Clinical and laboratory factors associated with interstitial lung disease in rheumatoid arthritis

The prevalence and risk factors of rheumatoid arthritis-associated interstitial lung disease: a systematic review and meta-analysis

BACKGROUND

Interstitial lung disease (ILD) is the most widespread and fatal pulmonary complication of rheumatoid arthritis (RA). Existing knowledge on the prevalence and risk factors of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is inconclusive. Therefore, we designed this review to address this gap.

MATERIALS AND METHODS

To find relevant observational studies discussing the prevalence and/or risk factors of RA-ILD, EMBASE, Web of Science, PubMed, and the Cochrane Library were explored. The pooled odds ratios (ORs) / hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated with a fixed/ random effects model. While subgroup analysis, meta-regression analysis and sensitivity analysis were carried out to determine the sources of heterogeneity, the I2 statistic was utilized to assess between-studies heterogeneity. Funnel plots and Egger's test were employed to assess publication bias. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, our review was conducted.

RESULTS

A total of 56 studies with 11,851 RA-ILD patients were included in this meta-analysis. The pooled prevalence of RA-ILD was 18.7% (95% CI 15.8-21.6) with significant heterogeneity (I2 = 96.4%). The prevalence of RA-ILD was found to be more likely as a result of several identified factors, including male sex (ORs = 1.92 95% CI 1.70-2.16), older age (WMDs = 6.89, 95% CI 3.10-10.67), having a smoking history (ORs =1.91, 95% CI 1.48-2.47), pulmonary comorbidities predicted (HRs = 2.08, 95% CI 1.89-2.30), longer RA duration (ORs = 1.03, 95% CI 1.01-1.05), older age of RA onset (WMDs =4.46, 95% CI 0.63-8.29), positive RF (HRs = 1.15, 95%CI 0.75-1.77; ORs = 2.11, 95%CI 1.65-2.68), positive ACPA (ORs = 2.11, 95%CI 1.65-2.68), higher ESR (ORs = 1.008, 95%CI 1.002-1.014), moderate and high DAS28 (≥3.2) (ORs = 1.87, 95%CI 1.36-2.58), rheumatoid nodules (ORs = 1.87, 95% CI 1.18-2.98), LEF use (ORs = 1.42, 95%CI 1.08-1.87) and steroid use (HRs= 1.70, 1.13-2.55). The use of biological agents was a protective factor (HRs = 0.77, 95% CI 0.69-0.87).

CONCLUSION(S)

The pooled prevalence of RA-ILD in our study was approximately 18.7%. Furthermore, we identified 13 risk factors for RA-ILD, including male sex, older age, having a smoking history, pulmonary comorbidities, older age of RA onset, longer RA duration, positive RF, positive ACPA, higher ESR, moderate and high DAS28 (≥3.2), rheumatoid nodules, LEF use and steroid use. Additionally, biological agents use was a protective factor.

Rheumatoid Arthritis-Related Lung Disease and Its Association With Mortality

PURPOSE

The aim of this study was to determine the association of rheumatoid arthritis-related lung disease (RA-LD) and its subtypes with all-cause mortality.

MATERIALS AND METHODS

For the present analyses, patients with RA who underwent computed tomography of the chest (chest-CT) were evaluated. RA-LD was defined in 4 subtypes as follows: interstitial lung disease (RA-ILD), airway disease (RA-AD), rheumatoid pulmonary nodules (RA-PN), and RA-related pleural disease (RA-PD). The date of RA-LD diagnosis was considered the date of the first chest-CT detecting the pathology. To assess the factors associated with mortality, multivariable logistic regression analyses were performed with variables selected based on their causal associations with the outcome.

RESULTS

Of 576 RA patients, 253 (43.9%) had RA-LD (38.7% male; mean age at RA-LD diagnosis, 59.9 ± 9.8 years). The most common subtype was RA-AD, which was detected in 119 (47.0%) patients followed by 107 (42.3%) with RA-ILD, 70 (27.7%) with RA-PN, and 31 (12.3%) with RA-PD. Sixty-one (24.1%) patients had 2+ subtypes. After median follow-up of 10.2 years, 97 (16.8%) died. The existence of at least 1 subtype and 2+ subtypes increased the all-cause mortality, as indicated by odds ratios of 1.60 (95% confidence interval [CI], 1.03-2.48) and 2.39 (95% CI, 1.26-4.54), respectively. Among RA-LD patients, RA-ILD and RA-PD were associated with increased mortality (odds ratios were 2.20 [95% CI, 1.18-4.08] and 1.62 [95% CI, 0.70-3.75], respectively).

CONCLUSIONS

In this study, RA-AD was the most common subtype, and the presence of RA-LD increased mortality. This effect was particularly pronounced in patients with RA-ILD and RA-PD or those presenting with 2+ subtypes.

[Low-dose methotrexate: Indications and side effects, particularly in cases of diffuse interstitial pneumonia]

INTRODUCTION

Methotrexate (MTX) is a folate antagonist used as an immunosuppressant in a number of conditions, including rheumatoid arthritis (RA). Low-dose MTX (MTX-LD) is associated with a risk of haematological, hepatic, gastrointestinal and pulmonary toxicity, which may up until now have limited its use.

STATE OF THE ART

In RA, data from retrospective cohorts have reported a possible excess risk of methotrexate toxicity in cases of underlying interstitial lung disease (ILD). However, recent prospective and retrospective multicentre studies have found no such increased risk, and have reassuringly concluded that MTX-LD can be prescribed in cases of RA-associated ILD (RA-ILD).

PERSPECTIVES AND CONCLUSIONS

Current recommendations are not to delay the introduction of MTX in patients with RA at risk of developing ILD or in the presence of RA-ILD with mild to moderate respiratory impairment.

The Lung in Rheumatoid Arthritis-Friend or Enemy?

Rheumatoid arthritis (RA) is a chronic autoimmune condition frequently found in rheumatological patients that sometimes raises diagnosis and management problems. The pathogenesis of the disease is complex and involves the activation of many cells and intracellular signaling pathways, ultimately leading to the activation of the innate and acquired immune system and producing extensive tissue damage. Along with joint involvement, RA can have numerous extra-articular manifestations (EAMs), among which lung damage, especially interstitial lung disease (ILD), negatively influences the evolution and survival of these patients. Although there are more and more RA-ILD cases, the pathogenesis is incompletely understood. In terms of genetic predisposition, external environmental factors act and subsequently determine the activation of immune system cells such as macrophages, neutrophils, B and T lymphocytes, fibroblasts, and dendritic cells. These, in turn, show the ability to secrete molecules with a proinflammatory role (cytokines, chemokines, growth factors) that will produce important visceral injuries, including pulmonary changes. Currently, there is new evidence that supports the initiation of the systemic immune response at the level of pulmonary mucosa where the citrullination process occurs, whereby the autoantibodies subsequently migrate from the lung to the synovial membrane. The aim of this paper is to provide current data regarding the pathogenesis of RA-associated ILD, starting from environmental triggers and reaching the cellular, humoral, and molecular changes involved in the onset of the disease.

Multidimensional biomarker approach integrating tumor markers, inflammatory indicators, and disease activity indicators may improve prediction of rheumatoid arthritis-associated interstitial lung disease

INTRODUCTION

Rheumatoid arthritis (RA) often leads to interstitial lung disease (ILD), significantly affecting patient outcomes. This study explored the diagnostic accuracy of a multi-biomarker approach to offer a more efficient and accessible diagnostic strategy for RA-associated ILD (RA-ILD).

METHODS

Patients diagnosed with RA, with or without ILD, at Beijing Tiantan Hospital from October 2019 to October 2023 were analyzed. A total of 125 RA patients were included, with 76 diagnosed with RA-ILD. The study focused on three categories of indicators: tumor markers, inflammatory indicators, and disease activity measures. The heatmap correlation analysis was employed to analyze the correlation among these indicators. Logistic regression was used to determine odds ratios (OR) for indicators linked to RA-ILD risk. Receiver-operating characteristic (ROC) curve analysis was employed to evaluate the diagnostic potential of these indicators for RA-ILD.

RESULTS

The results of logistic regression analysis showed that tumor markers (carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 125 (CA125), and cytokeratin 19 fragment (CYFRA21-1)), as well as inflammatory indicators (neutrophil, neutrophil-to-lymphocyte ratio (NLR), platelet, C-reactive protein (CRP)) and disease activity measures (disease activity score-28-CRP (DAS28-CRP), rheumatoid factor (RF), and anti-cyclic peptide containing citrulline (anti-CCP)), were significantly associated with RA-ILD. The correlation coefficients among these indicators were relatively low. Notably, the combination indicator 4, which integrated the aforementioned three categories of biomarkers, demonstrated improved diagnostic accuracy with an AUC of 0.857.

CONCLUSION

The study demonstrated that combining tumor markers, inflammatory indicators, and disease activity measures significantly enhanced the prediction of RA-ILD. Key Points • Multidimensional strategy: Integrated tumor markers, inflammatory indicators, and disease activity measures to enhance early detection of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). • Diagnostic accuracy: Employed heatmap correlation and logistic regression, identifying significant associations and improving diagnostic accuracy with a multidimensional biomarker combination. • Superior performance: The combined multidimensional biomarker strategy demonstrated higher diagnostic precision compared to individual or dual-category indicators. • Clinical relevance: Offers a promising, accessible approach for early detection of RA-ILD in clinical settings, potentially improving patient outcomes.

