Current and Emerging Drug Therapies for Connective Tissue Disease-Interstitial Lung Disease (CTD-ILD)

Pulmonary Hypertension in Connective Tissue Diseases Other than Systemic Sclerosis

Pulmonary hypertension (PH) is a known complication of certain connective tissue diseases (CTDs), with systemic sclerosis (SSc) being the most common in the Western world. However, PH in association with non-SSc CTD such as systemic lupus erythematous, mixed connective tissue disease, and primary Sjögren's syndrome constitutes a distinct subset of patients with inherently different epidemiologic profiles, pathophysiologic mechanisms, clinical features, therapeutic options, and prognostic implications. The purpose of this review is to inform a practical approach for clinicians evaluating patients with non-SSc CTD-associated PH.The development of PH in these patients involves a complex interplay between genetic factors, immune-mediated mechanisms, and endothelial cell dysfunction. Furthermore, the broad spectrum of CTD manifestations can contribute to the development of PH through various pathophysiologic mechanisms, including intrinsic pulmonary arteriolar vasculopathy (pulmonary arterial hypertension, Group 1 PH), left-heart disease (Group 2), chronic lung disease (Group 3), chronic pulmonary artery obstruction (Group 4), and unclear and/or multifactorial mechanisms (Group 5). The importance of diagnosing PH early in symptomatic patients with non-SSc CTD is highlighted, with a review of the relevant biomarkers, imaging, and diagnostic procedures required to establish a diagnosis.Therapeutic strategies for non-SSc PH associated with CTD are explored with an in-depth review of the medical, interventional, and surgical options available to these patients, emphasizing the CTD-specific considerations that guide treatment and aid in prognosis. By identifying gaps in the current literature, we offer insights into future research priorities that may prove valuable for patients with PH associated with non-SSc CTD.

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.

The Role of Small Airway Disease in Pulmonary Fibrotic Diseases

Small airway disease (SAD) is a pathological condition that affects the bronchioles and non-cartilaginous airways 2 mm or less in diameter. These airways play a crucial role in respiratory function and are often implicated in various pulmonary disorders. Pulmonary fibrotic diseases are characterized by the thickening and scarring of lung tissue, leading to progressive respiratory failure. We aimed to present the link between SAD and fibrotic lung conditions. The evidence suggests that SAD may act as a precursor or exacerbating factor in the progression of fibrotic diseases. Patients with fibrotic conditions often exhibit signs of small airway dysfunction, which can contribute to worsening respiratory symptoms and decreased lung function. Moreover, individuals with advanced SAD are at a heightened risk of developing fibrotic changes in the lung. The interplay between inflammation, environmental factors, and genetic predisposition further complicates this association. The early detection and management of SAD can potentially mitigate the progression of fibrotic diseases, highlighting the need for comprehensive clinical evaluation and research. This review emphasizes the need to understand the evolving connection between SAD and pulmonary fibrosis, urging further detailed research to clarify the causes and potential treatment between the two entities.

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.

Efficacy and safety of antifibrotic agents in the treatment of CTD-ILD and RA-ILD: A systematic review and meta-analysis

OBJECTIVE

The clinical spectrum of connective tissue disease-associated interstitial lung disease (CTD-ILD) and rheumatoid arthritis-associated interstitial lung disease (RA-ILD) ranges from asymptomatic findings on radiographic imaging to a rapidly progressive illness leading to respiratory failure and death. The treatment is always challenging due to the paucity of proven effective treatments. Nintedanib and pirfenidone are recently approved antifibrotics in idiopathic pulmonary fibrosis. This study aimed to investigate the efficacy and safety of antifibrotic agents in the treatment of CTD-ILD and RA-ILD.

METHODS

Relevant databases were searched for randomized controlled trials that compared pirfenidone or nintedanib with placebo in patients with CTD-ILD and RA-ILD. The primary outcome was the change in forced vital capacity (FVC). The odds ratio or risk ratio with 95% confidence interval (CI) was estimated for categorical data, and the mean difference with 95% CI was estimated for continuous data. The I² statistic was used to assess heterogeneity, and meta-analysis was performed when possible.

