Diagnosis and management of rheumatoid arthritis; What is the current role of established and new imaging techniques in clinical practice?

Implementation of artificial intelligence models in magnetic resonance imaging with focus on diagnosis of rheumatoid arthritis and axial spondyloarthritis: narrative review

Early diagnosis in rheumatoid arthritis (RA) and axial spondyloarthritis (axSpA) is essential to initiate timely interventions, such as medication and lifestyle changes, preventing irreversible joint damage, reducing symptoms, and improving long-term outcomes for patients. Since magnetic resonance imaging (MRI) of the wrist and hand, in case of RA and MRI of the sacroiliac joints (SIJ) in case of axSpA can identify inflammation before it is clinically discernible, this modality may be crucial for early diagnosis. Artificial intelligence (AI) techniques, together with machine learning (ML) and deep learning (DL) have quickly evolved in the medical field, having an important role in improving diagnosis, prognosis, in evaluating the effectiveness of treatment and monitoring the activity of rheumatic diseases through MRI. The improvements of AI techniques in the last years regarding imaging interpretation have demonstrated that a computer-based analysis can equal and even exceed the human eye. The studies in the field of AI have investigated how specific algorithms could distinguish between tissues, diagnose rheumatic pathology and grade different signs of early inflammation, all of them being crucial for tracking disease activity. The aim of this paper is to highlight the implementation of AI models in MRI with focus on diagnosis of RA and axSpA through a literature review.

Distinct Fluorescence Optical Imaging Patient Clusters Emerge for Seropositive and Seronegative Rheumatoid Arthritis

OBJECTIVE

To investigate whether digital activity fluorescence optical imaging (FOI) patterns of inflammation can identify distinct rheumatoid arthritis (RA) phenotypes.

METHODS

The hands of newly diagnosed patients with RA were evaluated by clinical examination, musculoskeletal ultrasound, and FOI. Inflammation on FOI was defined when capillary leakage and/or fluorophore perfusion was present. The FOI composite image was quantified into a digital disease activity (DACT) score, using novel computerized algorithms. Unsupervised clustering on FOI inflammatory patterns was used to identify subgroups of patients relative to anticyclic citrullinated peptides (ACPA) and/or rheumatoid factor (RF).

RESULTS

Of 1326 examined hand joints in 39 patients with RA (72% female; 56% ever-smokers; 54% RF positive and 69% ACPA positive), 400 (30%) showed inflammation by FOI, and 95% (37 of 39) of patients had DACT-FOI scores greater than 1. Unsupervised analysis on FOI patterns revealed two patient clusters, cluster 1 (n = 29) and cluster 2 (n = 10). The proportion of seropositive patients was significantly higher in cluster 1 versus cluster 2 (90%, 26 of 29 vs. 30%, 3 of 10; P < 0.01), whereas C-reactive-protein levels (minimum-maximum) were significantly higher in cluster 2 (20 mg/l [1-102]) versus cluster 1 (2 mg/l [0-119]; P = 0.01). A wider variety and proportion of inflamed joints emerged for patients with RA in cluster 2 versus cluster 1, in which inflammation was more concentrated around the wrists and the right metacarpophalangeal 2 (MCP2), bilateral MCP3, and, to a lesser degree, left MCP2 and proximal interphalangeal joint and tendon regions. Cluster 1 displayed lower mean (±SD) DACT scores compared with cluster 2 (3.6 ± 2.1 vs. 5.4 ± 2.1; P = 0.03).

CONCLUSION

FOI-based digital quantification of hand joint inflammation revealed two distinct RA subpopulations with and without ACPA and RF related autoantibodies.

The elucidation of the anti-inflammatory mechanism of EMO in rheumatoid arthritis through an integrative approach combining bioinformatics and experimental verification

Introduction: Emodin (EMO), a natural derivative of the anthraquinone family mainly extracted from rhubarb (Rheum palmatum), has previously been demonstrated to possess superior anti-inflammatory properties from a single target or pathway. In order to explore the underlying mechanism of action of EMO against rheumatoid arthritis (RA), a network pharmacology approach was employed. Methods: A gene expression profile from GSE55457 available from the Gene Expression Omnibus (GEO) database was used to identify the targets of EMO action. Further, single cell RNA sequencing data from GEO database of RA patients (GSE159117) were downloaded and analysed. To further investigate the anti-RA effect of EMO on MH7A cells, the expression of IL-6 and IL-1β were monitored. Finally, RNA-seq analyses were conducted on synovial fibroblasts from EMO-treated. Result: We screened the key targets of EMO against RA using network pharmacology methods, including HMGB1, STAT1, EGR1, NR3C1, EGFR, MAPK14, CASP3, CASP1, IL4, IL13, IKBKB and FN1, and their reliability was verified using ROC curve. Single-cell RNA sequencing data analysis showed that these core target proteins mainly played a role by modulating monocytes. The anti-RA effect of EMO was further verified with MH7A cells, which showed that EMO could block cell differentiation and reduce the expression of IL-6 and IL-1β. WB experiments confirmed that EMO could affect the expression of COX2, HMBG1 and the phosphorylation of p38. Finally, sequencing of synovial fibroblasts from rats treated with EMO showed consistent results with those predicted and verified, further proving the anti-inflammatory effect of EMO. Conclusion: Our research shows that EMO inhibits inflammatory response of rheumatoid arthritis (RA) by targeting HMGB1, STAT1, EGR1, NR3C1, EGFR, MAPK14, CASP3, CASP1, IL4, IL13, IKBKB, FN1 and Monocytes/macrophages.

