Interstitial lung disease in rheumatoid arthritis. Curr Rheumatol Rep. 2010;12:363-369. [PMID: 20628839 DOI: 10.1007/s11926-010-0116-z]

CTHRC1: An Emerging Hallmark of Pathogenic Fibroblasts in Lung Fibrosis

Pulmonary fibrosis is a chronic, progressive, irreversible lung disease characterized by fibrotic scarring in the lung parenchyma. This condition involves the excessive accumulation of extracellular matrix (ECM) due to the aberrant activation of myofibroblasts in the alveolar environment. Transforming growth factor beta (TGF-β) signaling is a crucial driver of fibrogenesis because it promotes excessive ECM deposition, thereby leading to scar formation and lung damage. A primary target of TGF-β signaling in fibrosis is Collagen Triple Helix Repeat Containing 1 (CTHRC1), a secreted glycoprotein that plays a pivotal role in ECM deposition and wound repair. TGF-β transcriptionally regulates CTHRC1 in response to tissue injury and controls the wound healing response through functional activity. CTHRC1 may also play an essential role in re-establishing and maintaining tissue homeostasis after wound closure by modulating both the TGF-β and canonical Wnt signaling pathways. This dual function suggests that CTHRC1 regulates tissue remodeling and homeostasis. However, deregulated CTHRC1 expression in pathogenic fibroblasts has recently emerged as a hallmark of fibrosis in multiple organs and tissues. This review highlights recent studies suggesting that CTHRC1 can serve as a diagnostic and prognostic biomarker for fibrosis in idiopathic pulmonary fibrosis, systemic sclerosis, and post-COVID-19 lung fibrosis. Notably, CTHRC1 expression is responsive to antifibrotic drugs that target the TGF-β pathway, such as pirfenidone and bexotegrast, indicating its potential as a biomarker of treatment success. These findings suggest that CTHRC1 may present new opportunities for diagnosing and treating patients with lung fibrosis.

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.

Association between choroidal thickness and interstitial lung disease in patients with rheumatoid arthritis: A cross-sectional study

Objectives

This study aimed to evaluate choroidal thickness (CT) in patients with rheumatoid arthritis (RA) and healthy controls and to determine its relationship with RA-associated interstitial lung disease (RA-ILD).

Patients and methods

A total of 63 patients with RA and 36 age- and sex-matched healthy controls were recruited in the cross-sectional study. Serological findings, Disease Activity Score-28, disease duration, and medical treatment of patients were recorded. Patients with RA were subdivided into two groups: patients with RA-ILD (Group 1) and patients with RA but without ILD (RA-noILD; Group 2). CTs were measured using enhanced depth imaging optical coherence tomography. CT was measured at five points: the subfoveal region, 750 μm nasal and temporal to the fovea, 1500 μm nasal and temporal to the fovea. Patients with RA-ILD were evaluated with delta high-resolution computed tomography (ΔHRCT) and pulmonary function test to determine the severity of interstitial lung disease.

Results

Four of 63 RA patients were excluded due to comorbidities. Thus, 59 RA patients, 20 in the RA-ILD group and 39 in the RA-noILD group, were included in the analyses. The RA groups were similar in terms of clinical characteristics and laboratory findings. There were statistically significant differences between Group 1, Group 2 and healthy controls (Group 3) compared to all CT values (p<0.05). The mean CT measured at 750 μm and 1500 μm nasal to the fovea was lowest in the RA-ILD group, followed by the RA-noILD and healthy groups (p<0.05). CT measurements did not correlate with the pulmonary function test and ΔHRCT.

Conclusion

RA-ILD patients had a thinner CT measured at nasal points. However, there was no association between CT measurements and the severity of ILD.

Proteomics: Potential techniques for discovering the pathogenesis of connective tissue diseases-interstitial lung disease

Interstitial lung disease (ILD) is one of the most serious lung complications of connective tissue disease (CTD). The application of proteomics in the past decade has revealed that various proteins are involved in the pathogenesis of each subtype of CTD-ILD through different pathways, providing novel ideas to study pathological mechanisms and clinical biomarkers. On this basis, a multidimensional diagnosis or prediction model is established. This paper reviews the results of proteomic detection of different subtypes of CTD-ILD and discusses the role of some differentially expressed proteins in the development of pulmonary fibrosis and their potential clinical applications.

Unmet needs and perspectives in rheumatoid arthritis-associated interstitial lung disease: A critical review

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by synovitis as the most common clinical manifestation, and interstitial lung disease (RA-ILD) represents one of the most common and potentially severe extra-articular features. Our current understanding of the mechanisms and predictors of RA-ILD is limited despite the demonstration that an early identification of progressive fibrosing forms is crucial to provide timely treatment with antifibrotic therapies. While high resolution computed tomography is the gold standard technique for the diagnosis and follow-up of RA-ILD, it has been hypothesized that serum biomarkers (including novel and rare autoantibodies), new imaging techniques such as ultrasound of the lung, or the application of innovative radiologic algorithms may help towards predicting and detecting early forms of diseases. Further, while new treatments are becoming available for idiopathic and connective tissue disease-associated forms of lung fibrosis, the treatment of RA-ILD remains anecdotal and largely unexplored. We are convinced that a better understanding of the mechanisms connecting RA with ILD in a subgroup of patients as well as the creation of adequate diagnostic pathways will be mandatory steps for a more effective management of this clinically challenging entity.