RESULTS

Ten studies with a total of 880 participants met the inclusion criteria. Of these, four studies were included in the meta-analysis. According to the pooled result, the annual decline of FVC was significantly decreased in the antifibrotic agent arm compared to that in the placebo arm (MD 70.58 mL/yr, 95% CI 40.55 to 100.61).

CONCLUSION

This review suggests a potential benefit and safety of antifibrotic treatment in slowing the decline of FVC in patients with CTD-ILD and RA-ILD. Further large-sample, random-controlled, high-quality trials are needed to provide more evidence in the decision-making regarding the use of antifibrotics in this group of patients.

CLINICAL TRIAL REGISTRATION

PROSPERO; No.: CRD42022369112; URL: https://www.crd.york.ac.uk/prospero/.

Monitoring small airway dysfunction in connective tissue disease-related interstitial lung disease: a retrospective and prospective study

BACKGROUND

Small airway dysfunction (SAD), a hallmark of early lung function abnormality, is a major component of several chronic respiratory disorders. The role of SAD in patients with connective tissue disease-related interstitial lung disease (CTD-ILD) has not been explored.

METHODS

We conducted a two-parts (retrospective and prospective) study to collect pulmonary function tests from CTD-ILD patients. SAD was defined as at least two of the three measures (MMEF, FEF 50%, and FEF 75%) must be 65% of predicted values. Spearman correlation coefficient was used to evaluate association between SAD and other pulmonary function parameters. Mixed effects regression modeling analysis was used to assess response to treatment.

RESULTS

CTD-ILD patients with SAD and without SAD were compared in this study. In the retrospective study, pulmonary function tests (PFTs) from 491 CTD-ILD patients were evaluated, SAD were identified in 233 (47.5%). CTD-ILD patients with SAD were less smokers (17.6% vs. 27.9%, p = 0.007) and more females (74.3% vs. 64.0%, p = 0.015) than those without SAD. CTD-ILD patients with SAD had lower vital capacity (% predicted FVC, 70.4 ± 18.3 vs. 80.0 ± 20.9, p < 0.001) and lower diffusion capacity (% predicted DLCO, 58.8 ± 19.7 vs. 63.8 ± 22.1, p = 0.011) than those without SAD. Among 87 CTD-ILD patients prospectively enrolled, significant improvement in % predicted FVC was observed at 12-months follow-up (6.37 ± 1.53, p < 0.001 in patients with SAD; 5.13 ± 1.53, p = 0.002 in patients without SAD), but not in diffusion capacity and SAD parameters.

CONCLUSION

In our cohort, about half of CTD-ILD patients have SAD, which is less frequent in smokers and more common in female patients. CTD-ILD patients with SAD have worse pulmonary function compared to those without SAD. Improvement of FVC but no improvement of SAD was observed in CTD-ILD patients after treatment.

Diagnosis and Pharmacologic Management of Fibrotic Interstitial Lung Disease

Interstitial lung disease is an umbrella term that encompasses a spectrum of parenchymal lung pathologies affecting the gas exchanging part of the lung. While many of these disease entities are not fibrotic in nature, a number can lead to pulmonary fibrosis which may or may not progress over time. Idiopathic pulmonary fibrosis is the prototypical, progressive fibrotic interstitial lung disease, which can lead to worsening hypoxemic respiratory failure and mortality within a number of years from the time of diagnosis. The importance of an accurate and timely diagnosis of interstitial lung diseases, which is needed to inform prognosis and guide clinical management, cannot be overemphasized. Developing a consensus diagnosis requires the incorporation of a variety of factors by a multidisciplinary team, which then may or may not determine a need for tissue sampling. Clinical management can be challenging given the heterogeneity of disease behavior and the paucity of controlled trials to guide decision making. This review addresses current paradigms and recent updates in the diagnosis and pharmacologic management of these fibrotic interstitial lung diseases.

Rituximab for connective tissue disease-associated interstitial lung disease: A systematic review and meta-analysis

OBJECTIVE

To assess the efficacy of rituximab (RTX) on lung function and the prevalence of adverse events (AEs) in connective tissue disease-associated interstitial lung disease (CTD-ILD) by meta-analysis.

