Rheumatoid arthritis-interstitial lung disease: manifestations and current concepts in pathogenesis and management

GZMK Facilitates Experimental Rheumatoid Arthritis Progression by Interacting with CCL5 and Activating the ERK Signaling

Synovial over-proliferation is a key event in the progression of rheumatoid arthritis (RA) disease. Ferroptosis may be essential for maintaining the balance between synovial proliferation and death. This study aimed to investigate the molecular mechanisms mediating the activation and ferroptosis of collagen-induced arthritis (CIA)-synovial fibroblasts (SFs). Differentially expressed genes (DEGs) in the synovial tissues of CIA rats and normal rats were screened through sequencing. The GSE115662 dataset from the GEO database was analyzed and screened for DEGs. The viability, proliferation, migration, invasion, cell cycle, and apoptosis of CIA-SFs were analyzed by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, flow cytometry, transwell migration, and invasion assays. The ferroptosis of CIA-SFs was assessed using matching reagent kits to detect indicators like reactive oxygen species, ferrous iron, malondialdehyde, glutathione, and superoxide dismutase. The interaction between Granzyme K (GZMK) and C-C motif chemokine 5 (CCL5) was determined by coimmunoprecipitation assay. We found abnormal GZMK expression in the GSE115662 database and mRNA sequencing data. GZMK was overexpressed in CIA-SFs, and GZMK promoted cell proliferation, migration, invasion, inflammation, and decreased cell apoptosis and ferroptosis in CIA-SFs. GZMK could interact with CCL5 to activate the ERK signaling. GZMK and CCL5 knockdown improved by reducing arthritis scores, redness and swelling of paws, and pathological changes in joint synovium of CIA rats. CCL5 overexpression reversed the effects of GZMK silencing on CIA-SFs cell proliferation, migration, invasion, apoptosis, and ferroptosis. We confirmed that GZMK accelerated experimental rheumatoid arthritis progression by interacting with CCL5 and activating the ERK signaling.

Neutrophil extracellular traps as immunofibrotic mediators in RA-ILD; pilot evaluation of the nintedanib therapy

Objective

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a significant pulmonary complication of RA. This study tried to elucidate the mechanisms enhancing inflammation and causing lung injury in RA-ILD, focusing on the role of neutrophil extracellular traps (NETs). The study also investigated the potential benefits of nintedanib in advanced disease.

Methods

Nine RA-ILD patients and nine healthy controls were included in the study. Inflammatory markers in patients' circulation were evaluated with immunoassays. The formation of NETs was examined using a citrullinated histone H3 (CitH3) ELISA and cell immunofluorescence. Inflammatory proteins expressed in neutrophils/NETs were studied with real-time qPCR and NET ELISA. To assess the effect of nintedanib, an intracellular tyrosine kinase inhibitor with antifibrotic properties, in RA-ILD a paired study was conducted in five patients before treatment administration and 16 weeks later.

Results

The soluble terminal complement complex sC5b-9 and the levels of CitH3 were significantly elevated in patients with RA-ILD, compared to healthy controls. In addition, neutrophils isolated from RA-ILD patients released NETs enriched with tissue factor and interleukin-17A. Inflammatory NETs had a dynamic role, increasing the fibrotic potential of human pulmonary fibroblasts (HPFs). On the other hand, nintedanib treatment decreased NETs and sC5b-9 levels in RA-ILD patients.

Conclusion

The findings propose an interplay between circulating NETs and HPFs, establishing the immunofibrotic aspects of RA-ILD. They also support the effectiveness of nintedanib in reducing key pathological processes of the disease. Further research is needed to fully understand these mechanisms and optimize treatment strategies for RA-ILD.

Primary Ciliary Dyskinesia Caused by Homozygous DNAAF1 Mutations Resulting from a Consanguineous Marriage: A Case Report from Japan

We present the case of a 58-year-old female patient with primary ciliary dyskinesia (PCD). She was born to parents with a consanguineous marriage. Chest computed tomography conducted at age 41 years indicated no situs inversus, and findings of bronchiectasis were limited to the middle and lingular lobes. Despite long-term macrolide therapy, bronchiectasis exacerbations frequently occurred. PCD was suspected because of the low nasal nitric oxide level (20.7 nL/min). Electron microscopy revealed outer and inner dynein arm defects, and a genetic analysis identified a homozygous single-nucleotide deletion in the DNAAF1 gene. Based on these results, the patient was diagnosed with PCD due to a biallelic DNAAF1 mutation.

2024 update of the recommendations of the French Society of Rheumatology for the diagnosis and management of patients with rheumatoid arthritis

The French Society of Rheumatology recommendations for managing rheumatoid arthritis (RA) has been updated by a working group of 21 rheumatology experts, 4 young rheumatologists and 2 patient association representatives on the basis of the 2023 version of the European Alliance of Associations for Rheumatology (EULAR) recommendations and systematic literature reviews. Two additional topics were addressed: people at risk of RA development and RA-related interstitial lung disease (RA-ILD). Four general principles and 19 recommendations were issued. The general principles emphasize the importance of a shared decision between the rheumatologist and patient and the need for comprehensive management, both drug and non-drug, for people with RA or at risk of RA development. In terms of diagnosis, the recommendations stress the importance of clinical arthritis and in its absence, the risk factors for progression to RA. In terms of treatment, the recommendations incorporate recent data on the cardiovascular and neoplastic risk profile of Janus kinase inhibitors. With regard to RA-ILD, the recommendations highlight the importance of clinical screening and the need for high-resolution CT scan in the presence of pulmonary symptoms. RA-ILD management requires collaboration between rheumatologists and pulmonologists. The treatment strategy is based on controlling disease activity with methotrexate or targeted therapies (mainly abatacept or rituximab). The prescription for anti-fibrotic treatment should be discussed with a pulmonologist with expertise in RA-ILD.

Relationship Between Early and Established Rheumatoid Arthritis Vascular Change of the Dorsalis Pedis Artery Observed with Ultrasound Imaging

BACKGROUND

Despite early treatment of rheumatoid arthritis (RA) being well established to prevent erosive joint damage, studies report persistent moderate to high disease activity. Other pathologies, for example, rheumatoid vasculitis (RV) may contribute symptoms that may not be captured by existing clinical assessment.

OBJECTIVES

To investigate ultrasound-observed changes in the proximal dorsalis pedis artery (DPA) between early (≤ 5 y) and established (>5 y) RA and the RA Disease Activity Index-5 (RADAI-5).

METHODS

Participants with early (n = 20) and established RA (n = 20) were recruited. Five parameters of the DPA were examined with a previously established ultrasound method. Independent t-tests and Cohen d statistics assessed differences and effect size between ultrasound parameters and RADAI-5, and the two groups. Pearson correlation assessed associations between ultrasound parameters and RADAI-5.

RESULTS

Majority of participants (98%) demonstrated arterial wall thickening regardless of disease duration. However, lumen diameter (Cohen's d = 0.972, p = 0.004) and artery diameter (Cohen's d = 0.694, p = 0.034) were decreased in established RA compared to early RA. No strong associations were found between RADAI-5 and ultrasound parameters, except for lumen diameter in early RA demonstrating a fair association to RADAI-5 (r = 0.445). The mean RADAI-5 score indicated moderate to high disease activity with no difference between early and established RA (p = 0.283).

CONCLUSION

Arterial wall thickening of the DPA indicating the precursory changes of RV was observed in most RA participants, with reductions in artery and lumen diameter occurring in established disease. However, the long-standing instrument RADAI-5 may not reflect symptoms and clinical impacts related to vascular changes among people with RA.