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.

Predictors of long-term prognosis in rheumatoid arthritis-related interstitial lung disease

The aim of the study was to identify specific clinical and serum protein biomarkers that are associated with longitudinal outcome of RA-associated interstitial lung disease (RA-ILD). 60 RA patients with clinical and serological profiles were assessed by HRCT and pulmonary function tests (PFTs) at baseline (Year 0) and 5 years post enrollment (Year 5). Progression versus non-progression was defined based on changes in Quantitative Modified HRCT scores and PFTs over time. Specific serum protein biomarkers were assessed in serum samples at baseline and Year 5 by Multiplex enzyme-linked immunosorbent assays (ELISAs). At Year 5, 32% of patients demonstrated progressive RA-ILD, 35% were stable, and 33% improved. Baseline age and rheumatoid factor (RF) were significantly different between RA-ILD outcomes of progression vs. no-progression (p < 0.05). Changes in levels of CXCL11/I-TAC and MMP13 over 5 years also distinguished pulmonary outcomes (p < 0.05). A final binary logistic regression model revealed that baseline age and changes in serum MMP13 as well as CXCL11/I-TAC were associated with RA-ILD progression at Year 5 (p < 0.01), with an AUC of 0.7772. Collectively, these analyses demonstrated that baseline clinical variables (age, RF) and shifts in levels of selected serum proteins (CXCL11/I-TAC, MMP13) were strongly linked to RA-ILD outcome over time.

Interstitial Lung Disease Associated With Autoimmune Rheumatic Diseases: Checklists for Clinical Practice

Background: Interstitial lung diseases (ILDs) are often associated with rheumatic diseases. Their early diagnosis and management are not only difficult, but also crucial, because they are associated with major morbidity and mortality and can be the first cause of death in autoimmune rheumatic diseases (ARDs). Objectives: By using methodologies, such as Nominal Group Technique (NGT) and Delphi Survey, the aims of this study were (1) to measure consensus between pulmonologists, radiologists, and rheumatologists experienced in the management of ARD-ILD; (2) to highlight the importance of a multidisciplinary approach; and (3) to provide clinicians with a practical tool aimed at improving the prompt recognition and follow-up of ILD associated with ARDs and of any possible rheumatic conditions underlying ILD. Results: During the NGT round, the Steering Committee defined 57 statements to be used in the Delphi survey. A total of 78 experts participated in the Delphi survey, namely 28 pulmonologists, 33 rheumatologists, and 17 radiologists. During this round, consensus on agreement was reached in 47 statements, while disagreement was not reached in any statements. A secondary questionnaire was drafted by the Steering Committee to obtain clearer indications on ILD-ARD "red-flags" and follow-up. Delphi Panelists took part also in the second-questionnaire survey. Answers from both surveys were used to draft two checklists of "red flags" sign or symptom suggestive of ILD and ARD, respectively, and two checklists on identification and monitoring of rheumatoid arthritis (RA) and systemic sclerosis (SSc) ILD. Limitations: This study is a consensus work, which cannot produce empiric data, and is limited to the Italian scenario. Conclusions: This work showed a high level of agreement, but also shows some divergent opinions between different experts. This underlines the importance of a multidisciplinary approach. Eventually, we believe the drafted checklists can help clinicians in the diagnosis and follow-up of ILD-ARD.

Association of Serum Biomarkers With Pulmonary Involvement of Rheumatoid Arthritis Interstitial Lung Disease: From KORAIL Cohort Baseline Data

Objective

The increase in mortality in rheumatoid arthritis (RA) patients with interstitial lung disease (ILD) is well known However, there are few studies on serum markers that can evaluate acute exacerbation or prognosis in RA-ILD patients The purpose of this study was to identify the association between biomarkers and lung lesions in patients with RA-ILD.

Methods

We analyzed 153 patients with serum samples in a prospective, multicenter cohort of Korean RA-ILD patients The serum levels of biomarkers, matrix metalloproteinase (MMP-7), surfactant protein-D (SP-D), and Krebs von den Lungen-6 (KL-6) were measured and correlated with forced vital capacity (FVC), diffusing capacity for carbon monoxide (DLCO) and the results of computed tomography (CT) CT results were interpreted semi-quantitatively according to the extent of lung lesions (grade 1, 0%∼25%; grade 2, 26%∼50%; grade 3, 51%∼75%; grade 4, 76%∼100%).

Results

MMP-7, SP-D, and KL-6 were negatively correlated with FVC (MMP-7, r=-0267, p=0001; SP-D, r=-0250, p=0002; KL-6, r=-0223, p=0006) and DLCO (MMP-7, r=-0404, p<0001; SP-D, r=-0286, p=0001; KL-6, r=-0226, p=0007) In addition, MMP-7, SP-D, and KL-6 tended to increase with higher grades of lung lesions on CT (MMP-7, p=0013; SP-D, p<0001; KL-6, p<0001).

Conclusion

MMP-7, SP-D, and KL-6 can be used to evaluate the functional and anatomical status of lung involvement in the RA-ILD patients.