METHODS

EMBASE, Web of Science, PubMed and ClinicalKey were searched up to July 16, 2021. The lung function (forced vital capacity, FVC% predicted, and diffusing capacity of the lung for carbon monoxide, DLCO% predicted) and prevalence of AEs of RTX in CTD-ILD were analyzed by meta-analysis, and 95% confidence interval (CI) was calculated. Subgroup analyses and meta-regression were used to explore the heterogeneity.

RESULTS

We identified 29 studies, including 827 CTD-ILD patients with a median age of 53.05 years. In observational studies, FVC% (mean difference - 1.24, 95% CI [-2.35, -0.12]; P = .030) and DLCO% (-7.71, [-11.79, -3.63]; P = .014) of CTD-ILD decreased significantly after RTX treatment. In randomized controlled trials, FVC% of CTD-ILD decreased after RTX treatment (-5.24, [-9.94, - 0.54]; P = .029), but the difference of DLCO% was not significant (1.15, [-4.33, 6.63]; P = .681). The prevalence of AEs, all-cause mortality and infections was 29.7% (95% CI [0.17, 0.42]), 11.6% (95% CI [0.08, 0.16]) and 20.9% (95% CI [0.15, 0.27]), respectively.

CONCLUSIONS

RTX was associated with AEs such as decreased pulmonary function, all-cause mortality, and infections in CTD-ILD. Adverse reactions during and after RTX treatment should be carefully monitored. Further prospective studies are needed to compare RTX with other immunosuppressants, antifibrotic drugs or placebos, which can provide therapeutic approaches for CTD-ILD.

Efficacy and safety of Chinese herbal medicines combined with cyclophosphamide for connective tissue disease-associated interstitial lung disease: A meta-analysis of randomized controlled trials

Objectives: To evaluate the effectiveness and safety of Chinese herbal medicines (CHMs) combined with cyclophosphamide (CTX) for connective tissue disease-associated interstitial lung disease (CTD-ILD) by performing a meta-analysis. Methods: We searched RCTs of Chinese herbal medicines therapy for connective tissue disease-associated interstitial lung disease in ten databases. Methodological quality assessment was performed by the Cochrane collaboration tool. RevMan v5.3 and Stata v14.0 software were used for performing data analysis. This study was conducted and reported following the PRISMA checklist. Results: Overall, seven RCTs with 506 participants were included for this analysis. Current data indicated that Chinese herbal medicines combined with cyclophosphamide contributed to a betterment in improving the clinical efficacy rate of connective tissue disease-associated interstitial lung disease [risk ratio (RR) = 1.21, 95% confidence interval (CI): (1.09, 1.35), p = 0.0003], tended to benefit improvement of lung function, which included VC [weighted mean difference (WMD) = 9.49, 95% CI: (5.54, 13.45), p < 0.00001], FVC [standardized mean difference (SMD) = 0.83, 95% CI: (0.36, 1.29), p = 0.0005], FEV1 [SMD = 0.54, 95% CI: (0.23, 0.86), p = 0.0008], TLC [SMD = 0.90, 95% CI: (0.68, 1.13), p < 0.00001], DLCO [SMD = 1.05, 95% CI: (0.38, 1.73), p = 0.002], and MVV [SMD = 0.83, 95% CI: (0.50, 1.17), p < 0.00001], and it also could significantly reduce the HRCT integral of lungs [SMD = -2.02, 95% CI: (-3.14, -0.91), p = 0.0004] and the level of ESR [WMD = -13.33, 95% CI: (-18.58, -8.09), p < 0.00001]. Furthermore, there was no statistical significance in the incidence of adverse events (AEs), which indicate that Chinese herbal medicines combined with cyclophosphamide is safe and does not increase adverse events compared with cyclophosphamide alone. Conclusion: Our analysis indicates that Chinese herbal medicines combined with cyclophosphamide may be a more effective strategy on the treatment of connective tissue disease-associated interstitial lung disease in the clinic. Because it included studies with relatively small sample size, the results need to be confirmed by more well-designed and large-scale RCTs. Systematic Review Registration: https://10.37766/inplasy2022.12.0010.

