Progression and mortality of interstitial lung disease in mixed connective tissue disease: a long-term observational nationwide cohort study

Clinically Relevant Biomarkers in Connective Tissue Disease-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) complicates connective tissue disease (CTD) with variable incidence and is a leading cause of death in these patients. To improve CTD-ILD outcomes, early recognition and management of ILD is critical. Blood-based and radiologic biomarkers that assist in the diagnosis CTD-ILD have long been studied. Recent studies, including -omic investigations, have also begun to identify biomarkers that may help prognosticate such patients. This review provides an overview of clinically relevant biomarkers in patients with CTD-ILD, highlighting recent advances to assist in the diagnosis and prognostication of CTD-ILD.

Innovations in the care of childhood interstitial lung disease associated with connective tissue disease and immune-mediated disorders

Childhood interstitial lung disease (chILD) associated with connective tissue and immune mediated disorders is the second most common chILD diagnostic category. As knowledge of the molecular and genetic underpinnings of these rare disorders advances, the recognized clinical spectrum of associated pulmonary manifestations continues to expand. Pulmonary complications of these diseases, including ILD, confer increased risk for morbidity and mortality and contribute to increased complexity for providers tasked with managing the multiple organ systems that can be impacted in these systemic disorders. While pulmonologists play an important role in diagnosis and management of these conditions, thankfully they do not have to work alone. In collaboration with a multidisciplinary team of subspecialists, the pulmonary and other systemic manifestations of these conditions can be managed effectively together. The goal of this review is to familiarize the reader with the classic patterns of chILD and other pulmonary complications associated with primary immune-mediated disorders (monogenic inborn errors of immunity) and acquired systemic autoimmune and autoinflammatory diseases. In addition, this review will highlight current, emerging, and innovative therapeutic strategies and will underscore the important role of multidisciplinary management to improving outcomes for these patients.

Evolution of diagnostic criteria and new insights into clinical testing in mixed connective tissue disease; anti-survival motor neuron complex antibody as a novel marker of severity of the disease

Mixed connective tissue disease (MCTD) is an autoimmune disorder characterized by a combination of clinical features from systemic lupus erythematosus, systemic sclerosis, and inflammatory muscle disease, along with the presence of positive anti-U1-ribonucleoprotein (U1-RNP) antibodies. The exact etiology of the disease remains unclear, but it is believed to involve vascular damage within the context of heightened autoimmune responses. Consequently, Raynaud's phenomenon and pulmonary arterial hypertension are observed in patients with MCTD. While specific biomarkers for MCTD have not yet been identified, the recent study of the utility of anti-survival motor neuron complex (SMN) antibodies in MCTD suggests a promising avenue for further research and the accumulation of additional evidence.

Pulmonary Manifestations of Sjögren's Disease

Sjögren's disease (SjD) is a chronic, progressive autoimmune condition of exocrine and extraglandular tissues. It can present with isolated disease characterized by lymphocytic infiltration of salivary or lacrimal glands, but in approximately one-third of the patients, lymphocytic infiltration extends beyond exocrine glands to involve extraglandular organs such as the lungs. Pulmonary complications have been reported to occur between 9 and 27% of patients with SjD across studies. Respiratory manifestations occur on a spectrum of severity and include airways disease, interstitial lung disease, cystic lung disease, and lymphoma. Lung involvement can greatly affect patients' quality of life, has a major impact on the overall prognosis, and frequently leads to alteration in the treatment plans, highlighting the importance of maintaining a high index of clinical suspicion and taking appropriate steps to facilitate early recognition and intervention.

Central Role of CT in Management of Pulmonary Fibrosis

With the approval of antifibrotic medications to treat patients with idiopathic pulmonary fibrosis and progressive pulmonary fibrosis, radiologists have an integral role in diagnosing these entities and guiding treatment decisions. CT features of early pulmonary fibrosis include irregular thickening of interlobular septa, pleura, and intralobular linear structures, with subsequent progression to reticular abnormality, traction bronchiectasis or bronchiolectasis, and honeycombing. CT patterns of fibrotic lung disease can often be reliably classified on the basis of the CT features and distribution of the condition. Accurate identification of usual interstitial pneumonia (UIP) or probable UIP patterns by radiologists can obviate the need for a tissue sample-based diagnosis. Other entities that can appear as a UIP pattern must be excluded in multidisciplinary discussion before a diagnosis of idiopathic pulmonary fibrosis is made. Although the imaging findings of nonspecific interstitial pneumonia and fibrotic hypersensitivity pneumonitis can overlap with those of a radiologic UIP pattern, these entities can often be distinguished by paying careful attention to the radiologic signs. Diagnostic challenges may include misdiagnosis of fibrotic lung disease due to pitfalls such as airspace enlargement with fibrosis, paraseptal emphysema, recurrent aspiration, and postinfectious fibrosis. The radiologist also plays an important role in identifying complications of pulmonary fibrosis-pulmonary hypertension, acute exacerbation, infection, and lung cancer in particular. In cases in which there is uncertainty regarding the clinical and radiologic diagnoses, surgical biopsy is recommended, and a multidisciplinary discussion among clinicians, radiologists, and pathologists can be used to address diagnosis and management strategies. This review is intended to help radiologists diagnose and manage pulmonary fibrosis more accurately, ultimately aiding in the clinical management of affected patients. ©RSNA, 2024 Supplemental material is available for this article.

Clinical characteristics of patients with connective tissue disease-related interstitial lung disease: a retrospective analysis

INTRODUCTION

Interstitial lung disease is one of the most critical manifestations of connective tissue diseases that may cause morbidity and mortality. This study aimed to evaluate the clinical and demographic characteristics and treatment of the patients with connective tissue disease-related interstitial lung disease.

METHOD

This retrospective observational study included patients from the Gulhane Rheumatology Interstitial Lung Disease cohort between October 2016 and June 2023. The patients were assessed retrospectively.

RESULTS

A total of 173 patients were included in the study with a mean age of 63.4 ± 11.9 years. The frequencies of CTD were 34.1% Sjogren's syndrome, 30.1% rheumatoid arthritis, 25.4% systemic sclerosis, 5.8% undifferentiated connective tissue disease, 2.9% idiopathic inflammatory myositis, 1.2% mixt connective tissue disease, and 0.6% systemic lupus erythematosus in decreasing frequencies. Nonspecific interstitial pneumonia, which was the most common interstitial lung disease pattern in 103 (59.5%) patients, was most frequent among patients with SS and SSc (p < 0.001 vs. p < 0.001). Usual interstitial pneumonia was most frequent among patients with RA (p < 0.001). All patients received immunosuppressive treatment, most commonly azathioprine. 57.2% were using immunosuppressives for ILD. Six patients had mortality, and infections were the leading cause.

CONCLUSIONS

As a critical manifestation of connective tissue diseases, immunosuppressive treatment is indispensable in the management of interstitial lung diseases especially those at an increased risk for progression. The treatment approaches should be assessed in a patient-based way. The patients under immunosuppressive treatment should be cautiously followed for infections. Key Points • Interstitial lung disease is a noteworthy manifestation of connective tissue diseases. • The clinical findings, treatment requirements, and progression vary according to the severity of the disease. • Immunosuppressive treatment may be essential in patients with worsening symptoms, impaired pulmonary function tests, and radiological findings.

Prognostic significance of natural killer cell depletion in predicting progressive fibrosing interstitial lung disease in idiopathic inflammatory myopathies

Objectives

Interstitial lung disease (ILD) is one of the common extramuscular involvement in idiopathic inflammatory myopathies (IIMs) (1). Several patients develop a progressive fibrosing ILD (PF-ILD) despite conventional treatment, resulting in a progressive deterioration in their quality of life (2). Here, we investigated the clinical and immune characteristics of IIM-ILD and risk factors for PF-ILD in IIM, mainly in anti-melanoma differentiation-associated protein 5 (anti-MDA5+) dermatomyositis (DM) and anti-synthetase syndrome (ASS).

Methods

Here, a prospective cohort of 156 patients with IIM-ILD were included in the longitudinal analysis and divided into the PF-ILD (n=65) and non-PF-ILD (n=91) groups, and their baseline clinical characteristics were compared. Univariate and multivariate Cox analyses were performed to identify the variables significantly associated with pulmonary fibrosis progression in the total cohort, then anti-MDA5+ DM and ASS groups separately.

