Leflunomide Use and Risk of Lung Disease in Rheumatoid Arthritis: A Systematic Literature Review and Metaanalysis of Randomized Controlled Trials

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.

Risk factors of mortality in patients with rheumatoid arthritis-associated interstitial lung disease: a single-centre prospective cohort study

OBJECTIVES

To determine the risk factors for mortality in Korean patients with rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) in comparison to patients with RA but without ILD (RA-nonILD).

METHODS

Data were extracted from a single-centre prospective cohort of RA patients with a chest computed tomography scan at an academic referral hospital in Korea. Patients with RA-ILD enroled between May 2017 and August 2022 were selected, and those without ILD were selected as comparators. The mortality rate was calculated, and the causes of each death were investigated. We used Cox proportional hazard regression with Firth's penalised likelihood method to identify the risk factors for mortality in patients with RA-ILD.

RESULTS

A total of 615 RA patients were included: 200 with ILD and 415 without ILD. In the RA-ILD group, there were 15 deaths over 540.1 person-years (PYs), resulting in mortality rate of 2.78/100 PYs. No deaths were reported in the RA-nonILD group during the 1669.9 PYs. The primary causes of death were infection (nine cases) and lung cancer (five cases), with only one death attributed to ILD aggravation. High RA activity (adjusted HR 1.87, CI 1.16-3.10), baseline diffusing capacity for carbon monoxide (DLCO) < 60% (adjusted HR 4.88, 95% CI 1.11-45.94), and usual interstitial pneumonia (UIP) pattern (adjusted HR 5.13, 95% CI 1.00-57.36) were identified as risk factors for mortality in RA-ILD patients.

CONCLUSION

Patients with RA-ILD have an elevated risk of mortality compared with those without ILD. Infection-related deaths are the main causes of mortality in this population. High RA activity, low DLCO, and the UIP pattern are significantly associated with the mortality in patients with RA-ILD.

Janus kinase inhibitors vs. abatacept about safety and efficacy for patients with rheumatoid arthritis-associated interstitial lung disease: a retrospective nested case-control study

BACKGROUND

Interstitial lung disease (ILD) related to rheumatoid arthritis (RA) is among the leading causes of death and an essential prognostic factor. There is only limited evidence for the safety of anti-rheumatic drugs for patients with RA-ILD. The aim of this study is to investigate the safety and efficacy of Janus kinase inhibitors (JAKis) by comparing it with abatacept (ABT) in patients with RA-ILD.

METHODS

This single centre, retrospective nested case-control study enrolled patients with RA-ILD treated with JAKi or ABT. To determine the safety of the two drugs for existing ILD, we compared their drug persistency, incidence rates of pulmonary complications, and change of chest computed tomography (CT) image. For their efficacy as RA treatment, disease activity scores and prednisolone (PSL)-sparing effect were compared. We performed propensity score matching to match the groups' patient characteristics.

RESULTS

We studied 71 patients with RA-ILD (ABT, n = 45; JAKi, n = 26). At baseline, the JAKi group had longer disease duration, longer duration of past bDMARD or JAKi use and higher usual interstitial pneumonia rate. After propensity score matching, no significant differences in patient characteristics were found between the two groups. No significant difference in the drug persistency rate for the first 2 years (ABT, 61.9%; JAKi, 42.8%; P = 0.256) was observed between the two matched groups. The incidence rate of pulmonary complications did not differ significantly between the two groups (P = 0.683). The CT score did not change after the treatment for the ABT group (Ground-glass opacities (GGO): P = 0.87; fibrosis: P = 0.78), while the GGO score significantly improved for the JAKi group (P = 0.03), although the number was limited (ABT: n = 7; JAKi: n = 8). The fibrosis score of the JAKi group did not change significantly.(P = 0.82). Regarding the efficacy for RA, a significant decrease in disease activity scores after the 1-year treatment was observed in both groups, and PSL dose was successfully tapered, although no significant differences were observed between the two drugs.

CONCLUSIONS

JAKi is as safe and effective as ABT for patients with RA-ILD. JAKi can be a good treatment option for such patients.

Identification, Monitoring, and Management of Rheumatoid Arthritis-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) is a frequent complication of rheumatoid arthritis (RA) that is associated with a significant increase in mortality. Several risk factors for the development of ILD in patients with RA have been identified, but ILD can still develop in the absence of these risk factors. Screening tools for RA-ILD are required to facilitate early detection of RA-ILD. Close monitoring of patients with RA-ILD for progression is crucial to enable timely implementation of treatment strategies to improve outcomes. Patients with RA are commonly treated with immunomodulatory therapies, although their efficacy in slowing the progression of RA-ILD remains the subject of debate. Clinical trials have shown that antifibrotic therapies slow decline in lung function in patients with progressive fibrosing ILDs, including patients with RA-ILD. The management of patients with RA-ILD should be based on multidisciplinary evaluation of the severity and progression of their ILD and the activity of their articular disease. Close collaboration between rheumatologists and pulmonologists is essential to optimize patient care.

The association between CYB5A gene rs1790834 polymorphism and clinical improvement after 6 months of leflunomide treatment in women with rheumatoid arthritis

INTRODUCTION/OBJECTIVES

Rheumatoid arthritis (RA) is a disease affecting around 1% of the population in developed countries and can be treated with leflunomide. The higher prevalence of RA among women and numerous previous studies suggested the crucial role of sex hormones. Cytochrome CYB5A regulates the synthesis of androgens. Therefore, the aim of this study was to determine the association between common CYB5A gene polymorphism and the response to leflunomide in women with RA.

METHODS

This study included 111 patients. All of them received oral leflunomide monotherapy at a dose of 20 mg daily. Women were genotyped for the presence of CYB5A rs1790834 polymorphism and evaluated monthly for 6 months following the initiation of treatment.