Diagnosing interstitial lung disease by multidisciplinary discussion: A review

The multidisciplinary meeting (MDM) has been endorsed in current international consensus guidelines as the gold standard method for diagnosis of interstitial lung disease (ILD). In the absence of an accurate and reliable diagnostic test, the agreement between multidisciplinary meetings has been used as a surrogate marker for diagnostic accuracy. Although the ILD MDM has been shown to improve inter-clinician agreement on ILD diagnosis, result in a change in diagnosis in a significant proportion of patients and reduce unclassifiable diagnoses, the ideal form for an ILD MDM remains unclear, with constitution and processes of ILD MDMs varying greatly around the world. It is likely that this variation of practice contributes to the lack of agreement seen between MDMs, as well as suboptimal diagnostic accuracy. A recent Delphi study has confirmed the essential components required for the operation of an ILD MDM. The ILD MDM is a changing entity, as it incorporates new diagnostic tests and genetic markers, while also adapting in its form in response to the obstacles of the COVID-19 pandemic. The aim of this review was to evaluate the current evidence regarding ILD MDM and their role in the diagnosis of ILD, the practice of ILD MDM around the world, approaches to ILD MDM standardization and future directions to improve diagnostic accuracy in ILD.

Prevalence of latent tuberculosis infection among patients with interstitial lung disease requiring immunosuppression

Objective

To characterize the prevalence of latent tuberculosis infection (LTBI) in patients with interstitial lung diseases (ILDs) requiring immunosuppression. Only 5 to 10% of individuals infected with Mycobacterium tuberculosis develop tuberculosis, and certain groups of patients have an increased risk of illness, such as the immunocompromised. Patients with ILDs are frequently treated with immunosuppressants and, therefore, might have a higher risk of developing the disease.

Methods

Prospective study conducted at the ILD reference center of the Federal University of Paraná from January 2019 to December 2020. The screening of LTBI was performed with the use of the tuberculin skin test (TST).

Results

The sample consisted of 88 patients, of whom 64.8% were women, with a mean age of 61.4 years. The most frequent diagnoses were autoimmune rheumatic disease ILD (38.6%) and hypersensitivity pneumonitis (35.2%). The most common immunosuppressant in use at the time of the TST was prednisone, either in combination with mycophenolate (19.3%) or alone (17.1%). The majority of participants had fibrotic lung disease, characterized by a reticular interstitial pattern on chest computed tomography (79.5%) and moderate to severe functional impairment (mean FVC 69.2%). A prevalence of LTBI of 9.1% (CI 95%, 2.1%-15.1%) was found, with a TST median of 13.

Conclusion

Patients with ILD who are treated with immunosuppressants are not commonly screened for LTBI, despite being under a greater risk of progression to active disease. This study suggests the need for a more cautious approach to these patients.

Thoracic Involvement in Systemic Autoimmune Rheumatic Diseases: Pathogenesis and Management

Thoracic involvement is one of the main determinants of morbidity and mortality in patients with autoimmune rheumatic diseases (ARDs), with different prevalence and manifestations according to the underlying disease. Interstitial lung disease (ILD) is the most common pulmonary complication, particularly in patients with systemic sclerosis (SSc), idiopathic inflammatory myopathies (IIMs) and rheumatoid arthritis (RA). Other thoracic manifestations include pulmonary arterial hypertension (PAH), mostly in patients with SSc, airway disease, mainly in RA, and pleural involvement, which is common in systemic lupus erythematosus and RA, but rare in other ARDs.In this review, we summarize and critically discuss the current knowledge on thoracic involvement in ARDs, with emphasis on disease pathogenesis and management. Immunosuppression is the mainstay of therapy, particularly for ARDs-ILD, but it should be reserved to patients with clinically significant disease or at risk of progressive disease. Therefore, a thorough, multidisciplinary assessment to determine disease activity and degree of impairment is required to optimize patient management. Nevertheless, the management of thoracic involvement-particularly ILD-is challenging due to the heterogeneity of disease pathogenesis, the variety of patterns of interstitial pneumonia and the paucity of randomized controlled clinical trials of pharmacological intervention. Further studies are needed to better understand the pathogenesis of these conditions, which in turn is instrumental to the development of more efficacious therapies.

IL-22 inhibits bleomycin-induced pulmonary fibrosis in association with inhibition of IL-17A in mice

BACKGROUND

Interstitial lung disease, a common extra-articular complication of connective tissue disease, is characterized by progressive and irreversible pulmonary inflammation and fibrosis, which causes significant mortality. IL-22 shows a potential in regulating chronic inflammation and possibly plays an anti-fibrotic role by protecting epithelial cells. However, the detailed effects and underlying mechanisms are still unclear. In this study, we explored the impact of IL-22 on pulmonary fibrosis both in vivo and in vitro.