Rheumatoid arthritis disease activity significantly impacts on the severity of interstitial lung disease

OBJECTIVES

Rheumatoid arthritis (RA) related interstitial lung disease (ILD) impacts on the treatment strategy and its prognosis in patients with RA. However, the relationship between RA disease activity and the severity of comorbid ILD has not been fully investigated. This study aimed to investigate the impact of RA disease activity on the severity of comorbid ILD in detail based on currently established visual scoring method along with physiological severity.

METHODS

Consecutive patients with RA visiting to our Rheumatology Centre between December 2020 and December 2023 were analysed. The radiological severity of ILD was evaluated by averaging the extent of the combined lesion of ground glass opacity, reticulation and honeycombing in 5% increments in six representative high-resolution computed tomography slices ranging from 0% (no involvement) to 100% (all lung fields affected) according to Goh and Walsh's method. Associations between the radiological and physiological severity of ILD and patients' features were investigated using linear regression analysis.

RESULTS

Among 124 patients (32 men, 92 women), the median age was 70 years, and the median disease duration was 2.92 years. Radiological severity of ILD was 0% (without ILD) in 107 (86.2%), ILD with extent < 10% in nine (7.2%), ILD with extent ≥10% and < 20% in three (2.4%), ILD with extent ≥20% in five (4.0%). Both disease activity score (DAS)28-erythrocyte sedimentation rate (ESR) (standardized coefficient = 0.199, P = 0.03) and rheumatoid factor titre (standardized coefficient = 0.247, P = 0.01) were significantly associated with the radiological quantitative severity of ILD in multivariate analysis adjusted for age, sex, disease duration, smoking status and anti-citrullinated peptide antibody titre. DAS28-ESR was significantly associated with forced vital capacity% predicted (standardized coefficient = -0.230, P = 0.047).

CONCLUSIONS

Disease activity of RA was significantly associated with the severity of RA-ILD both radiologically and physiologically.

Impact of interstitial lung disease on clinical remission and unfavourable events of rheumatoid arthritis: results from the IORRA cohort

OBJECTIVES

We aimed to examine the impact of concomitant interstitial lung disease (ILD) on achieving clinical remission and the occurrence of unfavourable clinical events in patients with RA.

METHODS

Among the participants in the Institute of Rheumatology, Rheumatoid Arthritis (IORRA) cohort from 2011 to 2012, patients not achieving remission of 28-joint disease activity score (DAS28) at baseline and those with chest CT images were enrolled. Based on the chest CT images, the patients were divided into two groups: the ILD group and non-ILD group. The associations among the presence of ILD with time to achieving DAS28 remission and development of death, hospitalized infection, major adverse cardiac events (MACE), or malignancy within 5 years were evaluated using time-dependent Cox regression models.

RESULTS

We enrolled 287 patients in the ILD group and 1235 in the non-ILD group. DAS28 remission was achieved at least once in 55.7% and 75.0% of the ILD and non-ILD groups within 5 years, respectively. Presence of ILD was significantly associated with failure to achieve DAS28 remission (adjusted hazard ratio [aHR]: 0.71; 95% CI: 0.58, 0.89). ILD was also a significant factor associated with death (aHR: 3.24; 95% CI: 2.08, 5.03), hospitalized infection (aHR 2.60; 95% CI: 1.77, 3.83), MACE (aHR: 3.40; 95% CI: 1.76, 6.58), and lung cancer (aHR: 16.0; 95% CI: 3.22, 79.2), but not with malignant lymphoma (aHR: 2.27; 95% CI: 0.59, 8.81).

CONCLUSION

Concomitant ILD was a significant factor associated with failure to achieve clinical remission and the occurrence of the unfavourable clinical events in patients with RA.

Screening for rheumatoid arthritis-associated interstitial lung disease-a Delphi-based consensus statement

OBJECTIVE

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a major driver of premature mortality in patients with rheumatoid arthritis (RA). Detection of RA-ILD is crucial but requires awareness among the treating physicians. To date, however, there is no international recommendation concerning screening for ILD in RA patients.

METHODS

After a systematic literature review, the modified Delphi technique in combination with the nominal group technique was used to provide a Delphi consensus statement elaborated by an expert panel of pneumonologists, rheumatologists, and a radiologist. Based on the available evidence, several clusters of questions were defined and discussed until consent was reached.

RESULTS

A screening algorithm for ILD in patients with RA based on clinical signs, respiratory symptoms, and risk factors has been developed. Further, the recommendations address diagnostic tools for RA-ILD and the follow-up of RA patients qualifying for ILD screening.

CXCL10 as a biomarker of interstitial lung disease in patients with rheumatoid arthritis

INTRODUCTION

Pulmonary involvement is a frequent and serious rheumatoid arthritis (RA) manifestation that affects 60%-80% of patients. CXCL10 is an inflammatory chemokine that regulates different biological responses, such as chemotaxis, angiogenesis, and inflammation.

AIM

This study aimed to identify the role of CXCL10 as a peripheral blood marker of RA-ILD and its correlation with disease activity.

PATIENTS AND METHODS

This cross-sectional study included 73 patients with RA (33 with ILD and 40 without ILD). Pulmonary function tests and high-resolution computed tomography were performed. Blood samples were taken for complete blood count and blood chemistry analysis, and human interferon-inducible protein 10 (IP-10/CXCL10) level. Statistical Package for the Social Sciences (version 22) was used for all statistical calculations.

RESULTS

The serum CXCL10 level and patient age (r=.393, p=.024), disease duration (r=.756, p<0.001), erythrocyte sedimentation rate (r=.516, p=.002), C-reactive protein (r=.539, p=.001), and rheumatoid factor (r=.663, p<.001) revealed a significant positive correlation. Furthermore, the Modified Health Assessment Questionnaire (r=-.418, p=.015) revealed a significant negative correlation. Patients with RA-ILD show significantly higher CXCL10 than those without ILD (p<.001).

CONCLUSION

CXCL10 is a useful RA disease activity biomarker and is an RA-ILD-sensitive biomarker, also CXCL10 is a significant predictor for development of RA-ILD.

Gene-respiratory disease interactions for rheumatoid arthritis risk

OBJECTIVE

We aimed to identify gene by respiratory tract disease interactions that increase RA risk.

METHODS

In this case-control study using the Mass General Brigham Biobank, we matched incident RA cases, confirmed by ACR/EULAR criteria, to four controls on age, sex, and electronic health record history. Genetic exposures included a validated overall genetic risk score (GRS) for RA, a Human Leukocyte Antigen (HLA) GRS for RA, and the MUC5B promoter variant, an established risk factor for RA-associated interstitial lung disease (ILD). Preceding respiratory tract diseases came from diagnosis codes (positive predictive value 86%). We estimated attributable proportions (AP) and multiplicative odds ratios (OR) with 95% confidence intervals (CI) for RA for each genetic and respiratory exposure using conditional logistic regression models, adjusting for potential confounders.

RESULTS

We identified 653 incident RA cases and 2,607 matched controls (mean 54 years, 76% female). The highest tertile of the overall GRS and the HLA GRS were both associated with increased RA risk (OR 2.28, 95% CI 1.89,2.74; OR 2.02, 95% CI 1.67-2.45). ILD and the HLA GRS exhibited a synergistic relationship for RA risk (OR for both exposures 4.30, 95% CI 1.28,14.38; AP 0.51, 95% CI-0.16,1.18). Asthma and the MUC5B promoter variant also exhibited a synergistic interaction for seropositive RA (OR for both exposures 2.58, 95% CI 1.10,6.07; AP 0.62, 95% CI 0.24,1.00).

CONCLUSION

ILD-HLA GRS and asthma-MUC5B promoter variant showed synergistic interactions for RA risk. Such interactions may prove useful for RA prevention and screening.

Causal association of rheumatoid arthritis with obstructive lung disease: Evidence from Mendelian randomization study

BACKGROUND

Observational studies have found an association between rheumatoid arthritis (RA) and risk of obstructive lung disease (ORDs). However, whether RA plays a role in ORDs development remains unclear.

OBJECTIVES

This study aimed to explore the causal association of RA with ORDs.

METHODS

Both univariable and multivariable Mendelian randomization (MR) analyses were employed. Summary statistics for RA were obtained from the genome-wide association study (GWAS) meta-analysis, and the GWAS data source of ORDs, including the chronic obstructive pulmonary disease (COPD) and asthma, was accessed from the FinnGen Biobank. Causal Analysis Using Summary Effect Estimates (CAUSE) method was used to improve statistical power. multivariable and two-step mediation MR was applied to calculate the independent and mediated effects.

RESULTS

The causal estimates by univariable and CAUSE results indicated genetic predisposition to RA had an effect on the increased risk of asthma/COPD (A/C) (ORCAUSE = 1.03; 95% CI: 1.02-1.04), COPD/asthma related infections (ACI) (ORCAUSE = 1.02; 95% CI: 1.01-1.03) and COPD/asthma related pneumonia or pneumonia derived septicemia (ACP) (ORCAUSE = 1.02; 95% CI: 1.01-1.03). Genetic predisposition to RA was significantly associated with early onset COPD (ORCAUSE = 1.02; 95% CI: 1.01-1.03) and asthma (ORCAUSE = 1.02; 95% CI: 1.01-1.03) risk and suggestively associated with non-allergic asthma (nAA) risk. After adjustment for confounders, independent causal effects remained for the associations of RA with risk of A/C, ACI, and ACP, as well as COPD, early-onset COPD, and asthma [total, nAA and allergic asthma (AA)] risk. Mediation analyses revealed no potential mediator.

CONCLUSION

This study indicates a causal effect of increased genetic predisposition to RA on an increased risk of ORDs, including COPD and asthma, especially early-onset COPD and nAA, and on asthma/COPD related infections, pneumonia or pneumonia derived septicemia.