RESULTS

After 6 months of therapy, patients with the GG genotype had higher DAS28 values and less improvement in DAS28 compared to patients with the GA and AA genotypes (p = 0.04). No statistically significant differences were found in relation to other disease activity parameters.

CONCLUSIONS

The results of the current study suggest a possible association of the CYB5A rs1790834 polymorphism with some disease activity parameters in RA patients treated with leflunomide during the initial therapy period. However, confirmation of the effect of this polymorphism on the efficacy of leflunomide treatment requires further studies. Key Points • Leflunomide is the synthetic disease-modifying anti-rheumatic drug used in the therapy of rheumatoid arthritis. • CYB5A rs1790834 gene polymorphism may influence the clinical improvement after 6 months of leflunomide treatment in women with rheumatoid arthritis.

Development and validation of HPLC method for simultaneous determination of Leflunomide and folic acid in the nanoparticulate system by reversed-phase HPLC

OBJECTIVE

The main objective of this study was to develop a highly sensitive, accurate, and reproducible analytical method for the simultaneous detection of LEF and FA in polymeric nanocarriers.

SIGNIFICANCE

Leflunomide (LEF), is widely employed in the treatment of rheumatoid arthritis (RA). However, long-term delivery of the drug is associated with systemic side effects. Therefore, folate (FA) conjugated LEF nanocarriers were fabricated for targeting the nanocarriers toward activated macrophages. HPLC is considered one of the most sensitive and precise analytical techniques for the simultaneous detection and estimation of different components in a particular sample.

METHODS

Analysis was performed on HPLC (Shimadzu 10 A), having a reversed-phase C-18 column (Beckmen, 250 X 4.6 mm, 5 µm) equipped with a photodiode detector set at a wavelength of 260 nm (LEF) and 285 nm (Folic acid). The isocratic mobile phase was composed of acetonitrile, water, and trimethylamine in a ratio of 65:35:0.5 at pH 4. Rapid analysis of both agents was performed, with a total run time of 10 min (FA = 2.1 ± 0.1 min, LEF = 5.9 ± 1 min) at a 1 mL/min flow rate.

RESULTS

The assay demonstrated good linearity of 0.9989 of 0.9997 for LEF and FA respectively with a recovery in the range of 95-100%. The method also depicted good specificity, and intra and inter-day precision based on relative standard deviation (RSD) values.

CONCLUSIONS

The study concludes, that the developed method was helpful in the detection and quantitation of lower values of both agents from polymeric nanocarriers.

Rheumatoid arthritis-associated interstitial lung disease hotspots and future directions: A Web-of-Science based scientometric and visualization study

OBJECTIVE

To identify new trends and potential hotspots in research on rheumatoid arthritis-associated interstitial lung disease (RA-ILD).

MATERIALS AND METHODS

The Web of Science (WOS) database was used to search for RA-ILD-related literature published between August 31, 2002 and August 31, 2022. CiteSpace 6.1.R3, VOSviewer version 1.6.17, Scimago Graphica, and Pajek V2.0 visualization software were used to conduct a comprehensive analysis and network visualization mapping of the authors, countries, institutions, journals, cited references, and keywords.

RESULTS

A total of 2412 articles were retrieved, and the number of articles published has grown annually since 2002. Eric L. Matteson was the most prolific author, and the Mayo Clinic and UNITED STATES have the highest publishing volume and influence. Clinical Rheumatology is the journal with the most papers published. Rheumatology was the most cited journal. The citation clusters and keywords concentrated on the mechanism, treatment, and predictive and prognostic factors.

CONCLUSION

Pathogenesis, treatment, and predictive and prognostic factors were among the RA-ILD research directions and hotspots. Antirheumatoid drugs, especially biologics and small molecule inhibitors, were among the most actively researched treatment options. The results of this study provides an in-depth understanding of the development of RA-ILD publications, aids researchers in understanding hotspots and trends and provides a new perspective for future RA-ILD research.

Interstitial lung disease in rheumatoid arthritis: A multidisciplinary problem in rheumatology and pulmonology

Rheumatoid arthritis (RA) is an immune-mediated rheumatic disease (IMRDs) characterized by chronic erosive arthritis and systemic damage to internal organs, leading to early disability and reduced life expectancy in patients. A particularly important place among the systemic manifestations of RA is occupied by interstitial lung diseases (ILD) – the most severe form of pulmonary pathology in RA, defined as RA-ILD, which is pathogenetically associated with risk factors (smoking, etc.) and autoimmune mechanisms underlying RA. RA-ILD is a subtype of RA characterized by a severe course and a poor prognosis и неблагоприятным прогнозом. The review presents new data regarding risk factors and biomarkers for RA-ILD; modern diagnostic capabilities based on the use of functional lung tests, high-resolution computed tomography, ultrasound examination of the lungs. Particular attention is paid to the efficacy and safety of pharmacotherapy, including methotrexate, biologics, JAK inhibitors, and antifibrotic therapy. An algorithm for the pharmacotherapy of RA-ILD has been proposed.

SER-SEPAR recommendations for the management of rheumatoid arthritis-related interstitial lung disease. Part 2: Treatment

OBJECTIVE

To develop multidisciplinary recommendations to improve the management of rheumatoid arthritis-related interstitial lung disease (RA-ILD).

METHODS

Clinical research questions relevant to the objective of the document were identified by a panel of rheumatologists and pneumologists selected based on their experience in the field. Systematic reviews of the available evidence were conducted, and evidence was graded according to the Scottish Intercollegiate Guidelines Network (SIGN) criteria. Specific recommendations were made.

RESULTS

Six PICO questions were selected, three of which analysed the safety and effectiveness of glucocorticoids, classical synthetic disease-modifying anti-rheumatic drugs (DMARDs) and other immunosuppressants, biological agents, targeted synthetic DMARDs, and antifibrotic therapies in the treatment of this complication. A total of 12 recommendations were formulated based on the evidence found and/or expert consensus.