Results

Peripheral blood lymphocyte counts, including T, B, and NK cell counts, were significantly lower in the PF-ILD group than in the non-PF-ILD group. This characteristic is also present in the comparison between patients with anti-MDA5+ DM and ASS. The multivariate Cox regression analysis revealed that age > 43.5 years [HR: 7.653 (95% CI: 2.005-29.204), p = 0.003], absolute NK cell count < 148 cells/μL [HR: 6.277 (95% CI: 1.572-25.067), p = 0.009] and absolute Th cell count < 533.2 cells/μL [HR: 4.703 (95% CI: 1.014-21.821), p = 0.048] were independent predictors of progressive fibrosing during 1-year follow-up for patients with anti-MDA5+ DM, while absolute count of NK cells < 303.3 cells/µL [HR: 19.962 (95% CI: 3.108-128.223), p = 0.002], absolute count of lymphocytes < 1.545×109/L [HR: 9.684 (95% CI: 1.063-88.186), p = 0.044], and ferritin > 259.45 ng/mL [HR: 6 (95% CI: 1.116-32.256), p = 0.037] were independent predictors of PF-ILD for patients with ASS.

Conclusions

Patients with anti-MDA5+ DM and ASS have independent risk factors for PF-ILD. Lymphocyte depletion (particularly NK cells) was significantly associated with PF-ILD within 1-year of follow-up for IIM-ILD.

Anti-survival motor neuron complex antibodies as a novel biomarker for pulmonary arterial hypertension and interstitial lung disease in mixed connective tissue disease

OBJECTIVE

The presence of anti-U1 RNP antibodies (Abs) is critical for diagnosing MCTD. The aim of this study is to evaluate the clinical relevance of anti-survival motor neuron (SMN) complex Abs, which often coexist with anti-U1 RNP Abs.

METHODS

A total of 158 newly diagnosed consecutive cases of SLE, SSc or MCTD with anti-U1 RNP Abs were enrolled in this multicentre observational study between April 2014 and August 2022. Serum anti-SMN complex Abs were screened by immunoprecipitation of 35S-methionine-labelled cell extracts, and associations between anti-SMN complex Abs positivity and clinical characteristics were analysed.

RESULTS

Anti-SMN complex Abs were detected in 36% of MCTD patients, which was significantly higher than that in SLE (8%) or SSc (12%). Among MCTD patients classified based on the combination of the clinical features of SLE, SSc and idiopathic inflammatory myopathies, anti-SMN complex Abs showed the highest prevalence in a subset with clinical features of all three components. Anti-SMN complex Abs-positive MCTD had a higher prevalence of pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD), which are related to poor prognosis, than negative patients. Moreover, all three cases of death within 1 year of the treatment were positive for anti-SMN complex Abs.

CONCLUSIONS

Anti-SMN complex Abs is the first biomarker of a typical subset of MCTD which bears organ damages such as PAH and ILD.

Clinical presentation, course, and prognosis of patients with mixed connective tissue disease: A multicenter retrospective cohort

OBJECTIVES

The objective of this study is to better characterize the features and outcomes of a large population of patients with mixed connective tissue disease (MCTD).

METHODS

We performed an observational retrospective multicenter cohort study in France. Patients who fulfilled at least one diagnostic criterion set for MCTD and none of the criteria for other differentiated CTD (dCTD) were included.

RESULTS

Three hundred and thirty patients (88% females, median [interquartile range] age of 35 years [26-45]) were included. The diagnostic criteria of Sharp or Kasukawa were met by 97.3% and 93.3% of patients, respectively. None met other classification criteria without fulfilling Sharp or Kasukawa criteria. After a median follow-up of 8 (3-14) years, 149 (45.2%) patients achieved remission, 92 (27.9%) had interstitial lung disease, 25 (7.6%) had pulmonary hypertension, and 18 (5.6%) died. Eighty-five (25.8%) patients progressed to a dCTD, mainly systemic sclerosis (15.8%) or systemic lupus erythematosus (10.6%). Median duration between diagnosis and progression to a dCTD was 5 (2-11) years. The presence at MCTD diagnosis of an abnormal pattern on nailfold capillaroscopy (odds ratio [OR] = 2.44, 95% confidence interval [95%CI] [1.11-5.58]) and parotid swelling (OR = 3.86, 95%CI [1.31-11.4]) were statistically associated with progression to a dCTD. Patients who did not progress to a dCTD were more likely to achieve remission at the last follow-up (51.8% vs. 25.9%).

CONCLUSIONS

This study shows that MCTD is a distinct entity that can be classified using either Kasukawa or Sharp criteria, and that only 25.8% of patients progress to a dCTD during follow-up.

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.

Association of anti-Ro52 autoantibody with interstitial lung disease in autoimmune diseases: a systematic review and meta-analysis

OBJECTIVES

Interstitial lung disease (ILD) is an important manifestation of autoimmune diseases that can lead to morbidity and mortality. Although several autoantibodies have been linked with ILD presentation and adverse outcomes, the association of anti-Ro52 antibody with ILD is less studied. Hence, we investigated this association in various autoimmune diseases in the current study.

DESIGN

We designed a systematic review and meta-analysis and did a comprehensive search from inception until 2 January 2023.

DATA SOURCES

A systematic search was conducted in four electronic databases: PubMed, Web of Science, Scopus and Embase.

ELIGIBILITY CRITERIA

Observational studies that reported ILD diagnosis (outcome) and anti-Ro antibody (exposure) status in any autoimmune conditions (population) were included. The association between rapidly progressive ILD (RP-ILD) and anti-Ro52 was studied in idiopathic inflammatory myopathies (IIM).

DATA EXTRACTION AND SYNTHESIS

Collected data included study characteristics and ORs with 95% CIs. Quality assessment was performed using a modified version of the Newcastle-Ottawa Scale for cross-sectional studies. Random effects meta-analysis was used to pool the effect estimates.

RESULTS

A total of 2353 studies were identified, from which 59 articles met the eligibility criteria. Anti-Ro52/SSA positivity was associated with ILD in all autoimmune disease subgroups: IIM (OR=3.08; 95% CI: 2.18 to 4.35; p value<0.001; I2=49%), systemic lupus (OR=2.43; 95% CI: 1.02 to 5.79; p=0.046; I2=71%), Sjogren (OR=1.77; 95% CI: 1.09 to 2.87; p=0.021; I2=73%), systemic sclerosis (OR=1.71; 95% CI: 1.04 to 2.83; p=0.036; I2=43%), mixed connective tissue disease (OR=3.34; 95% CI: 1.82 to 6.13; p<0.001; I2=0%). Additionally, anti-Ro52-positive myopathy patients were more likely to have simultaneous RP-ILD (OR=2.69; 95% CI:1.50 to 4.83; p<0.001; I2=71%).

CONCLUSION

Anti-Ro52/SSA positivity is associated with a higher frequency of ILD diagnosis in various autoimmune diseases. Anti-Ro52/SSA is also linked with a more severe lung involvement (RP-ILD). Future studies can investigate the benefits of screening for anti-Ro52 and its association with ILD development.

PROSPERO REGISTRATION NUMBER

CRD42022381447.

Walking the path of treatable traits in interstitial lung diseases

Interstitial lung diseases (ILDs) are complex and heterogeneous diseases. The use of traditional diagnostic classification in ILD can lead to suboptimal management, which is worsened by not considering the molecular pathways, biological complexity, and disease phenotypes. The identification of specific "treatable traits" in ILDs, which are clinically relevant and modifiable disease characteristics, may improve patient's outcomes. Treatable traits in ILDs may be classified into four different domains (pulmonary, aetiological, comorbidities, and lifestyle), which will facilitate identification of related assessment tools, treatment options, and expected benefits. A multidisciplinary care team model is a potential way to implement a "treatable traits" strategy into clinical practice with the aim of improving patients' outcomes. Multidisciplinary models of care, international registries, and the use of artificial intelligence may facilitate the implementation of the "treatable traits" approach into clinical practice. Prospective studies are needed to test potential therapies for a variety of treatable traits to further advance care of patients with ILD.

The molecular mechanism underlying dermatomyositis related interstitial lung disease: evidence from bioinformatic analysis and in vivo validation

Background

Dermatomyositis (DM) is an autoimmune and inflammatory disease that can affect the lungs, causing interstitial lung diseases (ILD). However, the exact pathophysiological mechanisms underlying DM-ILD are unknown. Idiopathic pulmonary fibrosis (IPF) belongs to the broader spectrum of ILD and evidence shows that common pathologic pathways might lie between IPF and DM-ILD.

Methods

We retrieved gene expression profiles of DM and IPF from the Gene Expression Omnibus (GEO) and utilized weighted gene co-expression network analysis (WGCNA) to reveal their co-expression modules. We then performed a differentially expressed gene (DEG) analysis to identify common DEGs. Enrichment analyses were employed to uncover the hidden biological pathways. Additionally, we conducted protein-protein interaction (PPI) networks analysis, cluster analysis, and successfully found the hub genes, whose levels were further validated in DM-ILD patients. We also examined the relationship between hub genes and immune cell abundance in DM and IPF. Finally, we conducted a common transcription factors (TFs)-genes network by NetworkAnalyst.

