Interstitial lung disease in connective tissue diseases: evolving concepts of pathogenesis and management

The Role of Nailfold Videocapillaroscopy in the Diagnosis and Monitoring of Interstitial Lung Disease Associated with Rheumatic Autoimmune Diseases

Interstitial lung disease (ILD) is a severe complication of certain connective tissue diseases (CTDs) such as systemic sclerosis (SSc), mixed connective tissue disease (MCTD), idiopathic inflammatory myopathies (IIM), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), and it is associated with nailfold videocapillaroscopy (NVC) changes and increased morbidity and mortality rates. Early diagnosis is crucial in order to prevent the progression of ILD, prevent respiratory failure and enhance the patient's overall quality of life. The most common paraclinical investigations are high-resolution computed tomography (HRCT) and functional respiratory tests such as forced vital capacity (FVC) and the diffusing capacity of the lungs for carbon monoxide (DLCO). The most frequent CTD associated with both ILD and NVC changes is systemic sclerosis. The "late" scleroderma pattern was the most common abnormality identified in NVC results in SSc patients. Other autoimmune diseases were also correlated with ILD and NVC changes, especially when the Raynaud phenomenon was present. Low capillary density was associated with the presence and severity of ILD and a reduction in FVC and DLCO. NVC can also differentiate the capillaroscopic changes in some particular types of ILD, such as the usual interstitial pneumonia (UIP) pattern from the non-specific interstitial pneumonia (NSIP) pattern. Nevertheless, further extensive research is necessary in order to establish the diagnostic value of NVC in CTD-ILD in clinical practice.

Interstitial lung disease in rheumatic diseases: an update of the 2018 review

INTRODUCTION

Interstitial lung disease (ILD) is a potential severe complication of various rheumatic diseases, typically connective tissue diseases (CTD), associated with significant morbidity and mortality. ILD may occur during the course of the disease but may also be its first manifestation. Several cell types are involved in ILD's pathogenesis, and if not controlled, pulmonary inflammation may lead to pulmonary fibrosis.

AREAS COVERED

We searched PubMed, Medline, and the Cochrane Library for papers published between 1995 and February 2017 in the first version, and between 2017 and April 2023 using combinations of words. The most frequent systemic rheumatic diseases associated with ILD are systemic sclerosis (SSc), rheumatoid arthritis (RA), and idiopathic inflammatory myositis. Treatment and monitoring guidelines are still lacking, and current treatment strategies have been extrapolated from the literature on SSc and established treatments for non-pulmonary systemic rheumatic manifestations.

EXPERT OPINION

Given the complexity of diagnosis and the paucity of treatment trials, managing CTD patients with ILD is challenging. It requires the skills of multidisciplinary CTD-ILD clinics including at least rheumatologists and lung specialists.

A versatile role for lung ultrasound in systemic autoimmune rheumatic diseases related pulmonary involvement: a narrative review

Systemic autoimmune rheumatic diseases (SARDs) related pulmonary disease is highly prevalent, with variable clinical presentation and behavior, and thus is associated with poor outcomes and negatively impacts quality of life. Chest high resolution computed tomography (HRCT) is still considered a fundamental imaging tool in the screening, diagnosis, and follow-up of pulmonary disease in patients with SARDs. However, radiation exposure, economic burden, as well as lack of point-of-care CT equipment limits its application in some clinical situation. Ultrasound has found a place in numerous aspects of the rheumatic diseases, including the vasculature, skin, muscle, joints, kidneys and in screening for malignancies. Likewise it has found increasing use in the lungs. In the past two decades, lung ultrasound has started to be used for pulmonary parenchymal diseases such as pneumonia, pulmonary edema, lung fibrosis, pneumothorax, and pleural lesions, although the lung parenchymal was once considered off-limits to ultrasound. Lung ultrasound B-lines and irregularities of the pleural line are now regarded two important sonographic artefacts related to diffuse parenchymal lung disease and they could reflect the lesion extent and severity. However, its role in the management of SARDs related pulmonary involvement has not been fully investigated. This review article will focus on the potential applications of lung ultrasound in different pulmonary scenarios related with SARDs, such as interstitial lung disease, diffuse alveolar hemorrhage, diaphragmatic involvement, and pulmonary infection, in order to explore its value in clinical daily practice.

Clinically Relevant Biomarkers in Connective Tissue Disease-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) complicates connective tissue disease (CTD) with variable incidence and is a leading cause of death in these patients. To improve CTD-ILD outcomes, early recognition and management of ILD is critical. Blood-based and radiologic biomarkers that assist in the diagnosis CTD-ILD have long been studied. Recent studies, including -omic investigations, have also begun to identify biomarkers that may help prognosticate such patients. This review provides an overview of clinically relevant biomarkers in patients with CTD-ILD, highlighting recent advances to assist in the diagnosis and prognostication of CTD-ILD.

Nintedanib combined with immunosuppressive agents improves forced vital capacity in connective tissue disease-associated PF-ILD: a single-center study

BACKGROUND

In 2020, Nintedanib (NTB), a tyrosine kinase inhibitor, was the first drug approved worldwide for treating progressive fibrosing interstitial lung disease (PF-ILD). This study evaluated the efficacy and safety of NTB in Japanese patients with CTD-associated PF-ILD in a real-world setting, as there are few reports on this topic. We also evaluated the efficacy and safety of combination therapy with NTB and immunosuppressive agents (IS).

METHODS

CTD-associated PF-ILD patients receiving NTB at our institution were included in this retrospective study. To evaluate the efficacy and safety of NTB, we investigated changes in forced vital capacity (FVC) (%), diffusing capacity for carbon monoxide (DLCO) (%), monthly change in FVC (%/month), serum Krebs von den Lungen-6 (KL-6) levels (U/mL) before and after NTB treatment, and adverse events (AEs) during NTB treatment. Moreover, to evaluate the efficacy of the NTB + IS combination therapy, we divided the patients into two groups: one received only NTB (NTB group), and the other received both NTB and IS (NTB + IS group) following the diagnosis of CTD-associated PF-ILD. We analyzed the differences in the changes of these variables between the two groups.

RESULTS

Twenty-six patients with CTD-associated PF-ILD were included. After NTB treatment, there were no significant deteriorations in FVC (%) and DLCO (%), while the monthly change in FVC (%/month) significantly increased (p < 0.001). The changes in FVC (%) and the monthly change in FVC (%/month) were significantly greater in the NTB + IS group than in the NTB group. Following NTB treatment, the mean serum KL-6 levels significantly decreased (p < 0.001). AEs associated with NTB in this study were similar to those in previous clinical trials, and there was no significant difference in the incidence of AEs between the two groups.

CONCLUSIONS

This study demonstrates that NTB is an effective medication for slowing the progression of CTD-associated PF-ILD in real-world settings. NTB + IS combination therapy for CTD-associated PF-ILD may be more effective than NTB alone in slowing the progression of CTD-associated PF-ILD.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Systemic Sclerosis in Males-Deciphering the Enigma of Erasmus Syndrome

Background

Systemic sclerosis is an autoimmune connective tissue disease characterized by fibrosis in skin and internal organs. Chronic exposure to silica may not only lead to silicosis of lungs but also systemic sclerosis. Systemic sclerosis is relatively commoner in females; however, occupational exposure to silica in males makes them vulnerable to silica--associated systemic sclerosis (Erasmus syndrome).

Objective

To describe the clinico-epidemiological aspects of systemic sclerosis in males in a retrospective cohort study.

Materials and Methods

The data were analysed retrospectively for demographic profile and clinical characteristics including examination findings, laboratory investigations, and treatments of all male patients diagnosed with systemic sclerosis with or without silica exposure, managed from January 2018 to December 2021.