CONCLUSIONS

We present the first official SER-SEPAR document with specific recommendations for RA-ILD management developed to resolve some common clinical questions, reduce clinical healthcare variability, and facilitate decision-making for patients.

Systematic review of the impact of drugs on diffuse interstitial lung disease associated with rheumatoid arthritis

OBJECTIVE

To review the available evidence on the impact of rheumatoid arthritis (RA) treatments in associated diffuse interstitial lung disease (ILD).

METHODS

Systematic review of studies evaluating the impact of pharmacological treatment in patients with RA and ILD. A bibliographic search in MEDLINE, EMBASE and Cochrane, a selection of articles and the methodological quality assessment (FLC 3.0 OSTEBA) and grading of the level of evidence (SING) of the selected articles were performed.

RESULTS

1,720 references were identified in primary search and 7 in manual or indirect. Forty-three articles were included: 7 systematic reviews, 2 randomized clinical trials, 5 cohort studies, 8 case-control studies and 21 case series. Methotrexate (MTX) and leflunomide (LEF) do not increase incidence, complications or mortality due to ILD. Although the results are not uniform, anti-TNF have often had worse outcomes in incidence, progression and mortality due to ILD than MTX, LEF, abatacept (ABA) and rituximab (RTX). The evidence found is scarce for JAK kinase and antifibrotic inhibitors, and controversial for IL-6 inhibitors.

CONCLUSIONS

There is no evidence that MTX or LEF worsens the prognosis of patients with AR-EPID. RTX and ABA seem to have better results than other biologicals, such us TNFi, often achieving stabilization and, in some cases, the improvement of ILD in patients with RA.

Safety of long-term use of four common conventional disease modifying anti-rheumatic drugs in rheumatoid arthritis

Conventional disease-modifying antirheumatic drugs (DMARDs) have been used in the management of rheumatoid arthritis for a long time. Whereas methotrexate (MTX) is the anchor drug, leflunomide, hydroxychloroquine and sulfasalazine are used along with MTX either in combination or sequentially. Together these four drugs are the most commonly used DMARDs. They are also used in combination with biological DMARDs (bDMARDs) to enhance their efficacy and MTX in particular to reduce antibodies against anti-tumour necrosis factor. Despite their widespread use, concerns regarding their safety especially when used long-term hinder their optimum use in clinical medicine. In this narrative review we have critically appraised the available literature regarding the safety of these four DMARDs when used long-term.

Leflunomide-induced interstitial pneumonitis: A rare occurrence in a case without underlying lung disease

Pneumonitis from leflunomide is uncommon due to leflunomide's relatively favorable drug profile. Leflunomide-induced pneumonitis (LEIP) is a rare condition reported mainly in Asia. We present a case of LEIP from an accidental leflunomide overdose in the setting of concomitant methotrexate use and no underlying lung disease. Our patient was treated successfully with cholestyramine and steroids. Due to its high mortality, clinicians should be aware of this condition and its treatment.

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

Rheumatoid arthritis (RA) is a systemic inflammatory disorder, with the most common extra-articular manifestation of RA being lung involvement. While essentially any of the lung compartments can be affected and manifest as interstitial lung disease (ILD), pleural effusion, cricoarytenoiditis, constrictive or follicular bronchiolitis, bronchiectasis, pulmonary vasculitis, and pulmonary hypertension, RA-ILD is a leading cause of death in patients with RA and is associated with significant morbidity and mortality. In this review, we focus on the common pulmonary manifestations of RA, RA-ILD and airway disease, and discuss evolving concepts in the pathogenesis of RA-associated pulmonary fibrosis, as well as therapeutic strategies, and have revised our previous review on the topic. A rational clinical approach for the diagnosis and management of RA-ILD, as well as an approach to patients with clinical worsening in the setting of treatment with disease-modifying agents, is included. Future directions for research and areas of unmet need in the realm of RA-associated lung disease are raised.

Rheumatoid arthritis (RA) is a systemic inflammatory disorder, with the most common extra-articular manifestation of RA being lung involvement. RA-ILD is a leading cause of death in RA patients and is associated with significant morbidity and mortality.https://bit.ly/3w6oY4i

Lack of association between CYB5A gene rs1790834 polymorphism and the response to leflunomide in women with rheumatoid arthritis

Aim

Leflunomide is a disease-modifying antirheumatic drug used in therapy for rheumatoid arthritis (RA). Previous studies indicated that oestrogens and androgens may affect the response to leflunomide in RA patients. The synthesis of androgens is regulated by cytochrome CYB5A. The aim of this study was to examine the association between the CYB5A gene rs1790834 polymorphism and the response to leflunomide in women with RA.

Methods

The study included 111 women diagnosed with RA. Leflunomide was administered in monotherapy at a dose of 20 mg/day. All patients underwent a monthly evaluation for 12 months after the initiation of treatment with leflunomide.

Results

After 12 months of therapy, the changes in individual disease activity parameters, such as: DAS28, ESR, CRP and VAS, were not statistically significantly different between rs1790834 genotypes in the Kruskal–Wallis test.

Conclusions

The results of our study suggest lack of statistically significant association between the CYB5A gene rs1790834 polymorphism and the response to leflunomide in women with RA.