Results

WGCNA revealed 258 intersecting genes, while DEG analysis identified 66 shared genes in DM and IPF. All of these genes were closely related to extracellular matrix and structure, cell-substrate adhesion, and collagen metabolism. Four hub genes (POSTN, THBS2, COL6A1, and LOXL1) were derived through intersecting the top 30 genes of the WGCNA and DEG sets. They were validated as active transcripts and showed diagnostic values for DM and IPF. However, ssGSEA revealed distinct infiltration patterns in DM and IPF. These four genes all showed a positive correlation with immune cells abundance in DM, but not in IPF. Finally, we identified one possible key transcription factor, MYC, that interact with all four hub genes.

Conclusion

Through bioinformatics analysis, we identified common hub genes and shared molecular pathways underlying DM and IPF, which provides valuable insights into the intricate mechanisms of these diseases and offers potential targets for diagnostic and therapeutic interventions.

In-depth characterization of pulmonary arterial hypertension in mixed connective tissue disease: a French national multicentre study

OBJECTIVE

Pulmonary arterial hypertension (PAH) is a leading cause of death in MCTD. We aimed to describe PAH in well-characterized MCTD patients.

METHODS

MCTD patients enrolled in the French Pulmonary Hypertension Registry with a PAH diagnosis confirmed by right heart catheterization were included in the study and compared with matched controls: MCTD patients without PAH, SLE patients with PAH and SSc patients with PAH. Survival rates were estimated by the Kaplan-Meier method and risk factors for PAH in MCTD patients and risk factors for mortality in MCTD-PAH were sought using multivariate analyses.

RESULTS

Thirty-six patients with MCTD-PAH were included in the study. Comparison with MCTD patients without PAH and multivariate analysis revealed that pericarditis, polyarthritis, thrombocytopenia, interstitial lung disease (ILD) and anti-Sm antibodies were independent predictive factors of PAH/PH in MCTD. Estimated survival rates at 1, 5 and 10 years following PAH diagnosis were 83%, 67% and 56%, respectively. MCTD-PAH presentation and survival did not differ from SLE-PAH and SSc-PAH. Multivariate analysis revealed that tobacco exposure was an independent factor predictive of mortality in MCTD-PAH.

CONCLUSION

PAH is a rare and severe complication of MCTD associated with a 56% 10-year survival. We identified ILD, pericarditis, thrombocytopenia and anti-Sm antibodies as risk factors for PAH in MCTD and tobacco exposure as a predictor of mortality in MCTD-PAH.

Incidence and prevalence of interstitial lung diseases worldwide: a systematic literature review

Interstitial lung disease (ILD) is a collective term representing a diverse group of pulmonary fibrotic and inflammatory conditions. Due to the diversity of ILD conditions, paucity of guidance and updates to diagnostic criteria over time, it has been challenging to precisely determine ILD incidence and prevalence. This systematic review provides a synthesis of published data at a global level and highlights gaps in the current knowledge base. Medline and Embase databases were searched systematically for studies reporting incidence and prevalence of various ILDs. Randomised controlled trials, case reports and conference abstracts were excluded. 80 studies were included, the most described subgroup was autoimmune-related ILD, and the most studied conditions were rheumatoid arthritis (RA)-associated ILD, systemic sclerosis associated (SSc) ILD and idiopathic pulmonary fibrosis (IPF). The prevalence of IPF was mostly established using healthcare datasets, whereas the prevalence of autoimmune ILD tended to be reported in smaller autoimmune cohorts. The prevalence of IPF ranged from 7 to 1650 per 100 000 persons. Prevalence of SSc ILD and RA ILD ranged from 26.1% to 88.1% and 0.6% to 63.7%, respectively. Significant heterogeneity was observed in the reported incidence of various ILD subtypes. This review demonstrates the challenges in establishing trends over time across regions and highlights a need to standardise ILD diagnostic criteria.PROSPERO registration number: CRD42020203035.

Clinically Relevant Biomarkers in Connective Tissue Disease-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) complicates connective tissue disease (CTD) with variable incidence and is a leading cause of death in these patients. To improve CTD-ILD outcomes, early recognition and management of ILD is critical. Blood-based and radiologic biomarkers that assist in the diagnosis CTD-ILD have long been studied. Recent studies, including -omic investigations, have also begun to identify biomarkers that may help prognosticate such patients. This review provides an overview of clinically relevant biomarkers in patients with CTD-ILD, highlighting recent advances to assist in the diagnosis and prognostication of CTD-ILD.

Predictive factors for progressive fibrosing interstitial lung disease in anti-synthetase syndrome

OBJECTIVES

Interstitial lung disease (ILD) is common in anti-synthetase syndrome (ASS). Progressive fibrosing ILD (PF-ILD) may develop in ILD with autoimmune features. Data on PF-ILDs in ASS as a group are scarce. This study aimed to explore the characteristics and predictors of PF-ILD in ASS patients.

METHODS

This retrospective study enrolled 96 ASS-ILD patients. Baseline clinical data were collected. PF-ILD assessments were conducted at every hospital visit during windows of 24 months after initial diagnosis. Phenotypic, survival features and predictors of PF-ILD were estimated through SPSS 22.0.

RESULTS

The results revealed that 35.42% (34/96) were evaluated to be PF-ILD with a median interval time of 14.73 months. Nonspecific interstitial pneumonia was the most common radiological pattern of PF-ILD. Ground glass opacity (GGO), traction bronchiectasis and reticulation were representative high-resolution computed tomography findings of this group. Compared with the non-progressive group, PF-ILD patients had higher frequencies of anti-Ro-52 antibodies (91.18% vs 66.13%, P = 0.007) and GGO in the lower + middle and lower + middle + upper zones of the left lung, as well as lower + middle zones in the right lung (85.30% vs 54.84%, P = 0.003; 64.71% vs 38.71%, P = 0.015; 82.35% vs 58.06%, P = 0.016). Multivariate Cox analysis identified that anti-Ro-52 antibody (hazards ratio [HR] 3.55, 95% CI 1.06-11.90, P = 0.040) and GGO in left lower + middle lung zones (HR 22.11, 95% CI 1.95-250.90, P = 0.012) were independent risk factors for PF-ILD.

CONCLUSIONS

PF-ILD was associated with poor prognosis. Over one-third of ASS-ILD patients may develop to PF-ILD. Anti-Ro-52 antibody positivity and GGO in left lower + middle lung zones were independent risk factors for PF-ILD in ASS patients.

Skin disorders and interstitial lung disease: Part II-The spectrum of cutaneous diseases with lung disease association

Part 2 of this 2-part CME introduces dermatologists to noninfectious inflammatory skin diseases associated with pulmonary involvement. In many cases, dermatologists may be the first physicians recognizing respiratory complications associated with these diagnoses. Because pulmonary involvement is often the leading cause of morbidity and mortality, dermatologists should be comfortable screening and monitoring for lung disease in high-risk patients, recognizing cutaneous stigmata of lung disease in these patients and referring to pulmonary specialists, when appropriate, for prompt treatment initiation. Some treatments used for skin disease may not be appropriate in the context of lung disease and hence, choosing a holistic approach is important. Interstitial lung disease and pulmonary hypertension are the most common pulmonary complications and a significant cause of mortality in autoimmune connective tissue diseases, especially systemic sclerosis, dermatomyositis, and mixed connective tissue disease. Pulmonary complications, notably interstitial lung disease, are also common and life-threatening in sarcoidosis and vasculitis, while they are variable in neutrophilic and autoimmune blistering diseases.