Results

Eight out of twelve patients were having silica exposure in the form of stone cutting, cement exposure, and working with concrete. The average age was 55 ± 10.72 years with average smoking exposure of around 24.4 ± 12.8 pack years. Skin thickening was reported by all patients with an average modified Rodnan score of 18.33/51 in diffuse and 7/51 in limited cutaneous systemic sclerosis. Raynaud's phenomenon and sclerodactyly were universal findings, while 9 (75%) patients had digital pitted scars. Antinuclear antibodies were present in all patients and specific antibodies substantiated the clinical assessment in almost all patients. Interstitial lung disease was the most common systemic finding present in 11 (91%) patients and tuberculosis was diagnosed in 2 (25%) cases with silica exposure. Gastrointestinal and cardiac system involvement was seen in 5 (41.6%) and 4 (33.3%) patients, respectively.

Conclusion

Systemic sclerosis in males against the gender predilection indicates the role of occupational exposure. Silicosis and systemic sclerosis synergistically add to lung damage, and at the same time, these patients are more prone to infections like tuberculosis.

The phenotype of mixed connective tissue disease patients having associated interstitial lung disease

OBJECTIVE

We aimed to compare two matched populations of patients with MTCD with and without associated ILD and to identify predictive factors for ILD progression and severity.

METHODS

This international multicenter retrospective study (14 tertiary hospitals), included MCTD patients who fulfilled at least one historical MCTD classification criteria. ILD was defined by the presence of typical chest high-resolution computed tomography (HRCT) abnormalities. Factors associated with ILD were assessed at baseline. Long-term progressive ILD was assessed in MCTD-ILD patients with multiple forced vital capacity (FVC) measurements.

RESULTS

300 patients with MCTD were included. Mean age at diagnosis was 39.7 ± 15.4 years and 191 (63.7%) were women. Mean follow-up was 7.8 ± 5.5 years. At baseline, we identified several factors associated with ILD presence: older age (p = 0.01), skin thickening (p = 0.03), upper gastro-intestinal (GI) symptoms (p<0.001), FVC <80% (p<0.0001), diffusing capacity for carbon monoxide <80% (p<0.0001), anti-topoisomerase antibodies (p = 0.01), SSA/Ro antibodies (p = 0.02), cryoglobulinemia (p = 0.04) and elevated C-reactive protein (p<0.001). Patients with MTCD-ILD were more likely to be treated with synthetic immunosuppressant agents (p<0.001) in particular mycophenolate mofetil (p = 0.03). Digital ulcers (DU) were identified as a risk factor for FVC decline >10%. During follow-up mortality was higher in the MTCD-ILD group (p<0.001).

CONCLUSION

In this large international cohort of patients with MTCD, we identified different factors associated with ILD. Our findings also provide evidence that MCTD-ILD patients have increased mortality and that DU are associated with progressive lung disease.

Lung involvement in juvenile idiopathic inflammatory myopathy: A systematic review

OBJECTIVE

Juvenile idiopathic inflammatory myopathies (JIIM) are a group of connective tissue disorders characterized by muscle inflammation and variable systemic involvement, including interstitial lung disease (ILD). Available data on JIIM-associated ILD are very limited. We performed a systematic review of the available clinical, laboratory, and radiological features of JIIM-associated ILD.

METHODS

A systematic literature review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

RESULTS

A total of 90 patients were identified, of whom 77.8% had JDM, 10% amyopathic JDM, 7.8% anti-synthetase syndrome, 3.3% overlap syndrome, and 1.1% juvenile polymyositis. Anti-melanoma differentiation-associated gene 5 (MDA-5/CADM-140) was the most frequently reported myositis-specific antibody (32.2%). At diagnosis of ILD, 55.5% of patients had respiratory symptoms. Ground glass opacity was the most reported radiological feature (52.9%). Thirty-three % of patients developed rapidly progressive (RP) lung disease; 26.7% were admitted to the intensive care unit (ICU); 28.9% died; all deaths were due to ILD, with a median interval of 2 months (IQR 1.5-4.7) between the onset of respiratory symptoms and death. Patients admitted to the ICU and who died of ILD were more likely to be male, to have a rapidly progressive pattern, progression of radiological features, and a higher level of KL-6.

CONCLUSIONS

MDA-5/CADM-14 is associated with RP-ILD. ILD is a rare but severe manifestation among the spectrum of systemic involvement associated with JIIM, with a high rate of ICU admission and mortality. Early recognition and aggressive treatment are needed to prevent a severe outcome.

The additional treatment value of immunoglobulin for the treatment of rheumatoid arthritis complicated with interstitial lung disease: A propensity score-matched pilot study

OBJECTIVE

To explore the additional treatment value of intravenous immunoglobulin injections for treating interstitial lung disease (ILD) caused by rheumatoid arthritis (RA).

METHODS

This pilot study included patients with RA-ILD. The RA-ILD patients were grouped by treatment agents: traditional agents (disease-modifying antirheumatic drugs, [D]MARDs] and glucocorticoids) and traditional agents plus immunoglobulin. A propensity matching score (PSM) was performed to balance the bias of baseline characteristics. The treatment efficacy and safety indicators were analyzed and compared between the two groups.

RESULTS

In total, 134 patients were included in this study. After PSM, 80 patients were finally included, with 40 in each group. The immunoglobulin group consisted of 12 men and 28 women with a mean age of 51.5 ± 8.4 years (22-75 years). The control group included 13 men and 27 women, with a mean age of 50.6 ± 8.2 years (25-74 years). The chronic obstructive pulmonary disease assessment test score in the immunoglobulin group was statistically lower after treatment than in the control group (19.1 ± 3.3 vs. 17.7 ± 3.4, p = .03). The 6-min walking distance (364.4 ± 54.3 vs. 332.3 ± 55.1, p = .04) and forced vital capacity (78.8 ± 12.6 vs. 66.6 ± 11.2, p = .05) were statistically higher in the immunoglobulin group. The high-resolution computed tomography score and erythrocyte sedimentation rate were both statistically lower in the immunoglobulin group (both p < .05). The adverse event rate did not differ between the two groups (p = .61).

CONCLUSION

The additional use of immunoglobulin intravenous injection is effective for the treatment of RA-ILD with no additional adverse effects.

Adipokines in interstitial lung diseases

Interstitial lung diseases (ILD) are a heterogenic group of respiratory diseases with complex pathogenesis. A growing number of evidence suggests role of adipose tissue and it's hormones (adipokines) in pathogenesis of various disorders, including lung tissue diseases. The aim of this study was to assess the concentrations of selected adipokines and their receptors (apelin, adiponectin, chemerin, chemerin receptor - CMKLR1) in patients with IPF (idiopathic pulmonary fibrosis) and sarcoidosis in comparison to healthy controls. We found changes in adipokines concentrations in ILD. Adiponectin concentrations were higher in all respiratory diseases patients in comparison to healthy controls. Apelin concentration in ILD patients was higher then those in healthy subjects. The trend of chemerin and CMKLR1 concentrations were similar, with highest concentrations seen in sarcoidosis. The study shows a difference of adipokines concentrations between patients with ILD and healthy controls. Adipokines are a potential marker and therapeutic target in patients with IPF and sarcoidosis.