METHODS

To induce pulmonary fibrosis, wild-type mice and IL-22 knockout mice were intratracheally injected with bleomycin followed by treatments with recombinant IL-22 or IL-17A neutralizing antibody. We investigated the role of IL-22 on bleomycin-induced pulmonary fibrosis and the mechanism in the possible interaction between IL-22 and IL-17A. Fibrosis-related genes were detected using RT-qPCR, western blot, and immunofluorescence. Inflammatory and fibrotic changes were assessed based on histological features. We also used A549 human alveolar epithelial cells, NIH/3T3 mouse fibroblast cells, and primary mouse lung fibroblasts to study the impact of IL-22 on fibrosis in vitro.

RESULTS

IL-22 knockout mice showed aggravated pulmonary fibrosis compared with wild-type mice, and injection of recombinant IL-22 decreased the severe fibrotic manifestations in IL-22 knockout mice. In cell culture assays, IL-22 decreased protein levels of Collagen I in A549 cells, NIH/3T3 cells, and primary mouse lung fibroblasts. IL-22 also reduced the protein level of Collagen I in NIH/3T3 cells which were co-cultured with T cells. Mechanistically, IL-22 reduced the Th17 cell proportion and IL-17A mRNA level in lung tissues, and treatment with an IL-17A neutralizing antibody alleviated the severe pulmonary fibrosis in IL-22 knockout mice. The IL-17A neutralizing antibody also reduced Collagen I expression in NIH/3T3 cells in vitro. Knockdown of IL-17A with siRNAs or administration of IL-22 in NIH/3T3 cells and MLFs decreased expression of Collagen I, an effect blocked by concurrent use of recombinant IL-17A.

CONCLUSIONS

IL-22 mediated an anti-fibrogenesis effect in the bleomycin-induced pulmonary fibrosis model and this effect was associated with inhibition of IL-17A.

Case Report: Successful Treatment of Refractory Interstitial Lung Disease With Cyclosporine A and Pirfenidone in a Child With SLE

Interstitial lung disease (ILD) as an initial manifestation of lupus is rare, especially in young children. Here, we report a case of a 3-year-old boy who presented with fever, shortness of breath, and facial erythema. Clinical examination suggested a diagnosis of active systemic lupus erythematosus (SLE) with butterfly rash, anemia, positive antinuclear antibody, positive anti-double-stranded DNA, and hypocomplementemia. On retrospective review of the patient’s records, multiple chest computed tomography (CT) images showed non-specific interstitial pneumonia + organizing pneumonia pattern, with no further autoimmune work-up during the visit to a respiratory department. In our opinion, persistent interstitial pneumonia may be a clue to connective tissue disease. The patient received steroid treatment for 1 year, and the radiological and immunological resolution was noted. However, he still suffered from cough and dyspnea. After a 1-year follow-up, he was hospitalized again for SLE relapse. While continuing corticosteroid therapy, the patient was given combination therapy consisting of cyclosporine A (CsA) and monthly-pulse cyclophosphamide for 6 months, and decreased proteinuria was noted. However, the patient’s respiratory symptoms and pulmonary radiologic findings did not improve significantly. With continued steroid therapy, the patient was started on a daily regimen of CsA and pirfenidone. Both drugs were sufficiently effective to allow gradual reduction of steroid dosage. After 2 years of treatment, marked improvements in symptoms, pulmonary function and chest CT images were observed. Our experience with this case emphasizes that prompt work-up for connective tissue disease (CTD) should be considered in young children with ILD, and pirfenidone might be a useful add-on therapy with immunosuppressive agents for refractory CTD-ILD in pediatric patients. Nevertheless, further clinical trials including larger numbers of patients need to assess the efficiency and safety of this combination therapy for refractory CTD-ILD.