Prevalence and clinical characteristics of symptomatic diffuse interstitial lung disease in rheumatoid arthritis in a Spanish population

BACKGROUND AND OBJECTIVES

In Spain, epidemiological studies of the prevalence of diffuse interstitial lung disease (ILD) in rheumatoid arthritis (RA) are limited. Our objective was to estimate the prevalence of symptomatic ILD in RA and its characteristics in our area.

MATERIALS AND METHODS

In our hospital's interdisciplinary rheumatology and pulmonology clinic, a prospective longitudinal observational study was designed in which we included RA with respiratory symptoms and ILD confirmed by high resolution computed tomography.

RESULTS

Of the 2729 people with RA in our area, 47 had symptomatic ILD, estimating a prevalence of symptomatic ILD in RA of 1.72% (95% CI 1.26-2.29) with an age at diagnosis of RA of 57.3 ± 13.3 years. It was more frequent in men, 60.6% had a history of smoking, and 84.3% and 84.7% had rheumatoid factor (RF) and anti-cyclic citrullinated peptide (Anti-CCP) antibodies, respectively. The most frequent pattern was usual interstitial pneumonitis (UIP), appearing in 28 (31.1%). Nonspecific interstitial pneumonia (NSIP) was more frequent in women, while the combined pulmonary fibrosis-emphysema (CPFE) syndrome presented exclusively in men.

CONCLUSIONS

We have analysed the prevalence of symptomatic RA-ILD in our area, which is lower than expected, probably in relation to the definitions used. We have also described that the UIP pattern is the most frequent in RA in our environment, followed by the NSIP. Lastly, we have analysed the prevalence of CPFE in RA, which reaches 13%, for the first time.

Interstitial Lung Disease and its Associations in Rheumatoid Arthritis: Data from a District General Hospital in Sri Lanka

Context:

Interstitial lung disease (ILD) is a frequent pulmonary manifestation of rheumatoid arthritis (RA). No Sri Lankan studies have determined the prevalence of lung disease in RA and its associations.

Aims:

To find the prevalence of ILD in RA and its association with rheumatoid factor (RF), erosions, Disease activity score in 28 joints (DAS 28), disease duration, Body mass index(BMI), erythrocyte sedimentation rate (ESR), smoking, and also to determine the prevalence of lung disease with demographic factors like age, sex, and income.

Settings and Design:

Questionnaire based retrospective study at a District General Hospital in Sri Lanka.

Materials and Methods:

Diagnosed RA patients included through convenient sampling as it was a simple method that could facilitate data collection in a short duration. Since all patients with a diagnosis of RA were eligible, all consecutive patients with a diagnosis of RA at the rheumatology clinics were included in the study. To reduce the bias a large sample of patients were used as well as patients attending different rheumatology clinics were included and also patients who were referred to the hospital from peripheries were included in the study. The calculated sample size was 384 and according to patient numbers attending clinics, a period of 6 months was decided to select the study sample.

Statistical Analysis Used:

Chi-Square calculation and logistic regression analysis using Minitab 17 software.

Results:

From 384 patients, the prevalence of ILD was 14.58%, been 5.4% in early RA (<2 years disease duration). Mean age of ILD group was 52.94 years (95% CI 64.66-41.22). Mean RA duration was 7.69 years (95% CI, 2.38-12.99). Male to female sex ratio of RA was 1:7, and that of ILD was 2:9. DAS 28 was 4.58 (95% CI, 3.48-5.68). Statistically significant associations were noted with ILD and DAS 28 (P = .0006), ESR (P = .005), RF (P = .03), erosions (P < .00001), and smoking (P < .05). Mean BMI was 22.67 kg and 75.78% had low income (<50 000 rupees/month = 327 US $).

Conclusions:

ILD significantly associates RA severity indices like DAS 28, ESR, erosions, RF, and also with smoking. No significant association was found with BMI or gender difference. Therefore, disease severity indices could be used to predict progression to ILD in RA.

Beyond the joints, the extra-articular manifestations in rheumatoid arthritis

Rheumatoid arthritis (RA) is an inflammatory disease typically affecting the joints, but the systemic inflammatory process may involve other tissues and organs. Many extra-articular manifestations are recognized, which are related to worse long outcomes. Rheumatoid nodules are the most common extra-articular feature, found in about 30% of patients. Secondary Sjögren's syndrome and pulmonary manifestations are observed in almost 10% of patients, also in the early disease. Active RA with high disease activity has been associated with an increased risk of such features. Male gender, smoking habit, severe joint disease, worse function, high pro-inflammatory markers levels, high titer of rheumatoid factor, and HLA-related shared epitope have been reported as clinical predictors of occurrence of these rheumatoid complications. In addition, there is a little evidence deriving from randomized controlled trials in this field, thus the therapeutic strategy is mainly empiric and based on small case series and retrospective studies. However, considering that these extra-articular manifestations are usually related to the more active and severe RA, an aggressive therapeutic strategy is usually employed in view of the poor outcomes of these patients. The extra-articular features of RA remain, despite the improvement of joint damage, a major diagnostic and therapeutic challenge, since these are associated with a poor prognosis and need to be early recognized and promptly managed.