The causal relationship between rheumatoid arthritis and interstitial lung disease in East Asian population: A two-sample Mendelian randomization study

To investigate the causal relationship between rheumatoid arthritis (RA) and interstitial lung disease (ILD) in the East Asian population, we utilized Mendelian randomization (MR). Publicly available summarized data from genome-wide association studies on RA (4199 cases and 208,254 controls), and the data on ILD (1046 cases and 176,974 controls) were obtained from BioBank Japan. Eligible single nucleotide polymorphisms from East Asian populations were obtained from genome-wide association studies as instrumental variables, and 11 RA-related single nucleotide polymorphisms (P < 5 × 10-8) were selected as instrumental variables. MR analysis was performed using inverse variance weighted, MR-Egger regression, weighted median, and MR-PRESSO with RA as the exposure data and ILD as the outcome data. Reliability was evaluated using Cochran Q test, MR-Egger intercept, leave-one-out analysis, and funnel plot. Inverse variance weighted results showed an odds ratio (95% confidence interval) of 1.29 (1.18-1.41), P = 3.99 × 10-8, indicating a positive association between RA and ILD. The reliability evaluation could adopt the fixed-effect model, and the absolute value of the MR-Egger regression intercept was 0.021, P > 0.05, and P value of Global Test in MR-PRESSO was 0.573. The test results of the leave-one-out showed that the results are robust, and the funnel plot indicated that the instrumental variables were not affected by potential factors. In conclusion, this study demonstrates that RA is a risk factor for ILD in the East Asian population.

Clinical utility of lung ultrasound for the detection of interstitial lung disease in patients with rheumatoid arthritis

OBJECTIVE

To establish the diagnostic value of lung ultrasound (LUS) in patients with rheumatoid arthritis (RA) for the detection of interstitial lung disease (ILD).

METHODS

A cross-sectional study was performed. Consecutive patients with RA (American College of Rheumatology/European League Against Rheumatism 2010 criteria) who had a chest high-resolution computed tomography (HRCT) performed within 12 months before inclusion, regardless of symptomatology, were included. Demographic, clinical, laboratory, and pharmacological data were recorded. Each patient underwent a LUS with assessment of B-lines (BL) and pleural irregularities (PI). HRCT was considered the gold standard for the confirmatory diagnosis of ILD. Receiver operating characteristic (ROC) curves were calculated to test the ability of LUS findings (BL and PI) in discriminating patients with ILD.

RESULTS

A total of 104 RA patients were included, of which 21.8% had ILD. Patients with ILD had more BL (median 26 versus 1, p<0.001) and PI (median 16 versus 5, p<0.001) than patients without ILD. The diagnostic accuracy in ROC curves was: area under the curve (AUC) 0.88 and 95% confidence interval (CI) 0.78-0.93 for BL and AUC 0.82 and 95% CI 0.74-0.89 for PI. The best cut-off points for (ILD detection) discriminating the presence of significant interstitial lung abnormalities were 8 BL and 7 PI.

CONCLUSIONS

The presence of 8 BL and/or 7 PI in the LUS showed an adequate cut-off value for discriminating the presence of significant interstitial lung abnormalities, evocative of ILD.

The Therapeutic Efficacy of Abatacept for Rheumatoid Arthritis-Associated Interstitial Lung Disease: Insights from a 12-Month Trial Using Semi-Quantitative Chest High-Resolution Computed Tomography Imaging

Background: Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a major complication of rheumatoid arthritis (RA), but effective treatment remains an unmet need in its management. Our aim was to evaluate the therapeutic efficacy of abatacept for RA-ILD. Methods: This observational retrospective study included patients with RA-ILD treated with abatacept between 2012 and 2021. Indices of RA disease activity and interstitial lung disease (Disease Activity Score in 28 joints using C-reactive Protein [DAS28-CRP], Simplified Disease Activity Index [SDAI], Clinical Disease Activity Index [CDAI], serum Krebs von den Lungen-6 levels, % forced vital capacity [%FVC], and semi-quantified chest high-resolution computed tomography scores) were evaluated before and 1 year after the start of abatacept administration. Results: Overall, 38 patients were included. DAS28-CRP, SDAI, and CDAI were significantly improved (all with p < 0.0001). Total ground-glass opacity scores were decreased in both patients with usual interstitial pneumonia (UIP)-like patterns and with non-UIP-like patterns (p = 0.008 and <0.002, respectively). Total fibrosis scores were also decreased in the UIP-like pattern group (p < 0.042). The %FVC remained stable. Conclusions: Abatacept significantly improves RA disease activity and reduces pulmonary inflammation in patients with RA-ILD.

Therapeutic single-cell landscape: methotrexate exacerbates interstitial lung disease by compromising the stemness of alveolar epithelial cells under systemic inflammation

BACKGROUND

Interstitial lung disease (ILD) poses a serious threat in patients with rheumatoid arthritis (RA). However, the impact of cornerstone drugs, including methotrexate (MTX) and TNF inhibitor, on RA-associated ILD (RA-ILD) remains controversial.

METHODS

Using an SKG mouse model and single-cell transcriptomics, we investigated the effects of MTX and TNF blockade on ILD.

FINDINGS

Our study revealed that MTX exacerbates pulmonary inflammation by promoting immune cell infiltration, Th17 activation, and fibrosis. In contrast, TNF inhibitor ameliorates these features and inhibits ILD progression. Analysis of data from a human RA-ILD cohort revealed that patients with ILD progression had persistently higher systemic inflammation than those without progression, particularly among the subgroup undergoing MTX treatment.

INTERPRETATION

These findings highlight the need for personalized therapeutic approaches in RA-ILD, given the divergent outcomes of MTX and TNF inhibitor.

FUNDING

This work was funded by GENINUS Inc., and the National Research Foundation of Korea, and Seoul National University Hospital.

[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.

Subcutaneous vs intravenous abatacept in rheumatoid arthritis-interstitial lung disease. National multicentre study of 397 patients

BACKGROUND

Evidence on abatacept (ABA) utility for rheumatoid arthritis (RA) - associated interstitial lung disease (ILD) is growing. Clinical trials have shown equivalence in subcutaneous (SC) and intravenous (IV) administration of ABA for articular manifestations. However, this has not been studied in respiratory outcomes.

OBJECTIVE

To compare the effectiveness of ABA in RA-ILD patients according to the route of administration.

METHODS

National retrospective multicentre study of RA-ILD patients on treatment with ABA. They were divided into 2 groups: a) IV, and b) SC. The following outcomes were analysed from baseline to final follow-up using linear mixed models: a) forced vital capacity (FVC), b) diffusing capacity of the lungs for carbon monoxide (DLCO), c) chest high resolution computed tomography (HRCT), d) dyspnoea, e) RA activity, and f) sparing corticosteroids effect.

RESULTS

A total of 397 patients were included (94 IV-ABA and 303 SC-ABA), median follow-up of 24 [10-48] months. After adjustment for possible confounders, FVC and DLCO remained stable during the first 24 months without differences between IV-ABA and SC-ABA (p = 0.6304 and 0.5337). Improvement/ stability of lung lesions in HRCT was observed in 67 % of patients (75 % IV-ABA, 64 % SC-ABA; p = 0.07). Dyspnoea stabilized/ improved in 84 % of patients (90 % IV-ABA, 82 % SC-ABA; p = 0.09). RA - disease activity improved in both groups. No statistically significant differences regarding any of the variables studied between the two groups were found. ABA was withdrawn in 87 patients (21.9 %), 45 % IV-ABA and 37 % SC-ABA (p = 0.29). ILD worsening and articular inefficacy were the most common reasons for ABA discontinuation.

CONCLUSION

In patients with RA-ILD, ABA seems to be equally effective regardless of the route of administration.

Distinct mucosal endotypes as initiators and drivers of rheumatoid arthritis

Rheumatoid arthritis (RA) is a potentially devastating autoimmune disease. The great majority of patients with RA are seropositive for anti-citrullinated protein antibodies (ACPAs), rheumatoid factors, or other autoantibodies. The onset of clinically apparent inflammatory arthritis meeting classification criteria (clinical RA) is preceded by ACPA seropositivity for an average of 3-5 years, a period that is designated as 'at-risk' of RA for ACPA-positive individuals who do not display signs of arthritis, or 'pre-RA' for individuals who are known to have progressed to developing clinical RA. Prior studies of individuals at-risk of RA have associated pulmonary mucosal inflammation with local production of ACPAs and rheumatoid factors, leading to development of the 'mucosal origins hypothesis'. Recent work now suggests the presence of multiple distinct mucosal site-specific mechanisms that drive RA evolution. Indicatively, subsets of individuals at-risk of RA and patients with RA harbour a faecal bacterial strain that has exhibited arthritogenic activity in animal models and that favours T helper 17 (TH17) cell responses in patients. Periodontal inflammation and oral microbiota have also been suggested to promote the development of arthritis through breaches in the mucosal barrier. Herein, we argue that mucosal sites and their associated microbial strains can contribute to RA evolution via distinct pathogenic mechanisms, which can be considered causal mucosal endotypes. Future therapies instituted for prevention in the at-risk period, or, perhaps, during clinical RA as therapeutics for active arthritis, will possibly have to address these individual mechanisms as part of precision medicine approaches.