Fibrotic Idiopathic Interstitial Lung Disease: The Molecular and Cellular Key Players

Interstitial lung diseases (ILDs) that are known as diffuse parenchymal lung diseases (DPLDs) lead to the damage of alveolar epithelium and lung parenchyma, culminating in inflammation and widespread fibrosis. ILDs that account for more than 200 different pathologies can be divided into two groups: ILDs that have a known cause and those where the cause is unknown, classified as idiopathic interstitial pneumonia (IIP). IIPs include idiopathic pulmonary fibrosis (IPF), non-specific interstitial pneumonia (NSIP), cryptogenic organizing pneumonia (COP) known also as bronchiolitis obliterans organizing pneumonia (BOOP), acute interstitial pneumonia (AIP), desquamative interstitial pneumonia (DIP), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), and lymphocytic interstitial pneumonia (LIP). In this review, our aim is to describe the pathogenic mechanisms that lead to the onset and progression of the different IIPs, starting from IPF as the most studied, in order to find both the common and standalone molecular and cellular key players among them. Finally, a deeper molecular and cellular characterization of different interstitial lung diseases without a known cause would contribute to giving a more accurate diagnosis to the patients, which would translate to a more effective treatment decision.

Iguratimod decreases bleomycin-induced pulmonary fibrosis in association with inhibition of TNF-α in mice

Severe interstitial lung disease secondary to connective tissue diseases, characterized by pulmonary inflammation and fibrosis, often have very poor prognosis due to lack of effective treatments. Iguratimod (IGU) shows encouraging efficacy in treating connective tissue diseases, however, the underlying mechanism is still to be elucidated. In this study, we investigated the impact of IGU on bleomycin-induced interstitial lung disease and the related tumor necrosis factor-α (TNF-α) signaling pathway in mice and in the alveolar epithelial cell A549. We found IGU decreased pulmonary inflammation and fibrosis and expression of fibrosis-related genes such as Collagen I, α-smooth muscle actin (α-SMA) and matrix metalloproteinase-2 (MMP-2) induced by bleomycin. IGU inhibited epithelial-mesenchymal transition as evidenced by decreased E-cadherin expression but increased vimentin expression. IGU reduced TNF-α production in the pulmonary fibrosis murine model and in the in vitro cultured A549 cells. Furthermore, IGU ameliorated TNF-α-induced severe pulmonary fibrosis and inhibited TNF-α-induced activation of NF-κB. In addition, IGU decreased IL-6 production and phosphorylation of STAT3. In conclusion, the IGU-mediated anti-fibrogenesis effect was associated with the inhibition of TNF-α and NF-κB.

Efficacy and Safety of Tripterygium Wilfordii Hook. F for Connective Tissue Disease-Associated Interstitial Lung Disease:A Systematic Review and Meta-Analysis

Background: Tripterygium wilfordii Hook. F (TwHF), a Chinese herbal medicine used to treat CTD-ILD patients in China, has been previously found to have immunoinhibitory, antifibrotic and anti inflammatory effects. It has also shown good results in treating autoimmune and inflammatory diseases. Objectives: This systematic review and meta-analysis aims to evaluate the efficacy and safety of TwHF for CTD-ILD. Methods: A systematic search was performed on PubMed, Embase, Cochrane Library, Web of Science, PsycINFO, Scopus, CNKI, Wanfang, VIP, and CBM databases up to May 2021. Randomized controlled trials (RCTs) comparing TwHF plus conventional therapy versus conventional therapy alone were included. We followed the PRISMA checklist, and applied Cochrane handbook 5.1.0 and RevMan 5.3 for data analysis and quality evaluation of the included studies. Results: Based on Cochrane handbook 5.1.0, nine RCTs consisting 650 patients met the inclusion/exclusion criteria and were selected for further analysis. The obtained data showed significant improvement in lung function with TwHF plus conventional treatment compared with conventional treatment (post-treatment FVC% (MD= 8.68, 95%Cl (5.10, 12.26), p < 0.00001), FEV1% (MD = 11.24, 95%Cl (6.87, 15.61), p < 0.00001), TLC% (MD = 5.28, 95%Cl (0.69, 9.87), p = 0.02)], but no significant difference in the post-treatment DLCO% [(MD = 4.40, 95%Cl (-2.29, 11.09), p = 0.20)]. Moreover, the data showed that TwHF combined with conventional treatment significantly reduced the HRCT integral of patients [MD = -0.65, 95% (-1.01, -0.30), p = 0.0003], the level of erythrocyte sedimentation rate (MD = -9.52, 95%Cl (-11.55, -7.49), p < 0.00001), c-reactive protein (CRP) (MD = -8.42, 95%Cl (-12.47, -4.38), p < 0.0001), and rheumatoid factor (MD = -25.48, 95%Cl (-29.36, -21.60), p < 0.00001). Compared to conventional therapy, TwHF combined with conventional therapy significantly improved clinical effects (RR = 1.33, 95%Cl (1.17, 1.51), p < 0.0001), in five trials with 354 patients. In terms of improvement of symptoms and signs, the TwHF group showed a more significant improvement than the conventional treatment group (Cough (MD = -0.96, 95%Cl (-1.43, -0.50), p < 0.0001), velcro rales (MD = -0.32, 95%Cl (-0.44, -0.20), p < 0.00001), shortness of breath (MD = -1.11, 95%Cl (-1.67, -0.56), p < 0.0001)], but no statistical difference in dyspnea (MD = -0.66, 95%Cl (-1.35, 0.03), p = 0.06). There was no statistical significance in the incidence of adverse reactions. Conclusion: The performed meta-analysis indicated that TwHF combined with conventional treatment was more beneficial to patients for improving symptoms, lung function and laboratory indicators. As it included studies with relatively small sample size, the findings require confirmation by further rigorously well-designed RCTs.

