Sjogren's syndrome and systemic sclerosis. Due to significant morbidity and mortality, we advocate routine ILD screening for all CTD patients including those with undifferentiated disease. Key Points: • Interstitial lung disease occurs in 9.7% of patients with underlying connective tissue disease. • Females are predominantly affected especially those with Sjogren's syndrome and systemic sclerosis. • Mortality occurs in roughly 1 in every 6 patients with CTD-ILD.

Interstitial Lung Disease and Other Pulmonary Manifestations in Connective Tissue Diseases

Lung involvement in connective tissue diseases is associated with substantial morbidity and mortality, most commonly in the form of interstitial lung disease, and can occur in any of these disorders. Patterns of interstitial lung disease in patients with connective tissue disease are similar to those seen in idiopathic interstitial pneumonias, such as idiopathic pulmonary fibrosis. It may be difficult to distinguish between the 2 ailments, particularly when interstitial lung disease presents before extrapulmonary manifestations of the underlying connective tissue disease. There are important clinical implications in achieving this distinction. Given the complexities inherent in the management of these patients, a multidisciplinary evaluation is needed to optimize the diagnostic process and management strategies. The aim of this article was to summarize an approach to diagnosis and management based on the opinion of experts on this topic.

Interstitial Lung Diseases in Developing Countries

More than 100 different conditions are grouped under the term interstitial lung disease (ILD). A diagnosis of an ILD primarily relies on a combination of clinical, radiological, and pathological criteria, which should be evaluated by a multidisciplinary team of specialists. Multiple factors, such as environmental and occupational exposures, infections, drugs, radiation, and genetic predisposition have been implicated in the pathogenesis of these conditions. Asbestosis and other pneumoconiosis, hypersensitivity pneumonitis (HP), chronic beryllium disease, and smoking-related ILD are specifically linked to inhalational exposure of environmental agents. The recent Global Burden of Disease Study reported that ILD rank 40th in relation to global years of life lost in 2013, which represents an increase of 86% compared to 1990. Idiopathic pulmonary fibrosis (IPF) is the prototype of fibrotic ILD. A recent study from the United States reported that the incidence and prevalence of IPF are 14.6 per 100,000 person-years and 58.7 per 100,000 persons, respectively. These data suggests that, in large populated areas such as Brazil, Russia, India, and China (the BRIC region), there may be approximately 2 million people living with IPF. However, studies from South America found much lower rates (0.4–1.2 cases per 100,000 per year). Limited access to high-resolution computed tomography and spirometry or to multidisciplinary teams for accurate diagnosis and optimal treatment are common challenges to the management of ILD in developing countries.

Pathological interpretation of connective tissue disease-associated lung diseases

Connective tissue diseases (CTDs) can affect all compartments of the lungs, including airways, alveoli, interstitium, vessels, and pleura. CTD-associated lung diseases (CTD-LDs) may present as diffuse lung disease or as focal lesions, and there is significant heterogeneity between the individual CTDs in their clinical and pathological manifestations. CTD-LDs may presage the clinical diagnosis a primary CTD, or it may develop in the context of an established CTD diagnosis. CTD-LDs reveal acute, chronic or mixed pattern of lung and pleural manifestations. Histopathological findings of diverse morphological changes can be present in CTD-LDs airway lesions (chronic bronchitis/bronchiolitis, follicular bronchiolitis, etc.), interstitial lung diseases (nonspecific interstitial pneumonia/fibrosis, usual interstitial pneumonia, lymphocytic interstitial pneumonia, diffuse alveolar damage, and organizing pneumonia), pleural changes (acute fibrinous or chronic fibrous pleuritis), and vascular changes (vasculitis, capillaritis, pulmonary hemorrhage, etc.). CTD patients can be exposed to various infectious diseases when taking immunosuppressive drugs. Histopathological patterns of CTD-LDs are generally nonspecific, and other diseases that can cause similar lesions in the lungs must be considered before the diagnosis of CTD-LDs. A multidisciplinary team involving pathologists, clinicians, and radiologists can adequately make a proper diagnosis of CTD-LDs.