Diagnostic delay of associated interstitial lung disease increases mortality in rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease whose main extra-articular organ affected is the lung, sometimes in the form of diffuse interstitial lung disease (ILD) and conditions the prognosis. A multicenter, observational, descriptive and cross-sectional study of consecutive patients diagnosed with RA-ILD. Demographic, analytical, respiratory functional and evolution characteristics were analyzed to evaluate the predictors of progression and mortality. 106 patients were included. The multivariate analysis showed that the diagnostic delay was an independent predictor of mortality (HR 1.11, CI 1.01-1.23, p = 0.035). Also, age (HR 1.33, 95% CI 1.09-1.62, p = 0.0045), DLCO (%) (HR 0.85, 95% CI 0.73-0.98, p = 0.0246), and final SatO2 (%) in the 6MWT (HR 0.62, 95% CI 0.39-0.99, p = 0.0465) were independent predictor variables of mortality, as well as GAP index (HR 4.65, 95% CI 1.59-13.54, p = 0.0051) and CPI index (HR 1.12, 95% CI 1.03-1.22, p = 0.0092). The withdrawal of MTX or LFN after ILD diagnosis was associated with disease progression in the COX analysis (HR 2.18, 95% CI 1.14-4.18, p = 0.019). This is the first study that highlights the diagnostic delay in RA-ILD is associated with an increased mortality just like happens in IPF.

Leflunomide Induces Dose-Dependent Lung Injury in Mice via Stimulating Vimentin and NLRP3 Inflammasome Production

Recently, the therapeutic importance of the anti-rheumatic drug, leflunomide, has been increased after the involvement of leflunomide in treating other autoimmune diseases and its promising role in retarding human malignancies. Few studies have focused on the safety in human or animals without clear outlining of the pathologic features on target organs. One clinical study related leflunomide with significant pulmonary complications in predisposed individuals. The current study examined the dose-dependent lung injury produced by leflunomide in healthy mice. Albino mice were allocated into four different groups. Group (1): Vehicle control group, Group (2–4): mice received leflunomide (2.5, 5 or 10 mg/kg), respectively, for 8 weeks and then lungs were dissected from the mice for histopathological examination and fibrosis evaluation (Masson’s trichrome staining and α-smooth muscle actin immunohistochemistry). Enzyme linked immunosorbent assay was used to assess the vimentin and other inflammatory factors in the lung homogenate whereas Western blot analysis was employed to assess α-smooth muscle actin, vimentin and collagen 1. Results indicated that leflunomide induced dose-dependent pulmonary injury and the high dose and increased the vimentin, inflammatory markers (NLRP3 and interlukin-1β). Histologic examination showed distorted architecture, marked inflammatory cells infiltrate and increase collagen content. The findings were supported by Western blotting and the immunohistochemical study which showed greater pulmonary α-smooth muscle actin and vimentin content. In conclusion, the current results highlighted that leflunomide produced dose-dependent pulmonary toxicities that requires further investigation of the nature of injury.

Efficacy and safety of abatacept in interstitial lung disease of rheumatoid arthritis: A systematic literature review

BACKGROUND

Interstitial lung disease (ILD) is a serious complication that represents the second leading cause of death in patients with rheumatoid arthritis (RA). Treatment of RA-ILD remains controversial. The absence of randomized clinical trials and specific ACR or EULAR therapeutic guidelines makes it difficult to establish solid therapeutic recommendations on this issue. In this scenario, real-world data is especially valuable.

OBJECTIVE

To review the literature evidence on the efficacy and safety of abatacept (ABA) for the treatment of rheumatoid arthritis (RA) with associated interstitial lung disease (ILD), given its clinical relevance and the lack of consensus on its therapeutic management.

METHODS

PUBMED and EMBASE were searched from the date of approval of ABA to the end of 2020 using a combination of RA, ILD and ABA terms following PRISMA guidelines. Identified studies were evaluated by two independent investigators.

RESULTS

Nine original studies (1 case series and 8 observational studies) were selected for inclusion in the systematic review. No randomized trial or meta-analysis were identified. The mean age of patients ranged from 61.2 to 75 years and the mean RA duration varied from 7.4 to 18 years. Subcutaneous ABA (74.5%-91%) predominated in combination with conventional synthetic DMARDs (csDMARDs) (58%-75%), and it was used as first-line biologic agent in 22.8%-64.9% of the patients. The mean course of ILD ranged from 1 to 6.7 years, being usual and nonspecific interstitial pneumonia the most frequent patterns. Improvement or stabilization of ILD imaging (76.6%-92.7%) and FVC or DLCO (>85%) was described after a mean follow-up of 17.4-47.8 months, regardless of the pattern of lung involvement, being more remarkable in patients with shorter evolution of ILD. ABA led to significantly lower ILD worsening rates than TNF inhibitors (TNFi) and was associated with a 90% reduction in the relative risk of deterioration of ILD at 24 months of follow-up compared to TNFi and csDMARDs. Combination with methotrexate may have a corticoid-sparing effect. No unexpected adverse events were identified.

CONCLUSIONS

Current evidence suggests that ABA may be a plausible alternative to treat RA patients with ILD. It would be highly desirable to develop prospective randomized controlled studies to confirm these findings.

A retrospective comparison of respiratory events with JAK inhibitors or rituximab for rheumatoid arthritis in patients with pulmonary disease

Janus kinase inhibitors (JAKi) are an exciting option for the treatment of rheumatoid arthritis (RA) but little is known about their safety and tolerability in patients with existing respiratory disorders. The objective was to compare pulmonary safety of JAKi versus rituximab in patients with concurrent interstitial lung disease (ILD) or bronchiectasis. We performed a retrospective electronic patient record review of patients with known ILD or bronchiectasis commencing JAKi or rituximab for the treatment of RA. Patients initiating treatment from January 2016 to February 2020 were included. Respiratory events (hospitalization or death from a respiratory cause) were compared using Kaplan–Meier survival analysis. We analysed patients who received JAKi (n = 28) and rituximab (n = 19) for a mean (SD) of 1.1 (0.62) and 2.14 (1) years respectively. Patients were predominantly female (68%), anti-CCP antibody positive (94%) and non-smoking (89%) with a median (IQR) percentage predicted FVC at baseline of 100% (82–115%) and percentage predicted TL_CO of 62% (54.5–68%). Respiratory events occurred in five patients treated with JAKi (18%; 5 hospitalizations, 2 deaths) and in four patients treated with rituximab (21%; 3 hospitalizations, 1 death). Respiratory event rates did not differ between groups (Cox-regression proportional hazard ratio = 1.38, 95% CI 0.36–5.28; p = 0.64). In this retrospective study, JAKi for the treatment of RA with existing ILD or bronchiectasis did not increase the rate of hospitalization or death due to respiratory causes compared to those treated with rituximab. JAK inhibition may provide a relatively safe option for RA in such patients.