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.

Clinical applications of mesenchymal stromal cell-based therapies for pulmonary diseases: An Update and Concise Review

Lung disorders are a leading cause of morbidity and death worldwide. For many disease conditions, no effective and curative treatment options are available. Mesenchymal stromal cell (MSC)-based therapy is one of the cutting-edge topics in medical research today. It offers a novel and promising therapeutic option for various acute and chronic lung diseases due to its potent and broad-ranging immunomodulatory activities, bacterial clearance, tissue regeneration, and proangiogenic and antifibrotic properties, which rely on both cell-to-cell contact and paracrine mechanisms. This review covers the sources and therapeutic potential of MSCs. In particular, a total of 110 MSC-based clinical applications, either completed clinical trials with safety and early efficacy results reported or ongoing worldwide clinical trials of pulmonary diseases, are systematically summarized following preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, including acute/viral pulmonary disease, community-acquired pneumonia (CAP), chronic obstructive pulmonary disease (COPD), bronchopulmonary dysplasia (BPD), interstitial lung diseases (ILD), chronic pulmonary fibrosis, bronchiolitis obliterans syndrome (BOS) and lung cancer. The results of recent clinical studies suggest that MSCs are a promising therapeutic approach for the treatment of lung diseases. Nevertheless, large-scale clinical trials and evaluation of long-term effects are necessary in further studies.

Cyclophosphamide for the treatment of Acute Exacerbation of Interstitial Lung Disease: A Review of the Literature

Acute exacerbation of interstitial lung disease is a serious and life-threatening event but little is known about its treatment. Cyclophosphamide has been proposed in randomized clinic trials as a treatment option in progressive cases of systemic sclerosis related interstitial lung disease. However, in acute exacerbation of interstitial lung disease, we found only small case series, and retrospective studies, mostly with no comparative groups which described the role of cyclophosphamide. Results of these studies showed mixed outcomes, with no robust evidence that cyclophosphamide adds any benefit in treating acute exacerbations of interstitial lung disease. More well-designed studies including randomized clinical trials are needed to better understand the role of cyclophosphamide during exacerbations of interstitial lung disease. In this review article, we summarize the current evidence on the use of cyclophosphamide in interstitial lung disease with a focus on the acute exacerbation events.

Immunomodulation in Autoimmune Interstitial Lung Disease

Interstitial lung diseases (ILDs) associated with autoimmune or systemic disease are increasingly recognized and our pathophysiological understanding rapidly expanding. Treatment modalities, however, are still mainly driven by established disease-modifying antirheumatic drugs (DMARDs) where, despite decades of experience of their use in the underlying diseases such as rheumatoid arthritis, mostly ret-rospective data exist informing their effect on the course of interstitial lung disease (ILD). In recent years, randomized trials investigating the effects of biological DMARDs (bDMARDs) have been completed or are currently running, generating new treatment options for often relentlessly progressive diseases. Herein, we summarize the evidence and current use of both synthetic DMARDs and bDMARDs in the context of ILDs associated with autoimmune/systemic disease.

