Rheumatoid Arthritis-associated Interstitial Lung Disease Patients Research Articles

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.

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.

Antifibrotic Agents in Rheumatoid Arthritis-Associated Interstitial Lung Disease: A Systematic Review and Meta-Analysis.

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a common extra-articular clinical manifestation of rheumatoid arthritis (RA) that has negative impacts on morbidity and mortality. In addition, there has been no proven treatment for RA-ILD to date. Thus, we planned a meta-analysis of a literature search to confirm the clinical effects of antifibrotic agents in RA-ILD patients. We conducted the literature search in Ovid MEDLIVE® databases, Cochrane Library databases, EMBASE, and KoreaMed and identified references elucidating the role of nintedanib or pirfenidone in adult patients with RA-ILD. Among the identified studies, those with comparative interventions, complete results of clinical trials, and available full text were included in the analysis. The primary outcome was the effect of the antifibrotic agent on disease progression in RA-ILD patients assessed with a mean difference in the change of forced vital capacity (FVC) and the proportion of patients with an increase in percent predicted FVC of 10% or more over 52 weeks. Analysis for heterogeneity was assessed through I2 statistics. Meta-analysis with a fixed effect model was performed on changes in FVC. A total of 153 articles were identified through database searches, of which 28 were excluded because of duplication. After additional screening, 109 studies were selected with full text and two articles qualified for analysis according to the set inclusion and exclusion criteria. As a result, two randomized controlled studies were selected, comparing nintedanib and pirfenidone to placebo, respectively. The meta-analysis revealed that antifibrotic agents showed a significant reduction in FVC decline compared to placebo in patients with RA-ILD (mean difference, 88.30; 95% CI, 37.10-139.50). Additionally, there were significantly fewer patients experienced an increase in percent predicted FVC of 10% or more in the antifibrotic agent group compared to the placebo group (Odds ratio 0.42; 95% CI 0.19-0.95, p = 0.04). There was no significant heterogeneity between the two included studies (χ2 = 0.35, p = 0.0007, I2 = 0%). The meta-analysis suggests that nintedanib and pirfenidone may have clinical utility in reducing disease progression in patients with RA-ILD. Further research is needed to confirm the clinical benefits of antifibrotic agents in RA-ILD.

Association of family sequence similarity gene 13A gene polymorphism and interstitial lung disease susceptibility: A systematic review and meta-analysis.

Among present reports, the T/G allelic variation at the rs2609255 locus of the family sequence similarity gene 13A (FAM13A) was considerable associated with susceptibility to interstitial lung diseases (ILDs). In this study, we summarized relevant studies and applied a meta-analysis to explore whether the polymorphism of rs2609255 site of the FAM13A gene can be utilized to predict susceptibility to idiopathic pulmonary fibrosis (IPF) patients or rheumatoid arthritis-associated interstitial lung disease (RA-ILD) or silicosis patients in different populations for the first time. We compared the frequency of G allele on rs2609255 site of FAM13A between the control subjects and IPF or RA-ILD or silicosis patients from different races by using meta-analysis. Nine studies were involved in this meta-analysis, including five IPF studies, two RA-ILD studies, and two silicosis studies, and containing 14 subgroups. We conducted separate meta-analyses for different races. In all individuals, a substantial link between the G allele of the FAM13A rs2609255 polymorphism and IPF (OR: 1.47, 95% CI: 1.33-1.63, p < 0.00001) was indicated. After dividing by ethnicity, the G allele was illustrated to be considerable correlation with IPF in Asian (OR: 2.63, 95% CI: 1.81-3.81, p < 0.00001) and with RA-ILD individuals (OR: 3.27, 95% CI: 1.26-8.49, p = 0.01). Conversely, there was no correlation with the G allele and IPF in European individuals (OR: 1.27, 95% CI: 0.89-1.83, p = 0.13) or silicosis in Chinese individuals (OR: 1.20, 95% CI: 0.99-1.46, p = 0.07). This is the first meta-analysis that provides evidence that the rs2609255 of FAM13A might increase susceptibility to RA-ILD, and IPF especially in Asian but not in European individuals, and not be correlated with silicosis in Chinese individuals, which indicated the differences in susceptibility to disease by race were noteworthy.

Progression of radiographic fibrosis in rheumatoid arthritis-associated interstitial lung disease.