Role of imaging in the diagnosis of diffuse and interstitial lung diseases

PURPOSE OF REVIEW

This review aims to provide a literature update focused on the role of imaging in the diagnosis, prognosis and quantification of interstitial lung diseases (ILDs). Special emphasis is given in the management of atypical cases and in the multidisciplinary team approach in reaching the diagnosis of the various ILDs.

RECENT FINDINGS

Accumulated knowledge on imaging has increased the accuracy of differential diagnosis in atypical cases, in overlap of findings and in secondary as opposed to idiopathic ILDs. There is increasing awareness about interstitial lung abnormalities in smokers' lungs from lung cancer screening and indirect evidence of linkage of fibrosis and smoking. Improvement in radiologic-pathologic correlation reveals less typical high-resolution computed tomography patterns to be predictive of pulmonary fibrosis. Major diagnostic criteria such as honeycombing may be hampered by the coexistence of emphysema. High-resolution computed tomography may predict clinical outcome and survival of patients in ILDs and is a decision maker in the multidisciplinary approach of diagnosis.

SUMMARY

High-resolution computed tomography plays a crucial role in the diagnosis, prognosis, quantification and monitoring of ILDs. It provides a definite noninvasive diagnosis in typical findings and helps in reaching the most accurate diagnosis in a multidisciplinary discussion in equivocal cases.

Sjögren Syndrome Complicated by Mucosa-Associated Lymphoid Tissue Lymphoma and Lymphocytic Interstitial Pneumonia

Sjögren syndrome (SS) is an autoimmune disease with exocrine glands dysfunction and multiorgan involvement. It is associated with increased risk of lymphoproliferative disorders, especially B-cell marginal zone lymphoma. While the role of F-18 Fluorodeoxyglucose position emission tomography/computed tomography (F-18 FDG PET/CT) for evaluation of lymphoma has been established, its use in patients with a chronic history of SS to evaluate for possible lymphoproliferative disorders or multiorgan involvement is limited. We present a case of chronic SS in which F-18 FDG PET/CT demonstrated FDG avid intraparotid and cervical lymph nodes pathologically proven to be mucosa-associated lymphoid tissue lymphoma. In addition, the patient had bibasilar cystic changes consistent with lymphocytic interstitial pneumonia.

Connective Tissue Disease-associated Interstitial Lung Diseases (CTD-ILD) - Report from OMERACT CTD-ILD Working Group

OBJECTIVE

Interstitial lung disease (ILD) is common in connective tissue disease (CTD) and is the leading cause of mortality. Investigators have used certain outcome measures in randomized controlled trials (RCT) in CTD-ILD, but the lack of a systematically developed, CTD-specific index that captures all measures relevant and meaningful to patients with CTD-ILD has left a large and conspicuous gap in CTD-ILD research.

METHODS

The CTD-ILD working group, under the aegis of the Outcome Measures in Rheumatology (OMERACT) initiative, has completed a consensus group exercise to reach harmony on core domains and items for inclusion in RCT in CTD-ILD. During the OMERACT 12 meeting, consensus was sought on domains and core items for inclusion in RCT. In addition, consensus was pursued on a definition of response in RCT. Consensus was defined as ≥ 75% agreement among the participants.

RESULTS

OMERACT 12 participants endorsed the domains with minimal modifications. Clinically meaningful progression for CTD-ILD was proposed as ≥ 10% relative decline in forced vital capacity (FVC) or ≥ 5% to < 10% relative decline in FVC and ≥ 15% relative decline in DLCO.

CONCLUSION

There is consensus on domains for inclusion in RCT in CTD-ILD and on a definition of clinically meaningful progression. Data-driven approaches to validate these results in different cohorts and RCT are needed.

Histopathology of lung disease in the connective tissue diseases

The pathologic correlates of interstitial lung disease (ILD) secondary to connective tissue disease (CTD) comprise a diverse group of histologic patterns. Lung biopsies in patients with CTD-associated ILD tend to demonstrate simultaneous involvement of multiple anatomic compartments of the lung. Certain histologic patterns tend to predominate in each defined CTD, and it is possible in many cases to confirm connective tissue-associated lung disease and guide patient management using surgical lung biopsy. This article will cover the pulmonary pathologies seen in rheumatoid arthritis, systemic sclerosis, myositis, systemic lupus erythematosus, Sjögren syndrome, and mixed CTD.