Predictors of Progression and Mortality in Patients with Prevalent Rheumatoid Arthritis and Interstitial Lung Disease: A Prospective Cohort Study

OBJECTIVES

To describe a prospective cohort of patients with rheumatoid arthritis associated with interstitial lung disease (RA-ILD) and identify risk factors associated with disease progression and mortality in this cohort.

PATIENTS AND METHODS

We performed a multicenter, prospective, observational study of patients with RA-ILD receiving disease-modifying antirheumatic drugs (DMARDs) between 2015 and 2020. The patients were assessed using high-resolution computed tomography and pulmonary function tests at baseline and at 60 months. The main endpoint was "Progression to ILD at the end of follow-up" in terms of the following outcomes: (1) improvement (i.e., improvement in forced vital capacity (FVC) ≥10% or diffusing capacity of the lungs for carbon monoxide (DLCO) ≥15% and absence of radiological progression); (2) nonprogression (stabilization or improvement in FVC ≤10% or diffusing capacity of the lungs for carbon monoxide (DLCO) <15% and absence of radiological progression); (3) progression (worsening of FVC >10% or DLCO >15% and radiological progression); or (4) death. We recorded demographic and clinical characteristics, lung function, and the incidence of adverse events. A Cox regression analysis was performed to identify factors associated with the worsening of ILD.

RESULTS

After 60 months, lung disease had stabilized in 66 patients (56.9%), improved in 9 (7.8%), and worsened in 23 (19.8%). Eighteen patients (15.5%) died, with a mean survival of 71.8 (1.9) months after diagnosis of ILD. The Cox multivariate analysis revealed the independent predictors of worsening of RA-ILD to be usual interstitial pneumonia (hazard ratio (HR), 2.6 (95%CI, 1.0-6.7)), FVC <80% (HR, 3.8 (95%CI, 1.5-6.7)), anticitrullinated protein antibody titers (HR, 2.8 (95%CI, 1.1-6.8)), smoking (HR, 2.5 (95%CI, 1.1-6.2)), and treatment with abatacept, tocilizumab, or rituximab (HR, 0.4 (95%CI, 0.2-0.8)). During follow-up, 79 patients (68%) experienced an adverse event, mostly infection (61%). Infection was fatal in 10/18 patients (55.5%) during follow-up.

CONCLUSIONS

Lung function is stable in most patients with RA-ILD receiving treatment with disease-modifying anti-rheumatic drugs (DMARDs), although one-third worsened or died. Identifying factors associated with worsening in RA-ILD is important for clinical management.

Immunomodulation in Autoimmune Interstitial Lung Disease

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

Treatment of Sarcoidosis: A Multidisciplinary Approach

Sarcoidosis is a systemic disease of unknown etiology defined by the presence of noncaseating granulomatous inflammation that can cause organ damage and diminished quality of life. Treatment is indicated to protect organ function and decrease symptomatic burden. Current treatment options focus on interruption of granuloma formation and propagation. Clinical trials guiding evidence for treatment are lacking due to the rarity of disease, heterogeneous clinical course, and lack of prognostic biomarkers, all of which contribute to difficulty in clinical trial design and implementation. In this review, a multidisciplinary treatment approach is summarized, addressing immunuosuppressive drugs, managing complications of chronic granulomatous inflammation, and assessing treatment toxicity. Discovery of new therapies will depend on research into pathogenesis of antigen presentation and granulomatous inflammation. Future treatment approaches may also include personalized decisions based on pharmacogenomics and sarcoidosis phenotype, as well as patient-centered approaches to manage immunosuppression, symptom control, and treatment of comorbid conditions.

Leflunomide in the treatment of BK polyomavirus associated nephropathy in kidney transplanted patients - A systematic review

BK polyomavirus (BKPyV) associated nephropathy (BKVAN) is seen in about 5% of renal transplant patients and can lead to chronic graft failure or graft loss. No effective therapy is available. Leflunomide has shown promising results in BKVAN. We performed a systematic review about the use of leflunomide for the treatment of BKVAN. The recommendations of the Cochrane Handbook of systematic Reviews were followed. Due to different study designs and endpoints no meta-analysis was performed. The literature search for primary studies yielded 274 results. Finally, twelve studies were included with a total of 267 patients. Clearance of BKPyV viremia was reported in 33.3% to 92.3% of cases and 27 graft losses (10.1%). The included studies were very heterogeneous, especially in terms of leflunomide dosing. Pharmacokinetics seem to have an important impact on the efficacy of leflunomide in BKVAN. There was no correlation between leflunomide serum levels and virus reduction. New adverse events of leflunomide have been described, e.g. haemolytic anaemia and thrombotic microangiopathy. Overall, the risk of bias in the studies was assessed as high and the quality of evidence was rated low. The role of leflunomide in BKVAN remains unclear, but further studies seem reasonable and should address pharmacokinetic aspects.

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

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

Systematic Review of the Impact of Drugs on Diffuse Interstitial Lung Disease Associated with Rheumatoid Arthritis

OBJECTIVE

To review the available evidence on the impact of rheumatoid arthritis (RA) treatments in associated diffuse interstitial lung disease (ILD).

METHODS

Systematic review of studies evaluating the impact of pharmacological treatment in patients with RA and ILD. A bibliographic search in MEDLINE, EMBASE and Cochrane, a selection of articles and the methodological quality assessment (FLC 3.0 OSTEBA) and grading of the level of evidence (SING) of the selected articles were performed.