Cardiac dysfunction in mixed connective tissue disease: a nationwide observational study

We aimed to identify cardiac function in patients with established mixed connective tissue disease (MCTD). This was a cross-sectional case-control study of well-characterised MCTD patients who had previously been included in a nationwide cohort. Assessments comprised protocol transthoracic echocardiography, electrocardiogram and blood samples. In patients only, we evaluated the findings of high-resolution pulmonary computed tomography and disease activity. We assessed 77 MCTD patients (mean age 50.5 ± 12.3 years) with a mean disease duration of 16.4 years, and 59 age- and sex-matched healthy controls (49.9 ± 11.7 years). By echocardiography, measures of left ventricular function, i.e. fractional shortening (38.1 ± 6.4% vs. 42.3 ± 6.6%, p < 0.001), mitral annulus plane systolic excursion (MAPSE) (13.7 ± 2.1 mm vs. 15.3 ± 2.3 mm, p < 0.001) and early diastolic velocity of the mitral annulus (e') (0.09 ± 0.02 m/s vs. 0.11 ± 0.03 m/s, p = 0.002) were subclinical and lower in patients than controls. Right ventricular dysfunction was found in patients assessed by tricuspid annular plane systolic excursion (TAPSE) (22.7 ± 4.0 mm vs. 25.5 ± 4.0 mm, p < 0.001). While cardiac dysfunction was not associated with pulmonary disease, e' and TAPSE were found to correlate with disease activity at baseline. In this cohort of MCTD patients, echocardiographic examinations demonstrated a higher frequency of cardiac dysfunction than in matched controls. Cardiac dysfunction was associated with disease activity at baseline, but was independent of cardiovascular risk factors and pulmonary disease. Our study indicates that cardiac dysfunction is part of the multi-organ affliction seen in MCTD.

Interstitial Lung Disease in Mixed Connective Tissue Disease: An Advanced Search

The spectrum of pulmonary manifestations associated with mixed connective tissue disease ranges from pulmonary hypertension and interstitial lung disease to pleural effusions, alveolar hemorrhage, and complications from the thromboembolic disease. Interstitial lung disease in mixed connective tissue disease is a frequently occurring entity, although in most cases it tends to be self-limited or slowly progressive. Despite this, a significant percentage of patients may present a progressive fibrosing phenotype, thus posing a great challenge regarding its therapeutic approach, given the scarcity of clinical studies that compare the efficacy of immunosuppressants available to date. Due to this, many recommendations are extrapolated from other diseases with similar characteristics such as systemic sclerosis and systemic lupus erythematosus. That is why it is proposed to carry out an advanced search of the literature in order to clarify its clinical, radiological, and therapeutic characteristics to achieve its evaluation from a holistic point of view.

Progressive pulmonary fibrosis: an expert group consensus statement

This expert group consensus statement emphasises the need for standardising the definition of progressive fibrosing interstitial lung diseases (F-ILDs), with an accurate initial diagnosis being of paramount importance in ensuring appropriate initial management. Equally, case-by-case decisions on monitoring and management are essential, given the varying presentations of F-ILDs and the varying rates of progression. The value of diagnostic tests in risk stratification at presentation and, separately, the importance of a logical monitoring strategy, tailored to manage the risk of progression, are also stressed. The term "progressive pulmonary fibrosis" (PPF) exactly describes the entity that clinicians often face in practice. The importance of using antifibrotic therapy early in PPF (once initial management has failed to prevent progression) is increasingly supported by evidence. Artificial intelligence software for high-resolution computed tomography analysis, although an exciting tool for the future, awaits validation. Guidance is provided on pulmonary rehabilitation, oxygen and the use of non-invasive ventilation focused specifically on the needs of ILD patients with progressive disease. PPF should be differentiated from acute deterioration due to drug-induced lung toxicity or other forms of acute exacerbations. Referral criteria for a lung transplant are discussed and applied to patient needs in severe diseases where transplantation is not realistic, either due to access limitations or transplantation contraindications. In conclusion, expert group consensus guidance is provided on the diagnosis, treatment and monitoring of F-ILDs with specific focus on the recognition of PPF and the management of pulmonary fibrosis progressing despite initial management.

Anti-MDA5 antibody dermatomyositis-associated rapidly progressive interstitial lung disease patient complicated with mixed connective tissue disease: A case report

Anti-MDA5 antibody dermatomyositis (DM) is a special type of myositis, which can potentially cause rapidly progressive interstitial lung disease (RP-ILD). Mixed connective tissue disease (MCTD) is a complex disease with different characteristics of autoimmune connective tissue disease, associated with ILD. Both are rare diseases, and few patients with both diseases have been reported. A 71-year-old woman complained of palpitations, with a 2 months history of rash around her hands, extensor surface of right elbow, and the nape of her neck. Subsequently, the patient had acute exacerbation of dyspnea and tachypnea. Anti-Ro52, U1 RNP and MDA5 antibodies were positive; the presenting evidence was suggestive of anti-MDA5⁺ DM-RP-ILD complicated with MCTD. Our patient deteriorated rapidly and had a fatal outcome, despite "triple therapy" for RP-ILD. This case illustrates that patients with coexisting anti-MDA5⁺ DM and MCTD have the former's typical clinical manifestations, and may develop ILD quickly rather than slowly as in MCTD, especially with the coexistence of anti-Ro52 antibodies.

Criteria for progressive fibrotic hypersensitivity pneumonitis in a Portuguese patient cohort

Background

Hypersensitivity pneumonitis (HP) is a syndrome caused by sensitisation to inhaled antigens that leads to an abnormal immune response in the airways and lung parenchyma. Some patients previously diagnosed with certain types of fibrotic interstitial lung diseases (f-ILDs), including fibrotic HP (f-HP), are susceptible to develop a progressive fibrosing phenotype (PF-ILD), despite initial state-of-the-art management.

Objectives

To characterise a cohort of patients with a multidisciplinary diagnosis (MTD) of chronic f-HP, who were followed up in an ILD outpatient clinic of a hospital in Portugal, and to assess the prevalence of PF-ILD criteria in these patients.

Methods

Data were collected from all patients with a definite or provisional diagnosis of f-HP after a multidisciplinary team discussion. Patients were followed up between December 2014 and July 2019. Data included clinical characteristics, high-resolution chest tomography (HRCT) disease patterns, lung function tests, bronchoalveolar lavage and further immunological work-up, biopsy reports (conventional transbronchial lung biopsy, transbronchial lung cryobiopsy or surgical video-assisted thoracoscopic lung biopsy), all ILD multidisciplinary team records and diagnostic confidence levels. Patients were assessed according to PF-ILD criteria as defined in the INBUILD trial.

Results

We identified 83 patients with an MTD of HP, who had been followed up for at least 12 months. Of these, 63 (75.9%) were diagnosed with f-HP. Of the 63 f-HP patients, 33.3% (n=21) fulfilled the predefined criteria for PF-HP: 66.7% had a relative decline of ≥10% forced vital capacity (FVC); 5% a relative decline of 5 - 9% FVC, with worsening symptoms or increased fibrosis on HRCT; and 23.8% had worsening respiratory symptoms with radiological progression.

Conclusion

This single-centre cohort study demonstrated that a third of f-HP patients presented with PF-ILD, as determined by progression during initial standard-of-care treatment. A usual interstitial pneumonia (UIP)/UIP-like pattern was present in >70% of patients with f-HP, and two-thirds of these patients had an FVC decline of ≥10%. PF-HP patients were also more exacerbation prone. According to recent trial data, this segment of patients can be considered possible candidates for antifibrotic treatment, with a reasonable prospect of effectiveness. Further efforts should focus on refining knowledge of longitudinal behaviour of large multicentric cohorts of f-HP patients, establishing a consensual and uniform definition of progression for use in clinical practice, as well as developing prognostic prediction tools to better (and early) inform the disease course.

Novel tracers for molecular imaging of interstitial lung disease: A state of the art review

Interstitial lung disease is an overarching term for a wide range of disorders characterized by inflammation and/or fibrosis in the lungs. Most prevalent forms, among others, include idiopathic pulmonary fibrosis (IPF) and connective tissue disease associated interstitial lung disease (CTD-ILD). Currently, only disease modifying treatment options are available for IPF and progressive fibrotic CTD-ILD, leading to reduction or stabilization in the rate of lung function decline at best. Management of these patients would greatly advance if we identify new strategies to improve (1) early detection of ILD, (2) predicting ILD progression, (3) predicting response to therapy and (4) understanding pathophysiology. Over the last years, positron emission tomography (PET) and single photon emission computed tomography (SPECT) have emerged as promising molecular imaging techniques to improve ILD management. Both are non-invasive diagnostic tools to assess molecular characteristics of an individual patient with the potential to apply personalized treatment. In this review, we encompass the currently available pre-clinical and clinical studies on molecular imaging with PET and SPECT in IPF and CTD-ILD. We provide recommendations for potential future clinical applications of these tracers and directions for future research.

Imaging of Lung Disease Associated with Connective Tissue Disease

There is a well-known association between the connective tissue disorders (CTDs) and lung disease. In addition to interstitial lung disease, the CTDs may affect the air spaces and pulmonary vasculature. Imaging tests are important not only in diagnosis but also in management of these complex disorders. In the present review, key aspects of the imaging of CTD-reated diseases are discussed.