Expert Opinion Guidance on the Detection of Early Connective Tissue Diseases in Interstitial Lung Disease

There is a significant variation in symptoms and clinical presentation of connective tissue disorders (CTD) associated with interstitial lung disease (ILD) (CTD-ILD). This presents difficulties in the diagnosis and treatment of CTD-ILD. Early detection and treatment of CTD-ILD using a multidisciplinary approach have been shown to enhance patient outcomes. This exercise aims to explore clinical components to develop a screening tool for pulmonologists for early detection of CTD in ILD and to provide a framework for a multidisciplinary approach in managing CTD-ILD. This in turn will lead to early treatment of CTD-ILD in collaboration with rheumatologists. A panel of 12 leading rheumatologists from the Middle East and North Africa (MENA) region met virtually to select the most relevant clinical findings to aid in identifying CTD-ILD. Twelve panellists opted to investigate seven of the most common inflammatory autoimmune disorders. The panel discussed how to improve the early detection of CTD-ILD. Clinical characteristics were categorized, and a nine-item questionnaire was created. A biphasic algorithm was developed to guide early referral to a rheumatologist based on the presence of one of nine clinical features of CTD (Phase 1) or the presence of CTD-specific antibodies (Phase 2). A brief questionnaire has been developed to serve as a simple and practical screening tool for CTD-ILD detection. Additional research is needed to validate and evaluate the tool in longitudinal cohorts.

Clinically Relevant Biomarkers in Connective Tissue Disease-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) complicates connective tissue disease (CTD) with variable incidence and is a leading cause of death in these patients. To improve CTD-ILD outcomes, early recognition and management of ILD is critical. Blood-based and radiologic biomarkers that assist in the diagnosis CTD-ILD have long been studied. Recent studies, including -omic investigations, have also begun to identify biomarkers that may help prognosticate such patients. This review provides an overview of clinically relevant biomarkers in patients with CTD-ILD, highlighting recent advances to assist in the diagnosis and prognostication of CTD-ILD.

Can transbronchial lung cryobiopsy benefit adaptive treatment strategies in connective tissue disease-associated interstitial lung disease?

BACKGROUND

Some patients with connective tissue disease (CTD)-associated interstitial lung disease (ILD) progress to pulmonary fibrosis over their disease course despite initial improvement, potentially indicating a poor prognosis. Transbronchial lung cryobiopsy (TBLC) is a new bioptic approach used in diffuse parenchymal lung diseases. This study of CTD-ILD assessed the utility of TBLC in determining therapeutic decision-making strategies.

METHODS

We analyzed medical records of 31 consecutive CTD-ILD patients who underwent TBLC focusing on radio-pathological correlation and disease course. A TBLC-based usual interstitial pneumonia (UIP) score was used that assessed three morphologic descriptors: i) patchy fibrosis, ii) fibroblastic foci, and iii) honeycombing.

RESULTS

Among the patients with CTD-ILD, 3 had rheumatoid arthritis, 2 systemic sclerosis, 5 polymyositis/dermatomyositis, 8 anti-synthetase syndrome, 6 Sjögren's syndrome, and 5 had microscopic polyangiitis. Pulmonary function test results showed a mean %FVC of 82.4% and %DL_CO of 67.7%. Among the 10 CTD patients and TBLC-proven pathological UIP, 3 patients had prominent inflammatory cells in addition to a framework of UIP, and pulmonary function of most patients improved with anti-inflammatory agents. Six (40%) of 15 patients with TBLC-based UIP score ≥ 1 had a progressive disease course during follow-up, of whom 4 patients received anti-fibrotic agents.

CONCLUSIONS

TBLC in patients with CTD-ILD can help determine an appropriate medication strategy, particularly when UIP-like lesions are present. TBLC may be useful when judging which agents to prioritize, anti-inflammatory or anti-fibrotic, is difficult. Moreover, additional information from TBLC may be beneficial when considering early intervention with anti-fibrotic agents in clinical practice.

Immune-mediated lung diseases: A narrative review

The role of immunity in the pathogenesis of various pulmonary diseases, particularly interstitial lung diseases (ILDs), is being increasingly appreciated as mechanistic discoveries advance our knowledge in the field. Immune-mediated lung diseases demonstrate clinical and immunological heterogeneity and can be etiologically categorized into connective tissue disease (CTD)-associated, exposure-related, idiopathic, and other miscellaneous lung diseases including sarcoidosis, and post-lung transplant ILD. The immunopathogenesis of many of these diseases remains poorly defined and possibly involves either immune dysregulation, abnormal healing, chronic inflammation, or a combination of these, often in a background of genetic susceptibility. The heterogeneity and complex immunopathogenesis of ILDs complicate management, and thus a collaborative treatment team should work toward an individualized approach to address the unique needs of each patient. Current management of immune-mediated lung diseases is challenging; the choice of therapy is etiology-driven and includes corticosteroids, immunomodulatory drugs such as methotrexate, cyclophosphamide and mycophenolate mofetil, rituximab, or other measures such as discontinuation or avoidance of the inciting agent in exposure-related ILDs. Antifibrotic therapy is approved for some of the ILDs (e.g., idiopathic pulmonary fibrosis) and is being investigated for many others and has shown promising preliminary results. A dire need for advances in the management of immune-mediated lung disease persists in the absence of standardized management guidelines.

Risk Factors of Severe COVID-19: A Review of Host, Viral and Environmental Factors

The clinical course and outcome of COVID-19 are highly variable, ranging from asymptomatic infections to severe disease and death. Understanding the risk factors of severe COVID-19 is relevant both in the clinical setting and at the epidemiological level. Here, we provide an overview of host, viral and environmental factors that have been shown or (in some cases) hypothesized to be associated with severe clinical outcomes. The factors considered in detail include the age and frailty, genetic polymorphisms, biological sex (and pregnancy), co- and superinfections, non-communicable comorbidities, immunological history, microbiota, and lifestyle of the patient; viral genetic variation and infecting dose; socioeconomic factors; and air pollution. For each category, we compile (sometimes conflicting) evidence for the association of the factor with COVID-19 outcomes (including the strength of the effect) and outline possible action mechanisms. We also discuss the complex interactions between the various risk factors.

Rituximab for the treatment of connective tissue disease-associated interstitial lung disease: A systematic review and meta-analysis

Background: Interstitial lung disease (ILD) is a common pulmonary disease often associated with significant morbidity and mortality in patients with connective tissue diseases (CTD). Currently, no gold-standard therapies are available for CTD-ILD. Recently, several studies have proposed that rituximab (RTX) may be effective for the treatment of CTD-ILD. Objectives: This study aimed to systematically evaluate the efficacy and safety of RTX for the treatment of CTD-ILD. Methods: Studies were selected from PubMed, Embase, and Cochrane Library, up to 20 July 2022. Improvement and stable rates were extracted as the main outcomes and pooled using the weighted mean proportion with fixed or random-effects models, in case of significant heterogeneity (I 2 > 50%). Safety analysis was performed based on the adverse events reported in all of the studies. Results: Thirteen studies (312 patients) were included in the meta-analysis. The follow-up durations ranged from 6 to 36 months. The pooled improvement rate was 35.0% (95% CI: 0.277-0.442), while the pooled stable rate was 59.2% (95% CI: 0.534-0.656). Anti-synthetase syndrome associated with ILD [ASS-ILD, 48.1% (95% CI, 0.373-0.620)] and idiopathic inflammatory myopathies associated with ILD [IIM-ILD, non-ASS, 47.4% (95% CI, 0.266-0.846)] had higher improvement rates than the other types. A total of 106 adverse events associated with RTX or progressive ILD were reported among the 318 patients, 55.7% of which were mild. Among 19 deaths, 17 were due to ILD progression, one to severe pulmonary arterial hypertension, and one to Pneumocystis jirovecii infection. Conclusion: RTX, which exhibits a satisfactory safety profile, is an effective treatment option for CTD-ILD, even in patients who fail to respond to other therapies. Further randomized trials are needed to assess the efficacy of rituximab compared to other treatments for CTD-ILD. Systematic review registration: PROSPERO, identifier (CRD42022363403).

Biomarkers of interstitial lung disease associated with primary Sjögren's syndrome

Objectives

The aim of this study was to investigate serum biomarkers linked to primary Sjögren's syndrome (pSS)-associated interstitial lung disease (ILD).