Impact of Sex, Serostatus, and Smoking on Risk for Rheumatoid Arthritis-Associated Interstitial Lung Disease Subtypes

OBJECTIVE

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) includes multiple subtypes with varying histopathology, prognosis, and potential treatments. Limited research has investigated risk factors for different RA-ILD subtypes. Therefore, we examined demographic, serologic, and lifestyle associations with RA-ILD subtypes.

METHODS

We systematically identified RA-ILD cases and RA controls without ILD (RA-noILD) in the Brigham RA Sequential Study and Mass General Brigham Biobank RA cohort. We determined RA-ILD subtype (usual interstitial pneumonia [UIP], nonspecific interstitial pneumonia [NSIP], and other/indeterminate) through chest high-resolution computed tomography imaging pattern. We investigated associations of demographic, lifestyle, and serologic factors with major RA-ILD subtypes using multivariable logistic regression.

RESULTS

Among 3,328 patients with RA, we identified 208 RA-ILD cases and 547 RA-noILD controls. RA-UIP was associated with older age (odds ratio [OR] 1.03 per year, 95% confidence interval [95% CI] 1.01-1.05), male sex (OR 2.15, 95% CI 1.33-3.48), and seropositivity (OR 2.08, 95% CI 1.24-3.48), whereas RA-NSIP was significantly associated only with seropositive status (OR 3.21, 95% CI 1.36-7.56). Nonfibrotic ILDs were significantly associated with smoking (OR 2.81, 95% CI 1.52-5.21). Having three RA-ILD risk factors (male, seropositive, smoking) had an OR of 6.89 (95% CI 2.41-19.7) for RA-UIP compared with having no RA-ILD risk factors.

CONCLUSION

Older age, seropositivity, and male sex were strongly associated with RA-UIP, whereas RA-related autoantibodies were associated with RA-NSIP. These findings suggest RA-ILD sex differences may be driven by RA-UIP and emphasize the importance of further studies to clarify RA-ILD heterogeneity and optimize screening and treatment approaches.

Association between flavonoid intake and rheumatoid arthritis among US adults

Basic research shows that flavonoids have anti-inflammatory effects that influence rheumatoid arthritis (RA) in rats. Investigating potential dietary interventions for RA helps prevent the onset and progression of the disease. Clinical evidence on the association of flavonoid and subclass intake with RA is lacking. Using three survey cycles of 2007-2008, 2009-2010, and 2017-2018 from the National Health and Nutrition Survey and the United States Department of Agriculture's Food and Nutrient Database for Dietary Studies (FNDDS), we analyzed 7,419 American adults (≥20 years old). The values of flavonoid and subclass intake were calculated using FNDDS. The status questions for self-reported RA were from the NHANES codebook. Weighted analyses, revealed that among the 7,419 participants included in this study (mean age of 44.69 years [standard error, 0.40] and 3,584 [48.31%] were female), 408 met the classification criteria for RA. According to the multivariable logistic regression model, compared with the risk of RA in the first quartile (Q1), the risks of RA in the second quartile (Q2), the third quartile (Q3) and the fourth quartile (Q4) were lower (Q2: OR=0.55, 95% CI: 0.38-0.80; Q3: OR=0.66, 95% CI: 0.44-0.97; Q4: OR=0.64, 95% CI: 0.46-0.89; trend: P=.03). The association between total flavonoids and RA remained significant after full consideration of confounding factors. With regard to the subclasses of flavonoids, high flavanones intake was associated with low RA prevalence in Model 3 (Q3: OR= 0.60, 95% CI:0.39-0.92; Q4: OR = 0.56, 95% CI: 0.32-0.99, trend: P=.02), but no such association was found in the other subclasses. Total flavonoids intake protected against RA, and the risk of developing RA decreased significantly with increasing intake of total flavonoids. Total flavonoids and flavanones were significantly associated with reduced RA risk for the American adult population. We highlighted the importance of employing diverse methodologies to assess the health effects of flavonoids.

Identification and Quantification of Precursory Changes of Rheumatoid Vasculitis in the Dorsalis Pedis Artery

OBJECTIVE

Rheumatoid arthritis (RA) is a systemic connective tissue autoimmune disease that can infiltrate arterial walls. The delay in diagnosis and treatment of rheumatoid vasculitis (RV) in patients with RA may lead to irreversible damage to the arterial walls of small-to-medium vessels, which has serious and devastating consequences, most notably lung and cardiac damage. In this work an ultrasound image-based biomarker was developed to detect precursory changes in RV.

METHODS

The ground truth was initiated from a medical diagnosis of RA, with arterial wall thickening of the proximal dorsalis pedis artery (DPA) indicating precursory changes of RV identified with ultrasound scanning. Ultrasound images of the DPA from 49 healthy subjects in the control group and 46 patients in the RA group were obtained. In total, 187 texture features were extracted from the images, followed by principal component analysis and linear discriminant analysis.

RESULTS

The proposed biomarker detected a significant difference between the two groups (p = 5.74 × 10-18) with an area under the receiver operating characteristic curve of 0.85. Ten major textural features contributing most heavily to the biomarker were identified, with these textures being consistent with clinical observations of RV identified in previous studies. Interscan reproducibility was assessed by computing the biomarker twice based on repeated scans of each ankle. High interscan reproducibility was demonstrated by a strong and significant Pearson's coefficient (r = 0.85, p < 0.01) between the two repeated measurements of the proposed biomarker.

CONCLUSION

The proposed biomarker can discriminate image textural differences seen in images acquired from RA patients, demonstrating precursory changes in RV compared with healthy controls. The major discriminative features identified in this study may facilitate the early identification and treatment of RV.

A Systematic Review of the Key Predictors of Progression and Mortality of Rheumatoid Arthritis-Associated Interstitial Lung Disease

BACKGROUND

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is an important extra-articular manifestation of rheumatoid arthritis (RA). Identifying patients at risk of progression and death is crucial for improving RA-ILD management and outcomes. This paper explores current evidence on prognostic factors in RA-ILD.

METHODS

We conducted a systematic literature review to examine the impact of clinical, radiological, and histological factors on lung function decline and the survival of RA-ILD patients. We searched electronic databases, including Medline and EMBASE, from inception to date. The incidence and prognosis of predictors were qualitatively analyzed, and univariate results were combined when feasible. Following the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)" guidelines, our systematic literature review involved a five-step algorithm. Out of 2217 records, 48 studies were eligible. These studies reported various prognostic factors, including demographic variables, clinical risk factors, serum markers, and preexisting treatments.

RESULTS

Lung function declined over time in 1225 subjects, with significant variability in smoking history and radiological/pathological UIP patterns. Severe lung fibrosis and abnormal pulmonary function tests (PFTs) were key univariate prognostic indicators, while age at initial presentation, RA disease activity, predicted DLCO percentage, and UIP pattern were the most reliable multivariate risk factors for ILD progression. Age, male gender, disease duration, RA activity, acute phase reactants, and specific serum biomarkers (Krebs vin den Lungen 6, surfactant protein D, and interleukin 6) were significantly associated with all-cause mortality.

CONCLUSIONS

RA-ILD is a severe complication of RA characterized by significant prognostic variability. Key prognostic factors include extensive fibrosis observed on imaging, a marked decline in lung function, high RA disease activity, and specific biomarkers. These factors can guide treatment strategies and improve patient outcomes.