Safety and tolerability of nintedanib in patients with interstitial lung diseases in subgroups by sex: a post-hoc analysis of pooled data from four randomised controlled trials

BACKGROUND

Nintedanib is a tyrosine kinase inhibitor used in the treatment of progressive fibrosing interstitial lung diseases (ILDs). We assessed the safety and tolerability of nintedanib in patients with autoimmune disease-related ILDs and with other ILDs in subgroups by sex.

METHODS

In this post-hoc analysis, we pooled data from the two INPULSIS trials in patients with idiopathic pulmonary fibrosis (IPF), the SENSCIS trial in patients with fibrosing ILDs associated with systemic sclerosis, and the INBUILD trial in patients with progressive fibrosing ILDs other than IPF. In each trial, patients were randomly assigned to receive oral nintedanib 150 mg twice daily or matched placebo. We assessed adverse events reported over 52 weeks in patients with autoimmune disease-related ILDs and other ILDs in subgroups by sex.

FINDINGS

In these analyses, we included 746 patients with autoimmune disease-related ILDs (523 [70%] were female, 223 [30%] were male; 615 [82%] had systemic sclerosis), of whom 370 (50%) received nintedanib (268 [72%] female and 102 [28%] male patients) and 376 (50%) received placebo (255 [68%] female and 121 [32%] male patients); and 1554 patients with other ILDs (437 [28%] female, 1117 [72%] male; 1061 [68%] with IPF), of whom 888 (57%) received nintedanib (237 [27%] female and 651 [73%] male patients) and 666 (43%) received placebo (200 [30%] female and 466 [70%] male patients). Of 102 male and 268 female patients with autoimmune disease-related ILDs treated with nintedanib, nausea was reported in 21 (21%) male and 92 (34%) female patients, vomiting in 12 (12%) male and 73 (27%) female patients, alanine aminotransferase increase in four (4%) male and 31 (12%) female patients, aspartate aminotransferase increase in three (3%) male and 23 (9%) female patients, and adverse events leading to dose reduction in 18 (18%) male and 101 (38%) female patients; 28 (27%) male and 107 (40%) female patients had at least one treatment interruption. Of 651 male and 237 female nintedanib-treated patients with other ILDs, nausea was reported in 135 (21%) male and 95 (40%) female patients, vomiting in 51 (8%) male and 70 (30%) female patients, alanine aminotransferase increase in 19 (3%) male and 31 (13%) female patients, aspartate aminotransferase increase in 17 (3%) male and 26 (11%) female patients, and adverse events leading to dose reduction in 106 (16%) male and 84 (35%) female patients; 155 (24%) male and 82 (35%) female patients had at least one treatment interruption. The proportions of patients with adverse events leading to discontinuation of nintedanib were similar between female and male patients with autoimmune disease-related ILDs (44 [16%] of 268 vs 17 [17%] of 102), but were greater among female than male patients with other ILDs (62 [26%] of 237 vs 112 [17%] of 651). Across subgroups by diagnosis and sex, diarrhoea was the most frequent adverse event associated with nintedanib (autoimmune-related ILDs: 198 [74%] of 268 female and 73 [72%] of 102 male patients; other ILDs: 155 [65%] of 237 female and 408 [63%] of 651 male patients), and was the event that most frequently led to treatment discontinuation (autoimmune-related ILDs: 20 [7%] female and five [5%] male patients; other ILDs: 16 [7%] female and 27 [4%] male patients).

INTERPRETATION

The adverse event profile of nintedanib was generally similar between male and female patients with autoimmune disease-related ILDs, and between male and female patients with other ILDs, but nausea, vomiting, liver enzyme elevations, dose reductions, and treatment interruptions were more frequent in female patients than in male patients. Sex should be considered in the monitoring and management of adverse events that might be associated with nintedanib.

FUNDING

Boehringer Ingelheim.

Anti-Ro52 Autoantibody Is Common in Systemic Autoimmune Rheumatic Diseases and Correlating with Worse Outcome when Associated with interstitial lung disease in Systemic Sclerosis and Autoimmune Myositis

This review highlights the 30 plus years research progress since the discovery of autoantibody to Ro52/TRIM21 in patients with systemic lupus erythematosus (SLE) and Sjögren's syndrome (SjS). After the initial expression cloning of the Ro52 cDNA, it has taken many years to the current understanding in the interesting biological function of Ro52 as an E3 ubiquitin ligase and its role in innate immune clearance of intracellular IgG-bound complex. Early observations show that anti-Ro52, mostly associated with anti-SS-A/Ro60 and/or anti-SS-B/La, is commonly found in SLE (40-70%), SjS (70-90%), neonatal lupus erythematosus (NLE, 75-90%), and subacute cutaneous lupus erythematosus (50-60%). Anti-Ro52 has long been postulated to play a direct pathogenic role in congenital heart block in NLE as well as in the QT interval prolongation in some adults. The widespread availability of the anti-Ro52 assay has led to the detection of anti-Ro52 in other diseases including autoimmune hepatitis (20-40%), systemic sclerosis (10-30%), and autoimmune myositis (20-40%). More than ten studies have pointed to an association of anti-Ro52 with interstitial lung disease and, more importantly, correlating with poor outcome and worse survival. Other studies are implicating an interesting role for anti-Ro52 in the diagnosis of certain cancers. Future studies are needed to examine the mechanism in the pathogenesis of anti-Ro52 and carefully documenting its causal relationships in different disease conditions.

Serologic phenotypes distinguish systemic lupus erythematosus patients developing interstitial lung disease and/or myositis

Objectives

To determine if serologic phenotypes could be identified in systemic lupus erythematosus patients developing interstitial lung disease (ILD) and/or myositis.

Methods

Adult SLE patients (without myositis/ILD at baseline) had annual assessments and serum sampling between 2000 and 2017. New-onset ILD was identified using the SDI pulmonary fibrosis item. New-onset myositis was identified using the SLICC Damage Index muscle atrophy/weakness item, the SLEDAI-2K item for myositis, and annual creatinine kinase testing. Chart review confirmed ILD/myositis cases and randomly sampled SLE patients from baseline formed our sub-cohort (N = 72). Cases and sub-cohort were compared regarding myositis-related biomarkers at baseline and at a randomly selected follow-up between baseline and end of observation (date of ILD/myositis diagnosis or Dec. 31, 2017). Descriptive analyses and hazards ratios (HRs) were generated for ILD/myositis incidence, focusing on baseline serology and adjusting for sex, race/ethnicity, age at SLE diagnosis, and SLE duration.

Results

Fourteen SLE patients developed ILD (N = 9), myositis (N = 3), and/or both (N = 2). Thirteen of those (92.9%) developing ILD/myositis had at least one biomarker at baseline, versus 47 (65.3%) SLE patients who never developed myositis/ILD. The most common biomarkers in myositis/ILD were KL-6, anti-Ro52, and anti-Ku. Baseline biomarkers tended to remain positive in follow-up. In multivariate Cox regressions, SLE patients had higher risk of developing myositis/ILD with elevated baseline KL-6 (adjusted hazard ratio 3.66; 95% confidence interval 1.01, 13.3). When updating biomarkers over time, we also saw correlations between anti-Smith and ILD/myositis.

Conclusions

Baseline myositis-related biomarkers were highly associated with ILD/myositis incidence. This is the first identification of biomarker phenotypes with ILD/myositis risk in SLE.

Nintedanib in Patients With Autoimmune Disease-Related Progressive Fibrosing Interstitial Lung Diseases: Subgroup Analysis of the INBUILD Trial

Objective

To analyze the efficacy and safety of nintedanib in patients with fibrosing autoimmune disease–related interstitial lung diseases (ILDs) with a progressive phenotype.

Methods

The INBUILD trial enrolled patients with a fibrosing ILD other than idiopathic pulmonary fibrosis, with diffuse fibrosing lung disease of >10% extent on high‐resolution computed tomography, forced vital capacity percent predicted (FVC%) ≥45%, and diffusing capacity of the lungs for carbon monoxide percent predicted ≥30% to <80%. Patients fulfilled protocol‐defined criteria for progression of ILD within the 24 months before screening, despite management deemed appropriate in clinical practice. Subjects were randomized to receive nintedanib or placebo. We assessed the rate of decline in FVC (ml/year) and adverse events (AEs) over 52 weeks in the subgroup with autoimmune disease–related ILDs.

Results

Among 170 patients with autoimmune disease–related ILDs, the rate of decline in FVC over 52 weeks was −75.9 ml/year with nintedanib versus −178.6 ml/year with placebo (difference 102.7 ml/year [95% confidence interval 23.2, 182.2]; nominal P = 0.012). No heterogeneity was detected in the effect of nintedanib versus placebo across subgroups based on ILD diagnosis (P = 0.91). The most frequent AE was diarrhea, reported in 63.4% and 27.3% of subjects in the nintedanib and placebo groups, respectively. AEs led to permanent discontinuation of trial drug in 17.1% and 10.2% of subjects in the nintedanib and placebo groups, respectively.