RESULTS

1,720 references were identified in primary search and 7 in manual or indirect. Forty-three articles were included: 7 systematic reviews, 2 randomized clinical trials, 5 cohort studies, 8 case-control studies and 21 case series. Methotrexate (MTX) and leflunomide (LEF) do not increase incidence, complications or mortality due to ILD. Although the results are not uniform, anti-TNF have often had worse outcomes in incidence, progression and mortality due to ILD than MTX, LEF, abatacept (ABA) and rituximab (RTX). The evidence found is scarce for JAK kinase and antifibrotic inhibitors, and controversial for IL-6 inhibitors.

CONCLUSIONS

There is no evidence that MTX or LEF worsens the prognosis of patients with AR-EPID. RTX and ABA seem to have better results than other biologicals, such as anti-TNF, often achieving stabilization and, in some cases, the improvement of ILD in patients with RA.

[Drug-induced interstitial lung disease: approaches to diagnostics and treatment]

Drug-induced interstitial lung disease (D-ILD) can be caused by various drugs, including antibiotics, amiodarone, antitumor, rheumatological and non-steroidal anti-inflammatory drugs. D-ILD includes hypersensitivity reactions, organizing and non-specific interstitial pneumonia, eosinophilic lung diseases, diffuse alveolar damage and alveolar hypoventilation. To exclude other causes of pulmonary diseases, an assessment of the medical history, physical data and examination results, which may include chest X-ray/multispiral computed tomography (MSCT), lung function tests, and bronchoscopy with bronchoalveolar lavage, are necessary. Diagnosis of D-ILD is difficult due to the heterogeneity of clinical, radiological and histological data. The X-ray pathological phenotype of D-ILD is different; a specific MSCT pattern has not been identified. Treatment includes drug withdrawal and, in some cases, glucocorticoid therapy, although there are no prospective studies on their effect on the outcome of the disease. This article provides various drugs that cause ILD, approaches to their diagnosis and treatment.

Treatment of Rheumatoid Arthritis-Associated Interstitial Lung Disease: Lights and Shadows

Rheumatoid arthritis (RA) is a chronic and systemic inflammatory disease affecting 0.5–1% of the population worldwide. Interstitial lung disease (ILD) is a serious pulmonary complication of RA and it is responsible for 10–20% of mortality, with a mean survival of 5–8 years. However, nowadays there are no therapeutic recommendations for the treatment of RA-ILD. Therapeutic options for RA-ILD are complicated by the possible pulmonary toxicity of many disease modifying anti-rheumatic drugs (DMARDs) and by their unclear efficacy on pulmonary disease. Therefore, joint and lung involvement should be evaluated independently of each other for treatment purposes. On the other hand, some similarities between RA-ILD and idiopathic pulmonary fibrosis and the results of the recent INBIULD trial suggest a possible future role for antifibrotic agents. From this perspective, we review the current literature describing the pulmonary effects of drugs (immunosuppressants, conventional, biological and target synthetic DMARDs and antifibrotic agents) in patients with RA and ILD. In addition, we suggest a framework for the management of RA-ILD patients and outline a research agenda to fill the gaps in knowledge about this challenging patient cohort.

The role of Chinese herbal medicine in the management of adverse drug reactions of leflunomide in treating rheumatoid arthritis

BACKGROUND

The high discontinuation rate in RA patients who use LEF might be attributed to their intolerance rather than irresponsibility. The concomitant administration of Leflunomide (LEF) with Chinese herbal medicine (CHM) provides a potential solution to preventing the adverse drug reactions (ADRs) induced by LEF during the treatment of rheumatoid arthritis (RA).

PURPOSE

To investigate whether co-administration of LEF with CHM could bring in both increased therapeutic outcomes and reduced ADRs due to the framework of treatment at the level of entire body.

STUDY DESIGN

The mechanism of LEF in RA treatment and the ADRs it induced was introduced based on recent papers. Reported clinical examples of CHM concurrent use with LEF was revealed to provide more evidence. The management of the ADRs caused by LEF was suggested by current researches on the concomitant therapy of CHM with LEF.

RESULTS

The active ingredients, compounds and medicinal herbs all demonstrated properties in relieving toxicities and reducing ADRs when used with LEF and reported in several clinical cases. The wide application of concurrent use of CHM with LEF is however hindered by the complex pathogenesis of RA which requires further scientific grounds for diagnosis and treatment.

CONCLUSION

This review introduced that the adoption of CHM is emerging as a novel strategy for the management of ADRs caused by LEF.

A retrospective study on the predictive implications of clinical characteristics and therapeutic management in patients with rheumatoid arthritis-associated interstitial lung disease

BACKGROUND

Rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) is associated with significant morbidity and is a critical cause of mortality in patients with RA.

OBJECTIVE

Our aim was to evaluate predictive and prognostic factors for RA-ILD and to describe the therapeutic management of the condition from a large China cohort.

METHODS

This was a retrospective cohort study. We collected data of 1121 RA patients who underwent chest HRCT from 2008 to 2017. Patients without ILD at RA diagnosis were included in the analysis. The development and evolution of ILD in RA patients were followed up. Determinants of ILD development and progression were identified through multivariable logistic analysis. Cox hazards analysis was used to determine significant variables associated with survival.