Exploring rheumatoid arthritis associated interstitial lung disease a retrospective study from two Saudi tertiary care centers

BACKGROUND

Interstitial lung disease (ILD) is an increasingly recognized complication of rheumatoid arthritis (RA) and is associated with significant morbidity and mortality. Many risk factors for RA-related ILD were reported. The current study aims to explore the features and risk factors of Saudi patients with RA-ILD.

METHODS

This is a multicenter, retrospective, observational study of patients with RA-ILD. Clinical and radiological data from patients with RA-ILD were obtained from electronic medical records, including demographics, clinical characteristics, laboratory tests, pulmonary function tests, ECHO, and HRCT images.

RESULT

Out of 732 patients, 57 had RA-ILD. The mean age at the time of ILD diagnosis was 61.9 (± 12.2) years. RA-ILD diagnosis was significantly less among females (p = 0.008). Patients who ever smoked had significantly more RA-ILD (p < 0.001). Patients with RA-ILD were more likely to present with medical comorbidities, namely diabetes (p < 0.001), hypertension (p < 0.001), ischemic heart disease (p < 0.001), and osteoarthritis (p = 0.030). The multivariate analysis revealed that the age (OR: 1.035, 95% CI: 48.45-52.86, p = 0.0001); gender (OR: 2.581, CI: 1.77-1.86, p = 0.001), DM (OR: 2.498, 95% Cl: 1.65-1.76, P = 0.0001), HTN (OR: 1.975, 95% Cl: 1.61-1.74, P = 0.019), IHD (OR: 6.043, 95% Cl: 1.89-1.93, P = 0.0001) have a significant positive association with RA-ILD. No significant differences were observed between seropositive parameters with or without RA-ILD (p > 0.05). The most common symptoms of RA-ILD were cough (55.6%) and dyspnea (30.2%), and the most common ILD pattern was Non-specific Interstitial Pneumonia (NSIP) (55.6%) followed by Usual Interstitial Pneumonia (UIP) (38.9%). Traction bronchiectasis (75.5%) and glass ground opacities (73.6%) were also observed. The mean FVC and DLCO at baseline were 64.6% and 53.3%, respectively.

CONCLUSION

In this cohort of patients, Saudi RA-ILD patients had a predominant NSIP pattern conversely to what is seen globally. These findings could be explained by the lower rates of smoking in our patient population. Future prospective national studies are needed to confirm the current findings and better evaluate RA-ILD epidemiology and risk factors.

A Systematic Review on Biomarkers: Are There Reliable Molecular Biomarkers in Patients With Rheumatoid Arthritis-Associated Interstitial Lung Disease?

Despite advances in the study of rheumatoid arthritis-associated interstitial lung disease (RA-ILD), the pulmonary manifestation remains an important cause of morbidity and mortality. However, there is a lack of biochemical markers for this manifestation in the literature. Therefore, the objective of this study was to carry out a qualitative systematic review on biochemical markers associated with RA-ILD in the PubMed, Web of Science, Embase, Cochrane Library, and Virtual Health Library (VHL) between January 2015 and July 2024, using the following descriptors: #1 "biomarkers" (MeSH) AND #2 "rheumatoid arthritis" (MeSH) AND #3 "Lung Diseases, Interstitial" (MeSH). Of the 1497 articles found, 27 presented eligibility criteria. The findings were divided into three sessions: "Main biomarkers for RA-ILD," "Other biomarkers for RA-ILD activity," and "Other biomarkers for RA-ILD prognosis." Among the evaluated markers, KL-6, RF, ACPA, ESR, and CRP appear to have prognostic value and association with damage in patients with RA-ILD. The association of some molecules such as sPD-1, sCD25, VCAM-1, MCP-1, and ADMA with tissue damage is intriguing. Longitudinal and randomized studies are imperative to comprehensively delineate the history of RA-ILD and evaluate potential serum biomarkers.

A nomogram model combining computed tomography-based radiomics and Krebs von den Lungen-6 for identifying low-risk rheumatoid arthritis-associated interstitial lung disease

Objectives

Quantitatively assess the severity and predict the mortality of interstitial lung disease (ILD) associated with Rheumatoid arthritis (RA) was a challenge for clinicians. This study aimed to construct a radiomics nomogram based on chest computed tomography (CT) imaging by using the ILD-GAP (gender, age, and pulmonary physiology) index system for clinical management.

Methods

Chest CT images of patients with RA-ILD were retrospectively analyzed and staged using the ILD-GAP index system. The balanced dataset was then divided into training and testing cohorts at a 7:3 ratio. A clinical factor model was created using demographic and serum analysis data, and a radiomics signature was developed from radiomics features extracted from the CT images. Combined with the radiomics signature and independent clinical factors, a nomogram model was established based on the Rad-score and clinical factors. The model capabilities were measured by operating characteristic curves, calibration curves and decision curves analyses.

Results

A total of 177 patients were divided into two groups (Group I, n = 107; Group II, n = 63). Krebs von den Lungen-6, and nineteen radiomics features were used to build the nomogram, which showed favorable calibration and discrimination in the training cohort [AUC, 0.948 (95% CI: 0.910-0.986)] and the testing validation cohort [AUC, 0.923 (95% CI: 0.853-0.993)]. Decision curve analysis demonstrated that the nomogram performed well in terms of clinical usefulness.

Conclusion

The CT-based radiomics nomogram model achieved favorable efficacy in predicting low-risk RA-ILD patients.

Serum YKL-40 and Serum Krebs von den Lungen-6 as Potential Predictive Biomarkers for Rheumatoid Arthritis-Associated Interstitial Lung Disease

BACKGROUND

Interstitial lung disease (ILD) is a common pulmonary manifestation of rheumatoid arthritis (RA) and is associated with a poor prognosis. However, the role of blood biomarkers in RA-associated interstitial lung disease (RA-ILD) is ill-defined. We aim to evaluate the role of YKL-40 and Krebs von den Lungen-6 (KL-6) in the diagnosis and severity evaluation of RA-ILD.

METHODS

45 RA-non-ILD patients and 38 RA-ILD patients were included. The clinical data and the levels of YKL-40 and KL-6 were measured and collected for all patients. The risk factors for RA-ILD were analyzed and their correlation with relevant indicators and predictive value for RA-ILD was explored.

RESULTS

The levels of YKL-40 and KL-6 in RA-ILD patients were higher than RA-non-ILD patients (p < .001). Both YKL-40 and KL-6 were correlated with the incidence of RA-ILD. The predictive power of combined KL-6 and YKL-40 for the presence of ILD was 0.789, with a sensitivity and specificity at 73.7% and 73.3%, respectively. In RA-ILD patients, both YKL-40 and KL-6 were positively correlated with the Scleroderma Lung Study (SLS) I score and negatively correlated with pulmonary function.

CONCLUSIONS

KL-6 and YKL-40 might be a useful biomarker in the diagnosis and severity evaluation of RA-ILD.

Rheumatoid arthritis extra-articular lung disease: new insights on pathogenesis and experimental drugs

INTRODUCTION

Pulmonary involvement is one of the most common extra-articular manifestations of rheumatoid arthritis (RA), a systemic inflammatory disease characterized by joint swelling and tenderness. All lung compartments can be interested in the course of RA, including parenchyma, airways, and, more rarely, pleura and vasculature.

AREAS COVERED

The aim of this paper is to review the main RA lung manifestations, focusing on pathogenesis, clinical and therapeutic issues of RA-related interstitial lung disease (ILD). Despite an increasing number of studies in the last years, pathogenesis of RA-ILD remains largely debated and the treatment of RA patients with lung involvement is still challenging in these patients.

EXPERT OPINION

Management of RA-ILD is largely based on expert-opinion. Due to the broad clinical manifestations, including both joints and pulmonary involvement, multidisciplinary discussion, including rheumatologist and pulmonologist, is essential, not only for diagnosis, but also to evaluate the best therapeutic approach and follow-up. In fact, the coexistence of different lung manifestations may influence the treatment response and safety. The identification of biomarkers and risk-factors for an early identification of RA patients at risk of developing ILD remains a need that still needs to be fulfilled, and that will require further investigation in the next years.