Methods

69 pSS patients were consecutively enrolled and evaluated via quantitative ILD scoring based on high-resolution computed tomography (HRCT). Biomarkers of interest were assessed by multiplex enzyme-linked immunosorbent assays (ELISAs).

Results

Among consecutively enrolled patients with pSS, the presence of pSS–ILD was 50% based on the presence of radiographically defined interstitial lung abnormalities (ILA) meeting specified criteria for mild/moderate (ILA 2) or severe (ILA 3) disease. Age, immunoglobulin M (IgM), C-reactive protein (CRP), and serum levels of eotaxin/CCL11, Krebs von den Lungen-6 (KL-6), TNFα, and TGFα were significantly higher in the combined pSS–ILD group (ILA 2 + ILA 3) than in the pSS–no-ILD and pSS–indeterminate ILD groups (ILA 0 and ILA 1, respectively) in unadjusted analyses (p < 0.05 for all variables). A binary logistic regression model revealed that disease duration and KL-6 levels were associated with the presence of pSS–ILD (p < 0.05). Complementary least absolute shrinkage and selection operator (LASSO) modeling showed that age, KL-6, and TNF-α effectively differentiated pSS–ILD (ILA 2 + ILA3) from pSS without ILD (ILA 0 + ILA 1), with an area under the curve (AUC) of 0.883 (p value < 0.0001).

Conclusions

Patient age, disease duration, and serum levels of both KL-6 and TNFα were the most discriminating factors associated with the presence of ILD in our pSS patients. Higher levels of CRP, IgM, eotaxin, TGFα, and TNFα should also prompt the search for occult as well as clinically evident lung involvement based on statistically significant univariate associations with pSS–ILD.

Clinical trial registration

None.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00828-3.

Interstitial lung disease independently associated with higher risk for COVID-19 severity and mortality: A meta-analysis of adjusted effect estimates

OBJECTIVE

The aim of this study was to address the association between interstitial lung disease and the risk for severity and mortality among patients with coronavirus disease 2019 (COVID-19).

METHODS

The electronic databases of PubMed, Web of Science and EMBASE were systematically searched. The pooled effect size with 95 % confidence interval (CI) was computed by a random-effects meta-analysis model. Heterogeneity test, sensitivity analysis, subgroup analysis, meta-regression analysis, Begg's test and Egger's test were performed.

RESULTS

A total of sixteen eligible studies with 217,260 COVID-19 patients were enrolled in this meta-analysis. The findings based on adjusted effect estimates indicated that pre-existing interstitial lung disease was significantly associated with higher risk for COVID-19 severity (pooled effect = 1.34 [95 % CI: 1.16-1.55]) and mortality (pooled effect = 1.26 [95 % CI: 1.09-1.46]). Consistent results were observed in the subgroup analysis stratified by sample size, age, the percentage of male patients, study design, setting, the methods for adjustment and the factors for adjustment. The results of meta-regression demonstrated that sample size, age and region might be the potential sources of heterogeneity. Sensitivity analysis exhibited that our results were stable and robust. No publication bias was observed in Egger's test and Begg's test.

CONCLUSION

This meta-analysis on the basis of adjusted effect estimates demonstrated that pre-existing interstitial lung disease was independently associated with significantly higher risk for COVID-19 severity and mortality.

Effect size of rituximab on pulmonary function in the treatment of connective-tissue disease-related interstitial lung disease: a systematic review and meta-analysis

BACKGROUND

Rituximab (RTX) has been previously reported as directed treatment in patients with connective-tissue disease-related interstitial lung diseases (CTD-ILD). A systematic assessment of treatment effect size on pulmonary function outcomes and related adverse effects in patients with CTD-ILD has not been previously reported.

METHODS

We performed a systematic review and meta-analysis of published reports from PubMed, Embase, and Cochrane Libraries. Randomized and non-randomized controlled trials, case-control, cohort, and case series (with five or more cases) containing individual pulmonary function data and adverse effects were included. Study endpoints were pre- and post-treatment change in percent predicted forced vital capacity (FVC %) and diffusion capacity for carbon monoxide (DLCO%), along with reported drug-related adverse events.

RESULTS

Twenty studies totaling 411 patients were identified with 14 included in the meta-analysis of pulmonary function and six in the descriptive review. Random effects meta-analysis of pre- and post-treatment pulmonary function findings demonstrated increases in FVC% (n = 296) (mean difference (MD) 4.57%, [95% CI 2.63-6.51]) and DLCO% (n = 246) (MD 5.0% [95% CI 2.71-7.29]) after RTX treatment. RTX treatment-related adverse effects were reported in 13.6% of the pooled cohort.

CONCLUSIONS

A systematic assessment of post-treatment effect size suggests a potential role for RTX in stabilizing or improving lung function in patients with CTD-ILD, with a modest but not insignificant adverse effect profile.

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

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

Circulating Th2 cell reduction and Th1/Th2 imbalance are correlated with primary Sjogren's syndrome-associated interstitial lung disease

OBJECTIVE

Primary Sjogren's syndrome (pSS) is a heterogeneous chronic autoimmune disorder characterized by lymphocyte infiltration of the exocrine glands and the involvement and dysfunction of multiple organs and tissues. Interstitial lung disease (ILD) is the most common type of respiratory system damage. This study ascertained the factors related to ILD in patients with pSS (pSS-ILD), such as altered levels of circulating lymphocyte subtypes.

METHODS

Eighty healthy controls and 142 patients diagnosed with pSS were included. The pSS patients were classified into groups with pSS-ILD or pSS without ILD (pSS-non-ILD). Baseline clinical and laboratory data were collected for all subjects, including the levels of lymphocytes measured by modified flow cytometry.

RESULTS

The pSS-ILD patients were older, had higher ESSDAI scores, had higher positivity rates for anti-SSB and anti-Ro52 antibodies, and had more frequent symptoms of respiratory system involvement than pSS-non-ILD patients. pSS-ILD patients had the lowest Th2 cell counts among the three groups. Although the absolute numbers of Treg and NK cells were lower in pSS patients with and without ILD than in the healthy controls, there was no significant difference between the two pSS groups. The Th1/Th2 ratio was significantly higher in patients with ILD than in patients without ILD. Further analysis showed that older age (OR=1.084), lower Th2 count (OR=0.947), higher Th1/Th2 ratio (OR=1.021), and positivity for anti-SSB (OR=3.620) and anti-Ro52 (OR=5.184) antibodies were associated with the occurrence of ILD in patients with pSS.

CONCLUSION

Decreased circulating Th2 cells and an elevated Th1/Th2 ratio may be the immunological mechanism underlying the development of ILD in pSS patients.

Interstitial Lung Disease in Rheumatoid Arthritis: A Practical Review

Rheumatoid arthritis (RA) is a systemic inflammatory disease, which primarily causes symmetric polyarthritis. An extrarticolar involvement is common, and the commonly involved organ is lungs. Although cardiac disease is responsible for most RA-related deaths, pulmonary disease is also a major contributor, accounting for ~10-20% of all mortality. Pulmonary disease is a common (60-80% of patients with RA) extra-articular complication of RA. Optimal screening, diagnostic, and treatment strategies of pulmonary disease remain uncertain, which have been the focus of an ongoing investigation. Clinicians should regularly assess patients with RA for the signs and symptoms of pulmonary disease and, reciprocally, consider RA and other connective tissue diseases when evaluating a patient with pulmonary disease of an unknown etiology. RA directly affects all anatomic compartments of the thorax, including the lung parenchyma, large and small airways, pleura, and less commonly vessels. In addition, pulmonary infection and drug-induced lung disease associated with immunosuppressive agents used for the treatment of RA may occur.