Clinical and preclinical pulmonary disease in newly diagnosed rheumatoid arthritis: a two-year follow-up study

OBJECTIVE

Pulmonary disease is a major cause of excess mortality among patients with rheumatoid arthritis (RA). Interstitial lung disease (ILD) is a feared complication, but the benefit of screening is unknown. The aim of this study was to assess the frequency of pulmonary disease, including ILD, in early RA.

METHOD

Patients with newly diagnosed RA were recruited prospectively at a single centre and underwent systematic pulmonary function tests (PFTs) and computed tomography (CT) scans at inclusion and after two years.

RESULTS

The study included 150 patients (mean age 57 years, 63% female; 59% current or former smokers). Of these, 136 underwent baseline PFTs and 137 CT. Mean forced expiratory volume in one second was 99% predicted and forced vital capacity 106%. Mean diffusing capacity of the lungs for carbon monoxide (DLCO) was 84% predicted. Frequently detected CT abnormalities were pulmonary nodules (42%), bronchiectasis (29%), and emphysema (20%). Two patients had clinically significant ILD and six had mild reticulation suggestive of preclinical ILD. No ILD progression was identified at two-year follow-up. Smoking was associated with DLCO<80% (p=0.004), combined hyperinflation and diffusion impairment (residual volume>120% and DLCO<80%) (p=0.004), and visual emphysema on CT (p<0.001).

CONCLUSION

Emphysema and bronchiectasis were common, but most patients had mild disease with preserved lung function. Preclinical or clinical ILD was seen in a minority in this early phase of RA. These findings suggest symptom-based screening and primary intervention focusing on smoking cessation rather than screening for ILD at the time of RA diagnosis.

Multimorbidity in rheumatoid arthritis: common mechanistic links and impact and challenges in routine clinical practice

Early identification and management of multimorbidity in patients with rheumatic and musculoskeletal diseases (RMDs), such as RA, is an integral, but often neglected, aspect of care. The prevalence and incidence of conditions such as osteoporosis, cardiovascular disease, pulmonary disease and malignancies, often co-existing with RA, continues to have significant implications for the management of this patient group. Multimorbidity in RMDs can be associated with inflammatory disease activity and target organ damage. Lifestyle factors, such as smoking and inactivity, further contribute to the burden of disease. Inflammation is the underlying factor, not just in RA but also many comorbidities. The current framework of a treat-to-target approach focuses on achieving early remission and inflammatory activity suppression. We describe how the comorbidity burden in people with RMDs impacts on disease outcome and treatment response. The importance of addressing comorbidity at an early stage and adopting a patient centred approach is critical in modern practice.

Etiology and Pathogenesis of Rheumatoid Arthritis-Interstitial Lung Disease

Interstitial lung disease (ILD) is one of the most serious extra-articular complications of rheumatoid arthritis (RA), which increases the mortality of RA. Because the pathogenesis of RA-ILD remains poorly understood, appropriate therapeutic strategies and biomarkers have not yet been identified. Thus, the goal of this review was to summarize and analyze the reported data on the etiology and pathogenesis of RA-ILD. The incidence of RA-ILD increases with age, and is also generally higher in men than in women and in patients with specific genetic variations and ethnicity. Lifestyle factors associated with an increased risk of RA-ILD include smoking and exposure to pollutants. The presence of an anti-cyclic citrullinated peptide antibody, high RA disease activity, and rheumatoid factor positivity also increase the risk of RA-ILD. We also explored the roles of biological processes (e.g., fibroblast-myofibroblast transition, epithelial-mesenchymal transition, and immunological processes), signaling pathways (e.g., JAK/STAT and PI3K/Akt), and the histopathology of RA involved in RA-ILD pathogenesis based on published preclinical and clinical models of RA-ILD in animal and human studies.

Prognostic factors affecting respiratory-related death in patients with rheumatoid arthritis complicated by interstitial lung disease: An ANSWER cohort study

The aim of this multi-centre retrospective study was to clarify the prognostic factors for respiratory-related death in patients with interstitial lung disease (ILD) complicated rheumatoid arthritis (RA). Patient background data, treatment regimen, and disease activity indicators of RA and ILD at baseline, 6 months after the diagnosis of ILD, and at the last follow-up visit were extracted. A total of 312 patients with RA-ILD (17 patients who died from respiratory-related causes and 295 survivors) were included. Patients who died from respiratory-related causes had an older median age, a higher proportion of being male, and a higher anti-cyclic citrullinated peptide antibody positivity rate than survivors (p = .0001, .038, and .016, respectively); they also had significantly higher baseline serum levels of Krebs von den Lungen-6 (KL-6) than survivors (p = .013). Patients who died from respiratory-related causes showed significantly greater changes in serum KL-6 levels between the 6-month time point and the last visit [ΔKL-6 (6 months - last)] than survivors (p = .011). Multivariate analysis showed that the ΔKL-6 (6 months - last) corrected by disease duration was a predictor of respiratory-disease-related death in patients with RA-ILD (p < .0001). Long-term increase in serum KL-6 levels is associated with respiratory-disease related death in patients with RA-ILD.

Integrating bioinformatic resources to identify characteristics of rheumatoid arthritis-related usual interstitial pneumonia

BACKGROUND

Rheumatoid arthritis (RA) is often accompanied by a common extra-articular manifestation known as RA-related usual interstitial pneumonia (RA-UIP), which is associated with a poor prognosis. However, the mechanism remains unclear. To identify potential mechanisms, we conducted bioinformatics analysis based on high-throughput sequencing of the Gene Expression Omnibus (GEO) database.

RESULTS

Weighted gene co-expression network analysis (WGCNA) analysis identified 2 RA-positive related modules and 4 idiopathic pulmonary fibrosis (IPF)-positive related modules. A total of 553 overlapped differentially expressed genes (DEG) were obtained, of which 144 in the above modules were further analyzed. The biological process of "oxidative phosphorylation" was found to be the most relevant with both RA and IPF. Additionally, 498 up-regulated genes in lung tissues of RA-UIP were screened out and enriched by 7 clusters, of which 3 were closely related to immune regulation. The analysis of immune infiltration showed a characteristic distribution of peripheral immune cells in RA-UIP, compared with IPF-UIP in lung tissues.

CONCLUSIONS

These results describe the complex molecular and functional landscape of RA-UIP, which will help illustrate the molecular pathological mechanism of RA-UIP and identify new biomarkers and therapeutic targets for RA-UIP in the future.

Anti-protein arginine deiminase antibodies are distinctly associated with joint and lung involvement in rheumatoid arthritis

OBJECTIVES

RA is a chronic inflammatory disease in which possible interstitial lung disease (ILD) is an extra-articular manifestation that carries significant morbidity and mortality. RF and ACPA are included in the RA classification criteria but prognostic and diagnostic biomarkers for disease endotyping and RA-ILD are lacking. Anti-protein arginine deiminase antibodies (anti-PAD) are a novel class of autoantibodies identified in RA. This study aimed to assess clinical features, ACPA and anti-PAD antibodies in RA patients with articular involvement and ILD.

METHODS

We retrospectively collected joint erosions, space narrowing, clinical features and lung involvement of a cohort of 71 patients fulfilling the 2010 ACR/EULAR RA classification criteria. Serum samples from these patients were tested for ACPA IgG (QUANTA Flash CCP3), and anti-PAD3 and anti-PAD4 IgG, measured with novel assays based on a particle-based multi-analyte technology (PMAT).

RESULTS

Anti-PAD4 antibodies were significantly associated with radiographic injury (P = 0.027) and erosions (P = 0.02). Similarly, ACPA levels were associated with erosive disease (P = 0.014). Anti-PAD3/4 double-positive patients displayed more joint erosions than patients with anti-PAD4 antibodies only or negative for both (P = 0.014 and P = 0.037, respectively). RA-ILD (15.5%, 11/71 patients) was associated with older age (P < 0.001), shorter disease duration (P = 0.045) and less erosive disease (P = 0.0063). ACPA were elevated in RA-ILD, while anti-PAD4 were negatively associated (P = 0.043).

CONCLUSION

Anti-PAD4 and anti-PAD3 antibodies identify RA patients with higher radiographic injury and bone erosions. In our cohort, ILD is associated with lower radiographic and erosive damage, as well as low levels of anti-PAD4 antibodies.

Factors associated with interstitial lung disease in patients with rheumatoid arthritis: A systematic review and meta-analysis

OBJECTIVES

Interstitial lung disease (ILD) is frequent in patients with rheumatoid arthritis (RA) and is a potentially life-threatening complication with significant morbidity and mortality. This meta-analysis aims to systematically determine the factors associated with the development of rheumatoid arthritis-related interstitial lung disease (RA-ILD).

MATERIALS AND METHODS

All primary studies which reported the factors associated with of RA-ILD were eligible for the review except case reports. The Cochrane Library, PubMed, Embase, Web of Science, Chinese Biological Medicine Database (CBM), China National Knowledge Infrastructure (CNKI), and WANFANG electronic databases were searched through to December 30, 2022, for studies investigating the factors associated with RA-ILD. The methodological quality assessment of the eligible studies was performed using the Newcastle-Ottawa Scale (NOS). 2 reviewers extracted relevant data independently. Then, weighed mean differences (WMDs) or pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were obtained for the relationships between the factors and RA-ILD. The statistical meta-analysis, subgroup and sensitivity analyses were performed using the Review Manager 5.3, and publication bias with Egger's test were performed using the Stata12.0 software.