Galangin: A Promising Flavonoid for the Treatment of Rheumatoid Arthritis-Mechanisms, Evidence, and Therapeutic Potential

Rheumatoid Arthritis (RA) is a chronic autoimmune disease characterized by progressive joint inflammation and damage. Oxidative stress plays a critical role in the onset and progression of RA, significantly contributing to the disease's symptoms. The complex nature of RA and the role of oxidative stress make it particularly challenging to treat effectively. This article presents a comprehensive review of RA's development, progression, and the emergence of novel treatments, introducing Galangin (GAL), a natural flavonoid compound sourced from various plants, as a promising candidate. The bioactive properties of GAL, including its anti-inflammatory, antioxidant, and immunomodulatory effects, are discussed in detail. The review elucidates GAL's mechanisms of action, focusing on its interactions with key targets such as inflammatory cytokines (e.g., TNF-α, IL-6), enzymes (e.g., SOD, MMPs), and signaling pathways (e.g., NF-κB, MAPK), which impact inflammatory responses, immune cell activation, and joint damage. The review also addresses the lack of comprehensive understanding of potential treatment options for RA, particularly in relation to the role of GAL as a therapeutic candidate. It highlights the need for further research and clinical studies to ascertain the effectiveness of GAL in RA treatment and to elucidate its mechanisms of action. Overall, this review provides valuable insights into the potential of GAL as a therapeutic option for RA, shedding light on its multifaceted pharmacological properties and mechanisms of action, while suggesting avenues for future research and clinical applications.

The interplay between rheumatic diseases and pulmonary health

Patients with rheumatic diseases (RDs) are prone to a number of comorbidities, particularly those affecting the respiratory system due to inflammatory and autoimmune mechanisms. Rheumatoid arthritis (RA), systemic sclerosis (SSc), and inflammatory idiopathic myopathies (IIMs) often present with progressive interstitial lung disease (ILD). The prevalence of ILD varies among patients with RDs, with 11% in RA, 47% in SSc, and 41% in IIMs. Some diagnostic markers, including KL-6, cytokines TNF-α and IL-6, and autoantibodies (anti-CCP), play a crucial role in assessing and predicting the course of pulmonary involvement in RDs. Lung fibrosis is a progressive disorder in SSc and RA, limiting the effiency of therapeutic interventions. Re-evaluating treatment approaches with disease-modifying anti-rheumatic drugs (DMARDs) is crucial for understanding their impact on the risk of lung affections. Despite initial concerns surrounding methotrexate, recent evidence points to its benefits in RA-associated interstitial lung disease (RA-ILD). Recognizing the intricate relationship between autoimmune RDs and lung affections is crucial for formulating effective treatment strategies. Emphasis is placed on collaborative efforts of rheumatologists and pulmonologists for early diagnosis, comprehensive care, and optimal patient outcomes in RA-ILD.

The enchanting canvas of CAR technology: Unveiling its wonders in non-neoplastic diseases

Chimeric antigen receptor (CAR) T cells have made a groundbreaking advancement in personalized immunotherapy and achieved widespread success in hematological malignancies. As CAR technology continues to evolve, numerous studies have unveiled its potential far beyond the realm of oncology. This review focuses on the current applications of CAR-based cellular platforms in non-neoplastic indications, such as autoimmune, infectious, fibrotic, and cellular senescence-associated diseases. Furthermore, we delve into the utilization of CARs in non-T cell populations such as natural killer (NK) cells and macrophages, highlighting their therapeutic potential in non-neoplastic conditions and offering the potential for targeted, personalized therapies to improve patient outcomes and enhanced quality of life.

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.

Pulmonary Hypertension in Connective Tissue Diseases Other than Systemic Sclerosis

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

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.

Bone and Joint-on-Chip Platforms: Construction Strategies and Applications

Organ-on-a-chip, also known as "tissue chip," is an advanced platform based on microfluidic systems for constructing miniature organ models in vitro. They can replicate the complex physiological and pathological responses of human organs. In recent years, the development of bone and joint-on-chip platforms aims to simulate the complex physiological and pathological processes occurring in human bones and joints, including cell-cell interactions, the interplay of various biochemical factors, the effects of mechanical stimuli, and the intricate connections between multiple organs. In the future, bone and joint-on-chip platforms will integrate the advantages of multiple disciplines, bringing more possibilities for exploring disease mechanisms, drug screening, and personalized medicine. This review explores the construction and application of Organ-on-a-chip technology in bone and joint disease research, proposes a modular construction concept, and discusses the new opportunities and future challenges in the construction and application of bone and joint-on-chip platforms.

Genetic evidence reveals a causal relationship between rheumatoid arthritis and interstitial lung disease

Background/purpose: Previous epidemiological studies have associated interstitial lung disease (ILD) with rheumatoid arthritis (RA), yet the causality of this relationship remains uncertain. This study aimed to investigate the genetic causal link between ILD and RA. Methods: Genome-wide association study (GWAS) statistics for ILD and RA were collected from public datasets. Relevant single-nucleotide polymorphisms (SNPs) were selected by executing quality control steps from the GWAS summary results. A two-sample bidirectional Mendelian randomization (MR) analysis was performed to assess the causal relationship between the two conditions. The MR analysis primarily used the inverse variance weighting (IVW), weighted median (WM), and MR-Egger regression methods. Sensitivity analyses, including MR-Egger, leave-one-out, and MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO), were conducted to evaluate the heterogeneity and pleiotropy. Replication analyses using Asian datasets were also conducted to enhance the robustness of our findings. Results: In the European population, RA was found to increase the risk of ILD by 9.6% (OR: 1.096, 95% CI: 1.023-1.174, p = 0.009). Conversely, ILD was associated with a 12.8% increased risk of RA (OR: 1.128, 95% CI: 1.013-1.256, p = 0.029). Replication analyses from Asian GWAS further supported these findings, particularly the increased risk of ILD attributable to RA (OR: 1.33, 95% CI: 1.18-1.49, p-value <0.001). Conclusion: Our findings underscore the clinical importance of screening for ILD in RA patients and suggest that effective management of RA could significantly benefit ILD patients. The potential applicability of novel RA treatments to ILD warrants further exploration. Additionally, racial disparities in the manifestation of these diseases should not be overlooked, as they may offer new perspectives for targeted therapies in diverse populations.

Resveratrol attenuates inflammation and fibrosis in rheumatoid arthritis-associated interstitial lung disease via the AKT/TMEM175 pathway

BACKGROUND AND PURPOSE

Interstitial lung disease (ILD) represents a significant complication of rheumatoid arthritis (RA) that lacks effective treatment options. This study aimed to investigate the intrinsic mechanism by which resveratrol attenuates rheumatoid arthritis complicated with interstitial lung disease through the AKT/TMEM175 pathway.

METHODS

We established an arthritis model by combining chicken type II collagen and complete Freund's adjuvant. Resveratrol treatment was administered via tube feeding for 10 days. Pathological changes in both the joints and lungs were evaluated using HE and Masson staining techniques. Protein expression of TGF-β1, AKT, and TMEM175 was examined in lung tissue. MRC-5 cells were stimulated using IL-1β in combination with TGF-β1 as an in vitro model of RA-ILD, and agonists of AKT, metabolic inhibitors, and SiRNA of TMEM175 were used to explore the regulation and mechanism of action of resveratrol RA-ILD.

RESULTS

Resveratrol mitigates fibrosis in rheumatoid arthritis-associated interstitial lung disease and reduces oxidative stress and inflammation in RA-ILD. Furthermore, resveratrol restored cellular autophagy. When combined with the in vitro model, it was further demonstrated that resveratrol could suppress TGF-β1 expression, and reduce AKT metamorphic activation, consequently inhibiting the opening of AKT/MEM175 ion channels. This, in turn, lowers lysosomal pH and enhances the fusion of autophagosomes with lysosomes, ultimately ameliorating the progression of RA-ILD.

CONCLUSION

In this study, we demonstrated that resveratrol restores autophagic flux through the AKT/MEM175 pathway to attenuate inflammation as well as fibrosis in RA-ILD by combining in vivo and in vitro experiments. It further provides a theoretical basis for the selection of therapeutic targets for RA-ILD.