Expression of S100A9 and KL-6 in common interstitial lung diseases

By evaluating S100 calcium binding protein A9 (S100A9) and Klebs von den Lungen-6 (KL-6) expression in patients with 4 common interstitial lung diseases (ILDs), we aimed to investigate whether S100A9 or KL-6 can be of any value in the differential diagnosis of these ILDs and simultaneously signal the disease progression.We collected the data of patients diagnosed with the 4 ILDs and underwent fiber-optic bronchoscopy and BAL in the First Affiliated Hospital, China Medical University from January 2012 to December 2020. The data related to BGA, C-reactive protein, pulmonary function test, total number and fraction of cells, T lymphocyte subsets in bronchoalveolar lavage fluid (BALF), and the expression of S100A9 and KL-6 in BALF and serum were collected. We analyzed, whether S100A9 or KL-6 could serve as a biomarker for differential diagnosis between the 4 common ILDs; whether the levels of S100A9 and KL-6 correlated with each other; whether they were correlated with other clinical parameters and disease severity.This study included 98 patients, 37 patients with idiopathic pulmonary fibrosis (IPF), 12 with hypersensitivity pneumonitis, 13 with connective tissue disease-associated ILD, and 36 with sarcoidosis (SAR): stage I (18), stage II (9), stage III (5), and stage IV (4). The expression of KL-6 in BALF was significantly higher in IPF patients than other 3 groups (all P-value < .05). However, there was no significant difference in the levels of S100A9 in BALF and serum between the 4 groups (P-value > .05). The levels of S100A9 in BALF of IPF patients was positively and significantly correlated with KL-6 expression and the percentage of neutrophils in BALF (P-value < .05). Along with the stage increase of SAR patients, the level of S100A9 in BALF gradually increased, which was negatively and significantly correlated with the forced vital capacity/predicted, carbon monoxide diffusing capacity/predicted%, and PaO2 (all P-value < .05).The expression of KL-6 in BALF can be used as a biomarker to differentiate IPF from the other 3 common ILDs. While, this was not the case with expression of S100A9 in BALF and serum. However, the expression S100A9 in BALF is useful to indicate the progression of SAR. Thus, simultaneous measurement of KL-6 and S100A9 levels in BALF makes more sense in differential diagnosing of the 4 common ILDS.

The utility of transbronchial lung biopsies to guide the treatment decision in patients with rheumatic inflammatory diseases: a retrospective cross-sectional study

The role of transbronchial lung biopsies (TBB) in the diagnostic workup of systemic inflammatory rheumatic disease-associated interstitial lung disease (SIRD-ILD) is unclear and TBB is not generally recommended. The study objective was to examine the utility of TBB to guide treatment in a population of patients with SIRD-ILD. All patients from the Department of Rheumatology, Rigshospitalet, Denmark, who had TBB performed, from 2002 to 2016 were identified. Patient demographics as well as smoking status, previous lung disease, pulmonary function test, SIRD-diagnosis, imaging results and immunomodulatory therapy pre- and post-bronchoscopy were obtained. Histology findings were used to dichotomize patients into a high-inflammatory group or a low-inflammatory group. The high-inflammation group primarily consisted of non-specific interstitial pneumonia, organizing pneumonia, lymphocytic infiltrating pneumonia and granulomatous inflammation whereas the low inflammation group primarily consisted of histological findings of usual interstitial pneumonitis and biopsies describing fibrosis and/or sparse unspecific inflammation. Therapeutic consequence was defined as intensification of therapy. Differences in treatment intensification were calculated using a binominal logistic regression model. Ninety-six patients had TBB performed. Biopsies from 55 patients were categorized as high inflammatory and 41 as low inflammatory, respectively. In the high-inflammatory group, 38 (69%) had their therapy intensified compared to 6 (14%) in the low-inflammatory group (Odds ratio 8.0, 95% confidence limits 3.2-20.0, P < 0.001). No procedure-related complications were registered. TBB findings can guide treatment strategy in SIRD-ILD patients with suspected activity in the pulmonary disease. TBB appears safe and could be considered as part of the diagnostic workup.

Combined obstructive airflow limitation associated with interstitial lung diseases (O-ILD): the bad phenotype ?

BACKGROUND

Patients suffering from combined obstructive and interstitial lung disease (O-ILD) represent a pathological entity which still has to be well clinically described. The aim of this descriptive and explorative study was to describe the phenotype and functional characteristics of a cohort of patients suffering from functional obstruction in a population of ILD patients in order to raise the need of dedicated prospective observational studies and the evaluation of the impact of anti-fibrotic therapies.

METHODS

The current authors conducted a retrospective study including 557 ILD patients, with either obstructive (O-ILD, n = 82) or non-obstructive (non O-ILD, n = 475) pattern. Patients included were mainly males (54%) with a mean age of 62 years.

RESULTS

Patients with O-ILD exhibited a characteristic functional profile with reduced percent predicted forced expired volume in 1 s (FEV1) [65% (53-77) vs 83% (71-96), p < 0.00001], small airway involvement assessed by maximum expiratory flow (MEF) 25/75 [29% (20-41) vs 81% (64-108), p < 0.00001], reduced sGaw [60% (42-75) vs 87% (59-119), p < 0.01] and sub-normal functional residual capacity (FRC) [113% (93-134) vs 92% (75-109), p < 0.00001] with no impaired of carbon monoxide diffusing capacity of the lung (DLCO) compared to those without obstruction. Total lung capacity (TLC) was increased in O-ILD patients [93% (82-107) vs 79% (69-91), p < 0.00001]. Of interest, DLCO sharply dropped in O-ILD patients over a 5-year follow-up. We did not identify a significant increase in mortality in patients with O-ILD. Interestingly, the global mortality was increased in the specific sub-group of patients with O-ILD and no progressive fibrosing ILD phenotype and in those with connective tissue disease associated ILD especially in case of rheumatoid arthritis.

CONCLUSIONS

The authors individualized a specific functional-based pattern of ILD patients with obstructive lung disease, who are at risk of increased mortality and rapid DLCO decline over time. As classically those patients are excluded from clinical trials, a dedicated prospective study would be of interest in order to define more precisely treatment response of those patients.

The use of exhaled air analysis in discriminating interstitial lung diseases: a pilot study

BACKGROUND

Fibrotic Interstitial lung diseases (ILD) are a heterogeneous group of chronic lung diseases characterized by diverse degrees of lung inflammation and remodeling. They include idiopathic ILD such as idiopathic pulmonary fibrosis (IPF), and ILD secondary to chronic inflammatory diseases such as connective tissue disease (CTD). Precise differential diagnosis of ILD is critical since anti-inflammatory and immunosuppressive drugs, which are beneficial in inflammatory ILD, are detrimental in IPF. However, differential diagnosis of ILD is still difficult and often requires an invasive lung biopsy. The primary aim of this study is to identify volatile organic compounds (VOCs) patterns in exhaled air to non-invasively discriminate IPF and CTD-ILD. As secondary aim, the association between the IPF and CTD-ILD discriminating VOC patterns and functional impairment is investigated.

METHODS

Fifty-three IPF patients, 53 CTD-ILD patients and 51 controls donated exhaled air, which was analyzed for its VOC content using gas chromatograph- time of flight- mass spectrometry.

RESULTS

By applying multivariate analysis, a discriminative profile of 34 VOCs was observed to discriminate between IPF patients and healthy controls whereas 11 VOCs were able to distinguish between CTD-ILD patients and healthy controls. The separation between IPF and CTD-ILD could be made using 16 discriminating VOCs, that also displayed a significant correlation with total lung capacity and the 6 min' walk distance.