Microbial Influences of Mucosal Immunity in Rheumatoid Arthritis

PURPOSE OF REVIEW

This review will summarize recent data defining the relationship between rheumatoid arthritis (RA) and the microbiome at mucosal sites throughout the body. It will highlight what is known, what is speculated, and current knowledge gaps regarding the microbiome in RA.

RECENT FINDINGS

An extensive relationship between the microbiome and immune cell function can influence RA-related inflammation and T cell and B cell biology. Studies are beginning to characterize microbial changes in individuals who are at risk for RA, which is a critical element needed to understand the influence of the microbiome on RA pathogenesis. Expanding our understanding of the microbiome in RA beyond the bacteria at the gut and oral mucosae into the lung and urogenital surfaces, including viral and fungal components, and establishing the relationship across mucosal sites will be critical in future work. Importantly, approaches to manipulate the microbiome could lead to novel therapeutic and preventive strategies.

Rheumatoid arthritis-associated interstitial lung disease: an overview of epidemiology, pathogenesis and management

Interstitial lung disease (ILD) accounts for the major cause of morbidity and mortality in rheumatoid arthritis (RA). However, little is known of the pathogenesis, diagnosis and treatment of RA-associated ILD. In this review, we describe our present understanding and ongoing research in RA-ILD. Its aetiology does appear to associate with anti-cyclic citrullinated peptide antibodies, MUC5B mutation and smoking. Another focus of this article is on recent diagnostic methods in RA-ILD. Compared with other methods, high-resolution computed tomography (HRCT) imaging is a main method for the evaluation of ILD in RA patients. Pulmonary function is better suited for assessing progression. An important topic relates to therapeutic intervention. Disease-modifying anti-rheumatic drugs (DMARDs) in RA lack strong evidence in the onset or worsening of ILD. The available literature support that methotrexate, leflunomide, abatacept and rituximab play beneficial roles in the prevention and treatment of RA-ILD.

Effect of H2 treatment in a mouse model of rheumatoid arthritis-associated interstitial lung disease

Rheumatoid arthritis (RA)-associated interstitial lung disease (ILD), a primary cause of mortality in patients with RA, has limited treatment options. A previously established RA model in D1CC transgenic mice aberrantly expressed major histocompatibility complex class II genes in joints, developing collagen II-induced polyarthritis and anti-cyclic citrullinated peptide antibodies and interstitial pneumonitis, similar to those in humans. Molecular hydrogen (H₂ ) is an efficient antioxidant that permeates cell membranes and alleviates the reactive oxygen species-induced injury implicated in RA pathogenesis. We used D1CC mice to analyse chronic lung fibrosis development and evaluate H₂ treatment effects. We injected D1CC mice with type II collagen and supplied them with H₂ -rich or control water until analysis. Increased serum surfactant protein D values and lung densities images were observed 10 months after injection. Inflammation was patchy within the perilymphatic stromal area, with increased 8-hydroxy-2'-deoxyguanosine-positive cell numbers and tumour necrosis factor-α, BAX, transforming growth factor-β, interleukin-6 and soluble collagen levels in the lungs. Inflammatory and fibrotic changes developed diffusely within the perilymphatic stromal area, as observed in humans. H₂ treatment decreased these effects in the lungs. Thus, this model is valuable for studying the effects of H₂ treatment and chronic interstitial pneumonia pathophysiology in humans. H₂ appears to protect against RA-ILD by alleviating oxidative stress.

Comprehensive review of current diagnostic and treatment approaches to interstitial lung disease associated with rheumatoid arthritis

Interstitial lung disease (ILD) is one of the extra-articular involvement forms of rheumatoid arthritis (RA), and it is associated with increased mortality. The presence of genetic susceptibility, smoking, rheumatoid factor positivity, and the presence of anticitrulline peptide antibodies are factors contributing to the development of ILD in patients with RA. Early diagnosis and treatment of ILD contribute to the reduction of morbidity and mortality. We herein evaluated the current literature for the diagnosis and treatment of RA-associated ILD.

Impact of interstitial lung disease on mortality of patients with rheumatoid arthritis

To identify the prevalence of interstitial lung disease (ILD) in Korean patients with rheumatoid arthritis (RA) and assess its effect on mortality. A total of 3555 patients with RA, with chest X-ray or chest computed tomography (CT) data at enrollment were extracted from the KORean Observational study Network for Arthritis cohort, a nationwide prospective cohort for patients with RA in Korea. The patients were classified into two groups: (1) an ILD group by chest X-ray or chest CT scan, and (2) a non-ILD group by these modalities. After comparing the characteristics of the groups at enrollment, mortalities were compared using the log-rank test. To explore the impact of ILD on mortality, Cox proportional hazard models were used. Sixty-four patients (1.8%) were identified with ILD. Male and older patients were more common in the ILD group. During a mean follow-up of 24 months, 6 patients (9.4%) in the ILD group and 25 patients (0.7%) in the non-ILD group died; the survival rate was significantly worse in the ILD group (p < 0.01). On adjusted analysis, ILD was significantly associated with increased mortality (HR 7.89, CI 3.16-19.69, p < 0.01); the risk of death in patients with ILD was even higher than in patients with cardiovascular disease (CVD, HR 4.10, CI 1.79-9.37, p < 0.01). The prevalence of ILD was 1.8% in Korean patients with RA. ILD is a major risk factor for mortality in patients with RA.