RESULTS

A total of 22 articles were screened for a meta-analysis which involved 1887 RA-ILD patients and 8066 RA without ILD patients. Some identified factors that were associated with an increased risk of RA-ILD included male sex (OR = 1.92, 95% CI: 1.54-2.39; P < 0.00001), older age (WMD = 5.77 years, 95% CI: 3.50-8.04; P < 0.00001), longer duration of RA (WMD = 0.80 years, 95% CI 0.12-1.47; P = 0.02), older age at onset of RA (WMD = 6.41 years, 95% CI: 3.17-9.64; P = 0.0001), smoking (OR = 1.69, 95% CI: 1.30-2.18; P < 0.0001). Five factors of laboratory items associated with the development of RA-ILD were evaluated in the meta-analysis. Compared with RA without ILD patients, positive rheumatoid factor (RF) (OR = 1.72, 95% CI: 1.47-2.01; P < 0.00001) and positive anti-citrullinated protein antibodies (ACPA) (OR = 1.58, 95% CI: 1.31-1.90; P < 0.00001) increased the risk of RA-ILD. Meanwhile, RF titer (WMD = 183.62 (IU/mL), 95% CI: 66.94-300.30; P = 0.002) and ACPA titer (WMD = 194.18 (IU/mL), 95% CI: 115.89-272.47; P < 0.00001) were significantly associated with increased risk of RA-ILD. Elevated erythrocyte sedimentation rate (ESR) (WMD = 7.41 (mm/h), 95% CI: 2.21-12.61; P = 0.005) and C-reactive protein (CRP) (WMD = 4.98 (mg/L), 95% CI: 0.76-9.20; P = 0.02) were also significantly associated with the development of the RA-ILD, whereas antinuclear antibody (ANA) positive status was not significantly associated with increased risk of RA-ILD (OR = 1.27, 95% CI: 1.00-1.60; P = 0.05).

CONCLUSIONS

This meta-analysis showed that male gender, older age, longer duration of RA, older age at onset of RA, smoking, positive RF, positive ACPA, elevated RF titer, elevated ACPA titer, higher ESR and higher CRP were associated with RA-ILD.

Four-factor risk score for the prediction of interstitial lung disease in rheumatoid arthritis

OBJECTIVE

Interstitial lung disease (ILD) is one of the commonest systemic complications in patients with rheumatoid arthritis (RA) and carries a significant morbidity and mortality burden. We aimed to identify key variables to risk-stratify RA patients in order to identify those at increased risk of developing ILD. We propose a probability score based on the identification of these variables.

METHODS

A retrospective, multicentre study using clinical data collected between 2010 and 2020, across 20 centres.

RESULTS

A total of 430 RA (210 with ILD confirmed on high-resolution computed tomography (HRCT)) patients were evaluated. We explored several independent variables for the risk of developing ILD in RA and found that the key significant variables were smoking (past or present), older age and positive rheumatoid factor/anti-cyclic citrullinated peptide. Multivariate logistic regression models were used to form a scoring system for categorising patients into high and low risk on a scale of 0-9 points and a cut-off score of 5, based on the area under the receiver operating characteristic curve of 0.76 (CI 95% 0.71-0.82). This yielded a sensitivity of 86% and a specificity of 58%. High-risk patients should be considered for investigation with HRCT and monitored closely.

CONCLUSION

We have proposed a new model for identifying RA patients at risk of developing ILD. This approach identified four simple clinical variables: age, anti-cyclic citrullinated peptide antibodies, Rheumatoid factor and smoking, which allowed development of a predictive scoring system for the presence of ILD in patients with RA.

Inflammatory Biomarkers in the Diagnosis and Prognosis of Rheumatoid Arthritis-Associated Interstitial Lung Disease

This study aimed to identify inflammatory factors and soluble cytokines that act as biomarkers in the diagnosis and prognosis of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). We performed a nested prospective observational case-control study of patients with RA-ILD matched by sex, age, and time since the diagnosis of RA. All participants underwent pulmonary function testing and high-resolution computed tomography. ILD was defined according to the criteria of the American Thoracic Society/European Respiratory Society; the progression of lung disease was defined as the worsening of FVC > 10% or DLCO > 15%. Inflammation-related variables included the inflammatory activity measured using the DAS28-ESR and a multiplex cytokine assay. Two Cox regression models were run to identify factors associated with ILD and the progression of ILD. The study population comprised 70 patients: 35 patients with RA-ILD (cases) and 35 RA patients without ILD (controls). A greater percentage of cases had higher DAS28-ESR (p = 0.032) and HAQ values (p = 0.003). The variables associated with RA-ILD in the Cox regression analysis were disease activity (DAS28) (HR [95% CI], 2.47 [1.17-5.22]; p = 0.017) and high levels of ACPA (HR [95% CI], 2.90 [1.24-6.78]; p = 0.014), IL-18 in pg/mL (HR [95% CI], 1.06 [1.00-1.12]; p = 0.044), MCP-1/CCL2 in pg/mL (HR [95% CI], 1.03 [1.00-1.06]; p = 0.049), and SDF-1 in pg/mL (HR [95% CI], 1.00 [1.00-1.00]; p = 0.010). The only variable associated with the progression of ILD was IL-18 in pg/mL (HR [95% CI], 1.25 [1.07-1.46]; p = 0.004). Our data support that the inflammatory activity was higher in patients with RA-ILD than RA patients without ILD. Some cytokines were associated with both diagnosis and poorer prognosis in patients with RA-ILD.

Peripheral Blood Biomarkers for Rheumatoid Arthritis-Associated Interstitial Lung Disease: A Systematic Review

BACKGROUND

Biomarkers have been proposed as tools to aid in the identification and prognostication of interstitial lung disease (ILD) in rheumatoid arthritis (RA). We performed a systematic review of studies evaluating peripheral blood biomarkers and their association with RA-ILD and its prognosis.

METHODS

Medline, Embase, the Cochrane Library, and Scopus were queried for relevant studies, with the final search update on July 12, 2021. We included studies evaluating peripheral blood biomarkers for the identification and/or prognostication of RA-ILD, extracting the performance of individual biomarkers for identifying RA-ILD, and predicting prognosis. Modified versions of the Quality Assessment of Diagnostic Accuracy Studies 2 and the Quality in Prognosis Studies tools were used for quality assessment.

RESULTS

Seventy studies met eligibility criteria. Study and patient characteristics, analytical methods, strength and consistency of associations, and study quality were heterogeneous. A total of 92 biomarkers were positively associated and 12 were negatively associated with RA-ILD among patients with RA in one or more report. Only a small number of biomarkers were evaluated in multiple cohorts using adjusted analyses. Biomarkers most strongly associated with RA-ILD overlapped with those identified for idiopathic pulmonary fibrosis. Few prognostic biomarkers of RA-ILD were identified.

CONCLUSION

Several peripheral blood biomarkers are associated with the presence of RA-ILD, but few have been assessed in multivariable models, have been externally validated, have discriminated RA-ILD from other lung disease, or have prognosticated the disease course. High-quality studies investigating and validating peripheral biomarkers in RA-ILD are needed before they can be employed in clinical care.

Clinical characteristics of rheumatoid arthritis patients with interstitial lung disease: baseline data of a single-center prospective cohort

BACKGROUND

To introduce a prospective cohort for rheumatoid arthritis (RA) patients with interstitial lung disease (ILD) and to identify their clinical features in comparison with RA patients without ILD.

METHODS

Using a multidisciplinary collaborative approach, a single-center cohort for RA patients with ILD (RA-ILD) was established in May 2017, and enrolment data from May 2017 to March 2021 were used to compare the clinical features of RA patients without ILD (RA-non ILD). Multivariable logistic regression analysis was used to identify factors associated with ILD in RA patients.

RESULTS

Among 148 RA-ILD and 410 RA-non ILD patients, participants in the RA-ILD group were older (65.8 ± 9.9 vs. 58.0 ± 10.4 years, P < 0.001) and included more males (35.8% vs. 14.6%, P < 0.001) than in the RA-non ILD group. The RA-ILD group had a higher proportion of late-onset RA patients (age ≥ 60 years) than in the comparator group (43.9% vs. 14.2%, P < 0.001). Multivariable logistic regression analysis showed that higher age at RA onset (OR 1.056, 95% CI 1.021-1.091), higher body mass index (BMI; OR 1.65, 95% CI 1.036-2.629), smoking history (OR 2.484, 95% CI 1.071-5.764), and oral glucocorticoid use (OR 3.562, 95% CI 2.160-5.874) were associated with ILD in RA patients, whereas methotrexate use was less likely to be associated with ILD (OR 0.253, 95% CI 0.155-0.412).

CONCLUSIONS

Higher age at RA onset, smoking history, and higher BMI were associated with the presence of ILD among RA patients. Oral glucocorticoids were more frequently used whereas methotrexate was less likely to be used in RA-ILD patients.

Sexual Dimorphism in Interstitial Lung Disease

Interstitial lung diseases (ILD) are a group of heterogeneous progressive pulmonary disorders, characterised by tissue remodelling and/or fibrotic scarring of the lung parenchyma. ILD patients experience lung function decline with progressive symptoms, poor response to treatment, reduced quality of life and high mortality. ILD can be idiopathic or associated with systemic or connective tissue diseases (CTD) but idiopathic pulmonary fibrosis (IPF) is the most common form. While IPF has a male predominance, women are affected more greatly by CTD and therefore associated ILDs. The mechanisms behind biological sex differences in these progressive lung diseases remain unclear. However, differences in environmental exposures, variable expression of X-chromosome related inflammatory genes and sex hormones play a role. Here, we will outline sex-related differences in the incidence, progression and mechanisms of action of these diseases and discuss existing and novel cellular and pre-clinical studies. Furthermore, we will highlight how sex-differences are not adequately considered in pre-clinical disease models, how gender bias exists in clinical diagnosis and how women are underrepresented in clinical trials. Future action on these observations will hopefully shed light on the role of biological sex in disease development, identify potential targets for intervention and increase female participant numbers in clinical trials.