Preclinical interstitial lung disease (pILD) may represent the early stages of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). However, the characteristics, clinical outcomes, and risk factors associated with fibrosis progression in RA-ILD, including pILD and ILD, remain poorly understood. Baseline data were compared between patients with RA-ILD and those with RA alone. Multivariate logistic regression and Cox regression analyses were performed to identify risk factors associated with the prevalence and imaging progression of RA-ILD, respectively. Among the 371 enrolled RA patients, 32.3% had RA-ILD. Multiple logistic regression analyses identified age over 60.0 years (OR 2.22), smoking (OR 2.09), diabetes mellitus (DM) (OR 3.09), mixed connective tissue disease (MCTD) (OR 2.98), serum lactate dehydrogenase (LDH) levels exceeding 250.0 U/L (OR 6.73), and positive anti-cyclic citrullinated peptide (anti-CCP) antibody (OR 2.06) as independent risk factors for RA-ILD (p< 0.05 or 0.01). Among the 98 RA-ILD patients who underwent follow-up for a median duration of 19.1 months, 51.0% demonstrated fibrotic progression on high-resolution computed tomography (HRCT). Multiple Cox regression analysis identified DM (HR 2.03), Disease Activity Score in 28 joints-Erythrocyte Sedimentation Rate (DAS28-ESR) greater than 5.1 (HR 2.21), and baseline HRCT scores exceeding 5.0 (HR 2.30) as independent risk factors for fibrosis progression in RA-ILD (p< 0.05 or 0.01). Nearly one-third of RA patients in this cohort had prevalent pILD or ILD, and half of them demonstrated imaging progression during follow-up. DM, higher DAS28-ESR, and advanced HRCT scores were identified as independent risk factors for progressive fibrosis in RA-ILD.

Abatacept in usual and in non-specific interstitial pneumonia associated with rheumatoid arthritis

ObjectiveTo compare the effectiveness of abatacept (ABA) in Rheumatoid Arthritis-associated Interstitial Lung Disease (RA-ILD) according to the radiological patterns of usual (UIP) or non-specific interstitial pneumonia (NSIP). MethodsFrom an observational longitudinal multicentre study of 263 RA-ILD patients treated with ABA, those with UIP or NSIP were selected. Lung function, chest high resolution computerised tomography (HRCT) and dyspnoea were recorded and compared in both groups from baseline to the end of follow-up (progression definitions: improvement or worsening >10% of FVC or DLCO, changes in HRCT extension and 1-point change in the mMRC scale, respectively). Differences between final and baseline visits were calculated as the average difference (95% CI) through mixed effects models regression. ResultsWe studied 190 patients with UIP (n=106) and NSIP (n=84). General features were similar in both groups except for older age, positive rheumatoid factor, and previous sulfasalazine therapy, which were more frequent in patients with UIP. ILD duration up to ABA initiation was relatively short: median 16 [4-50] and 11 [2-36] months (p=0.36) in UIP and NSIP, respectively. Mean baseline FVC and DLCO were 82% and 63% in UIP and 89% and 65% in NSIP, respectively. Both parameters remained stable during 24 months with ABA. HRCT lesions and dyspnoea improved/stabilized in 73.1% and 90.5% and 72.9% and 94.6% of UIP and NSIP patterns, respectively. ConclusionABA seems equally effective in stabilizing dyspnoea, lung function and radiological impairment in both UIP and NSIP patterns of RA-ILD. Early administration of ABA may prevent RA-ILD progression, regardless of the radiological pattern.

Clinical features of acute exacerbation in rheumatoid arthritis–associated interstitial lung disease: Comparison with idiopathic pulmonary fibrosis

BackgroundSeveral studies have reported that acute exacerbation (AE), which occurs during the clinical course of idiopathic pulmonary fibrosis (IPF), also occurs in rheumatoid arthritis–associated interstitial lung disease (RA-ILD). However, the incidence, clinical features, and risk factors for AE, a major cause of death of RA-ILD patients, and the differences in clinical aspects of AE between RA-ILD and IPF have yet to be fully understood. MethodsWe retrospectively reviewed data on 149 RA-ILD patients and 305 IPF patients. We investigated the frequency of AE and compared the clinical data between RA-ILD with and without AE to clarify the risk factor for AE. We also compared the post-AE prognosis and cause of death between RA-ILD and IPF patients. ResultsTwenty-seven (18.1%) RA-ILD patients and 84 (27.5%) IPF patients developed AE. The median survival time (MST) after AE of RA-ILD and IPF was 277 days and 60 days, respectively (log rank, p = 0.038). In a multivariate analysis, hypoalbuminemia [odds ratio (O.R.) 0.090 (95%CI 0.011–0.733), p = 0.012] and % carbon monoxide diffusion capacity (%DLCO) [O.R. 0.810 (95%CI 0.814–0.964), p < 0.01] were independent risk factors for AE. AE was the most frequent cause of death of RA-ILD and IPF. ConclusionRA-ILD patients could develop AE, and AE was not uncommon in RA-ILD or IPF. %DLCO and hypoalbuminemia were predictive factors of AE in RA-ILD. The prognosis after AE of RA-ILD was significantly better than that of IPF. The most frequent cause of death in RA-ILD and IPF was AE.