CONCLUSIONS

This study reports for the first time that specific VOC profiles can be found to differentiate IPF and CTD-ILD from both healthy controls and each other. Moreover, an ILD-specific VOC profile was strongly correlated with functional parameters. Future research applying larger cohorts of patients suffering from a larger variety of ILDs should confirm the potential use of breathomics to facilitate fast, non-invasive and proper differential diagnosis of specific ILDs in the future as first step towards personalized medicine for these complex diseases.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prediction of long-term mortality by using machine learning models in Chinese patients with connective tissue disease-associated interstitial lung disease

Background

The exact risk assessment is crucial for the management of connective tissue disease-associated interstitial lung disease (CTD-ILD) patients. In the present study, we develop a nomogram to predict 3‑ and 5-year mortality by using machine learning approach and test the ILD-GAP model in Chinese CTD-ILD patients.

Methods

CTD-ILD patients who were diagnosed and treated at the First Affiliated Hospital of Zhengzhou University were enrolled based on a prior well-designed criterion between February 2011 and July 2018. Cox regression with the least absolute shrinkage and selection operator (LASSO) was used to screen out the predictors and generate a nomogram. Internal validation was performed using bootstrap resampling. Then, the nomogram and ILD-GAP model were assessed via likelihood ratio testing, Harrell’s C index, integrated discrimination improvement (IDI), the net reclassification improvement (NRI) and decision curve analysis.

Results

A total of 675 consecutive CTD-ILD patients were enrolled in this study, during the median follow-up period of 50 (interquartile range, 38–65) months, 158 patients died (mortality rate 23.4%). After feature selection, 9 variables were identified: age, rheumatoid arthritis, lung diffusing capacity for carbon monoxide, right ventricular diameter, right atrial area, honeycombing, immunosuppressive agents, aspartate transaminase and albumin. A predictive nomogram was generated by integrating these variables, which provided better mortality estimates than ILD-GAP model based on the likelihood ratio testing, Harrell’s C index (0.767 and 0.652 respectively) and calibration plots. Application of the nomogram resulted in an improved IDI (3- and 5-year, 0.137 and 0.136 respectively) and NRI (3- and 5-year, 0.294 and 0.325 respectively) compared with ILD-GAP model. In addition, the nomogram was more clinically useful revealed by decision curve analysis.

Conclusions

The results from our study prove that the ILD-GAP model may exhibit an inapplicable role in predicting mortality risk in Chinese CTD-ILD patients. The nomogram we developed performed well in predicting 3‑ and 5-year mortality risk of Chinese CTD-ILD patients, but further studies and external validation will be required to determine the clinical usefulness of the nomogram.

Rituximab for interstitial pneumonia with autoimmune features at two medical centres

Objectives

Many patients with interstitial lung disease (ILD) have autoimmune manifestations but do not meet criteria for a systemic rheumatic disease. A subset meets criteria for interstitial pneumonia with autoimmune features (IPAF) and have ILD requiring therapy. We conducted a multicentre observational study to examine the use of rituximab (RTX) in IPAF.

Methods

Patients from Mass General Brigham (MGB) and University of Chicago Medicine (UCM) were included if they were ≥18 years old, met the 2015 classification criteria for IPAF and were treated with RTX. Clinical improvement was defined as improvement in four out of four domains at 1 year after RTX initiation: documented clinician global assessment; oxygen requirement; need for respiratory-related hospitalization; and survival.

Results

At MGB, 36 IPAF patients (mean age 61 years, 44% female) were treated with RTX. At 1 year, 18 (50%) were clinically improved, 12 (33%) were stable, and 6 (17%) died from progressive respiratory failure. At UCM, 14 IPAF patients (mean age 53 years, 71% female) were treated with RTX. At 1 year, eight (57%) were improved, two (14%) were stable, three (21%) died from progressive respiratory failure, and one (7%) was lost to follow-up. Two patients experienced minor infusion reactions, and two patients discontinued therapy owing to adverse events (infections).

Conclusion

In patients with IPAF treated with RTX at two medical centres, the majority (40 [80%]) demonstrated improvement/stability at 1 year. These findings call for prospective studies, including randomized clinical trials, to determine the risks, benefits and cost effectiveness of RTX in IPAF.

Pre-existing interstitial lung disease in patients with coronavirus disease 2019: A meta-analysis

Background

The impact of pre-existing interstitial lung disease (ILD) on the severity and mortality of COVID-19 remains largely unknown. The purpose of this meta-analysis was to investigate the prevalence of ILD among patients with COVID-19 and figure out the relationship between ILD and the poor clinical outcomes of COVID-19.

Methods

A systematic literature search was conducted in the PubMed, EMBASE, Web of Science and MedRxiv Database from 1 January 2020 to 26 May 2021.

Results

15 studies with 135,263 COVID-19 patients were included for analysis of ILD prevalence. The pooled prevalence of comorbid ILD in patients with COVID-19 was 1.4% (95% CI, 1.1%-1.8%, I² = 91%) with significant between-study heterogeneity. Moreover, the prevalence of ILD in non-survival patients with COVID-19 was 2.728-folds higher than that in corresponding survival patients (RR = 2.728, 95% CI 1.162–6.408, I² = 54%, p = 0.021). Additionally, 2–3 studies were included for comparison analysis of clinical outcome between COVID-19 patients with and without ILD. The results showed that the mortality of COVID-19 patients with ILD was remarkably elevated compared with patients without ILD (RR = 2.454, 95% CI 1.111–5.421, I² = 87%, p = 0.026). Meanwhile, the pooled RR of ICU admission for ILD vs. non-ILD cases with COVID-19 was 3.064 (95% CI 1.889–4.972, I² = 0, p < 0.0001). No significant difference in utilizing rate of mechanical ventilation was observed between COVID-19 patients with and without ILD.

Conclusions

There is great variability in ILD prevalence among patients with COVID-19 across the globe. Pre-existing ILD is associated with higher severity and mortality of COVID-19.

Acetylated Diacylglycerol 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol in Autoimmune Arthritis and Interstitial Lung Disease in SKG Mice

Acetylated diacylglycerol 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) is a lipid molecule from the antlers of sika deer that might reduce inflammation by effectively controlling neutrophil infiltration, endothelial permeability and inflammatory chemokine production. Therefore, we evaluated the modulatory effect of PLAG on arthritis and interstitial lung disease (ILD) in an autoimmune arthritis model. We injected curdlan into SKG mice and PLAG was orally administered every day from 3 weeks to 20 weeks after the curdlan injection. The arthritis score was measured every week after the curdlan injection. At 20 weeks post-injection, the lung specimens were evaluated with H&E, Masson's trichrome and multiplexed immunofluorescent staining. Serum cytokines were also analyzed using a Luminex multiple cytokine assay. PLAG administration decreased the arthritis score until 8 weeks after the curdlan injection. However, the effect was not sustained thereafter. A lung histology revealed severe inflammation and fibrosis in the curdlan-induced SKG mice, which was attenuated in the PLAG-treated mice. Furthermore, immunofluorescent staining of the lung tissue showed a GM-CSF+ neutrophil accumulation and a decreased citrullinated histone 3 expression after PLAG treatment. PLAG also downregulated the levels of IL-6 and TNF-α and upregulated the level of sIL-7Rα, an anti-fibrotic molecule. Our results indicate that PLAG might have a preventative effect on ILD development through the resolution of NETosis in the lung.