Risk factors for rheumatoid arthritis-associated interstitial lung disease: a retrospective study

Background

The objective of this study was to assess clinical and imaging features of rheumatoid arthritis (RA) associated with interstitial lung disease (ILD), (RA-ILD) group, in comparison to RA without ILD (RA-C) and to identify the associated factors to ILD.

Methods

This was a retrospective comparative study (from June 2015 to March 2022) including RA patients aged ≥18 years. The RA-C control group was matched according to age (±2 years), gender, and RA duration (±2 years). General data, RA characteristics, ILD features, and treatment modalities were recorded. Statistical analysis was performed to determine the predictive factors of ILD.

Results

A total of 104 patients were included (52 RA-ILD and 52 RA-C); sex ratio was 0.36. Mean age was 66.3±11 years (RA-ILD) versus 65.6±10.8 years (RA-C) (p=0.72). In comparison to RA-C, RA-ILD patients were significantly higher smokers (p=0.01) and physically inactive (p=0.01). Regarding RA features, RA-ILD patients have significantly increased positive anti-citrullinated peptide antibody (ACPA) (p=0.01), ACPA rate (p<0.001), erosive disease (p<0.001), and disease activity score (p<0.001). Mean time to ILD diagnosis was 5.85±7.16 years. Chest high-resolution computed tomography (HRCT) patterns of disease were identified: nonspecific interstitial pneumonia (NSIP) (28.8%), usual interstitial pneumonia (UIP) (17.3%), organizing pneumonia (OP) (25%), acute interstitial pneumonia (13.5%), and respiratory bronchiolitis (3.8%). Multivariate analysis identified smoking, high baseline DAS28 (disease activity score 28) and ACPA positivity as predictive factors of ILD.

Conclusion

Our results confirmed the reported associated factors of ILD in RA (smoking, higher disease activity, ACPA positivity). Thus, we need to target the modifiable factors by supporting and educating RA patients to quit smoking and intensify disease modifying anti-rheumatoid drugs (DMARD) to reach remission.

Safety and Effectiveness of Abatacept in a Prospective Cohort of Patients with Rheumatoid Arthritis–Associated Interstitial Lung Disease

Objective: To prospectively evaluate the safety and efficacy profile of abatacept in patients with rheumatoid arthritis–associated interstitial lung disease (RA-ILD). Methods: We performed a prospective observational multicenter study of a cohort of patients with RA-ILD treated with abatacept between 2015 and 2021. Patients were evaluated using high-resolution computed tomography and pulmonary function tests at initiation, 12 months, and the end of follow-up. The effectiveness of abatacept was evaluated based on whether ILD improved, stabilized, progressed, or was fatal. We also evaluated factors such as infection, hospitalization, and inflammatory activity using the 28-joint Disease Activity Score with the erythrocyte sedimentation rate (DAS28-ESR). Cox regression analysis was performed to identify factors associated with progression of lung disease. Results: The study population comprised 57 patients with RA-ILD treated with abatacept for a median (IQR) of 27.3 (12.2–42.8) months. Lung disease had progressed before starting abatacept in 45.6% of patients. At the end of follow-up, lung disease had improved or stabilized in 41 patients (71.9%) and worsened in 13 (22.8%); 3 patients (5.3%) died. No significant decreases were observed in forced vital capacity (FVC) or in the diffusing capacity of the lung for carbon monoxide (DLCO).The factors associated with progression of RA-ILD were baseline DAS28-ESR (OR [95% CI], 2.52 [1.03–3.12]; p = 0.041), FVC (OR [95% CI], 0.82 [0.70–0.96]; p = 0.019), and DLCO (OR [95% CI], 0.83 [0.72–0.96]; p = 0.018). Only 10.5% of patients experienced severe adverse effects. Conclusion: Pulmonary function and joint inflammation stabilized in 71% of patients with RA-ILD treated with abatacept. Abatacept had a favorable safety profile.

Pulmonary fibrosis associated with rheumatoid arthritis: from pathophysiology to treatment strategies

INTRODUCTION

Rheumatoid arthritis (RA) is the most common inflammatory autoimmune disease, characterised by symmetric destructive arthritis and synovitis. Lung involvement is frequent, including in the form of interstitial lung disease (ILD). RA-ILD often presents with a radiologic and pathologic pattern of usual interstitial pneumonia, similar to idiopathic pulmonary fibrosis, highlighting the similarities between the two diseases, but other patterns and pathological associations are described.

AREAS COVERED

This article reviews the pathogenesis of pulmonary fibrosis in the setting of rheumatoid arthritis as well as the current and future therapeutic options.

EXPERT OPINION

Pulmonary fibrosis in the setting of RA-ILD is an example of genotype-environment interaction and involves multiple mechanisms including autoimmunity, inflammation and fibrogenesis. Despite that ILD conveys most of the exceeding mortality in RA patients, there are no official guidelines for the management of RA-ILD. Attention should be paid to potential lung toxicity of RA treatment even though some of them might help stabilise the ILD. Current standard of care is often composed of glucocorticoids that may be associated with immunosuppressive therapy. Following the approval of antifibrotic therapy for ILDs with a progressive fibrosing phenotype, current works are evaluating the benefit of such treatment in RA-ILD.

Predictors of progression in rheumatoid arthritis-associated interstitial lung disease: A single-center retrospective study from China

AIM

Interstitial lung disease (ILD) is a common extra-articular manifestation of rheumatoid arthritis (RA) and is associated with high mortality, especially in progressive ILD. We aimed to identify predictors of disease progression in the early stages of ILD in a large sample of patients with RA.

METHOD

The medical records of 201 RA-ILD patients were retrospectively analyzed. According to changes in their pulmonary function tests, patients were divided into progressive disease and stable disease groups. Data were collected on clinical characteristics, laboratory findings, chest high-resolution computed tomography, and therapeutic agents. Univariate and multivariate analyses were performed to identify predictors of ILD progression.

RESULTS

During a median follow up of 38 months, 105 (52.5%) patients were diagnosed with progressive ILD. These patients were mostly male, past or present smokers (P = 0.028, P = 0.021, respectively). Higher Health Assessment Questionnaire-Disability Index score and higher Disease Activity Score in 28 joints with erythrocyte sedimentation rate (DAS28-ESR) were observed in the ILD progression group (P = 0.003, P < 0.001, respectively). There were no significant differences in baseline respiratory symptoms, pulmonary function, or laboratory features. Multivariate analysis indicated that high DAS28-ESR, definite usual interstitial pneumonia pattern, fibrosis score, and less use of cyclophosphamide were independent risk factors for RA-ILD progression. Fifteen (7.46%) patients died during the follow up, and the most frequent cause of death was lung infection.

CONCLUSION

Our results suggested that high disease activity, definite usual interstitial pneumonia pattern, fibrosis score, and less use of cyclophosphamide at the onset of ILD may indicate the progression of ILD in RA patients.

Identification of biomarkers by machine learning classifiers to assist diagnose rheumatoid arthritis-associated interstitial lung disease

Background

This study aimed to search for blood biomarkers among the profiles of patients with RA-ILD by using machine learning classifiers and probe correlations between the markers and the characteristics of RA-ILD.

Methods

A total of 153 RA patients were enrolled, including 75 RA-ILD and 78 RA-non-ILD. Routine laboratory data, the levels of tumor markers and autoantibodies, and clinical manifestations were recorded. Univariate analysis, least absolute shrinkage and selection operator (LASSO), random forest (RF), and partial least square (PLS) were performed, and the receiver operating characteristic (ROC) curves were plotted.

Results

Univariate analysis showed that, compared to RA-non-ILD, patients with RA-ILD were older (p < 0.001), had higher white blood cell (p = 0.003) and neutrophil counts (p = 0.017), had higher erythrocyte sedimentation rate (p = 0.003) and C-reactive protein (p = 0.003), had higher levels of KL-6 (p < 0.001), D-dimer (p < 0.001), fibrinogen (p < 0.001), fibrinogen degradation products (p < 0.001), lactate dehydrogenase (p < 0.001), hydroxybutyrate dehydrogenase (p < 0.001), carbohydrate antigen (CA) 19–9 (p < 0.001), carcinoembryonic antigen (p = 0.001), and CA242 (p < 0.001), but a significantly lower albumin level (p = 0.003). The areas under the curves (AUCs) of the LASSO, RF, and PLS models attained 0.95 in terms of differentiating patients with RA-ILD from those without. When data from the univariate analysis and the top 10 indicators of the three machine learning models were combined, the most discriminatory markers were age and the KL-6, D-dimer, and CA19-9, with AUCs of 0.814 [95% confidence interval (CI) 0.731–0.880], 0.749 (95% CI 0.660–0.824), 0.749 (95% CI 0.660–0.824), and 0.727 (95% CI 0.637–0.805), respectively. When all four markers were combined, the AUC reached 0.928 (95% CI 0.865–0.968). Notably, neither the KL-6 nor the CA19-9 level correlated with disease activity in RA-ILD group.

Conclusions

The levels of KL-6, D-dimer, and tumor markers greatly aided RA-ILD identification. Machine learning algorithms combined with traditional biostatistical analysis can diagnose patients with RA-ILD and identify biomarkers potentially associated with the disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02800-2.

