Fragmented gelsolins are increased in rheumatoid arthritis-associated interstitial lung disease with usual interstitial pneumonia pattern

Biomarkers of rheumatoid arthritis-associated interstitial lung disease: a systematic review and meta-analysis

Background

Interstitial Lung Disease (ILD) represents the most common extra-articular manifestation of Rheumatoid Arthritis (RA) and is a major cause of mortality. This study aims to identify and evaluate biomarkers associated with Rheumatoid Arthritis-Associated Interstitial Lung Disease (RA-ILD).

Methods

We searched PubMed, Cochrane Library, EMBASE, and Web of Science databases for studies related to biomarkers of RA-ILD up until October 7, 2023. The Newcastle-Ottawa Scale (NOS) and standards recommended by the Agency for Healthcare Research and Quality (AHRQ) were used for quality assessment, and meta-analysis was conducted using Stata18.0 software.

Results

A total of 98 articles were assessed for quality, 48 of which were included in the meta-analysis. 83 studies were of high quality, and 15 were of moderate quality. The meta-analysis showed significant differences in biomarkers such as C-Reactive Protein (CRP), Erythrocyte Sedimentation Rate (ESR), Anti-Cyclic Citrullinated Peptide (anti-CCP) antibody, Rheumatoid Factor (RF), Krebs von den Lungen-6 (KL-6), Surfactant Protein D (SP-D), Carcinoembryonic Antigen (CEA), Carbohydrate Antigen 19-9 (CA19-9), Matrix Metalloproteinase-7 (MMP-7), C-X-C Motif Chemokine Ligand 10 (CXCL-10), and Neutrophil-to-Lymphocyte Ratio (NLR) between RA-ILD patients and RA patients. However, Platelet-to-Lymphocyte Ratio [Platelet-to-Lymphocyte Ratio (PLR)], Cancer Antigen 125 [Cancer Antigen 125 (CA-125)], and Cancer Antigen 153 [Cancer Antigen 153 (CA-153)] did not show significant differences between the two groups. KL-6, MMP-7, and Human Epididymis Protein 4 (HE4) are negatively correlated with lung function, and KL-6 is associated with the prognosis of RA-ILD.

Conclusions

Biomarkers hold promising clinical value for prediction, diagnosis, severity assessment, and prognosis evaluation in RA-ILD. However, these findings need to be validated through multicenter, large-sample, prospective cohort studies.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023448372.

Etiology and Pathogenesis of Rheumatoid Arthritis-Interstitial Lung Disease

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

Proteomics: Potential techniques for discovering the pathogenesis of connective tissue diseases-interstitial lung disease

Interstitial lung disease (ILD) is one of the most serious lung complications of connective tissue disease (CTD). The application of proteomics in the past decade has revealed that various proteins are involved in the pathogenesis of each subtype of CTD-ILD through different pathways, providing novel ideas to study pathological mechanisms and clinical biomarkers. On this basis, a multidimensional diagnosis or prediction model is established. This paper reviews the results of proteomic detection of different subtypes of CTD-ILD and discusses the role of some differentially expressed proteins in the development of pulmonary fibrosis and their potential clinical applications.

Biomarkers in Progressive Fibrosing Interstitial Lung Disease: Optimizing Diagnosis, Prognosis, and Treatment Response

Interstitial lung disease (ILD) comprises a heterogenous group of diffuse lung disorders that commonly result in irreversible pulmonary fibrosis. While idiopathic pulmonary fibrosis (IPF) is the prototypical progressive fibrosing ILD (PF-ILD), a high proportion of patients with other ILD subtypes develop a PF-ILD phenotype. Evidence exists for shared pathobiology leading to progressive fibrosis, suggesting that biomarkers of disease activity may prove informative across the wide spectrum of ILDs. Biomarker investigation to date has identified a number of molecular markers that predict relevant ILD endpoints, including disease presence, prognosis, and/or treatment response. In this review, we provide an overview of potentially informative biomarkers in patients with ILD, including those suggestive of a PF-ILD phenotype. We highlight the recent genomic, transcriptomic, and proteomic investigations that identified these biomarkers and discuss the body compartments in which they are found, including the peripheral blood, airway, and lung parenchyma. Finally, we identify critical gaps in knowledge within the field of ILD biomarker research and propose steps to advance the field toward biomarker implementation.