Liposomes Loaded with Everolimus and Coated with Hyaluronic Acid: A Promising Approach for Lung Fibrosis

Chronic lung allograft dysfunction (CLAD) and interstitial lung disease associated with collagen tissue diseases (CTD-ILD) are two end-stage lung disorders in which different chronic triggers induce activation of myo-/fibroblasts (LFs). Everolimus, an mTOR inhibitor, can be adopted as a potential strategy for CLAD and CTD-ILD, however it exerts important side effects. This study aims to exploit nanomedicine to reduce everolimus side effects encapsulating it inside liposomes targeted against LFs, expressing a high rate of CD44. PEGylated liposomes were modified with high molecular weight hyaluronic acid and loaded with everolimus (PEG-LIP(ev)-HA400kDa). Liposomes were tested by in vitro experiments using LFs derived from broncholveolar lavage (BAL) of patients affected by CLAD and CTD-ILD, and on alveolar macrophages (AM) and lymphocytes isolated, respectively, from BAL and peripheral blood. PEG-LIP-HA400kDa demonstrated to be specific for LFs, but not for CD44-negative cells, and after loading everolimus, PEG-LIP(ev)-HA400kDa were able to arrest cell cycle arrest and to decrease phospho-mTOR level. PEG-LIP(ev)-HA400kDa showed anti-inflammatory effect on immune cells. This study opens the possibility to use everolimus in lung fibrotic diseases, demonstrating that our lipids-based vehicles can vehicle everolimus inside cells exerting the same drug molecular effect, not only in LFs, but also in immune cells.

Systemic Sclerosis Associated Interstitial Lung Disease and Nintedanib: A Rare Disease and a Promising Drug

Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is a rare disease with a progressive nature, eventually leading to lung fibrosis. Nintedanib, a tyrosine kinase inhibitor, is a widely accepted drug for treating idiopathic pulmonary fibrosis (IPF), a disease that shares some similarities with SSc-ILD regarding pathological disease processes. In this review, we aim to discuss the pathogenesis of SSc-ILD and the overall role of nintedanib in the management of SSc-ILD. SSc-ILD involves multiple pathological mediators contributing to various pathways that ultimately cause lung fibrosis. The pathogenesis of SSc-ILD is a complex phenomenon and still needs further study. Nintedanib has demonstrated its efficacy in the treatment of SSc-ILD by reducing the progression of the pathological process. It has also proven its clinical significance in the management of SSc-ILD. However, the currently available literature does not have any evidence to compare the effectiveness of nintedanib with the already available treatment modalities such as cyclophosphamide (CYC), mycophenolate mofetil (MMF), and azathioprine (AZT). The current literature also lacks information about nintedanib's long-term consequences on patients with SSc-ILD. Therefore, to create better evidence-based treatment guidelines, we recommend that researchers conduct randomized clinical trials comparing nintedanib to MMF, CYC, AZT, etc., and continue surveillance to explore the long-term consequences of nintedanib.

Emerging drug delivery strategies for idiopathic pulmonary fibrosis treatment

Idiopathic pulmonary fibrosis (IPF) is a debilitating and fatal condition that causes severe scarring of the lungs. While the pathogenesis of IPF continues to be extensively studied and several factors have been considered, an exact cause has yet to be established. With inadequate treatment options and no cure available, overall disease prognosis is still poor. Existing oral therapies, pirfenidone and nintedanib, may attempt to improve the patients' quality of life by mitigating symptoms and slowing disease progression, however chronic doses and systemic deliveries of these drugs can lead to severe side effects. The lack of effective treatment options calls for further investigation of restorative as well as additional palliative therapies for IPF. Nanoparticle-based sustained drug delivery strategies can be utilized to ensure targeted delivery for site-specific treatment as well as long-acting therapy, improving overall patient compliance. This review provides an update on promising strategies for the delivery of anti-fibrotic agents, along with an overview of key therapeutic targets as well as relevant emerging therapies currently being evaluated for IPF treatment.

Recent advances in the diagnosis and management of interstitial pneumonia with autoimmune features: the perspective of rheumatologists

Interstitial pneumonia with autoimmune feature (IPAF) is a recently established disease entity that is comprised of interstitial lung diseases with evidence of autoimmune features but that does not fulfill the criteria for definite autoimmune rheumatic diseases. The classification criteria for IPAF were defined by the European Respiratory Society and American Thoracic Society in 2015. However, further studies to establish IPAF subgroups and treatment modalities for each subgroup are still needed. In this review, we discuss recent advances regarding IPAF and raise critical points for the diagnosis and management of patients with IPAF from the perspective of rheumatologists.

Tobacco Smoking and Risk for Pulmonary Fibrosis: A Prospective Cohort Study From the UK Biobank

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease of unknown origin. A limited number of small studies show an effect of tobacco smoking on risk of IPF, but second-hand smoking has not been examined.

RESEARCH QUESTION

Are smoking-related exposures associated with risk of IPF and does interaction between them exist?

STUDY DESIGN AND METHODS

We designed a prospective cohort study using UK Biobank data, including 437,453 nonrelated men and women of White ethnic background (40-69 years of age at baseline). We assessed the effect of tobacco smoking-related exposures on risk for IPF using Cox regression adjusted for age, sex, Townsend deprivation index, and home area population density. We also examined potential additive and multiplicative interaction between these exposures. Multiple imputation with chained equations was used to address missing data.

RESULTS

We identified 802 incident IPF cases. We showed an association between smoking status (hazard ratio [HR], 2.12; 95% CI, 1.81-2.47), and maternal smoking (HR, 1.38; 95% CI, 1.18-1.62) with risk of IPF. In ever smokers, a dose-response relationship was observed between pack-years of smoking and risk of IPF (HR per 1-pack-year increase, 1.013; 95% CI, 1.009-1.016). Furthermore, an additive and multiplicative interaction was observed between maternal smoking and smoking status, with a relative excess risk due to interaction of 1.00 (95% CI, 0.45-1.54) and a ratio of HRs of 1.50 (95% CI, 1.05-2.14).

INTERPRETATION

Active and maternal tobacco smoking have an independent detrimental effect on risk of IPF and work synergistically. Also, intensity of smoking presents a dose-response association with IPF, strengthening the hypothesis for a potentially causal association.

Safety and efficacy of rituximab in connective tissue disease-associated interstitial lung disease: A systematic review and meta-analysis

OBJECTIVE

Rituximab (RTX) is widely used in the treatment of connective tissue disease (CTD) because it can target and eliminate pathogenic B cells. Interstitial lung disease (ILD) is one of the common complications of CTD; however, the clinical benefits of RTX in connective tissue disease-associated interstitial lung disease (CTD-ILD) are still controversial. This meta-analysis was performed to systematically evaluate the efficacy and safety of RTX in CTD-ILD patients.

METHODS

We performed a systematic online query in PubMed, Cochrane, and Embase up to February 2020. Randomized controlled trials and observational studies on the use of RTX and conventional treatment in CTD-ILD patients were comprehensively reviewed and investigated.

RESULTS

In total, 6 studies, including 242 participants, were analysed. The pooled results showed that RTX is superior to conventional treatment methods in improving forced vital capacity and modified Rodnan skin scores (MRSS) in patients with systemic sclerosis (P＜0. 05), but there was no statistically significant difference between RTX and conventional treatment method in the improvement of lung diffusion function. The risk of adverse effects declined in the RTX therapy groups compared with the conventional therapy groups in terms of infection and the blood system.

CONCLUSION

The pooled results of this meta-analysis indicated that RTX is well tolerated, and RTX is able to improve or stabilize pulmonary function in CTD-ILD patients.

Pulmonary Manifestations of Rheumatic Diseases in Children

Children with rheumatic disease have rare pulmonary manifestations that may cause significant morbidity and mortality. These children are often clinically asymptomatic until disease has significantly progressed, so they should be screened for pulmonary involvement. There has been recent recognition of a high mortality-related lung disease in systemic-onset juvenile idiopathic arthritis; risk factors include onset of juvenile idiopathic arthritis less than 2 years of age, history of macrophage activation syndrome, presence of trisomy 21, and history of anaphylactic reaction to biologic therapy. Early recognition and treatment of lung disease in children with rheumatic diseases may improve outcomes.

Air pollutants and development of interstitial lung disease in patients with connective tissue disease: a population-based case-control study in Taiwan

OBJECTIVE

The aim of this study was to assess the association between air pollutant exposure and interstitial lung disease (ILD) in patients with connective tissue diseases (CTDs).