Fragmented gelsolins are increased in rheumatoid arthritis-associated interstitial lung disease with usual interstitial pneumonia pattern

BACKGROUND

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) occurs in 10%-30% of patients with RA, and interstitial lung disease (ILD) is associated with increased mortality in up to 10% of patients with RA. The pathogenesis of RA-ILD is virtually unknown. The aim of this study is to investigate the proteins related to UIP pattern by comparing to OP pattern in RA-ILD using proteome analysis of bronchoalveolar lavage fluid (BALF).

METHODS

Proteomic differences in BALF were compared between the UIP pattern and OP pattern by examining BALF from 5 patients with the UIP pattern and 7 patients with the OP pattern by two-dimensional gel electrophoresis and mass spectrometry.

RESULTS

In individual comparisons of BALF samples, the levels of the protein gelsolin and Ig kappa chain C region were significantly higher in the UIP pattern than in the OP pattern. In contrast, the levels of α-1 antitrypsin, CRP, haptoglobin β, and surfactant protein A (isoform number 5) were all significantly higher in the OP pattern than in the UIP pattern. Gelsolin was cleaved into two fragments, a C-terminal half and N-terminal half, and the levels of both were significantly higher in the UIP pattern than in the OP pattern.

CONCLUSIONS

Fragmented gelsolins may be associated with the pathogenesis of fibrosis in RA-ILD.

Rheumatoid arthritis-associated lung disease

Comprehensive, up-to-date review of RA-associated lung diseases including pathogenesis and managementhttp://ow.ly/FBaNZ

Clinical features of rheumatoid arthritis-associated interstitial lung disease

Interstitial lung disease (ILD) is the most common extra-articular manifestations of rheumatoid arthritis (RA) in the lung. This study aimed to identify clinical features of RA-associated ILD (RA-ILD). Patients with RA were retrospectively enrolled and sub-classified as RA-ILD or RA without ILD based on high-resolution computed tomography imaging. Pulmonary function testing parameters and levels of RA-related biomarkers, tumour markers, and acute-phase proteins were compared between the two groups. Logistic regression model was used to assess the strength of association between RA-ILD and clinical features of interest. Receiver operating characteristic analysis was performed to assess potential predictive value of clinical features for detecting RA-ILD. Comparison analysis indicated that the percentage of predicted value of total lung capacity, inspiratory capacity, and diffusion capacity of the lung for carbon monoxide (DLCO) were reduced in patients with RA-ILD. Tumour markers CA15–3 and CA125 were increased in patients with RA-ILD. Logistic regression analysis revealed that decreased DLCO was related to the increased likelihood of RA-ILD (OR = 0.94, 95%CI = [0.91, 0.98]). The cut-off point at 52.95 percent of predicted value could sensitively discriminate RA patients with or without ILD. Our study suggested that DLCO value could be a useful tool for detecting ILD in patients with RA.

The use of mycophenolate mofetil in experimental encapsulating peritoneal sclerosis

INTRODUCTION

Encapsulated peritoneal sclerosis (EPS) is a rare complication of long-term peritoneal dialysis usually associated with the inadequacy and early termination of dialysis modality. Adequate treatment of peritoneal fibrosis has not been achieved by medical intervention so far. Mycophenolate mofetil (MMF), which inhibits inosine monophosphate dehydrogenase reversibly and highly selectively, is the most widely used drug for maintenance immunosupression in renal transplantation. Recent studies have shown that MMF has also antifibrotic effects. In this study, we evaluated the effects of MMF on EPS model in rats based on antifibrotic effects.

MATERIALS AND METHODS

Twenty-four Wistar albino rat have been randomly divided into four groups. Group I (control group) received isotonic saline intraperitoneally (i.p) 2 ml/day for (0-3rd weeks). Group II (chlorhexidine (CG) group) received CG 2 ml/day i.p. for (0-3rd weeks). Group III (chlorhexidine + MMF group) received CG (2 ml/day) i.p. for (0-3rd weeks) plus MMF 30 mg/kg/day peroral (4th-6th weeks). Group IV (resting group) received CG 2 ml/day) i.p. (0-3rd weeks) plus peritoneal resting without any treatment (4th-6th weeks) At the end of the sixth weeks, all of the rats were killed. All of the groups were analyzed in terms of peritoneal thickness, degree of inflammation, vasculopathy, neovascularization and fibrosis. Also, the parietal peritoneal tissue samples were evaluated for matrix metalloproteinase 2 (MMP-2) by using the immunohistochemical analysis.

RESULTS

When the CG group was compared with the MMF group, the medication resulted in a statistically significant reduction in peritoneal thickness, inflammation and fibrosis score (53.23 ± 16.24 vs. 17.22 ± 3.62, 1 ± 1.225 vs. 1 ± 0, 1.6 ± 0.548 vs. 0.2 ± 0.447, respectively, all p < 0.05). In the resting group, no beneficial effects on morphological abnormality of the peritoneum were observed as compared with MMF group. However, according to immunohistochemical analysis of the expression of MMP-2 on peritoneal samples, the highest expression of MMP-2 was observed in the MMF group.