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

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

Development of a Novel Diagnostic Biomarker Set for Rheumatoid Arthritis Using a Proteomics Approach

Background

Rheumatoid arthritis (RA) is an autoimmune disease that starts with inflammation of the synovial membrane. Studies have been conducted to develop methods for efficient diagnosis of RA and to identify the mechanisms underlying RA development. Blood samples can be useful for detecting disturbance of homeostasis in patients with RA. Nanoliquid chromatography-tandem mass spectrometry (LC-MS/MS) is an efficient proteomics approach to analyze blood sample and quantify serum proteins.

Methods

Serum samples of 18 healthy controls and 18 patients with RA were analyzed by LC-MS/MS. Selected candidate biomarkers were validated by enzyme-linked immunosorbent assay (ELISA) using sera from 43 healthy controls and 44 patients with RA.

Results

Thirty-eight proteins were significantly differentially expressed by more than 2-fold in healthy controls and patients with RA. Based on a literature survey, we selected six candidate RA biomarkers. ELISA was used to evaluate whether these proteins effectively allow distinguishing patients with RA from healthy controls and monitoring drug efficacy. SAA4, gelsolin, and vitamin D-binding protein were validated as potential biomarkers of RA for screening and drug efficacy monitoring of RA.

Conclusions

We identified a panel of three biomarkers for RA which has potential for application in RA diagnosis and drug efficacy monitoring. Further, our findings will aid in understanding the pathogenesis of RA.

Identification of apolipoprotein A-I in BALF as a biomarker of sarcoidosis

Background: Sarcoidosis goes into remission in two-thirds of patients with sarcoidosis, but about 20 % of patients develop pulmonary fibrosis. The mechanisms of pulmonary fibrosis in sarcoidosis and differences in pathogenesis between clinical stages are still unclear. Objectives: The aim of this study was investigating proteins associated with clinical stages by comparing bronchoalveolar lavage fluid (BALF) protein between stage I and stage IV using proteome analysis. Methods: Proteomic differences in BALF were compared between stage I and stage IV by examining BALF from 8 stage I patients and 5 stage IV patients by two-dimensional gel electrophoresis and mass spectrometry. Results: In individual comparisons of BALF samples, the levels of apolipoprotein (Apo) A-I fragment, fibrinogen γ chain, calcyphosine, complement C3, and surfactant protein A were significantly higher in stage I than in stage IV. In contrast, none of the proteins examined significantly higher in stage IV than in stage I. To confirm the results of Apo A-I in the BALF proteome, we performed enzyme-linked immunosorbent assay (ELISA) in a larger group. The concentration of BALF Apo A-I was significantly higher in stage I patients than in stage IV patients (0.70 [0.13-0.89] vs. 0.15 [0.08-0.21] ng/μg protein, p=0.003). Conclusion: The involvement of BALF Apo A-I in sarcoidosis may differ between stage I and stage IV. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 5-15).

Recent advances in the pathogenesis, prediction, and management of rheumatoid arthritis-associated interstitial lung disease

PURPOSE OF REVIEW

To provide an overview of recently published articles covering interstitial lung disease associated with rheumatoid arthritis (RA-ILD).

RECENT FINDINGS

Over the past year, many studies replicated previous findings in more diverse and occasionally larger populations internationally. Specifically, the association among cigarette smoking, high rheumatoid factor titer, elevated anticitrullinated protein antibody (ACPA) levels, and RA-ILD was strengthened. Clinical characteristics, autoantibodies, and biomarkers to aid in RA-ILD development, progression, and mortality prediction were explored. Finally, direct and indirect treatment effects were highlighted.

SUMMARY

The ability to identify risk factors for preclinical RA-ILD has been enhanced, but the proper management strategy for these patients is yet to be defined. ACPAs and cigarette smoking are highly associated with RA-ILD, but the mechanistic relationship between lung injury and autoantibody generation remains unknown. There is conflicting evidence regarding the significance of a usual interstitial pneumonia (UIP) versus non-UIP pattern on high-resolution computed tomography. The use of biologic agents in patients with rheumatoid arthritis does not appear to increase the risk of incident ILD or RA-ILD exacerbation. Randomized prospective studies of specific therapy for RA-ILD are still lacking.