SETTING

A nationwide, population-based, matched case-control study in Taiwan.

PARTICIPANTS

Using the 1997-2013 Taiwanese National Health Insurance Research Database, we identified patients with newly diagnosed CTD during 2001-2013, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), dermatomyositis (DMtis)/polymyositis (PM) and primary Sjögren's syndrome (pSS).

PRIMARY AND SECONDARY OUTCOME MEASURES

Patients with newly diagnosed ILD during 2012-2013 were identified as ILD cases, and selected patients with CTD without ILD matching (1:4) the CTD cases for CTD diagnosis, age, gender, disease duration and year of ILD diagnosis date were identified as non-ILD controls. Data of hourly level of air pollutants 1 year before the index date were obtained from the Taiwan Environmental Protection Agency. The association between ILD and air pollutant exposure was evaluated using logistic regression analysis shown as adjusted ORs (aORs) with 95% CIs after adjusting for potential confounders.

RESULTS

We identified 505 newly diagnosed CTD-ILD patients, including 82 with SLE, 210 with RA, 47 with SSc, 44 with DMtis/PM and 122 with pSS. Ozone (O₃) exposure (per 10 ppb) was associated with a decreased ILD risk in patients with CTD (aOR, 0.51; 95% CI, 0.33 to 0.79) after adjusting for potential confounders.

CONCLUSIONS

A previously unrecognised inverse correlation was found between O₃ exposure and ILD in patients with RA and SSc. Further studies are warranted to explore the underlying mechanisms.

Automated CT Analysis of Major Forms of Interstitial Lung Disease

This study aimed to determine diagnostic and prognostic differences in major forms of interstitial lung disease using quantitative CT imaging. A retrospective study of 225 subjects with a multidisciplinary diagnosis of idiopathic pulmonary fibrosis (IPF), interstitial pneumonia with autoimmune features (IPAF), connective tissue disease (CTD), or chronic hypersensitivity pneumonitis (cHP) was conducted. Non-contrast CT scans were analyzed using the Computer Aided Lung Informatics for Pathology Evaluation and Rating (CALIPER) program. Resulting data were analyzed statistically using ANOVA and Student’s t-test. Univariate, multivariable, and receiver operating characteristic analyses were conducted on patient mortality data. CALIPER analysis of axial distribution on CT scans in those with IPF demonstrated greater peripheral volumes of reticulation than either CTD (p = 0.033) or cHP (p = 0.007). CTD showed lower peripheral ground-glass opacity than IPF (p = 0.005) and IPAF (p = 0.004). Statistical analysis of zonal distributions revealed reduced lower zone ground-glass opacity in cHP than IPF (p = 0.044) or IPAF (p = 0.018). Analysis of pulmonary vascular-related structure (VRS) volume by diagnosis indicated greater VRS volume in IPF compared to CTD (p = 0.003) and cHP (p = 0.003) as well as in IPAF compared to CTD (p = 0.007) and cHP (p = 0.007). Increased reticulation (p = 0.043) and ground glass opacity (p = 0.032) were predictive of mortality on univariate analysis. Increased pulmonary VRS volume was predictive of mortality (p < 0.001) even after multivariate analysis (p = 0.041). Quantitative CT imaging revealed significant differences between ILD diagnoses in specific CT findings in axial and, to a lesser degree, zonal distributions. Increased pulmonary VRS volume seems to be associated with both diagnosis and survival.

The potential utility of anterior upper lobe honeycomb-like lesion in interstitial lung disease associated with connective tissue disease

BACKGROUND

Interstitial lung disease (ILD) is associated with high morbidity and mortality in patients with connective tissue disease (CTD). Because some patients with CTD overlap present with ILD first, with CTD diagnosed later, specific radiologic signs are needed to help differentiate each CTD or CTD-ILD from idiopathic ILD.

OBJECTIVES

To determine whether specific CT findings can help differentiate CTD as rheumatoid arthritis (RA), systemic sclerosis (SSc), or polymyositis/dermatomyositis (PM/DM).

METHODS

We analyzed 143 consecutive ILD patients with RA, SSc, or PM/DM. We assessed diagnostic accuracy of CT findings of CTD-ILD, CT pattern, and signs including "anterior upper lobe honeycomb-like lesion" and "low attenuation area (LAA) within an interstitial abnormality" for each CTD-ILD. Prognostic predictors were determined using Cox regression models.

RESULTS

Subjects were 78 patients with RA-ILD, 38 with SSc-ILD, 24 with PM/DM-ILD, and 3 with overlapping CTD-ILD. High frequency of anterior upper lobe honeycomb-like lesion suggests that CTD-ILD is due to RA-ILD (22%) rather than SSc-ILD (8%) or PM/DM-ILD (8%), whereas LAA within an interstitial abnormality suggests that CTD-ILD is due to SSc-ILD (26%) rather than RA-ILD (4%) or PM/DM-ILD (0%). Multivariate analysis showed that while not associated with survival, current or ex-smoker, honeycombing, and acute exacerbation were negative prognostic factors of mortality.

CONCLUSIONS

The tendency is high for RA-ILD, in which anterior upper lobe honeycomb-like lesion is a specific feature, to show UIP or NSIP/UIP pattern, combined emphysema, and honeycombing; SSc-ILD to show NSIP pattern and LAA within an interstitial abnormality; and PM/DM-ILD to show NSIP pattern and non-honeycombing.

Increases in tumor markers are associated with primary Sjögren's syndrome-associated interstitial lung disease

Aims:

Interstitial lung disease (ILD) is the most common type of pulmonary involvement of extraglandular complication in patients with primary Sjögren’s syndrome (pSS), but the diagnosis of pSS-associated ILD (pSS-ILD) is still challenging. This study aimed to investigate the levels of serum tumor markers in pSS patients with or without ILD (pSS-non-ILD) and explore its diagnostic value for pSS-ILD.

Methods:

A total of 168 pSS-ILD patients and age- and sex-matched 538 pSS-non-ILD were recruited. The levels of peripheral tumor markers, including carbohydrate antigen (CA)153, CA125, CA19-9, carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), β-human chorionic gonadotropin, alpha fetoprotein, CA724, and complexed prostate specific antigen, the clinical manifestations, and general laboratory indicators were measured and collected.

Results:

Compared with pSS-non-ILD, pSS-ILD patients had higher levels of disease activity indicators, such as EULAR Sjögren’s syndrome disease activity index, ESR, and CRP, and elevated serum levels of tumor markers: NSE, CEA, CA125, and CA153. The serum levels of CA153 [odds ratio (OR) = 4.521, 95% confidence interval (CI) = [1.871, 10.928)] and CEA [OR = 2.879, 95% CI = (1.305, 6.353)] were significantly correlated with the onset of SS-ILD. CA153 was the only tumor marker with area under receiver operating characteristic curve (AUC) over 0.7 [AUC = 0.743, 95% CI = (0.70, 0.79)].

Conclusion:

Tumor markers increased in serum of pSS-ILD patients. Higher CA153 levels are significantly correlated to the increased risk of ILD in patients with pSS and may be directly involved in the pathogenesis of pSS-ILD. Serum CA153 had the best diagnostic value in those tumor markers for pSS-ILD without malignancy.

Connective Tissue Disease-Associated Interstitial Lung Disease: Evaluation and Management

Interstitial lung disease is common among patients with connective tissue disease and is an important contributor to morbidity and mortality. Infection and drug toxicity must always be excluded as the cause of radiographic findings. Immunosuppression remains a mainstay of therapy despite few controlled trials supporting its use. When a decision regarding therapy initiation is made, considerations include an assessment of disease severity as well as a determination of the rate of progression. Because patients may have extrathoracic disease activity, a multidisciplinary approach is crucial and should include supportive and nonpharmacologic management strategies.