RESULTS

A total of 923 patients without ILD at RA diagnosis were identified and enrolled. Among them, 278 cases (30.12%) were diagnosed as ILD during follow-up. Logistic regression analysis showed that advanced age (> 60 years old) at RA onset (OR: 1.485), male (OR: 1.882), short duration of RA (0~5 years) (OR: 2.099), RF positive (OR: 1.728), elevated lactate dehydrogenase (LDH) (OR: 3.032), and no medication (OR: 1.833) were closely correlated to the development of RA-ILD. No correlation was found between ILD development and traditional DMARDs such as methotrexate and leflunomide. According to the follow-up data, 83 RA-ILD patients were identified as interstitial lung disease (ILD) progression, and 102 participants were stable. Logistic regression modeling demonstrated that DLCO% < 45% (OR: 3.025) and UIP possible pattern on HRCT (OR: 3.476) were independent risk factors for the ILD progression. No correlation was found between ILD progression and traditional DMARDs such as methotrexate and leflunomide. A total of 53 RA-ILD deaths occurred during follow-up. Cox hazards analysis revealed that advanced age (> 60 years old) at RA-ILD diagnosis (HR: 3.181) and extensive lung involvement on HRCT (HR: 2.401) were associated with worse survival. Treatment with cyclophosphamide (HR: 0.210) was associated with better survival.

CONCLUSIONS

Advanced age, male, short duration of RA, RF positive, elevated LDH, and no medication are closely correlated with RA-ILD. No correlation was found between traditional DMARDs and ILD development. DLCO% < 45% and UIP possible pattern are predictive factors for ILD progression. No correlation was found between traditional DMARDs and ILD progression. Advanced age and extensive lung involvement on HRCT independently predict mortality; cyclophosphamide treatment helps to improve the prognosis of RA-ILD.Key Points• We designed this study to investigate the predictive and prognostic factors for RA-ILD and to explore the potential role of DMARDs in the evolution of RA-ILD from the development to progression and death.• Patients without ILD at RA diagnosis were enrolled and followed up retrospectively.• Our results showed that no correlation was found between traditional DMARDs and the development and progression of ILD, and regular treatment may improve the development of RA-ILD.• Our results revealed that clinical variables appeared predictive implications for the diagnosis of ILD and physiological and radiological variables appeared predictive implications for the prognosis of ILD, which can provide reference to rheumatologists and help to improve poor prognosis of RA-ILD.

Methotrexate-Associated Pneumonitis and Rheumatoid Arthritis-Interstitial Lung Disease: Current Concepts for the Diagnosis and Treatment

Rheumatoid arthritis (RA) is a type of inflammatory arthritis that affects ~1% of the general population. Although arthritis is the cardinal symptom, many extra-articular manifestations can occur. Lung involvement and particularly interstitial lung disease (ILD) is among the most common. Although ILD can occur as part of the natural history of RA (RA-ILD), pulmonary fibrosis has been also linked with methotrexate (MTX); a condition also known as MTX-pneumonitis (M-pneu). This review aims to discuss epidemiological, diagnostic, imaging and histopathological features, risk factors, and treatment options in RA-ILD and M-pneu. M-pneu, usually has an acute/subacute course characterized by cough, dyspnea and fever. Several risk factors, including genetic and environmental factors have been suggested, but none have been validated. The diagnosis is based on clinical and radiologic findings which are mostly consistent with non-specific interstitial pneumonia (NSIP), more so than bronchiolitis obliterans organizing pneumonia (BOOP). Histological findings include interstitial infiltrates by lymphocytes, histiocytes, and eosinophils with or without non-caseating granulomas. Treatment requires immediate cessation of MTX and commencement of glucocorticoids. RA-ILD shares the same symptomatology with M-pneu. However, it usually has a more chronic course. RA-ILD occurs in about 3-5% of RA patients, although this percentage is significantly increased when radiologic criteria are used. Usual interstitial pneumonia (UIP) and NSIP are the most common radiologic patterns. Several risk factors have been identified for RA-ILD including smoking, male gender, and positivity for anti-citrullinated peptide antibodies and rheumatoid factor. Diagnosis is based on clinical and radiologic findings while pulmonary function tests may demonstrate a restrictive pattern. Although no clear guidelines exist for RA-ILD treatment, glucocorticoids and conventional disease modifying antirheumatic drugs (DMARDs) like MTX or leflunomide, as well as treatment with biologic DMARDs can be effective. There is limited evidence that rituximab, abatacept, and tocilizumab are better options compared to TNF-inhibitors.

[Pulmonary involvement in rheumatoid arthritis]

Pulmonary involvement in patients with rheumatoid arthritis, in particular interstitial lung diseases (RA-ILD) is of great clinical importance. Patients should be asked about symptoms of pulmonary involvement and the lungs should be clinically examined even during the diagnostic procedure and regularly during the course of the disease. Before initiation of a basic pharmacological treatment an X‑ray examination of thoracic organs is obligatory. In cases of conspicuous clinical or radiological findings, extended diagnostic procedures with lung function testing (body plethysmography with diffusion measurement) and high resolution computed tomography (CT) should be performed, depending on the findings. The differential diagnosis of interstitial lung alterations in patients with RA is broad and should consider side effects of the basis medication in addition to infectious causes. The optimal pharmacological treatment of RA-ILD is not sufficiently clarified. The value of methotrexate (MTX) has changed because, in contrast to previous assumptions, a better course could be observed under MTX treatment, at least in mild to moderate courses of RA-ILD. In the case of a clinically relevant RA-ILD, tumor necrosis factor (TNF) blockers should be avoided because a dramatic deterioration of pulmonary function has sometimes been observed. Among biological disease-modifying antirheumatic drugs (DMARD), rituximab and abatacept are currently preferred. The role of Janus kinase (JAK) inhibitors in RA-ILD is currently being discussed but limited data are available. Patients with RA-ILD benefit from a close collaboration between pulmonologists and rheumatologists.