CONCLUSION

MMF was effective for the treatment of encapsulating peritoneal fibrosis in our rat model. Most recently, MMF may be first choice for EPS due to antifibrotic effect.

Biomarkers of rheumatoid arthritis-associated interstitial lung disease

OBJECTIVE

Interstitial lung disease (ILD) is a relatively common extraarticular manifestation of rheumatoid arthritis (RA) that contributes significantly to disease burden and excess mortality. The purpose of this study was to identify peripheral blood markers of RA-associated ILD that can facilitate earlier diagnosis and provide insight regarding the pathogenesis of this potentially devastating disease complication.

METHODS

Patients with RA who were enrolled in a well-characterized Chinese identification cohort or a US replication cohort were subclassified as having RA-no ILD, RA-mild ILD, or RA-advanced ILD, based on high-resolution computed tomography scans of the chest. Multiplex enzyme-linked immunosorbent assays (ELISAs) and Luminex xMAP technology were used to assess 36 cytokines/chemokines, matrix metalloproteinases (MMPs), and acute-phase proteins in the identification cohort. Unadjusted and adjusted logistic regression models were used to quantify the strength of association between RA-ILD and biomarkers of interest.

RESULTS

MMP-7 and interferon-γ-inducible protein 10 (IP-10)/CXCL10 were identified by multiplex ELISA as potential biomarkers for RA-ILD in 133 RA patients comprising the Chinese identification cohort (50 RA-no ILD, 41 RA-ILD, 42 RA-indeterminate ILD). The findings were confirmed by standard solid-phase sandwich ELISA in the Chinese identification cohort as well as an independent cohort of US patients with RA and different stages of ILD (22 RA-no ILD, 49 RA-ILD, 15 RA-indeterminate ILD), with statistically significant associations in both unadjusted and adjusted logistic regression analyses.

CONCLUSION

Levels of MMP-7 and IP-10/CXCL10 are elevated in the serum of RA patients with ILD, whether mild or advanced, supporting their value as pathogenically relevant biomarkers that can contribute to noninvasive detection of this extraarticular disease complication.

Interstitial lung disease in rheumatoid arthritis: Current concepts in pathogenesis, diagnosis and therapeutics

Rheumatoid arthritis (RA) is the most common chronic autoimmune inflammatory joint disease. RA-associated interstitial lung disease (RA-ILD) is a major extra-articular complication and causes symptoms that lead to a deterioration in the quality of life, high utilization of health resources, and an increased risk of earlier mortality. Early in the course of RA-ILD, symptoms are highly variable, making the diagnosis difficult. Therefore, a rational diagnostic strategy that combines an adequate clinical assessment with the appropriate use of clinical tests, including pulmonary function tests and high-resolution computed tomography, should be used. In special cases, lung biopsy or bronchioalveolar lavage should be performed to achieve an early diagnosis. Several distinct histopathological subtypes of RA-ILD are currently recognized. These subtypes also have different clinical presentations, which vary in therapeutic response and prognosis. This article reviews current evidence about the epidemiology of RA-ILD and discusses the varying prevalence rates observed in different studies. Additionally, aspects of RA-ILD pathogenesis, including the role of cytokines and other molecules such as autoantibodies, as well as the evidence linking several drugs used to treat RA with lung damage will be discussed. Some aspects of the clinical characteristics of RA-ILD are noted, and diagnostic strategies are reviewed. Finally, this article analyzes current treatments for RA-ILD, including immunosuppressive therapies and biologic agents, as well as other therapeutic modalities. The prognosis of this severe complication of RA is discussed. Additionally, this paper examines updated evidence from studies identifying an association between drugs used for the treatment of RA and the development of ILD.

A retrospective study of clinical characteristics of interstitial lung disease associated with rheumatoid arthritis in Chinese patients

Background

Interstitial lung disease (ILD) in rheumatoid arthritis (RA) is associated with a poor prognosis. The purpose of this study was to assess the characteristics of ILD that are associated with RA.

Material/Methods

This was a retrospective study of 544 Chinese patients with RA (427 women and 117 men). RA-ILD was diagnosed by high-resolution computed tomography (HRCT). Patients with RA-ILD or with RA alone were compared in terms of age, sex distribution, duration of disease, clinical and laboratory parameters, history of smoking, and medication.

Results

Based on HRCT imaging, 83 (15.26%) patients with RA were diagnosed with ILD. ILD was more frequent in older patients (59.60±9.66 vs. 50.54±13.76 years, P<0.001), in those with a longer duration of disease (7.46±7.40 vs. 5.27±6.32 years, P=0.013) and in male patients (34.9% vs. 19.1%, P=0.001). RA-ILD was found to be associated with hepatitis B surface antigen (HBsAg) positivity (odds ratio [OR]=2.56, 95% confidence interval [95% CI] 1.02–6.43) and smoking (OR=3.38, 95% CI 1.65–6.95). Higher levels of C-reactive protein (OR=3.59, 95% CI 1.58–8.15), anti-cyclic citrullinated peptide (CCP) (OR=2.24, 95% CI 2.09–4.13), and rheumatoid factor (OR=3.72, 95% CI 1.56–8.86) were detected in association with RA-ILD. RA-ILD was more frequently observed in patients treated with steroids (OR=1.91, 95% CI 1.18–3.09) or Tripterygium wilfordii (OR=2.56, 95% CI 1.21–5.40). Age (OR=2.20, 95% CI 1.04–4.65), age at RA onset (OR=2.55, 95% CI 1.11–5.90), anti-CCP (OR=2.47, 95% CI 1.19–5.17), and steroid use (OR=1.83, 95% CI 1.04–3.20) were independently associated with RA-ILD in multivariate analysis.