Conclusion

In the INBUILD trial, nintedanib slowed the rate of decline in FVC in patients with progressive fibrosing autoimmune disease–related ILDs, with AEs that were manageable for most patients.

Video Abstract

Clinical Features of Anti-Synthetase Syndrome Associated with Prognosis in Patients with Dermatomyositis and Polymyositis

We evaluated whether the clinical features of anti-synthetase syndrome (ASA)—myositis, fever, arthritis, mechanic’s hand, Raynaud’s phenomenon and interstitial lung disease—are relevant to prognosis in patients with dermatomyositis/polymyositis (DM/PM). A retrospective analysis was performed to identify patients diagnosed with DM/PM according to Bohan and Peter criteria. Clinical information, laboratory data and the presence of ASA clinical features at disease diagnosis were searched, and the outcomes of all-cause mortality, intensive care unit admission and disease remission at 1 year were assessed. Among the 86 patients included, fever (36.0%) and interstitial lung disease (26.7%) were the most common ASA clinical features. During the follow-up, 12 patients experienced death, and 7 of the 12 deaths (58.3%) occurred within 3 months of DM/PM diagnosis. Mortality was more frequently observed in those presenting with fever than in those without (25.8% versus 7.3%, p = 0.024). Multivariable Cox proportional analysis revealed that male sex (hazard ratio [HR] 5.53, 95% confidence interval [CI] 1.65, 18.49, p < 0.01) and fever (HR 4.20, 95% CI 1.26, 14.01, p = 0.02) independently predicted mortality. The clinical impact of fever was consistent in both sexes. Fever could be a warning signal heralding the poor outcome of mortality in patients with DM/PM, especially in early disease phases.

Myositis Antibodies and Interstitial Lung Disease

BACKGROUND

Interstitial lung disease (ILD) comprises a heterogeneous group of inflammatory and fibrotic conditions, often resulting in progressive lung function decline and increased mortality. Connective tissue disease (CTD) should be considered in all patients with ILD, as distinguishing between CTD-ILD and other forms of fibrotic lung disease has important therapeutic and prognostic implications. The idiopathic inflammatory myopathies (IIM) represent a CTD subtype of growing interest to ILD experts. The expansion and availability of myositis-specific and myositis-associated antibody testing has allowed for improved disease detection and characterization.

CONTENT

In this review, we highlight the relationship between myositis antibodies and ILD. Select forms of IIM, such as the antisynthetase syndrome and clinically amyopathic dermatomyositis can present with rapidly progressive ILD, warranting timely disease diagnosis and management. Disease phenotypes, prevalence, laboratory testing, prognosis, and management strategies are described according to select myositis antibodies.

SUMMARY

Myositis antibodies provide valuable information for clinicians managing patients with ILD. This review aims to increase awareness of their role in disease detection, pathophysiology, and possibly therapeutics.

An updated review of anti-Ro52 (TRIM21) antibodies impact in connective tissue diseases clinical management

Anti-Ro52 (or anti-TRIM21) antibodies are part of the family of anti-Ro/SSA antibodies, historically markers of Sjögren syndrome and systemic lupus erythematosus. Anti-Ro52 antibodies represent one the most frequently encountered autoantibodies in patients with connective tissue disease (primary Sjögren syndrome, systemic lupus erythematosus, systemic sclerosis and idiopathic inflammatory myopathies). Because of their lack of specificity and detection in patients with non-autoimmune disorders, the usefulness of anti-Ro52 testing in connective tissue diseases is still matter of debate among clinicians and immunologists. Autoantibodies are mainly diagnostic markers for autoimmune diseases but some of them can also be directly involved in the generation of tissue damage. Over the past decade several authors reported associations of anti-Ro52 antibodies with some clinical features - especially interstitial lung disease - and survival in patients with connective tissue diseases. There is also a growing evidence of the role of anti-Ro52 antibodies in the pathogenesis of connective tissue diseases. In this review, we comprehensively discuss the clinical associations of anti-Ro52 antibodies in the different connective tissue diseases and the recent advances on their potential role in the inflammatory response.

Interstitial Lung Disease in Connective Tissue Diseases: Survival Patterns in a Population-Based Cohort

Objectives: Interstitial lung disease (ILD) is associated with impaired survival among patients with connective tissue diseases (CTDs), but population-based data on the frequency of ILD and pulmonary hypertension (PH) in different CTD subtypes and the impact on survival are sparse. Methods: We included patients with a first-time ICD-10 diagnosis of systemic sclerosis (SSc), mixed connective tissue disease (MCTD), myositis, systemic lupus erythematosus (SLE), or Sjögren’s disease registered in the Danish National Patient Registry between 2000 and 2015. Among these, we identified patients with ILD and PH. Using Kaplan–Meier analysis, we assessed survival for the five subtypes of CTD ± ILD and compared survival among CTD patients overall ± ILD with survival in the general population ± ILD. Results: We identified 11,731 patients with a diagnosis of CTD; 637 (5.4%) had a diagnosis of ILD. The proportion of patients with ILD was higher in SSc (13.4%) and MCTD (9.1%) than in myositis (6.0%), SLE (4.1%), and Sjögren (2.8%). Fifty-one percent were diagnosed with ILD in their fifties and sixties. PH was more frequent in SSc (7.5%) and MCTD (4.1%). Five-year survival was 73.3% (66.7–80.6) in SSc-ILD, 81.0% (69.0–95.1) in MCTD-ILD, 84.7% (77.3–92.9) in myositis-ILD, 83.5% (76.2–91.5) in SLE-ILD, and 84.7 (78.4–91.6) in Sjögren-associated ILD. Survival in CTD-ILD overall was impaired for all age groups compared with CTD alone. Age-stratified survival was comparable between CTD-ILD and ILD in the general population. The survival gap between ILD and non-ILD increased with age. Conclusion: Survival was comparable between different CTD-ILD subtypes and comparable to survival in non-CTD-ILD.

Characteristics and Predictors of Progression Interstitial Lung Disease in Rheumatoid Arthritis Compared with Other Autoimmune Disease: A Retrospective Cohort Study

Objectives: To describe the characteristics and progression of interstitial lung disease in patients with associated systemic autoimmune disease (ILD-SAI) and to identify factors associated with progression and mortality. Patients and methods: We performed a multicenter, retrospective, observational study of patients with ILD-SAI followed between 2015 and 2020. We collected clinical data and performed pulmonary function testing and high-resolution computed tomography at diagnosis and at the final visit. The main outcome measure at the end of follow-up was forced vital capacity (FVC) >10% or diffusing capacity of the lungs for carbon monoxide >15% and radiological progression or death. Cox regression analysis was performed to identify factors associated with worsening of ILD. Results: We included 204 patients with ILD-SAI: 123 (60.3%) had rheumatoid arthritis (RA), 58 had (28.4%) systemic sclerosis, and 23 (11.3%) had inflammatory myopathy. After a median (IQR) period of 56 (29.8–93.3) months, lung disease had stabilized in 98 patients (48%), improved in 33 (16.1%), and worsened in 44 (21.5%). A total of 29 patients (14.2%) died. Progression and hospitalization were more frequent in patients with RA (p = 0.010). The multivariate analysis showed the independent predictors for worsening of ILD-SAI to be RA (HR, 1.9 [95% CI, 1.3–2.7]), usual interstitial pneumonia pattern (HR, 1.7 [95% CI, 1.0–2.9]), FVC (%) (HR, 2.3 [95% CI, 1.4–3.9]), and smoking (HR, 2.7 [95%CI, 1.6–4.7]). Conclusion: Disease stabilizes or improves after a median of 5 years in more than half of patients with ILD-SAI, although more than one-third die. Data on subgroups and risk factors could help us to predict poorer outcomes.