Risk factors for the progression of rheumatoid arthritis-related interstitial lung disease: Clinical features, biomarkers, and treatment options

ObjectivesThe clinical heterogeneity of the progression of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is high, and there is a lack of consensus on the clinical relevance and medical protocols. The purpose of this study is to explore the impact of clinical characteristics, new biomarkers and treatment options on the prognosis of RA-ILD patients and to explore whether these factors can predict the progression and death of these patients. MethodsWe retrospectively collected case data on RA-ILD patients who visited or were admitted to Changhai Hospital between October 2010 and September 2021. We followed up and finally included 75 patients. The main outcome indicator of disease progression was pulmonary functional impairment, which was assessed by changes of high-resolution computed tomography (HRCT) score or pulmonary function test before and after treatment. The demographics, clinical characteristics, laboratory tests, and treatment plans of RA-ILD patients in the progressive and stable groups were compared and analyzed. Clinically relevant variables were identified, and the incidence of pulmonary dysfunction and adverse events was recorded. Cox regression analysis was used to determine factors related to the progression of ILD. ResultsThe mean age of RA-ILD onset was 64.0 years (SD 10.3), and 53 (70.7%) patients were female. Thirty-two (42.7%) patients had lung dysfunction, who were classified as the progressive group, and 13 (40.6%) of them died. In univariate analyses, male, smoking, high HRCT scores at baseline, RF-IgA>200 RU/ml, diffusing capacity of the lungs for carbon monoxide (DLCO), and usual interstitial pneumonia (UIP) pattern were significant risk factors for disease progression; while use of Leflunomide (LEF) was associated with better prognosis. The multivariate analysis revealed that RF-IgA>200 RU/ml (hazard ratio [HR] 3.17 [95% confidence interval (CI) 1.29, 7.81], P = 0.012), UIP pattern (HR 3.94 [95% CI 1.68, 9.26], P = 0.002), and male (HR 2.52 [95% CI 1.16, 5.46], P = 0.019) were significantly correlated with unfavorable outcomes in patients with RA-ILD. LEF (HR 0.25 [95% CI 0.10, 0.61], P = 0.002) was related to a better prognosis. However, it might be related to investigating medications changes after baseline. ConclusionOur data suggests that male, UIP pattern, and increased RF-IgA may be potential predicting factors for poor prognosis of RA-ILD patients. We report a significant association between high titer of RF-IgA at baseline and RA-ILD progression for the first time, which might be a potentially important biomarker for the prognosis of RA-ILD.

Acute exacerbation of rheumatoid arthritis-associated interstitial lung disease: mortality and its prediction model

BackgroundPatients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD), like those with idiopathic pulmonary fibrosis (IPF), might develop an unexpected acute exacerbation (AE)—a rapidly progressing and deadly respiratory decline. Although AE incidence and risk factors in RA-ILD patients are known, their post-AE clinical course remains unknown owing to the rarity of AE-RA-ILD. This multicentre retrospective study evaluated post-AE mortality and prognostic variables in AE-RA-ILD patients and created a mortality prediction model for AE-RA-ILD.MethodsThis research comprised 58 patients with AE-RA-ILD and 96 with AE-IPF (a control disease). Multivariate Cox regression analysis was performed to identify prognostic variables. A prediction model was created with recursive partitioning (decision tree).ResultsThe post-AE 90-day mortality rate in the overall AE-RA-ILD group was 48.3%; percent predicted forced vital capacity within 12 months before AE onset (baseline %FVC) and PaO2/FiO2 ratio at AE onset (P/F at AE) were independent predictors of mortality. Post-AE 90-day mortality rates were 40.6% and 43.8%, respectively, in AE-RA-ILD and AE-IPF patients propensity score-matched for age, sex, baseline %FVC and P/F at AE (P = 1.0000). In AE-RA-ILD patients, C-indices of baseline %FVC and P/F at AE to predict post-AE 90-day mortality were 0.604 and 0.623, respectively. A decision tree model based on these prognostic factors classified AE-RA-ILD patients into mild, moderate and severe groups (post-AE 90-day mortality rates: 20.8%, 64.0% and 88.9%, respectively; P = 0.0002); the C-index improved to 0.775.ConclusionsPost-AE mortality was high in AE-RA-ILD patients similar to AE-IPF patients. The discovered prognostic factors and our mortality prediction model may aid in the management of AE-RA-ILD patients.