Observational studies: Ambient air pollution and hospitalization for RA-ILD in a heavily polluted city in China

Little is known within the medical community about the impact of air pollution on hospital admissions due to rheumatoid arthritis associated with interstitial lung disease (RA-ILD). Our research aimed to explore whether there is a correlation and to estimate how the association was distributed across various lags in Jinan, China.The relationships between ambient air pollutant concentrations, including PM2.5, PM10, sulfur dioxide (SO2), ozone (O3), and nitrogen dioxide (NO2), and monthly hospitalizations for RA-ILD were studied by employing a general linear model with a Poisson distribution. This time-series study was performed from January 1st, 2015 to December 31st, 2019.In the 5-year study, there were 221 hospitalizations for RA-ILD in Jinan city. The levels of PM2.5, PM10, SO2, and NO2 were significantly related to the number of admissions for RA-ILD. PM2.5, PM10, and SO2 showed the most significant effect on the month (lag 0), and NO2 was most related to RA-ILD at a lag of two months (lag 2). The monthly admissions of RA-ILD increased by 0.875% (95% CI: 0.375-1.377%), 0.548% (95% CI: 0.148-0.949%), 1.968% (95% CI: 0.869-3.080%), and 1.534% (95% CI: 0.305-2.778%) for each 10 μg/m3 increase in PM2.5, PM10, SO2 and NO2, respectively.This study might add more detailed evidence that higher levels of PM2.5, PM10, SO2 and NO2 increase the risk of hospitalizations for RA-ILD. Further study of the role of air pollution in the pathogenesis of RA-ILD is warranted.

Airway Disease in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a common condition affecting approximately 1% of the general population. RA is a multisystem disorder that causes progressive articular destruction through synovial inflammation. One of the most common extraarticular manifestations of RA is pulmonary involvement, where all compartments of the pulmonary system can be impacted (e.g., pulmonary vasculature, pleura, parenchyma, and the airways). Although it has been known for decades that a portion of patients with RA develop interstitial lung disease, and recent advancements in understanding the genetic risk and treatment for RA-interstitial lung disease have drawn attention, more recent data have begun to highlight the significance of airway disease in patients with RA. Yet, little is known about the underlying pathogenesis, clinical impact, or optimal treatment strategies for airway disease in RA. This review will focus on airway disease involvement in patients with RA by highlighting areas of clinical inquiry for pulmonologists and rheumatologists and discuss areas for future research. Finally, we discuss a potential screening algorithm for providers when approaching patients with RA with respiratory complaints.

Consensus recommendations on managing the selected comorbidities including cardiovascular disease, osteoporosis, and interstitial lung disease in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA)-related comorbidities, including cardiovascular disease (CVD), osteoporosis (OP), and interstitial lung disease (ILD), are sub-optimally managed. RA-related comorbidities affect disease control and lead to impairment in quality of life. We aimed to develop consensus recommendations for managing RA-related comorbidities.

METHODS

The consensus statements were formulated based on emerging evidence during a face-to-face meeting of Taiwan rheumatology experts and modified through three-round Delphi exercises. The quality of evidence and strength of recommendation of each statement were graded after a literature review, followed by voting for agreement. Through a review of English-language literature, we focused on the existing evidence of management of RA-related comorbidities.

RESULTS

Based on experts' consensus, eleven recommendations were developed. CVD risk should be assessed in patients at RA diagnosis, once every 5 years, and at changes in DMARDs therapy. Considering the detrimental effects of nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids on CVD risks, we recommend using the lowest possible dose of corticosteroids and prescribing NSAIDs cautiously. The OP/fragility fracture risk assessment includes dual-energy X-ray absorptiometry and fracture risk assessment (FRAX) in RA. The FRAX-based approach with intervention threshold is a useful strategy for managing OP. RA-ILD assessment includes risk factors, pulmonary function tests, HRCT imaging and a multidisciplinary decision approach to determine RA-ILD severity. A treat-to-target strategy would limit RA-related comorbidities.

CONCLUSIONS

These consensus statements emphasize that adequate control of disease activity and the risk factors are needed for managing RA-related comorbidities, and may provide useful recommendations for rheumatologists on managing RA-related comorbidities.

Autoantibody Seropositivity and Risk for Interstitial Lung Disease in a Prospective Male-Predominant Rheumatoid Arthritis Cohort of U.S. Veterans

Rationale: Prior studies investigating associations of rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) seropositivity with risk for rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) have mostly used cross-sectional or case-control designs.Objectives: To determine whether combined autoantibody seropositivity and higher individual autoantibody concentrations were associated with increased risk for RA-ILD in a prospective RA cohort.Methods: Within the Veterans Affairs Rheumatoid Arthritis prospective registry, we performed a cross-sectional study of prevalent ILD and a retrospective cohort study of incident ILD (diagnosed after at least 12 mo of longitudinal follow-up). We used logistic and Cox regression methods to determine whether combined RF/ACPA seropositivity and higher autoantibody concentrations were independently associated with greater risk for prevalent and incident ILD, respectively.Results: Among 2,328 participants (median age 64 yr, 89.3% male), 100 (4.3%) subjects had prevalent ILD at enrollment. During 14,281 patient-years of follow-up, 83 (3.7%) of the remaining 2,228 were subsequently diagnosed with incident ILD (5.8 cases per 1,000 person-years). Patients with combined RF/ACPA seropositivity had a higher probability of prevalent ILD compared with seronegative subjects (odds ratio [OR], 2.90; 95% confidence interval [CI], 1.24-6.78). RF titers demonstrated a monotonic association with prevalent ILD (OR, 2.69; 95% CI, 1.11-6.51 for low-positive [15-45 IU/ml] titers; OR, 3.40; 95% CI, 1.61-7.18 for high-positive [>45 IU/ml] titers; P for trend 0.01). Patients with high-positive (>15 U/ml) ACPA titers were also at higher risk for prevalent ILD (OR, 1.91; 95% CI, 1.04-3.49) compared with ACPA-negative subjects. Combined RF/ACPA seropositivity was not associated with increased risk for incident ILD, nor were high- or low-positive RF or ACPA titers. In a piecewise linear spline model, however, RF titers greater than 90 IU/ml independently correlated with increased risk for incident ILD (hazard ratio, 1.68, 95% CI, 1.02-2.77).Conclusions: Combined RF/ACPA seropositivity and individual autoantibody concentrations were strongly associated with prevalent but not incident RA-ILD. Only patients with RF concentrations >90 IU/ml were observed to be at higher risk of incident RA-ILD.

Prevalence, incidence and cause-specific mortality of rheumatoid arthritis-associated interstitial lung disease among older rheumatoid arthritis patients

OBJECTIVE

We aimed to investigate the prevalence, incidence and cause-specific mortality of RA-associated interstitial lung disease (RA-ILD) among older US patients with RA.

METHODS

We performed a nationwide cohort study using Medicare claims data (parts A, B and D for 2008-2017). RA was identified with a validated algorithm using RA diagnosis codes and DMARD prescription. RA-ILD was identified with a validated algorithm using ILD diagnosis codes by a rheumatologist/pulmonologist. RA-ILD was categorized as prevalent or incident relative to the initial RA observation (baseline/index date). We compared the total mortality of RA-ILD to RA without ILD using multivariable Cox regression, adjusting for baseline covariates. For cause-specific mortality, Fine and Gray subdistribution hazard ratios (sdHRs) were estimated to handle competing risks of alternative mortality causes.

RESULTS

Among 509 787 RA patients (mean age 72.6 years, 76.2% female), 10 306 (2.0%) had prevalent RA-ILD at baseline. After baseline, 13 372 (2.6%) developed RA-ILD during 1 873 127 person-years of follow-up (median 3.0 years/person). During follow-up, 38.7% of RA-ILD patients died compared with 20.7% of RA patients without ILD. After multivariable adjustment, RA-ILD had an HR of 1.66 (95% CI 1.60, 1.72) for total mortality. Accounting for competing risk of other causes of death, RA-ILD had an sdHR of 4.39 (95% CI 4.13, 4.67) for respiratory mortality and an sdHR of 1.56 (95% CI 1.43, 1.71) for cancer mortality compared with RA without ILD.

CONCLUSIONS

RA-ILD was present or developed in nearly 5% of patients in this nationwide study of older patients with RA. Compared with RA without ILD, RA-ILD was associated with excess total, respiratory and cancer mortality that was not explained by measured factors.

Abatacept in rheumatoid arthritis-associated interstitial lung disease: short-term outcomes and predictors of progression

INTRODUCTION

Interstitial lung disease in rheumatoid arthritis (RA-ILD) is an extra-articular involvement that impairs the prognosis and for which there is still no well-coded treatment. The aim of this study was to evaluate abatacept (ABA) effectiveness and safety in patients with RA-ILD.

METHODS

RA-ILD patients who started ABA treatment were consecutively enrolled. Chest high-resolution computed tomography (HRCT), clinical, laboratory and respiratory function variables were collected at baseline and after 18 months of ABA treatment. HRCT abnormalities were evaluated using a computer-aided method (CaM). ABA response was established based on the change in the percentage of fibrosis evaluated at HRCT-CaM, dividing patients into "worsened" (progression ≥ 15%), "improved" (reduction ≥ 15%), and "stable" (changes within the 15% range). The multivariate regression model was used to assess the associations between RA characteristics and ABA response.

RESULTS

Forty-four patients (81% women, mean age 59.1 ± 8.0, mean disease duration of 7.5 ± 3.1 years) were studied. Five patients (11.4%) showed RA-ILD progression, 32 patients (72.6%) were considered stable, and 7 patients (16.0%) showed an RA-ILD improvement. The proportion of current smokers was significantly different between "worsened" patients, respect to those defined as "improved/stable" (p = 0.01). Current smoking habit (p = 0.005) and concomitant methotrexate treatment (p = 0.0078) were the two variables related to RA-ILD progression in multivariate regression analysis.