Conclusions

RA-ILD was associated with age, age at RA onset, anti-CCP, and steroid use. Anti-CCP antibodies might be important biomarkers of RA-ILD.

Interstitial Lung Disease and Rheumatoid Arthritis: A Review

Interstitial lung diseases (ILDs) are a group of diffuse parenchymal lung disorders that are classified according to different clinical, radiological and histopathological features. Interstitial lung disease can be primary or it can be due to a secondary cause, such as an underlying connective tissue disease (CTD). Rheumatoid arthritis (RA) is the most common CTD, and ILD can be found in a quarter of RA patients. Interstitial lung disease has a significant impact on RA patients in terms of their burden of disease and quality of life. Despite this it remains largely understudied and pathogenesis is unclear. Newer imaging techniques include ultrasound and 18F-FDG PET/CT. Therapeutics that show promise include mycophenolate mofetil and rituximab. Paradoxically, some of the agents that are good in treating articular manifestations in RA patients can result in the worsening or development of ILD.

Interstitial Lung Disease of the UIP Variant as the Only Presenting Symptom of Rheumatoid Arthritis

Rheumatoid arthritis is a chronic inflammatory disease primarily manifesting with symptoms of joint pain. It also involves multiple organ systems in the body, including the lungs. Interstitial lung disease (ILD) is the most common form of pulmonary involvement in rheumatoid arthritis (RA). Without the typical symptoms such as chronic joint pain, establishing the diagnosis of RA could be quite challenging and a high index of suspicion is thereby required to diagnose ILD in patients with RA, thereby delaying treatment and increasing morbidity and mortality. We report a case of a 67-year-old Hispanic male with no previous history of rheumatoid arthritis or symptoms of typical joint pain who comes to the hospital only with the chief complaints of progressive worsening of shortness of breath for a duration of 6 months and was eventually diagnosed with ILD of the usual interstitial pneumonia variant with serologies positive for rheumatoid arthritis.

A roadmap to promote clinical and translational research in rheumatoid arthritis-associated interstitial lung disease

Rheumatoid arthritis (RA) is a systemic inflammatory disorder affecting approximately 1.3 million adults in the United States. Approximately 10% of these individuals with RA have clinically evident interstitial lung disease (RA-ILD), and an additional one-third demonstrate subclinical ILD on chest CT scan. The risk of death for individuals with RA-ILD is three times higher than for patients with RA without ILD, with a median survival after ILD diagnosis of only 2.6 years. Despite the high prevalence and mortality of RA-ILD, little is known about its molecular features and its natural history. At present, we lack a standard validated approach to the definition, diagnosis, risk stratification, and management of RA-ILD. In this perspective, we discuss the importance of clinical and translational research and how ongoing research efforts can address important gaps in our knowledge over the next few years. Furthermore, recommendations are made to design multicenter collaborative studies that will expedite the development of clinical trials designed to decrease the significant morbidity and mortality associated with RA-ILD.

Lung involvement and drug-induced lung disease in patients with rheumatoid arthritis

Interstitial lung disease (ILD) is a common extra-articular manifestation of rheumatoid arthritis (RA) and a significant cause of morbidity and mortality. Usual interstitial pneumonia and nonspecific interstitial pneumonia seem to be the most frequent patterns in RA patients with ILD, although the proportion of patients with usual interstitial pneumonia is higher than among patients with other systemic rheumatic autoimmune diseases. RA patients with ILD most frequently present with chronic symptoms of cough and dyspnea when climbing stairs or walking uphill. A physical examination may reveal inhalatory crackles and a pulmonary function test demonstrates restrictive physiology, often with reduced diffusing capacity. High-resolution computed tomography is generally sufficient to confirm a diagnosis of ILD, although a minority of cases may require a surgical lung biopsy. Conventional disease-modifying antirheumatic drugs such as methotrexate (MTX) or leflunomide (LEF) and biological agents such as TNF-blocking agents or rituximab may trigger or aggravate ILD in RA patients, and infections may contribute to increased mortality in such patients. LEF should not be used in patients with a history of MTX pneumonitis. The prevalence of interstitial pneumonia among RA patients treated with anti-TNF agents ranges from 0.5 to 3%; however, as the evidence that anti-TNF increases or decreases the risk of ILD is controversial, it is not clear whether this indicates more severe RA requiring biological therapy or the effect of exposure to potentially toxic drugs such as MTX or LEF. The development of treatment-related ILD is a paradoxical adverse event, and patients should be warned about this rare but serious complication of biological or disease-modifying antirheumatic drug therapy.