A validation of register-derived diagnoses of interstitial lung disease in patients with inflammatory arthritis: data from the NOR-DMARD study

OBJECTIVE

There is a lack of knowledge concerning the validity of the interstitial lung disease (ILD) diagnoses used in epidemiological studies on rheumatic diseases. This paper seeks to verify register-derived ILD diagnoses using chest computed tomography (CT) and medical records as a gold standard.

METHOD

The Norwegian Anti-Rheumatic Drug Register (NOR-DMARD) is a multicentre prospective observational study of patients with inflammatory arthritis who start treatment with disease-modifying anti-rheumatic drugs. NOR-DMARD is linked to the Norwegian Patient Registry (NPR) and Cause of Death Registry. We searched registers for ILD coded by ICD-10 J84 or J99 among patients with rheumatoid arthritis, psoriatic arthritis, or spondyloarthritis. We extracted chest CT reports and medical records from participating hospitals. Two expert thoracic radiologists scored examinations to confirm the ILD diagnosis. We also searched medical records to find justifications for the diagnosis following multidisciplinary evaluations. We calculated the positive predictive values (PPVs) for ILD across subsets.

RESULTS

We identified 71 cases with an ILD diagnosis. CT examinations were available in 65/71 patients (91.5%), of whom ILD was confirmed on CT in 29/65 (44.6%). In a further 10 patients, medical records confirmed the diagnosis, giving a total of 39/71 verified cases. The PPV of a register-derived ILD diagnosis was thus 54.9%. In a subset of patients who had received an ILD code at two or more time-points and had a CT scan taken within a relevant period, the PPV was 72.2%.

CONCLUSION

The validity of register-based diagnoses of ILD must be carefully considered in epidemiological studies.

Sirtuins and Cellular Senescence in Patients with Idiopathic Pulmonary Fibrosis and Systemic Autoimmune Disorders

The sirtuin family is a heterogeneous group of proteins that play a critical role in many cellular activities. Several degenerative diseases have recently been linked to aberrant sirtuin expression and activity because of the involvement of sirtuins in maintaining cell longevity and their putative antiaging function. Idiopathic pulmonary fibrosis and progressive pulmonary fibrosis associated with systemic autoimmune disorders are severe diseases characterized by premature and accelerated exhaustion and failure of alveolar type II cells combined with aberrant activation of fibroblast proliferative pathways leading to dramatic destruction of lung architecture. The mechanisms underlying alveolar type II cell exhaustion in these disorders are not fully understood. In this review, we have focused on the role of sirtuins in the pathogenesis of idiopathic and secondary pulmonary fibrosis and their potential as biomarkers in the diagnosis and management of fibrotic interstitial lung diseases.

Serum netrin-1 levels are high in Rheumatoid arthritis associated interstitial lung disease

BACKGROUND

Recent data show that netrin-1 has a role in development of pulmonary fibrosis. This study was aimed to investigate serum netrin-1 level and its relation to interstitial lung disease(ILD) in patients with rheumatoid arthritis (RA).

METHOD

42 RA patients with RA-ILD, 58 RA patients without RA-ILD (RA non-ILD group), and 61 healthy volunteers were included in this study. The modified DAS28-ESR score was used to calculate disease activity in RA patients. Using the quantitative immunoassay method, Serum netrin-1 levels were measured with an ELISA kit (Catalog number: E-EL-H2328; lab science, lot number: GZWTKZ5SWK, Texas, USA).

RESULTS

The median value of netrin-1 was found to be significantly higher in the RA-ILD group (82.9 [59.9-124]) compared to both the RA non-ILD group(52.9 [49.5-73.1])(B = -0.006, OR = 0.994, CI 95 %=0.989-0.999, P = 0.018) and the control group(53.5 [49.5-87.5]) (B: -0.005, OR: 0.994, CI 95 %: 0.990-0.999, p: 0.022). A cut-off value of 61.78 for netrin-1 was found to have a sensitivity of 73.8 % and a specificity of 69 % for the diagnosis of RA-ILD (AUC [95 %Cl] = 0.771 [0.679-0.862], p < 0.0001).It was found that high serum netrin-1 level was strongly associated with the RA-usual interstitial pneumonia(UIP) pattern and poorly related to the RA-nonspecific interstitial pneumonia(NSIP) pattern compared to the RA non-ILD group.

CONCLUSIONS

Netrin-1 is elevated in the serum of patients with RA-ILD, especially in the UIP pattern. Netrin-1 may be a potential candidate for predicting the development of RA-ILD that should be investigated in the pathophysiological and therapeutic fields..

Standardized 3D-CT lung volumes for patients with acute exacerbation of rheumatoid arthritis-associated interstitial lung disease

OBJECTIVES

Fibrotic interstitial lung disease (ILD) is a progressive lung disease characterized by loss of lung volume, resulting in a leading cause of death in patients with RA. Crucially, acute exacerbation (AE) of ILD shows higher morbidity and mortality with rapid deterioration of the lungs. However, a quantitative assessment for physiological changes at AE has yet to be performed. This study hypothesized that quantitative assessments of lung volume (LV) accurately indicate disease severity and mortality risk in patients with AE-RA-ILD.

METHODS

This multicentre cohorts study quantitatively assessed physiological changes of RA-ILD at diagnosis (n = 54), at AE (discovery-cohorts; n = 20, and validation-cohort; n = 33), and controls (n = 35) using 3D CT (3D-CT) images. LV was quantitatively measured using 3D-CT and standardized by predicted forced vital capacity.

RESULTS

Patients with RA-ILD at diagnosis showed decreased LV, predominantly in lower lobes, compared with controls. Further substantial volume loss was found in upper- and lower lobes at AE compared with those at diagnosis. During AE, decreased standardized 3D-CT LV was associated with a worse prognosis in both cohorts. Subsequently, standardized 3D-CT LV was identified as a significant prognostic factor independent of age, sex and the presence of UIP pattern on CT by multivariate analyses. Notably, a composite model of age and standardized 3D-CT LV successfully classified mortality risk in patients with AE-RA-ILD.

CONCLUSION

Volume loss at AE in patients with RA-ILD was associated with increased mortality. Assessing physiological change using standardized 3D-CT might help evaluate disease severity and mortality risk in patients with AE-RA-ILD.

Clinical characteristics and outcome of lung cancer in patients with fibrosing interstitial lung disease

BACKGROUND

Lung cancer (LC) is an important comorbidity of interstitial lung disease (ILD) and has a poor prognosis. The clinical characteristics and outcome of each ILD subtype in LC patients have not been sufficiently investigated. Therefore, this study aimed to evaluate the difference between idiopathic pulmonary fibrosis (IPF) and non-IPF ILD as well as prognostic factors in patients with ILD-LC.

METHODS

The medical records of 163 patients diagnosed with ILD-LC at Asan Medical Center from January 2018 to May 2023 were retrospectively reviewed. Baseline characteristics and clinical outcomes were compared between the IPF-LC and non-IPF ILD-LC groups, and prognostic factors were analyzed using the Cox proportional-hazard model.

RESULTS

The median follow-up period was 11 months after the cancer diagnosis. No statistically significant differences were observed in clinical characteristics and mortality rates (median survival: 26 vs. 20 months, p = 0.530) between the groups. The independent prognostic factors in patients with ILD-LC were higher level of Krebs von den Lungen-6 (≥ 1000 U/mL, hazard ratio [HR] 1.970, 95% confidence interval [CI] 1.026-3.783, p = 0.025) and advanced clinical stage of LC (compared with stage I, HR 3.876 for stage II, p = 0.025, HR 5.092 for stage III, p = 0.002, and HR 5.626 for stage IV, p = 0.002). In terms of treatment, surgery was the significant factor for survival (HR 0.235; 95% CI 0.106-0.520; p < 0.001).

CONCLUSIONS

No survival difference was observed between IPF-LC and non-IPF ILD-LC patients. A higher level of Krebs von den Lungen-6 may act as a prognostic marker in ILD-LC patients.

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.