Annual variation rate of KL-6 for predicting acute exacerbation in patients with rheumatoid arthritis-associated interstitial lung disease

Objectives This study evaluated the prognostic factors for acute exacerbation (AE), including sequential changes in Krebs von den Lungen-6 (KL-6) levels, in rheumatoid arthritis-associated interstitial lung disease (RA-ILD) patients. Methods This was a retrospective observational study. We reviewed 125 patients diagnosed with RA-ILD between 2010 and 2019. We defined ΔKL-6 as the annual variation rate of KL-6 one visit before AE onset (or the last visit). The Cox regression analysis was used for evaluating significant variables associated with AE. We analysed the overall survival and respiratory-related death-free survival. Results Thirty-three patients (26.4%) developed AE during the observation period. The univariate analysis revealed that KL-6 levels at RA-ILD diagnosis [hazard ratio (HR), 1.11; 95% confidence interval (CI), 1.05–1.15; p < .01) and ΔKL-6 (HR: 3.69; 95% CI: −1.36 to 7.96; p = .01] were significantly associated with AE. ΔKL-6 was an independent prognostic factor for AE in the multivariate analysis (HR: 3.37; 95% CI: −1.16 to 8.87; p = .03). Patients with AE had a significantly higher overall mortality rate (p = .02) and respiratory-related mortality rate (p < .01) than those without AE. Conclusion ΔKL-6 can be a prognostic marker for detecting AE in RA-ILD patients.

Efficacy and safety of tofacitinib in rheumatoid arthritis-associated interstitial lung disease: TReasure real-life data.

Rheumatoid arthritis associated interstitial lung disease (RA-ILD) is a major concern in RA. These patients have been included in clinical trials and in the post-marketing setting of RA patients using tofacitinib. We aimed to assess the real-life efficacy and safety of tofacitinib in patients with RA-ILD. RA patients with ILD diagnosis based on the HRCT images of the lungs from eight different centres recruited to study. As a control group, RA patients without ILD under tofacitinib were included. Demographic data, patients' characteristics, available pulmonary function tests regarding RA and RA-ILD at the visit in which tofacitinib was initiated and for the last follow-up visit under tofacitinib were recorded. Reasons for tofacitinib discontinuation were also recorded. Drug retention rates were compared by log-rank test. p-value <0.05 was considered statistically significant. A total of 47(42.6% male) RA patients with RA-ILD and a control group of 387 (17.8% male) patients without RA-ILD were included in analysis. After the median of 12 (9-19) months follow-up, mean FEV1%; 82.1 vs. 82.8 (pre/post-treatment, respectively, p=0.08), mean FVC%; 79.8 vs. 82.8 (pre/post-treatment, respectively, p=0.014) were stable and worsening was observed in 2/18 (11.1%) patients. Retention rates were similar (p=0.21, log-rank). In RA-ILD group, most common cause of drug discontinuation was infections (6.3 vs. 2.4 per 100 patient-years). Treatment strategy of RA-ILD patients is still based on small observational studies. A high rate of discontinuation due to infections was observed in RA-ILD patients under tofacitinib; however, RA-ILD patients were older than RA patients without ILD.

Interstitial lung disease throughout the rheumatoid arthritis disease course.

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. 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. 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.

Prognostic role of blood KL-6 in rheumatoid arthritis-associated interstitial lung disease.