CONCLUSION

Treatment with ABA is associated with a RA-ILD stability or improvement in the 88.6% of patients. Current smoking habit and concomitant treatment with methotrexate are the modifiable factors associated with RA-ILD worsening. Key Points • Abatacept plays a favourable role in the control of RA-ILD, with a significant worsening in only 11.4% of patients during a 18-month follow-up period. • The predictive variables related to RA-ILD progression during abatacept therapy are the concomitant treatment with methotrexate and current smoking habit.

Serum anti-citrullinated protein antibodies and rheumatoid factor increase the risk of rheumatoid arthritis-related interstitial lung disease: a meta-analysis

BACKGROUND

This meta-analysis aims to determine the association between antibodies including anti-citrullinated protein antibodies (ACPA) and rheumatoid factors (RF) and risk of rheumatoid arthritis-related interstitial lung disease (RA-ILD).

METHODS

PubMed, Embase, and Cochrane were searched up to September 13, 2020, for studies investigating the risk of RA-ILD in ACPA-positive patients. The statistical meta-analysis and sensitivity analysis were performed using the Review Manager 5.4 and Stata16.0 software, respectively.

RESULTS

Total 1 double-blind randomized controlled study and 16 observational studies, including 992 RA-ILD patients and 2223 RA-non ILD patients, met the inclusion criteria of the meta-analysis. Compared with ACPA-negative patients, positive serum ACPA increased the risk of RA-ILD (OR = 2.51; 95% CI: 1.35-4.68; P = 0.004) and serum ACPA titer was significantly correlated with risk of RA-ILD (SMD = 0.39; 95% CI: 0.17-0.62; P = 0.0006). In a region-based subgroup analysis, ACPA titer in Asian, European, and African populations was significantly related to the risk of RA-ILD, while there was no significant correlation in the Americans (SMD =  - 0.03; 95% CI: - 0.89-0.83; P = 0.95), especially in the USA (SMD = 0.37; 95% CI: - 0.26-0.99; P = 0.25). In addition, serum positive RF increased the risk of RA-ILD (OR = 2.85; 95% CI: 2.19-3.71; P < 0.00001) and serum RF titer was significantly correlated with the risk of RA-ILD (SMD = 0.35; 95% CI: 0.23-0.46; P < 0.00001). However, for the analysis of RF dichotomous data, the funnel shape was asymmetric and the p value of egger test was less than 0.05, which indicated potential publication bias.

CONCLUSIONS

ACPA and RF positive patients have greater risk of RA-ILD, and RA patients positive for ACPA should be paid more attention.

KEY POINTS

• Autoantibodies ACPA and RF increase the risk of RA-ILD. • Regions may be related to RA-ILD.

Acute exacerbation of rheumatoid arthritis-associated interstitial lung disease: clinical features and prognosis

OBJECTIVES

RA-associated interstitial lung disease (RA-ILD) is commonly associated with acute exacerbations (ILD-AE). This study examined the clinical characteristics and risk factors of ILD-AE and mortality of RA-ILD.

METHODS

We retrospectively collected data on 165 RA-ILD patients who visited or were admitted to our hospital between January 2007 and December 2019. We compared the clinical characteristics of patients who did and did not develop ILD-AE and identified variables significantly associated with ILD-AE. We also compared the admission characteristics of those who survived and those who died after admission for ILD-AE. ILD-AE was defined using previously proposed criteria, modified slightly for application to RA-ILD.

RESULTS

The mean patient age was 73.6 years (s.d. 9.7) and 97 (71.9%) patients were female. Thirty (22.2%) patients developed ILD-AE, 13 (43.3%) of whom died. In univariate analyses, neither the usual interstitial pneumonia (UIP) pattern nor MTX was associated with ILD-AE. In multivariate analyses, the UIP pattern was significantly associated with ILD-AE [odds ratio (OR) 2.55 (95% CI 1.05, 6.20), P = 0.038]. In the Cox proportional hazards model, the UIP pattern [hazard ratio (HR) 4.67 (95% CI 1.02, 21.45), P = 0.048] was significantly associated with death, while MTX use [HR 0.16 (95% CI 0.04, 0.72), P = 0.016] was significantly associated with survival.

CONCLUSION

Our data suggest that the UIP pattern is related to ILD-AE. Furthermore, both the UIP pattern and non-use of MTX might be related to death from ILD-AE in RA-ILD.

Pulmonary fibrosis in relation to genetic loci in an inception cohort of patients with early rheumatoid arthritis from northern Sweden

Objectives

Pulmonary manifestations in RA are common comorbidities. Interstitial lung disease (ILD), both idiopathic and in RA, has been associated with several genetic variants. We assessed pulmonary fibrosis (PF) in an inception cohort of RA patients in relation to genetic variants and disease-related factors.

Methods

A total of 1466 early RA patients were consecutively included and followed prospectively from the index date until death or 31 December 2016. Clinical and laboratory data and treatment were continuously registered according to the Swedish Rheumatology Quality Register. DNA was available from 1184 patients and 571 151 genome-wide single-nucleotide polymorphisms (SNPs) were analysed. Thirteen identified genetic variants were extracted. At follow-up, the patients answered a questionnaire regarding disease progression and lung involvement that was validated by reviewing medical records and analysing radiological examinations.

Results

The prevalence of PF was 5.6% and the annualized incidence rate was 5.0/1000 (95% CI 3.80, 6.54). Four SNPs were associated with PF in RA: rs35705950 [MUC5B; OR 2.5 (95% CI 1.5, 4.0), adjusted P-value = 0.00016, q-value = 0.0021]; rs111521887 [TOLLIP; OR 1.9 (95% CI 1.3, 2.8), adjusted P-value = 0.0014, q-value = 0.0092]; rs2609255 [FAM13A; OR 1.7 (95% CI 1.1, 2.5), adjusted P-value = 0.013, q-value = 0.055] and rs2736100 [TERT; OR 1.5 (95% CI 1.0, 2.2), adjusted P-value = 0.046, q-value = 0.15]. Older age and RF positivity were associated with increased risk, while MTX treatment was associated with a lower risk of PF.

Conclusions

Development of PF in an inception cohort of RA patients was associated with 4 of 12 ILD risk genes. RA-related factors except for age at diagnosis and RF positivity were of limited importance in PF development.

Two sides of the same coin? A review of the similarities and differences between idiopathic pulmonary fibrosis and rheumatoid arthritis-associated interstitial lung disease

Rheumatoid arthritis associated interstitial lung disease (RA-ILD) and idiopathic pulmonary fibrosis (IPF) are distinct diseases; however, they share several clinical, radiographic and genetic features. For instance, usual interstitial pneumonia (UIP), which is an ILD pattern required for a diagnosis of IPF, is also the most common ILD pattern in RA-ILD. The presence of UIP in RA-ILD is a poor prognostic sign with outcomes similar to those seen in IPF. The recent finding of a shared genetic susceptibility between IPF and RA-ILD has sparked additional interest in this relationship. This review outlines these similarities and differences in clinical presentation, appearance and outcomes in RA-ILD and IPF.In addition, this review highlights previous research in molecular biomarkers in both conditions, exploring areas of overlap and distinction. This focus on biomarkers in IPF and RA-ILD aims to highlight potential areas of discovery and clues to a potential shared pathobiology through investigation of novel molecular markers or the repurposing of biomarkers from one condition to the other.The drive to better understand RA-ILD by leveraging our knowledge of IPF is underscored by our divergent treatment paradigms for these conditions and the concern for potential harm. As a result of advancing our understanding of the links between IPF and RA-ILD, current strategies for diagnosis, screening and treatment of ILD may fundamentally change in the coming years. Until then, clinicians face difficult clinical questions regarding the co-management of the articular disease and the ILD in RA.

Interstitial lung disease throughout the rheumatoid arthritis disease course

PURPOSE OF REVIEW

To summarize the current understanding of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) throughout the rheumatoid arthritis (RA) disease course from preclinical to established disease.

RECENT FINDINGS

ILD is a serious extra-articular manifestation of RA. Multiple studies have demonstrated a high prevalence of both subclinical and clinical ILD throughout the RA disease course. Investigations of patients without RA have demonstrated an association between RA-related autoantibodies like anticitrullinated protein antibodies (ACPA) and interstitial abnormalities on lung imaging. A significant proportion of RA-ILD patients develop ILD prior to articular manifestations, suggesting that the lung plays a central role in RA development, perhaps through ACPA production. RA-ILD also occurs in early RA, when exuberant autoantibody production and systemic inflammation may propagate pulmonary disease activity. In patients with established RA, a high burden of subclinical and clinical ILD results in significant morbidity, mortality, and healthcare expenditure. Multiple epidemiologic and genetic risk factors, as well as serum biomarkers, have been associated with RA-ILD.

SUMMARY

Subclinical and clinical ILD occur frequently in preclinical, early, and established RA and may play a key role in RA-related autoantibody production and disease progression. Further studies are needed to better understand the risk factors, prognosis, and potential therapies for RA-ILD.

A dose-dependent beneficial effect of methotrexate on the risk of interstitial lung disease in rheumatoid arthritis patients

Objectives

The aim of the study was to assess the influence of different factors, including treatment, on the risk of ILD in the course of RA.

Methods

A total of 109 RA patients were included in the analysis. High-resolution computed tomography (HRCT) of chest was obtained in each patient. Patients were classified as having ILD (ILD group) or not (N-ILD group). The ILD was graded using the semi-quantitative Warrick scale of fibrosis. Warrick extent score (WES) and Warrick severity score (WSS) were calculated separately for each patient, then combined to obtain a global score (WGS).