Impact of combined pulmonary fibrosis and emphysema on lung cancer risk and mortality in rheumatoid arthritis: A multicenter retrospective cohort study

OBJECTIVE

Combined pulmonary fibrosis and emphysema (CPFE) is a syndrome characterized by the coexistence of emphysema and fibrotic interstitial lung disease (ILD). The aim of this study was to examine the effect of CPFE on lung cancer risk and lung cancer-related mortality in patients with rheumatoid arthritis (RA).

METHODS

We conducted a multicenter retrospective cohort study of patients newly diagnosed with lung cancer at five community hospitals between June 2006 and December 2021. Patients were followed until lung cancer-related death, other-cause death, loss to follow-up, or the end of the study. We used the cumulative incidence function with Gray's test and Fine-Gray regression analysis for survival analysis.

RESULTS

A total of 563 patients with biopsy-proven lung cancer were included (82 RA patients and 481 non-RA patients). The prevalence of CPFE was higher in RA patients than in non-RA patients (40.2% vs.10.0%) at lung cancer diagnosis. During follow-up, the crude incidence rate of lung cancer-related death was 0.29 and 0.10 per patient-year (PY) in RA and non-RA patients, and 0.32 and 0.07 per PY in patients with CPFE and patients without ILD or emphysema, respectively. The estimated death probability at 5 years differed between RA and non-RA patients (66% vs. 32%, p<0.001) and between patients with CPFE and patients without ILD or emphysema (71% vs. 24%, p<0.001). In addition to clinical cancer stage and no surgery within 1 month, RA and CPFE were identified as independent predictive factors for increased lung cancer-related mortality (RA: adjusted hazard ratio [HR], 2.49; 95% confidence interval [CI], 1.65-4.76; CPFE: adjusted HR 2.01; 95% CI 1.24-3.23).

CONCLUSIONS

RA patients with lung cancer had a higher prevalence of CPFE and increased cancer-related mortality compared with non-RA patients. Close monitoring and optimal treatment strategies tailored to RA patients with CPFE are important to improve the poor prognosis of lung cancer.

Interstitial Lung Disease in Rheumatoid Arthritis: A Review

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder. Although the joints are typically the first area affected in RA, it can also involve extra-articular regions. This article provides an overview on rheumatoid arthritis-associated interstitial lung disease (RA-ILD), a component of the disease manifestations leading to significant morbidity and mortality. Managing these pulmonary symptoms in people with RA poses a number of difficulties for medical professionals. In this review article, we shed light on the prevalence of RA-ILD and the common pulmonary manifestations of RA, while focusing on the evolving pathogenesis concepts that link them to RA's autoimmune cascade. We also address the diagnostic challenges and the available screening modalities that aid in the early recognition and effective management of these pulmonary complications. Furthermore, glucocorticoids, disease-modifying antirheumatic medications, immunosuppressive medications, and biological agents are among the pharmacological approaches that have been explored in this review study.

Prevalence and clinical characteristics of patients with rheumatoid arthritis with interstitial lung disease using unstructured healthcare data and machine learning

OBJECTIVES

Real-world data regarding rheumatoid arthritis (RA) and its association with interstitial lung disease (ILD) is still scarce. This study aimed to estimate the prevalence of RA and ILD in patients with RA (RAILD) in Spain, and to compare clinical characteristics of patients with RA with and without ILD using natural language processing (NLP) on electronic health records (EHR).

METHODS

Observational case-control, retrospective and multicentre study based on the secondary use of unstructured clinical data from patients with adult RA and RAILD from nine hospitals between 2014 and 2019. NLP was used to extract unstructured clinical information from EHR and standardise it into a SNOMED-CT terminology. Prevalence of RA and RAILD were calculated, and a descriptive analysis was performed. Characteristics between patients with RAILD and RA patients without ILD (RAnonILD) were compared.

RESULTS

From a source population of 3 176 165 patients and 64 241 683 EHRs, 13 958 patients with RA were identified. Of those, 5.1% patients additionally had ILD (RAILD). The overall age-adjusted prevalence of RA and RAILD were 0.53% and 0.02%, respectively. The most common ILD subtype was usual interstitial pneumonia (29.3%). When comparing RAILD versus RAnonILD patients, RAILD patients were older and had more comorbidities, notably concerning infections (33.6% vs 16.5%, p<0.001), malignancies (15.9% vs 8.5%, p<0.001) and cardiovascular disease (25.8% vs 13.9%, p<0.001) than RAnonILD. RAILD patients also had higher inflammatory burden reflected in more pharmacological prescriptions and higher inflammatory parameters and presented a higher in-hospital mortality with a higher risk of death (HR 2.32; 95% CI 1.59 to 2.81, p<0.001).

CONCLUSIONS

We found an estimated age-adjusted prevalence of RA and RAILD by analysing real-world data through NLP. RAILD patients were more vulnerable at the time of inclusion with higher comorbidity and inflammatory burden than RAnonILD, which correlated with higher mortality.

Expansion of distinct peripheral blood myeloid cell subpopulations in patients with rheumatoid arthritis-associated interstitial lung disease

OBJECTIVES

Interstitial lung disease (ILD) is associated with significant mortality in rheumatoid arthritis (RA) patients with key cellular players remaining largely unknown. This study aimed to characterize inflammatory and myeloid derived suppressor cell (MDSC) subpopulations in RA-ILD as compared to RA, idiopathic pulmonary fibrosis (IPF) without autoimmunity, and controls.

METHODS

Peripheral blood was collected from patients with RA, RA-ILD, IPF, and controls (N = 60, 15/cohort). Myeloid cell subpopulations were identified phenotypically by flow cytometry using the following markers:CD45,CD3,CD19,CD56,CD11b,HLA-DR,CD14,CD16,CD15,CD125,CD33. Functionality of subsets were identified with intracellular arginase-1 (Arg-1) and inducible nitric oxide synthase (iNOS) expression.

RESULTS

There was increased intermediate (CD14++CD16+) and nonclassical (CD14+/-CD16++) and decreased classical (CD14++CD16-) monocytes in RA, RA-ILD, and IPF vs. control. Intermediate monocytes were higher and classical monocytes were lower in RA-ILD vs. RA but not IPF. Monocytic (m)MDSCs were higher in RA-ILD vs. control and RA but not IPF. Granulocytic (g)MDSCs did not significantly differ. In contrast, neutrophils were increased in IPF and RA-ILD patients with elevated expression of Arg-1 sharing similar dimensional clustering pattern. Eosinophils were increased in RA-ILD vs. controls, RA and IPF. Across cohorts, iNOS was decreased in intermediate/nonclassical monocytes but increased in mMDSCs vs. classical monocytes. In RA-ILD, iNOS positive mMDSCs were increased versus classic monocytes.

CONCLUSIONS

Myeloid cell subpopulations are significantly modulated in RA-ILD patients with expansion of CD16+ monocytes, mMDSCs, and neutrophils, a phenotypic profile more aligned with IPF than other RA patients. Eosinophil expansion was unique to RA-ILD, potentially facilitating disease pathogenesis and providing a future therapeutic target.

Global research trends in DNA methylation in rheumatoid arthritis: A bibliometric analysis and visual analysis

Rheumatoid arthritis (RA) is a prevalent autoimmune disorder with a significant global economic burden. Epigenetic modifications, particularly DNA methylation, play a crucial role in RA. This study conducted a bibliometric analysis to explore the evolving trends and predominant themes in RA and DNA methylation research over the past two decades. A total of 1800 articles met the inclusion criteria, and the analysis revealed consistent growth in the literature, with a notable increase in output after 2019. The research involved 70 countries, 2139 academic institutions, 23,365 unique authors, and 58,636 co-cited authors. The United States emerged as a dominant contributor in this research domain. The significance of DNA methylation in shaping research directions for RA management is increasingly evident. Recent investigations have shed light on the pivotal role of DNA methylation in RA, particularly in characterizing synovial tissue and exploring the underlying mechanisms of disease pathogenesis. This study provides valuable insights into the landscape of DNA methylation research in RA and highlights the importance of epigenetics in autoimmune diseases.