Rheumatoid arthritis–associated interstitial lung disease (RA-ILD) has a variable clinical course for which predicting prognosis is difficult. However, the role of blood biomarkers in RA-ILD is ill-defined. The aim of this study was to investigate the prognostic value of Krebs von den Lungen-6 (KL-6) levels in RA-ILD patients. The medical records of 84 patients with RA-ILD were retrospectively reviewed. Plasma KL-6 levels were measured by Nanopia KL-6 assay (SEKISUI MEDICAL, Tokyo), using latex-enhanced immunoturbidimetric assay. The median follow-up period was 61 months. Mean age was 61.4 years, 45.2% were men, 44.0% were ever-smokers, and 35.7% showed a usual interstitial pneumonia (UIP) pattern on high-resolution computed tomography. The median KL-6 level at baseline was 741.2 U/mL (interquartile range, 439.7–1308.9 U/mL). On multivariate logistic regression analysis, a high KL-6 level (≥ 640 U/mL) was an independently associated with a UIP pattern (odds ratio [OR], 5.173; P = 0.005) with old age (OR, 1.104, P = 0.005). On multivariate Cox analysis, a high KL-6 level (≥ 685 U/mL) was an independent prognostic factor for the mortality (hazard ratio [HR], 2.984; P = 0.016) with a older age (HR, 1.061; P = 0.030), male sex (HR, 3.610; P = 0.001), lower forced vital capacity (HR, 0.957; P = 0.002), and a UIP pattern (HR, 4.034; P = 0.002). Our results suggest that high KL-6 levels might be useful as a biomarker for the presence of a UIP pattern and prognosis in patients with RA-ILD.

Platelet/Lymphocyte, Lymphocyte/Monocyte, and Neutrophil/Lymphocyte Ratios as Biomarkers in Patients with Rheumatoid Arthritis and Rheumatoid Arthritis-Associated Interstitial Lung Disease.

BackgroundThe objective of this study was to assess the diagnostic value of platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), and neutrophil/lymphocyte ratio (NLR) as biomarkers in patients with rheumatoid arthritis (RA) and rheumatoid arthritis-associated interstitial lung disease (RA-ILD).Material/MethodsDemographic and laboratory data were acquired for 198 RA and 103 RA-ILD patients and 290 healthy controls. The subjects were categorized into female and male groups and further subcategorized based on age into <60 years and ≥60 years subgroups. One-way analysis of variance (ANOVA), receiver operating characteristics (ROC), Pearson analysis, multiple linear regression analysis, and logistic regression analysis were performed to analyze the association of PLR, NLR, and LMR with RA and RA-ILD.ResultsMean PLR and NLR were lowest in the control group, followed by the RA and RA-ILD groups (p<0.05). Mean LMR was lowest in the RA-ILD group, followed by the RA and control groups (p<0.05). The area under the ROC (AUROC) values of the PLR to distinguish between RA and controls, RA-ILD and controls, and RA-ILD and RA were 0.676, 0.776, and 0.650, respectively (p<0.001). Multiple linear regression analysis suggested a significantly positive association between the level of PLR and the level of DAS28 (p<0.001). The odds ratio of PLR was 1.101 for RA (p=0.023) and 1.217 for RA-ILD (p<0.001) when compared to the controls.ConclusionsPLR may be applied as a new biomarker for predicting and diagnosing RA and RA-ILD and for distinguishing RA-ILD patients from RA patients and healthy subjects.

Increased circulating Wnt5a protein in patients with rheumatoid arthritis-associated interstitial pneumonia (RA-ILD)

An early diagnosis of interstitial lung disease (ILD) is important for guiding treatments of rheumatoid arthritis (RA)-associated ILD (RA-ILD) in clinical settings. The non-canonical Wnt signaling representative ligand Wnt5a was recently found to involve in idiopathic pulmonary fibrosis (IPF) and pathogenesis of RA. The goal of this study was to examine the clinical relevance of Wnt5a in RA-ILD. In this report, the clinical relevance of plasma Wnt5a protein was evaluated in 40 RA-ILD patients and 41 non-ILD RA cohorts. The results showed an elevated Wnt5a protein in plasmas of RA-ILD patients compared with non-ILD RA patients (p < 0.01), which was positively correlated with the plasma level of rheumatoid factor (RF). Of note, more abundant Wnt5a was also found in patients with usual interstitial pneumonia (UIP) than those with nonspecific interstitial pneumonia (NSIP) and other ILD patterns. More importantly, the disease severity was correlated with the circulating Wnt5a as ascertained by high-resolution computed tomography (HRCT)-UIP scores. The multiple-factor non-conditional logistic regression analysis further revealed that the age, RA duration, smoking and plasma Wnt5a were risk factors with clinical significance for RA-ILD. Interestingly, more Wnt5a-positive patients were identified in RA-ILD smokers relative to RA-ILD never-smokers, and longer smoking duration was strongly correlated with Wnt5a in RA-ILD patients. In consistence, ROC curve also suggested that the Wnt5a was a potential candidate biomarker for identifying patients with RA-UIP. These results demonstrate that the circulating Wnt5a may be a risk factor and potential biomarker for identifying UIP and accessing the severity and progression of ILD in RA patients.