Role of autoantibodies in the diagnosis and prognosis of interstitial lung disease in autoimmune rheumatic disorders

Interstitial lung disease (ILD) has been recognized as a frequent manifestation associated with a substantial morbidity and mortality burden in patients with autoimmune rheumatic disorders. Serum autoantibodies are considered good biomarkers for identifying several subsets or specific phenotypes of ILD involvement in these patients. This review features the role of several autoantibodies as a diagnostic and prognostic biomarker linked to the presence ILD and specific ILD phenotypes in autoimmune rheumatic disorders. The case of the diverse antisynthetase antibodies in the antisynthease syndrome or the anti-melanoma differentiation-associated 5 protein (MDA5) antibodies as a marker of a severe condition such as rapidly progressive ILD in patients with clinically amyopathic dermatomyositis are some of the associations herein reported in the group of myositis spectrum disorders. Specific autoantibodies such as the well-known anti-topoisomerase I (anti-Scl70) or the anti-Th/To, anti-U11/U12 ribonucleoprotein, and anti-eukaryotic initiation factor 2B (eIF2B) antibodies seems to be specifically linked to ILD in patients with systemic sclerosis. Overlap syndromes between systemic sclerosis and myositis, also have good ILD biomarkers, which are the anti-PM/Scl and anti-Ku autoantibodies. Lastly, other not so often reported disorders as being associated with ILD but recently most recognized as is the case of rheumatoid arthritis associated ILD or entities herein included in the miscellaneous disorders section, which include anti-neutrophil cytoplasmic antibody-associated interstitial lung disease, Sjögren's syndrome or the mixed connective tissue disease, are also discussed.

Diagnosis and Management of Fibrotic Interstitial Lung Diseases

Nonidiopathic pulmonary fibrosis (non-IPF) progressive fibrotic interstitial lung diseases (PF-ILDs) are a heterogeneous group of ILDs, often challenging to diagnose, although an accurate diagnosis has significant implications for both treatment and prognosis. A subgroup of these patients experiences progressive deterioration in lung function, physical performance, and quality of life after conventional therapy. Risk factors for ILD progression include older age, lower baseline pulmonary function, and a usual interstitial pneumonia pattern. Management of non-IPF P-ILD is both pharmacologic and nonpharmacologic. Antifibrotic drugs, originally approved for IPF, have been considered in patients with other fibrotic ILD subtypes, with favorable results in clinical trials.

The other connective tissue disease-associated interstitial lung diseases: Sjogren's syndrome, mixed connective tissue disease, and systemic lupus erythematosus

PURPOSE OF REVIEW

We review the clinical manifestations of three less common connective tissue disease (CTD)-associated interstitial lung diseases (ILDs): Sjogren's syndrome (SjS), mixed CTD (MCTD), and systemic lupus erythematosus (SLE).

RECENT FINDINGS

SjS is classically associated with lymphocytic interstitial pneumonia and cystic lung disease, but the most common type of ILD in Sjogren's patients is nonspecific interstitial pneumonia. ILD is prevalent in MCTD and associated with worse survival. SLE-associated ILD, while rare, is more common in those with CTD overlap syndromes. Regardless of underlying cause, a subset of patients with fibrotic CTD-associated ILD develop a progressive course for which antifibrotic agents and lung transplantation should be considered.

SUMMARY

An understanding of the characteristics of ILD in SjS, MCTD, and SLE is important for the pulmonary specialist. Future research should identify risk factors for progression and develop additional treatment modalities for both CTD-related autoimmune features and progressive ILD.

Characterization of Interstitial Lung Disease Associated With Anti-Ribonucleoprotein Antibodies

OBJECTIVES

Interstitial lung disease (ILD) is a common feature of mixed connective tissue disease. However, many patients do not meet the criteria for mixed connective tissue disease and thus may be diagnosed as interstitial pneumonia with autoimmune features. The aim of this study was to characterize ILD associated with anti-ribonucleoprotein (RNP) antibodies.

METHODS

Chest computed tomography scans of patients with anti-RNP antibody who were seen between January 2011 and October 2015 were reviewed. The underlying disease was classified with international criteria using clinical and serological features.

RESULTS

Among 544 patients with anti-RNP antibodies, 188 had a chest computed tomography scan, and 48 (26%) of them had radiological features of ILD. The presence of ILD was significantly associated with dyspnea, crackles, arthritis, Raynaud phenomenon, myositis, and sicca syndrome. The most frequent pattern was nonspecific interstitial pneumonia in 39 patients (81%). Among patients with ILD, 17 (35%) had a radiological pattern consisting of cysts and ground-glass attenuation not fulfilling the lymphoid interstitial pneumonia criteria. In 3 patients, cysts were related to fibrosis; in 14 patients, cysts corresponded to an original ILD pattern.

CONCLUSIONS

Interstitial lung disease was found in 26% of patients with anti-RNP antibodies independently of the underlying disease. Anti-RNP-associated ILD mainly corresponds to nonspecific interstitial pneumonia or an original pattern consisting of cysts and ground-glass attenuation.

Comorbidities in rheumatic diseases need special consideration during the COVID-19 pandemic

Comorbidities in rheumatic and musculoskeletal diseases (RMDs) not only increase morbidity and mortality but also confound disease activity, limit drug usage and increase chances of severe infections or drug-associated adverse effects. Most RMDs lead to accelerated atherosclerosis and variable manifestations of the metabolic syndrome. Literature on COVID-19 in patients with RMDs, and the effects of various comorbidities on COVID-19 was reviewed. The initial data of COVID-19 infections in RMDs have not shown an increased risk for severe disease or the use of different immunosuppression. However, there are some emerging data that patients with RMDs and comorbidities may fare worse. Various meta-analyses have reiterated that pre-existing hypertension, cardiovascular disease, stroke, diabetes, chronic kidney disease, heart failure, lung disease or obesity predispose to increased COVID-19 mortality. All these comorbidities are commonly encountered in the various RMDs. Presence of comorbidities in RMDs pose a greater risk than the RMDs themselves. A risk score based on comorbidities in RMDs should be developed to predict severe COVID-19 and death. Additionally, there should be active management of such comorbidities to mitigate these risks. The pandemic must draw our attention towards, and not away from, comorbidities.

Prevalence and risk factors of interstitial lung disease in patients with primary Sjögren's syndrome: A systematic review and meta-analysis

OBJECTIVE

To systematically review the prevalence and risk factors for interstitial lung disease (ILD) in patients with primary Sjögren's syndrome (pSS).

METHODS

We searched PubMed, Embase, and Cochrane Library from inception to December 2019. Two investigators reviewed records according to predefined criteria. We calculated the pooled prevalence, weighted mean differences (WMDs), odds ratio (OR) and 95% confidence intervals (CIs) using a random effects model, and performed subgroup analysis, sensitivity analysis, and Egger's test.

RESULTS

In 23 studies with 6157 pSS patients, the pooled prevalence of ILD in pSS patients was 13% (95% CI: 9-19). The pSS-ILD prevalence was higher in Asia (20%) than that in Europe (10%). Male gender (OR = 1.92, 95% CI: 1.26-2.95), elder age (WMD = 9.25 years, 95% CI: 2.78-15.72) and higher C-reactive protein (CRP) (WMD = 3.92 mg/L, 95% CI: 0.27-1.61) was associated with ILD in pSS patients.

CONCLUSION

Interstitial lung disease was prevalent in pSS patients. Elder age, male gender and higher CRP were risk factors for pSS-ILD. Our data highlighted the importance of screening for ILD in high-risk pSS patients.

Clinical and Immunological Profile of Mixed Connective Tissue Disease and a Comparison of Four Diagnostic Criteria

Mixed connective tissue disease (MCTD) was initially described as a chronic immune-mediated disease with overlapping features of systemic lupus erythematosus, scleroderma, and polymyositis. We conducted a cross-sectional study to describe the clinical and immunological profile of patients with MCTD and to compare the four diagnostic criteria, namely, Sharp, Kasukawa, Alarcón-Segovia, and Khan criteria. A total of 291 patients who were admitted from June 2007 to June 2017 and fulfilled the inclusion criteria were included in the study. A clinical diagnosis of MCTD was made in 111 patients, of whom 103 (92.8%) were women. The mean age at presentation was 39.3 years (SD ± 11.6). The most common organ systems that were involved were musculoskeletal system (95.5%), skin and mucosa (78.4%), and the gastrointestinal and hepatobiliary systems (56%). The maximum sensitivity was for the Kasukawa criteria with a sensitivity of 77.5% (95% CI 68.4-84.6) and specificity of 92.2% (95% CI 87-95.5). The Kahn criteria and Alarcón-Segovia criteria had the maximum specificity; the Alarcón-Segovia criteria had a sensitivity of 69.4% (95% CI 59.8-77.6) and a specificity of 99.4% (95% CI 96.5-99.9), while the Kahn criteria had a sensitivity of 52.3% (95% CI 42.6-61.7) and a specificity of 99.4% (95% CI 96.5-99.9). The sensitivity and specificity of Sharp criteria were 57.7% (95% CI 47.9-66.87) and 90% (95% CI 84.4-93.8), respectively.

Role of Gas6 and TAM Receptors in the Identification of Cardiopulmonary Involvement in Systemic Sclerosis and Scleroderma Spectrum Disorders

Background

Few biomarkers are available for early identification of pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD) in systemic sclerosis (SS) and scleroderma spectrum disorders (SSD).