The NLRP3 Inflammasome as a Pathogenic Player Showing Therapeutic Potential in Rheumatoid Arthritis and Its Comorbidities: A Narrative Review

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterized by chronic synovitis and the progressive destruction of cartilage and bone. RA is commonly accompanied by extra-articular comorbidities. The pathogenesis of RA and its comorbidities is complex and not completely elucidated. The assembly of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activates caspase-1, which induces the maturation of interleukin (IL)-1β and IL-18 and leads to the cleavage of gasdermin D with promoting pyroptosis. Accumulative evidence indicates the pathogenic role of NLRP3 inflammasome signaling in RA and its comorbidities, including atherosclerotic cardiovascular disease, osteoporosis, and interstitial lung diseases. Although the available therapeutic agents are effective for RA treatment, their high cost and increased infection rate are causes for concern. Recent evidence revealed the components of the NLRP3 inflammasome as potential therapeutic targets in RA and its comorbidities. In this review, we searched the MEDLINE database using the PubMed interface and reviewed English-language literature on the NLRP3 inflammasome in RA and its comorbidities from 2000 to 2023. The current evidence reveals that the NLRP3 inflammasome contributes to the pathogenesis of RA and its comorbidities. Consequently, the components of the NLRP3 inflammasome signaling pathway represent promising therapeutic targets, and ongoing research might lead to the development of new, effective treatments for RA and its comorbidities.

Predictors of fibrogenesis in children with JIA: a single-center pilot study

BACKGROUND

Patients with rheumatological diseases are at high risk of developing irreversible fibrotic changes, both articular and extra-articular, as a result of tissue damage caused by the chronic phase of persistent inflammation. Thus, our purpose was to study early markers of fibrosis formation in children with juvenile idiopathic arthritis (JIA).

METHODS

Seventy patients with juvenile idiopathic arthritis, namely, polyarthritis (64.29%) and oligoarthritis (35.71%) variant JIA (mean age 13.3 years, 64.29% girls, 35.71% boys), were included in this 4-year prospective study. Basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) levels were determined by ELISA kits.

RESULTS

We evaluated bFGF (mean: 7478.21 pg/ml; min: 4171.56 pg/ml; max: 18,011.25 pg/ml) and VEGF (mean: 342.47 pg/ml; min: 23.68 pg/ml; max: 2158.91 pg/ml) levels in children with JIA. Children with JIA had a higher VEGF level when JIA onset occurred after 15 years of age and they had a high disease activity; additionally, a higher bFGF level was observed in children older than 14 years and in those with a JIA onset after 15 years of age, the oligoarticular variant, a moderate disease activity and regardless of MTX administration but more often when MTX was administered at a dosage from 10 to 12.5 mg/m2/week.

CONCLUSIONS

Laboratory screening of fibrosis formation predictors could help identify patients who may be at greater risk of adverse outcomes. Children with JIA had higher bFGF and VEGF levels when JIA onset occurred after 15 years of age, depending on disease activity.

A case report of extra-articular manifestation of rheumatoid arthritis: Rheumatoid nodules in lungs

Rheumatoid arthritis is a systemic inflammatory disorder primarily affecting joints but not limited to the joints alone. Extra-articular manifestations involve skin, ocular, gastrointestinal, pulmonary, cardiac, renal, neurological, and hematological systems. Among them, skin manifestations (20%) are most common, presenting as nodules on the extensor surfaces of the upper and lower extremities. In rare cases these nodules can also be detected within the heart and lungs. Interestingly, rheumatoid nodules are often seen in patients on leflunomide, methotrexate, or tumor necrosis factor-alpha antagonists. Nevertheless, definitive diagnosis requires a histopathological analysis. In this case report, we presented a 49-year-old male patient with a relatively short period of disease activity leading to rheumatoid nodules in the lungs. Considering the ongoing COVID-19 pandemic and that tuberculosis was still endemic in Kazakhstan, achieving the definite diagnosis was challenging. Initial imaging study revealed bilateral polysegmental pneumonia. The tests for COVID-19 and pulmonary tuberculosis were negative. A follow-up chest computed tomography scan had signs of disseminated lung lesions of unknown origin. Lung biopsy showed a morphological picture of productive granulomas characteristic for tuberculosis. However, at the second look, typical scarring granulomas typically seen in rheumatoid nodules were observed.

Therapeutic Approaches for the Treatment of Interstitial Lung Disease: An Exploratory Review on Molecular Mechanisms

BACKGROUND

Interstitial Lung Diseases (ILDs) are characterized by shortness of breath caused by alveolar wall inflammation and/or fibrosis.

OBJECTIVE

Our review aims to study the depth of various variants of ILD, diagnostic procedures, pathophysiology, molecular dysfunction and regulation, subject and objective assessment techniques, pharmacological intervention, exercise training and various modes of delivery for rehabilitation.

METHOD

Articles are reviewed from PubMed and Scopus and search engines.

RESULTS

ILD is a rapidly progressing disease with a high mortality rate. Each variant has its own set of causal agents and expression patterns. Patients often find it challenging to self-manage due to persistent symptoms and a rapid rate of worsening. The present review elaborated on the pathophysiology, risk factors, molecular mechanisms, diagnostics, and therapeutic approaches for ILD will guide future requirements in the quest for innovative and tailored ILD therapies at the molecular and cellular levels.

CONCLUSION

The review highlights the rationale for conventional and novel therapeutic approaches for better management of ILD.

Association between combined exposure to dioxins and arthritis among US adults: a cross-sectional study

Dioxins and dioxin-like compounds (DLCs) are common pollutants hazardous to human health. We applied 12 dioxins and DLCs data of 1851 participants (including 484 arthritis patients) from National Health Examination Survey (NHANES) 2001-2004 and quadrupled them into rank variables. Multivariate logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models were used to explore the relationship between individual or mixed exposure to the pollutants and arthritis after adjusting for multiple covariates. In multivariable logistic regression with an individual dioxin or DLC, almost every chemical was significantly positively associated with arthritis, except PCB66 (polychlorinated biphenyl 66) and 1,2,3,4,6,7,8-heptachlorodibenzofuran (hpcdf). The WQS model indicated that the combined exposure to the 12 dioxins and DLCs was positively linked to arthritis (OR: 1.884, 95% CI: 1.514-2.346), with PCB156 (weighted 0.281) making the greatest contribution. A positive trend between combined exposure and arthritis was observed in the BKMR model, with a posterior inclusion probability (PIP) of 0.987 for PCB156, which was also higher than the other contaminants.

Survival differences in rheumatoid arthritis interstitial lung disease and idiopathic pulmonary fibrosis may be explained by delays in presentation: results from multivariate analysis in a monocentric UK study

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) has a better prognosis compared to idiopathic pulmonary fibrosis (IPF). Recent data suggest that antifibrotics are effective in slowing progression across both groups. Hence, we designed this study to investigate the similarities and differences between these groups of patients. This is a retrospective cohort study examining baseline data, progression and outcomes in patients with RA-ILD and IPF prior to antifibrotic use in the Coventry ILD database. Ethics approval was obtained from the University Hospital Coventry and Warwickshire NHS Trust. Statistical analysis was performed using R software and Cox's proportional hazards technique was used for survival analysis. We identified 131 cases, including 49 patients with IPF, 34 patients with RA-ILD and 48 patients with other forms of idiopathic interstitial pneumonia. At baseline, there were significant differences in the groups with RA-ILD patients being significantly younger (65.7 vs 72.4 years), had preserved lung volumes (FVC 95% vs 84.7%) and higher gas transfer (61.5% vs 48.2%) compared to IPF patients. 5-year survival was better for RA-ILD compared to IPF (87.5% vs 40.4%, p = 0.0042). Univariate analysis revealed gas transfer, FVC, age, sex and phenotype (IPF or RA-ILD) were all significant predictors, but multivariate analysis revealed that gas transfer and age were both significantly associated with prognosis, whereas sex, FVC or phenotype were not significant. This study suggests that the difference between RA-ILD and IPF prognosis may be due to demographics and early diagnosis rather than the diseases behaving differently. This has important management implications.

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.