Risk factors for progression and prognosis of rheumatoid arthritis-associated interstitial lung disease: single center study with a large sample of Chinese population.

Factors associated with progression and survivals in rheumatoid arthritis-associated interstitial lung disease (RA-ILD) have not been described in a large center China cohort. Seven-hundred and ninety-one consecutive RA patients who completed lung HRCT were considered as potential participants in this retrospective cohort study. Determinants of ILD progression were identified through multivariable logistic analysis. Cox hazards analysis was used to determine significant variables associated with survival. Of 307 patients diagnosed with RA-ILD, 266 were finally included. The 3-year survival rate of RA-ILD patients was 81.24%, and the 5-year survival rate was 69.71%. A total of 82 deaths occurred during follow-up, of which 56 died of respiratory failure due to ILD progression and/or pneumonia while 14 with malignancies (8 with lung cancer). Logistic regression analysis showed that anti-CCP antibody high titer positive (OR: 4.03, 95% CI: 1.04-15.69) and DLCO% < 45% (OR: 8.31, 95% CI: 2.17-31.75) were independent risk factors for the ILD progression. Cox hazards analysis revealed that advanced age (> 60years old) of RA-ILD diagnosis (HR: 2.32, 95% CI: 1.27-4.25) and extensive lung involvement on HRCT (HR: 2.19, 95% CI: 1.24-3.87) were associated with worse survival. Treatment with cyclophosphamide (HR: 0.43, 95% CI: 0.26-0.69) was associated with better survival. In RA-ILD patients, anti-CCP antibody high titer positive and DLCO% < 45% are risk factors for ILD progression. Advanced age and extensive lung involvement on HRCT, rather than the baseline UIP pattern, independently predict mortality after controlling for potentially influential variables. Furthermore, cyclophosphamide treatment helps to improve the prognosis in real-world experience.

The serum level and significance of lysyl oxidase-like 2 in patients with rheumatoid arthritis-associated interstitial lung disease.

Our previous experiments found that lysyl oxidase-like 2 (LOXL2) may be a useful preclinical serological marker for pulmonary fibrosis in the mouse model. The role of LOXL2 in rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is still unclear. We investigated whether serum LOXL2 levels are associated with RA-ILD patients. The levels of serum LOXL2 were measured by enzyme-linked immunosorbent assay in 49 RA-ILD patients (21 patients with ILD disease duration < 3months; 28 patients with ILD disease duration > 3months), 43 RA patients without ILD and 20 normal healthy controls. We assessed the correlations between the serum LOXL2 levels and clinical variables. Serum LOXL2 levels were significantly higher in RA patients than in normal healthy controls (326.79±192.56 vs. 53.27±35.86pg/ml, P<0.01). No significant difference was present between the RA-ILD group and RA without ILD group (298.87±219.85 vs. 358.60±152.16pg/ml, P=0.13). Notably, the serum LOXL2 levels were significantly higher in patients with ILD disease duration < 3months than in those with ILD disease duration > 3months (462.71±208.97 vs. 175.99±130.55pg/ml, P<0.01) or without ILD (462.71±208.97 vs. 358.60±152.16pg/ml, P=0.03). The serum LOXL2 levels in RA-ILD patients significantly correlated with DAS28 (rs=0.31, P=0.034), C-reactive protein (rs=0.41, P=0.004), rheumatoid factor (rs=0.41, P=0.003), forced vital capacity (rs=- 0.39, P=0.02), and diffusion capacity of the lung for carbon monoxide (rs=- 0.44, P=0.009). LOXL2 may be involved in the pathogenesis of rheumatoid arthritis-associated interstitial lung disease and might be helpful in early diagnosis of RA-ILD.

Shared genetic predisposition in rheumatoid arthritis-interstitial lung disease and familial pulmonary fibrosis.