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.

Structured report for chest high-resolution computed tomography in patients with connective tissue disease: Impact on the report quality as perceived by referring clinicians

RATIONALE AND OBJECTIVES

To evaluate the impact on perceived report quality of referring rheumatologists for a chest high-resolution computed tomography (HRCT) structured report (SR) template for patients with connective tissue disease (CTD), compared to the traditional narrative report (NR).

MATERIALS AND METHODS

We retrospectively considered 123 HRCTs in patients with CTD. Three radiologists, blinded to the original NRs they wrote during clinical routine, re-reported each HRCT using an SR dedicated template. We then divided all NR-SR couples into three groups (41 HRCT each). Each group was evaluated by one of three rheumatologists (R1, R2, R3), who expressed their perceived report quality for the respective pools of NRs and SRs in terms of completeness, clarity (both on a 10-points scale), and clinical relevance (on a 5-points scale). The Wilcoxon test and the McNemar test were used for statistical analysis.

RESULTS

For each rheumatologist, SR received higher ratings compared to NR for completeness (median ratings: R1, 10 vs. 7; R2, 10 vs. 8; R3, 10 vs. 6, all p < 0.0001), clarity (median ratings: R1, 10 vs. 7; R2, 10 vs. 8; R3, 10 vs. 7, all p < 0.0001), and clinical relevance (median ratings: R1, 5 vs. 4; R2, 5 vs. 4; R3, 5 vs. 1, all p < 0.0001). After rating dichotomization, the use of SR led to a significant increase (p < 0.01) in completeness, clarity, and clinical relevance as compared to NR, except for clarity as perceived by R2 (p = 1).

CONCLUSION

Referring rheumatologists' perceived report quality for structured reporting of HRCT in patients with CTD was superior to narrative reporting.

Association between systemic sclerosis and risk of lung cancer: results from a pool of cohort studies and Mendelian randomization analysis

BACKGROUND

Population-based cohort studies have indicated that systemic sclerosis (SSc) may be associated with an increased risk of lung cancer. However, there are few studies that comprehensively investigate their correlation and the causal effect remains unknown.

METHODS

A systematic search of PubMed, Web of Science, Cochrane Library and Embase from the inception dates to December 1, 2019 was carried out. Meta-analysis was performed to calculate odds ratio (OR) and corresponding 95% confidence interval (CI) using random-effects models. Subgroup analyses were performed regarding gender. Two-sample Mendelian randomization (MR) was carried out with summary data from published genome-wide association studies of SSc (Neale Lab, 3871 individuals; UK Biobank, 463,315 individuals) and lung cancer (International Lung Cancer Consortium, 27,209 individuals; UK Biobank, 508,977 individuals). Study-specific estimates were summarized using inverse variance-weighted, weighted median, and MR-Egger method.

RESULTS

Through meta-analysis of 10 population-based cohort studies involving 12,218 patients, we observed a significantly increased risk of lung cancer among patients with SSc (OR 2.80, 95% CI 1.55-5.03). In accordance with subgroup analysis, male patients (OR 4.11, 95% CI 1.92-8.79) had a 1.5-fold higher lung cancer risk compared with female patients (OR 2.73, 95% CI 1.41-5.27). However, using a score of 11 SSc-related single nucleotide polymorphisms (p < 5*10^-8) as instrumental variables, the MR study did not support a causality between SSc and lung cancer (OR 1.001, 95% CI 0.929-1.100, p = 0.800). Specifically, subgroup MR analyses indicated that SSc was not associated with increased risks of non-small-cell lung cancer (OR 1.000, 95% CI 0.999-1.000, p = 0.974), including lung adenocarcinoma (OR 0.996, 95% CI 0.906-1.094, p = 0.927), squamous cell lung carcinoma (OR 1.034, 95% CI 0.937-1.140, p = 0.507), nor small-cell lung cancer (OR 1.000, 95% CI 0.999-1.000, p = 0.837).

CONCLUSIONS

This study indicated an increased risk of lung cancer among patients with SSc by meta-analysis, whereas the MR study did not support a causality between the two diseases. Further studies are warranted to investigate the factors underlying the attribution of SSc to lung cancer risk.