Results

In univariate analysis the presence of ILD was associated positively with age (P = 5x10^-6) and negatively with MTX treatment (P = 0.0013), mean MTX dose per year of treatment (P = 0.003) and number of DMARDs used (P = 0.046). On multivariate analysis only age and treatment with MTX were independently associated with the presence of ILD. WGS was significantly lower in patients treated with MTX in a dose of ≥15 mg/week (MTX≥15 group) as compared to patients treated with lower doses of MTX (0<MTX<15 group) or not treated with MTX (N-MTX group) (P = 0.04 and P = 0.037, respectively). The ILD prevalence was higher in N-MTX group than in 0<MTX<15 group (P = 0.0036) and MTX≥15 group (0.0007). The difference in ILD prevalence between MTX≥15 and 0<MTX<15 groups was not significant, but the latter group had higher WES (P = 0.044) and trended to have higher WSS and WGS.

Consclusions

We found a beneficial effect of MTX on RA-ILD. Importantly, this effect seems to be dose dependent.

Analysis of Clinical-Analytical Characteristics in Patients with Rheumatoid Arthritis and Interstitial Lung Disease: Case-Control Study

OBJECTIVES

To study the differences between rheumatoid arthritis (RA)-interstitial lung disease (ILD) patients and RA patients without ILD in severity markers and disease activity and to identify factors associated with the presence of ILD in RA patients.

PATIENTS AND METHODS

Patients: RA-ILD patients selected from a multicentre cohort in Andalusia, Spain.

CONTROLS

RA-patients without ILD paired by sex, age and disease duration.

PROTOCOL

RA patients are reviewed every 3-6months in rheumatology consultation. All patients are reviewed according to a predetermined protocol with systematic data collection.

OUTCOMES

description of ILD type, differences in severity markers and disease activity in both groups. Other variables: ILD type by imaging technique (HRCT): nonspecific interstitial pneumonia (NSIP)/usual interstitial pneumonia (UIP). Lung function by PTF. Activity and severity markers of arthritis by DAS28-ESR, HAQ, RF, ACPA and erosions. Treatment with DMARD.

STATISTICAL ANALYSIS

descriptive and paired T-test or Chi-square test followed by binary logistic regression (DV: ILD in patients with RA).

RESULTS

Eighty-two patients were included, 41 RA-ILD and 41 RA controls. RF and ACPA positivity, serositis and osteoporosis were more frequent in RA-ILD patients. No significant differences in DAS28 were observed (P=.145) between RA-ILD and RA control patients. RA-ILD patients presented worse HAQ scores (P=.006). All patients were treated with disease modifying antirheumatic drugs (DMARDs). The risk of developing ILD in RA patients is tripled by a history of smoking or the presence of erosive arthritis (R²=.36).

CONCLUSIONS

The results of our study support the higher frequency of UIP and NSIP in RA patients. DLCO is the most sensitive parameter to detect ILD in RA patients. Our study showed that ILD in RA patients was associated with RA severity (presence of erosions and ACPA) and with a history of smoking.

Systematic review and meta-analysis of the risk of rheumatoid arthritis-associated interstitial lung disease related to anti-cyclic citrullinated peptide (CCP) antibody

OBJECTIVE

To clarify the risk of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) related to anti-cyclic citrullinated peptide (CCP) antibody.

ELIGIBILITY CRITERIA

Patients with RA with and without ILD were eligible. The primary outcome was the prevalence or incidence of ILD. Primary studies of any design aside from a case report were eligible.

INFORMATION SOURCES

Medline, EMBASE, Science Citation Index Expanded and Cochrane Central Register of Controlled Trials were searched from the inception through 12 November 2019.

DATA EXTRACTION AND RISK OF BIAS

Two reviewers independently selected eligible reports, extracted relevant data and assessed risk of bias using a modified Quality in Prognostic Studies tool.

DATA SYNTHESIS

Meta-analysis was conducted using a random-effects model.

QUALITY OF EVIDENCE

The Grades of Recommendation, Assessment, Development and Evaluation system was applied.

RESULTS

Among 29 out of 827 records retrieved through electronic databases and four additional reports identified from other sources, 29 studies were focused for the review. A total of 10158 subjects were included and the mean age at inclusion was between 45.8 and 63.9 years. The mean RA duration was between 4.3 and 14.9 years. The positivity of anti-CCP antibody ranged from 50.7% to 95.8%. All studies except for two were deemed as high risk of bias. A pooled analysis of univariate results demonstrated that the presence of anti-CCP antibody was significantly associated with RA-ILD with an OR of 2.10 (95% CI: 1.59 to 2.78). Similarly, the titre of anti-CCP antibody was significantly higher for RA-ILD with a standardised mean difference of 0.42 (95% CI: 0.20 to 0.65). These results were confirmed by multivariate analysis in the majority of studies and consistent by any subgroup and sensitivity analyses.

CONCLUSION

The presence and higher titres of anti-CCP antibody were suggested to be significantly associated with an increased risk of RA-ILD. However, the quality of evidence was rated as low or very low.

Pharmacological Interventions for Pulmonary Involvement in Rheumatic Diseases

Among the diverse forms of lung involvement, interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are two important conditions in patients with rheumatic diseases that are associated with significant morbidity and mortality. The management of ILD and PAH is challenging because the current treatment often provides only limited patient survival benefits. Such challenges derive from their common pathogenic mechanisms, where not only the inflammatory processes of immune cells but also the fibrotic and proliferative processes of nonimmune cells play critical roles in disease progression, making immunosuppressive therapy less effective. Recently, updated treatment strategies adopting targeted agents have been introduced with promising results in clinical trials for ILD ad PAH. This review discusses the epidemiologic features of ILD and PAH among patients with rheumatic diseases (rheumatoid arthritis, myositis, and systemic sclerosis) and the state-of-the-art treatment options, focusing on targeted agents including biologics, antifibrotic agents, and vasodilatory drugs.

Utility of pulmonary ultrasound to identify interstitial lung disease in patients with rheumatoid arthritis

OBJECTIVES

To analyze the diagnostic utility of lung ultrasound (US) to detect interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients comparing with high-resolution computed tomography (HRCT) PATIENTS AND METHODS: We performed a cross-sectional, observational study in patients with RA-ILD (cases) controlled with a group of RA patients without ILD (controls) paired by sex, age, and time of disease evolution. Patients were assessed using HRCT, PFT, and US. The main variables were B-line number, evaluation of the lung-US score already described, pleural irregularities, and A pattern US lost. ROC curve analysis was performed to establish the cut-off point of the US B-lines number for detecting the presence of significant RA-ILD in relation to HRCT, and logistic regression analysis was performed to identify the intercostal spaces.

RESULTS

Seventy-one patients were included, 35 (49.2%) with ILD-RA and 36 (50.8%) RA controls. Regarding US score, we found that the detection of 5.5 lines in a reduced score of 8 intercostal spaces had a sensitivity = 62.2%, specificity = 91.3%, PPV = 88.4%, and NPV = 69.5%. In multivariate analysis, the intercostal spaces which showed independent association with ILD were 3rd right anterior axillary space (OR [IC 95%] 19.0 [1.3-27.5]), 8th right posterior axillary space (OR [IC 95%] 0.04 [0.0-0.6]), 8th right subscapular space (OR [IC 95%] 16.5 [1.8-45.5]), 9th right paravertebral space (OR [IC 95%] 7.11 [1.0-37.1]), and 2nd left clavicular middle space (OR [IC 95%] 21.9 [1.26-37.8]).

CONCLUSIONS

Lung ultrasound could be a useful tool for ILD diagnosis associated with rheumatoid arthritis. A 8-space reduced score showed a similar total predictive capacity than 72-space score. Key Points • Lung ultrasound could be a useful tool for ILD diagnosis associated with rheumatoid arthritis. • The 72-space evaluation is highly sensitive, whereas a simplified score enables a more specific and faster diagnosis. • The number of B lines is correlated with DLCO, ACPA, inflammatory activity, and physical function.

Rheumatoid Arthritis Interstitial Lung Disease: Measuring and Predictive Factors Among Patients Treated in Rehabilitation Clinics at Royal Medical Services

Introduction

Autoimmune diseases have increasing importance in modern medicine and cover increasing areas of medicine including rheumatoid arthritis interstitial lung disease.

Aim

The main aims of this study are to evaluate the association of some autoimmune variables in patients with rheumatoid arthritis interstitial lung disease.

Methods

A retrospective study was conducted from files of patients with rheumatoid arthritis interstitial lung disease. A total of 210 files of intended patients were included in this study. The study was conducted in rehabilitation clinics at Royal Medical Services. Study variables include some demographic variables such as age, and gender; clinical variables such as disease related factors such as duration, diagnostic criteria; predictive factors such as rheumatoid factors, smoking, and MTX treatment. Data were collected and entered into excel spreadsheet to create raw data. The analysis of data was carried out using the software SPSS version 21. Descriptive statistical parameters were used to describe data including means and standard deviations for continuous variables. Frequency and percentages were used to describe categorized variables such as gender. The relationships between study variables were computed using independent T test, and One Way ANOVA test. Significance was determined if α≤ 0.05.

Results

The prevalence of RA-ILD was 3.70%. The study participants were subdivided into two groups according to MTX treatment, non-exposed group and exposed group. There were significant relationships between MTX treatment and study variables including gender, age of (rheumatoid arthritis) RA onset, smoking, and rheumatoid factor (RF). The progression of RA-ILD was impacted by gender, age of (rheumatoid arthritis) RA onset, smoking, rheumatoid factor (RF), and MTX treatment.

Conclusion

Patients with RA and RA-ILD follow similar clinical characteristics in other studies except MTX treatment, but this can't be generalized because of small number of RA-ILD patients.