Rheumatoid Arthritis-associated Interstitial Lung Disease in Greece: A Multicentre Epidemiological and Clinical Study

Interstitial Lung Disease (ILD) represents one of the most severe complications of Rheumatoid Arthritis (RA). Preliminary data from the RA Greek cohort show a prevalence of 5.3%. Due to scarcity of data, little is known regarding the epidemiological and clinical features of Greek patients with RA-ILD. Moreover, use of pulmonary function tests for prognostic purposes in patients with RA-ILD is still not sufficiently studied. Interestingly, the treatment approach of patients with RA-ILD remains controversial due to high risk of infection, possible drug-related pulmonary toxicity, and scarce evidence regarding the efficacy of medications used in these patients. The aim of this research protocol is to collect data from patients with RA-ILD followed in multiple centres across Greece in order to identify the clinical and epidemiological features of these patients. The second part of the study focuses on the prospective data collection regarding the progression of ILD, the response to different treatment modalities and the incidence of adverse events attributed either to the disease itself or to its treatment in patients with RA-ILD. This study may provide useful evidence in exploring both the natural history and the risk factors contributing to the development of ILD, as well as the efficacy and the adverse events attributed to the medications used in Greek patients with RA-ILD; thus ameliorating the therapeutic approach of RA-ILD patients in daily clinical practice.

Drug-Induced Interstitial Lung Disease: A Systematic Review

Background: Drug-induced interstitial lung disease (DIILD) occurs as a result of numerous agents, but the risk often only becomes apparent after the marketing authorisation of such agents. Methods: In this PRISMA-compliant systematic review, we aimed to evaluate and synthesise the current literature on DIILD. Results: Following a quality assessment, 156 full-text papers describing more than 6000 DIILD cases were included in the review. However, the majority of the papers were of low or very low quality in relation to the review question (78%). Thus, it was not possible to perform a meta-analysis, and descriptive review was undertaken instead. DIILD incidence rates varied between 4.1 and 12.4 cases/million/year. DIILD accounted for 3–5% of prevalent ILD cases. Cancer drugs, followed by rheumatology drugs, amiodarone and antibiotics, were the most common causes of DIILD. The radiopathological phenotype of DIILD varied between and within agents, and no typical radiological pattern specific to DIILD was identified. Mortality rates of over 50% were reported in some studies. Severity at presentation was the most reliable predictor of mortality. Glucocorticoids (GCs) were commonly used to treat DIILD, but no prospective studies examined their effect on outcome. Conclusions: Overall high-quality evidence in DIILD is lacking, and the current review will inform larger prospective studies to investigate the diagnosis and management of DIILD.

Clinical, Epidemiological, and Histopathological Features of Respiratory Involvement in Rheumatoid Arthritis

Although by definition rheumatoid arthritis (RA) is an articular disorder, it is a systemic disease, and 18–40% of patients experience extra-articular manifestations (EAMs). The involvement of the respiratory system occurs in about 30–40% of RA patients, and in about 10–20% of them it represents the first manifestation of RA. A wide range of pulmonary manifestations are detectable in RA patients, including pulmonary parenchymal disease, pleural involvement, and airway and pulmonary inflammation. The clinical, radiological, and histological spectra of respiratory manifestations in RA reflect chronic immune activation, increased susceptibility to infection (often related to immunosuppressive medications), or direct drug. The type and severity of pulmonary involvement influence the prognosis, ranging from mild self-limiting conditions to severe life-threatening complications. Herein, we reviewed the various manifestations of respiratory involvement in RA, providing an overview on epidemiological, histological, clinical, and radiological data.

Risk of liver disease in methotrexate treated patients

Methotrexate is the first line drug treatment for a number of rheumatic and non-rheumatic diseases. It is effective in controlling disease activity and preventing disease-related damage, and significantly cheaper than many alternatives. Use in rheumatoid arthritis infers a significant morbidity and mortality benefit. Methotrexate is generally well tolerated but can cause symptomatic adverse events. Multiple serious adverse events have been attributed to methotrexate, based largely on older reports using high or daily doses, and subsequent case reports and circumstantial evidence. The risk with modern dosing regimens: Lower doses, weekly schedules, and concomitant folic acid is less clear. Clarification and dissemination of the actual risk is crucial so appropriate judgements can be made for patients who may benefit from this treatment. Methotrexate has been associated with a range of liver related adverse events ranging from asymptomatic transaminase elevations to fibrosis and fatal hepatic necrosis. Concern over potential liver toxicity has resulted in treatment avoidance, cessation, or recommendations for investigations which may be costly, invasive and unwarranted. Modern laboratory monitoring of liver blood tests may also influence the risk of more serious complications. The majority of present day studies report an approximate doubling of the relative risk of elevated transaminases in methotrexate treated patients but no increased risk of symptomatic or severe liver related adverse events. In this article we will review the evidence around methotrexate and liver related adverse events.

Risk of serious infection in patients with rheumatoid arthritis-associated interstitial lung disease

The objective of this study is to assess the occurrence of and risk factors for serious infections in rheumatoid arthritis (RA)-associated interstitial lung disease (ILD). All patients with RA-ILD (ACR 1987 criteria for RA) seen at a single center from 1998 to 2014 were identified and manually screened for study inclusion. Follow-up data were abstracted until death or December 31, 2015. Serious infection was defined as requiring antimicrobial therapy and hospitalization. Risk of infection was analyzed by person-year (py) methods using time-dependent covariates started when the medication was first used and stopped 30 days after the medication was discontinued. Of the 181 included patients, 87 (48 %) were female. The mean age at ILD diagnosis was 67.4 (±9.9) years, and median follow-up time was 3.1 (range: 0.01 to 14.8) years. Higher infection rates were observed during the first year after ILD diagnosis (14.1 per 100 py) than subsequently (5.7 per 100 py; p = 0.001). Pneumonia was the most common (3.9 per 100 py). Overall infection risk was higher in organizing pneumonia (OP) (27.1 per 100 py) than usual interstitial pneumonia (7.7 per 100 py) or non-specific interstitial pneumonia (5.5 per 100 py) (p < 0.001). The highest infection rate observed was with a daily prednisone use >10 mg per day (15.4 per 100 py). Patients with RA-ILD are at risk of serious infection. Prednisone use >10 mg per day was associated with higher rates of infection. Immunosuppressive drug use governed by concern for risk of infection in patients with ILD resulting in channeling bias cannot be excluded.