Despite its high prevalence and mortality, little is known about the pathogenesis of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). Given that familial pulmonary fibrosis (FPF) and RA-ILD frequently share the usual pattern of interstitial pneumonia and common environmental risk factors, we hypothesised that the two diseases might share additional risk factors, including FPF-linked genes. Our aim was to identify coding mutations of FPF-risk genes associated with RA-ILD.We used whole exome sequencing (WES), followed by restricted analysis of a discrete number of FPF-linked genes and performed a burden test to assess the excess number of mutations in RA-ILD patients compared to controls.Among the 101 RA-ILD patients included, 12 (11.9%) had 13 WES-identified heterozygous mutations in the TERT, RTEL1, PARN or SFTPC coding regions. The burden test, based on 81 RA-ILD patients and 1010 controls of European ancestry, revealed an excess of TERT, RTEL1, PARN or SFTPC mutations in RA-ILD patients (OR 3.17, 95% CI 1.53-6.12; p=9.45×10-4). Telomeres were shorter in RA-ILD patients with a TERT, RTEL1 or PARN mutation than in controls (p=2.87×10-2).Our results support the contribution of FPF-linked genes to RA-ILD susceptibility.

Understanding the determinants of health-related quality of life in rheumatoid arthritis-associated interstitial lung disease

RationaleHealth-related quality of life (HRQL) is impaired among patients with interstitial lung disease (ILD). Little is understood about HRQL in specific subtypes of ILD. ObjectivesThe aim of this study was to characterize and identify clinical determinants of HRQL among patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD) and compare them to patients with idiopathic pulmonary fibrosis (IPF). MethodsWe identified patients with a diagnosis of RA-ILD and IPF from an ongoing longitudinal cohort of ILD patients. HRQL was measured at their baseline visit using the Short Form Health Survey (SF-36), versions 1 and 2. Regression models were used to characterize and understand the relationship between selected baseline clinical covariates, the physical component score (PCS) and mental component score (MCS) of the SF-36. Measurements and main resultsRA-ILD patients (n = 50) were more likely to be younger and female compared to IPF patients (n = 50). After controlling for age and pulmonary function, RA-ILD patients had a lower HRQL compared to IPF patients, as measured by the PCS (P = 0.03), with significant differences in two of four PCS domains – bodily pain (P < 0.01) and general health (P = 0.01). Clinical covariates most strongly associated with a lower PCS in RA-ILD patients compared to IPF patients were the presence of joint pain or stiffness and dyspnea severity (P < 0.01). Mental and emotional health, as measured by the MCS, was similar between RA-ILD and IPF patients. ConclusionThe physical components of HRQL appear worse in RA-ILD patients compared to IPF patients as measured by the PCS of the SF-36. Differences in the PCS of the SF-36 can be explained in part by dyspnea severity and joint symptoms among patients with RA-ILD.

Are risk predicting models useful for estimating survival of patients with rheumatoid arthritis-associated interstitial lung disease?

BackgroundRisk predicting models have been applied in idiopathic pulmonary fibrosis (IPF), but still not validated in patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD). The purpose of this study was to test the suitability of three prediction models as well as individual lung function and demographic factors for evaluating the prognosis of RA-ILD patients.MethodsClinical and radiological data of 59 RA-ILD patients was re-assessed. GAP (gender, age, physiologic variables) and the modified interstitial lung disease (ILD)-GAP as well as the composite physiologic indexes (CPI) were tested for predicting mortality using the goodness-of-fit test and Cox model. Potential predictors of mortality were also sought from single lung function parameters and clinical characteristics.ResultsThe median survival was 152 and 61 months in GAP / ILD-GAP stages I and II (p = 0.017). Both GAP and ILD-GAP models accurately estimated 1-year, 2-year and 3-year mortality. CPI (p = 0.025), GAP (p = 0.008) and ILD-GAP (p = 0.028) scores, age (p = 0.002), baseline diffusion capacity to carbon monoxide (DLCO) (p = 0.014) and hospitalization due to respiratory reasons (p = 0.039), were significant predictors of mortality in the univariate analysis, whereas forced vital capacity (FVC) was not predictive. CPI score (HR 1.03, p = 0.018) and baseline DLCO (HR 0.97, p = 0.011) remained significant predictors of mortality after adjusting for age.ConclusionsGAP and ILD-GAP are applicable for evaluating the risk of death of patients with RA-ILD in a similar manner as in those with IPF. Baseline DLCO and CPI score also predicted survival.