Aims

To evaluate Gas6, sAxl, and sMer as biomarkers for cardiopulmonary complications of SS and SSD.

Methods

In a cross-sectional observational study, we recruited 125 consecutive patients, affected by SS and SSD and referred to a tertiary-level pulmonary hypertension outpatient clinic. All patients underwent a comprehensive evaluation for identification of PAH and ILD. Gas6, sMer, and sAxl concentrations were measured with ELISA protocols, and concentrations were compared according to PAH or ILD.

Results

Nineteen subjects had pulmonary hypertension (PH) (14 PAH), and 39 had ILD (6 severe). Plasma sMer was increased in PAH (18.6 ng/ml IQR [11.7-20.3]) with respect to the absence (12.4 [8.0-15.8]) or other form of pulmonary hypertension (9.6 [7.4-12.5]; K–W variance p < 0.04). Conversely, Gas6 and sAxl levels were slightly increased in mild ILD (25.8 ng/ml [19.5-32.1] and 24.6 [20.1-32.5]) and reduced in severe ILD (16.6 [15.0-22.1] and 15.5 [14.9-22.4]) in comparison to no evidence of ILD (23.4 [18.8-28.1] and 21.6 [18.1-28.4]; K–W, p ≤ 0.05). Plasma sMer ≥ 19 ng/ml has 50% sensitivity and 92% specificity in PAH identification (area under the ROC curve (AUC) 0.697, p < 0.03). Values of Gas6 ≤ 24.5 ng/ml and of sAxl ≤ 15.5 ng/ml have 100% and 67% sensitivity and 47% and 86% specificity, respectively, in identifying severe ILD (Gas6 AUC 0.787, p < 0.001; sAxl AUC 0.705, p < 0.05).

Conclusions

The assay of Gas6 sAxl and sMer may be useful to help in the identification of PAH and ILD in SS and SSD patients. The Gas6/TAM system seems to be relevant in cardiopulmonary complications of SS and SSD and merits further investigations.

Progression of fibrosing interstitial lung disease

Fibrotic interstitial lung diseases (ILDs) are often challenging to diagnose and classify, but an accurate diagnosis has significant implications for both treatment and prognosis. A subset of patients with fibrotic ILD experience progressive deterioration in lung function, physical performance, and quality of life. Several risk factors for ILD progression have been reported, such as male sex, older age, lower baseline pulmonary function, and a radiological or pathological pattern of usual interstitial pneumonia. Morphological similarities, common underlying pathobiologic mechanisms, and the consistently progressive worsening of these patients support the concept of a progressive fibrosing (PF)-ILD phenotype that can be applied to a variety of ILD subtypes. The conventional approach has been to use antifibrotic medications in patients with idiopathic pulmonary fibrosis (IPF) and immunosuppressive medications in patients with other fibrotic ILD subtypes; however, recent clinical trials have suggested a favourable treatment response to antifibrotic therapy in a wider variety of fibrotic ILDs. This review summarizes the literature on the evaluation and management of patients with PF-ILD, and discusses questions relevant to applying recent clinicial trial findings to real-world practice.

18F-AzaFol for Detection of Folate Receptor-β Positive Macrophages in Experimental Interstitial Lung Disease-A Proof-of-Concept Study

Background: Interstitial lung disease (ILD) is a common and severe complication in rheumatic diseases. Folate receptor-β is expressed on activated, but not resting macrophages which play a key role in dysregulated tissue repair including ILD. We therefore aimed to pre-clinically evaluate the potential of 18F-AzaFol-based PET/CT (positron emission computed tomography/computed tomography) for the specific detection of macrophage-driven pathophysiologic processes in experimental ILD. Methods: The pulmonary expression of folate receptor-β was analyzed in patients with different subtypes of ILD as well as in bleomycin (BLM)-treated mice and respective controls using immunohistochemistry. PET/CT was performed at days 3, 7, and 14 after BLM instillation using the 18F-based folate radiotracer 18F-AzaFol. The specific pulmonary accumulation of the radiotracer was assessed by ex vivo PET/CT scans and quantified by ex vivo biodistribution studies. Results: Folate receptor-β expression was 3- to 4-fold increased in patients with fibrotic ILD, including idiopathic pulmonary fibrosis and connective tissue disease-related ILD, and significantly correlated with the degree of lung remodeling. A similar increase in the expression of folate receptor-β was observed in experimental lung fibrosis, where it also correlated with disease extent. In the mouse model of BLM-induced ILD, pulmonary accumulation of 18F-AzaFol reflected macrophage-related disease development with good correlation of folate receptor-β positivity with radiotracer uptake. In the ex vivo imaging and biodistribution studies, the maximum lung accumulation was observed at day 7 with a mean accumulation of 1.01 ± 0.30% injected activity/lung in BLM-treated vs. control animals (0.31 ± 0.06% % injected activity/lung; p < 0.01). Conclusion: Our preclinical proof-of-concept study demonstrated the potential of 18F-AzaFol as a novel imaging tool for the visualization of macrophage-driven fibrotic lung diseases.

Demographic and clinical predictors of progression and mortality in connective tissue disease-associated interstitial lung disease: a retrospective cohort study

BACKGROUND

Connective tissue disease-associated interstitial lung disease (CTD-ILD) is associated with reduced quality of life and poor prognosis. Prior studies have not identified a consistent combination of variables that accurately predict prognosis in CTD-ILD. The objective of this study was to identify baseline demographic and clinical characteristics that are associated with progression and mortality in CTD-ILD.

METHODS

Patients were retrospectively identified from an adult CTD-ILD clinic. The predictive significance of baseline variables on serial forced vital capacity (FVC), diffusion capacity (DLCO), and six-minute walk distance (6MWD) was assessed using linear mixed effects models, and Cox regression analysis was performed to assess impact on mortality.

RESULTS

359 patients were included in the study. Median follow-up time was 4.0 (IQR 1.5-7.6) years. On both unadjusted and multivariable analysis, male sex and South Asian ethnicity were associated with decline in FVC. Male sex, positive smoking history, and diagnosis of systemic sclerosis (SSc) vs. other CTD were associated with decline in DLCO. Male sex and usual interstitial pneumonia (UIP) pattern predicted decline in 6MWD. There were 85 (23.7%) deaths. Male sex, older age, First Nations ethnicity, and a diagnosis of systemic sclerosis vs. rheumatoid arthritis were predictors of mortality on unadjusted and multivariable analysis.

CONCLUSION

Male sex, older age, smoking, South Asian or First Nations ethnicity, and UIP pattern predicted decline in lung function and/or mortality in CTD-ILD. Further longitudinal studies may add to current clinical prediction models for prognostication in CTD-ILD.

Progressive fibrosing interstitial lung disease associated with systemic autoimmune diseases

Interstitial lung disease (ILD) is a common manifestation of systemic autoimmune diseases and a leading cause of death in these patients. A proportion of patients with autoimmune ILDs develop a progressive fibrosing form of ILD, characterized by increasing fibrosis on high-resolution computed tomography, worsening of lung function, and early mortality. Autoimmune disease-related ILDs have a variable clinical course and not all patients will require treatment, but all patients should be monitored for signs of progression. Apart from systemic sclerosis-associated ILD, the limited evidence to support the efficacy of immunosuppression as a treatment for ILDs is based mainly on small retrospective series and expert opinion. Non-clinical data suggest that there are commonalities in the mechanisms that drive progressive fibrosis in ILDs with an immunological trigger as in other forms of progressive fibrosing ILD. This suggests that nintedanib and pirfenidone, drugs known to slow disease progression in patients with idiopathic pulmonary fibrosis, may also slow the progression of ILD associated with systemic autoimmune diseases. In the SENSCIS® trial, nintedanib reduced the rate of ILD progression in patients with systemic sclerosis-associated ILD. The results of other large clinical trials will provide further insights into the role of anti-fibrotic therapies in the treatment of autoimmune disease-related ILDs.

Pulmonary Manifestations of Systemic Sclerosis and Mixed Connective Tissue Disease

Systemic sclerosis (SSc) is a rare disease characterized by widespread collagen deposition resulting in fibrosis. Although skin involvement is the most common manifestation and also the one that determines the classification of disease, mortality in SSc is usually a result of respiratory compromise in the form of interstitial lung disease (ILD) or pulmonary hypertension (PH). Clinically significant ILD is seen in up to 40% of patients and PH in up to 20%. Treatment with either cyclophosphamide or mycophenolate has been shown to delay disease progression, whereas rituximab and lung transplantation are reserved for refractory cases.