The multifaceted aspects of interstitial lung disease in rheumatoid arthritis

Interstitial lung disease (ILD) is a relevant extra-articular manifestation of rheumatoid arthritis (RA) that may occur either in early stages or as a complication of long-standing disease. RA related ILD (RA-ILD) significantly influences the quoad vitam prognosis of these patients. Several histopathological patterns of RA-ILD have been described: usual interstitial pneumonia (UIP) is the most frequent one, followed by nonspecific interstitial pneumonia (NSIP); other patterns are less commonly observed. Several factors have been associated with an increased risk of developing RA-ILD. The genetic background plays a fundamental but not sufficient role; smoking is an independent predictor of ILD, and a correlation with the presence of rheumatoid factor and anti-cyclic citrullinated peptide antibodies has also been reported. Moreover, both exnovo occurrence and progression of ILD have been related to drug therapies that are commonly prescribed in RA, such as methotrexate, leflunomide, anti-TNF alpha agents, and rituximab. A greater understanding of the disease process is necessary in order to improve the therapeutic approach to ILD and RA itself and to reduce the burden of this severe extra-articular manifestation.

Asymptomatic preclinical rheumatoid arthritis-associated interstitial lung disease

Objective. Interstitial lung disease (ILD) is a common extra-articular manifestation of rheumatoid arthritis (RA) and a significant cause of morbidity and mortality. The objective of this study was to define high-resolution chest CT (HRCT) and pulmonary function test (PFT) abnormalities capable of identifying asymptomatic, preclinical forms of RA-ILD that may represent precursors to more severe fibrotic lung disease. Methods. We analyzed chest HRCTs in consecutively enrolled RA patients and subsequently classified these individuals as RA-ILD or RA-no ILD based on the presence/absence of ground glass opacification, septal thickening, reticulation, traction bronchiectasis, and/or honeycombing. Coexisting PFT abnormalities (reductions in percent predicted FEV1, FVC, TLC, and/or DLCO) were also used to further characterize occult respiratory defects. Results. 61% (63/103) of RA patients were classified as RA-ILD based on HRCT and PFT abnormalities, while 39% (40/103) were designated as RA-no ILD. 57/63 RA-ILD patients lacked symptoms of significant dyspnea or cough at the time of HRCT and PFT assessment. Compared with RA-no ILD, RA-ILD patients were older and had longer disease duration, higher articular disease activity, and more significant PFT abnormalities. Conclusion. HRCT represents an effective tool to detect occult/asymptomatic ILD that is highly prevalent in our unselected, university-based cohort of RA patients.

Diagnosis and treatment of connective tissue disease-associated interstitial lung disease

Interstitial lung disease (ILD) is one of the most serious pulmonary complications associated with connective tissue diseases (CTDs), resulting in significant morbidity and mortality. Although the various CTDs associated with ILD often are considered together because of their shared autoimmune nature, there are substantial differences in the clinical presentations and management of ILD in each specific CTD. This heterogeneity and the cross-disciplinary nature of care have complicated the conduct of prospective multicenter treatment trials and hindered our understanding of the development of ILD in patients with CTD. In this update, we present new information regarding the diagnosis and treatment of patients with ILD secondary to systemic sclerosis, rheumatoid arthritis, dermatomyositis and polymyositis, and Sjögren syndrome. We review information on risk factors for the development of ILD in the setting of CTD. Diagnostic criteria for CTD are presented as well as elements of the clinical evaluation that increase suspicion for CTD-ILD. We review the use of medications in the treatment of CTD-ILD. Although a large, randomized study has examined the impact of immunosuppressive therapy for ILD secondary to systemic sclerosis, additional studies are needed to determine optimal treatment strategies for each distinct form of CTD-ILD. Finally, we review new information regarding the subgroup of patients with ILD who meet some, but not all, diagnostic criteria for a CTD. A careful and systematic approach to diagnosis in patients with ILD may reveal an unrecognized CTD or evidence of autoimmunity in those previously believed to have idiopathic ILD.

Lung involvement in connective tissue diseases: a comprehensive review and a focus on rheumatoid arthritis

The lungs are frequently involved in Connective Tissue Diseases (CTDs). Interstitial lung disease (ILD) is one of the most common pleuropulmonary manifestations that affects prognosis significantly. In practice, rheumatologists and other physicians tend to underestimate the impact of CTD-ILDs and diagnose respiratory impairment when it has reached an irreversible fibrotic stage. Early investigation, through clinical evidence, imaging and - in certain cases - lung biopsy, is therefore warranted in order to detect a possible ILD at a reversible initial inflammatory stage. In this review, we focus on lung injury during CTDs, with particular attention to ILDs, and examine their prevalence, clinical manifestations and histological patterns, as well as therapeutic approaches and known complications till date. Although several therapeutic agents have been approved, the best treatment is still not certain and additional trials are required, which demand more knowledge of pulmonary involvement in CTDs. Our central aim is therefore to document the impact that lung damage has on CTDs. We will mainly focus on Rheumatoid Arthritis (RA), which - unlike other rheumatic disorders - resembles Idiopathic Pulmonary Fibrosis (IPF) in numerous aspects.