An Evidence-Based Update on the Potential Association between Rheumatoid Arthritis and Lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) represents an uncommon disorder characterized by cystic lung destruction and chronic respiratory failure. Lung damage caused by various mechanisms may represent a hypothesis for studying the association between LAM and rheumatoid arthritis (RA), which is the most prevalent autoinflammatory rheumatic disease and may affect the lungs as an extra-articular manifestation. Despite their distinct clinical presentations, the pathophysiology of both disorders includes dysregulated immunological function, abnormal cellular development, and inflammation. Current research suggests a potential relationship between RA and LAM, as some RA patients have been reported to develop LAM. However, the association of RA and LAM raises important therapeutic dilemmas. For this reason, the trajectory of a patient who was identified in our medical records as suffering from both LAM and RA, treated with many novel molecules and biological therapy, but with a negative outcome due to respiratory and multiorgan failure, has been exemplified. The delay in the diagnosis of LAM is due to a correlation between RA and LAM, worsening the vital prognosis and also hindering pulmonary transplantation. In addition, extensive research is essential for understanding the potential connection between these two disorders and discovering any similar mechanisms involved that may underlie their occurrence. This may contribute to the development of new therapeutic options that target shared pathways implicated in the pathogenesis of RA and LAM.

Practical Implementation of Artificial Intelligence-Based Deep Learning and Cloud Computing on the Application of Traditional Medicine and Western Medicine in the Diagnosis and Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA), an autoimmune disease of unknown etiology, is a serious threat to the health of middle-aged and elderly people. Although western medicine, traditional medicine such as traditional Chinese medicine, Tibetan medicine and other ethnic medicine have shown certain advantages in the diagnosis and treatment of RA, there are still some practical shortcomings, such as delayed diagnosis, improper treatment scheme and unclear drug mechanism. At present, the applications of artificial intelligence (AI)-based deep learning and cloud computing has aroused wide attention in the medical and health field, especially in screening potential active ingredients, targets and action pathways of single drugs or prescriptions in traditional medicine and optimizing disease diagnosis and treatment models. Integrated information and analysis of RA patients based on AI and medical big data will unquestionably benefit more RA patients worldwide. In this review, we mainly elaborated the application status and prospect of AI-assisted deep learning and cloud computation-oriented western medicine and traditional medicine on the diagnosis and treatment of RA in different stages. It can be predicted that with the help of AI, more pharmacological mechanisms of effective ethnic drugs against RA will be elucidated and more accurate solutions will be provided for the treatment and diagnosis of RA in the future.

Nanomaterials for the Diagnosis and Treatment of Inflammatory Arthritis

Nanomaterials have received increasing attention due to their unique chemical and physical properties for the treatment of rheumatoid arthritis (RA), the most common complex multifactorial joint-associated autoimmune inflammatory disorder. RA is characterized by an inflammation of the synovium with increased production of proinflammatory cytokines (IL-1, IL-6, IL-8, and IL-10) and by the destruction of the articular cartilage and bone, and it is associated with the development of cardiovascular disorders such as heart attack and stroke. While a number of imaging tools allow for the monitoring and diagnosis of inflammatory arthritis, and despite ongoing work to enhance their sensitivity and precision, the proper assessment of RA remains difficult particularly in the early stages of the disease. Our goal here is to describe the benefits of applying various nanomaterials as next-generation RA imaging and detection tools using contrast agents and nanosensors and as improved drug delivery systems for the effective treatment of the disease.

Should ultrasound be used routinely in the diagnosis of rheumatoid arthritis?

INTRODUCTION

A growing body of evidence indicates the benefits of early diagnosis of rheumatoid arthritis (RA) and prompt treatment with disease-modifying anti-rheumatic drugs (DMARDS) in terms of relieving symptoms, improving prognosis, and reducing long-term complications. There is however some controversy over the most beneficial method of imaging in providing accurate early diagnosis. Though current practice favours clinical and radiological assessment, this is increasingly supplemented by ultrasound techniques (and, to a lesser extent, CT and MRI scanning). While EULAR and ESSR favour the use of ultrasonography (US) as the first-line investigation in cases of suspected RA, a recent NICE review upholds the traditional place of plain film radiographs of hands and feet to detect erosions as early signs of synovitis. This review considers the evidence for US in the early diagnosis of RA and the case for it becoming the primary assessment modality in rheumatology clinics.

AIMS

This paper aims to assess the current literature on the efficacy of ultrasonography in diagnosing early RA, by comparing US with alternative imaging modalities. The goal is to propose the most appropriate method of diagnosis to improve early initiation of DMARD treatment for optimum disease outcomes.

METHODS

Searches for related studies and review articles were carried out using electronic databases and hand searches. Additional references were gleaned from the bibliographies of included papers. Related articles and pop-outs from PubMed were also used. The search was refined in PubMed, by only using reviews which were written in English and published in past 10 years and had full free text available.

RESULTS

This review confirms that US has a high level of sensitivity in diagnosing RA (and hence a low risk of missing cases of RA which might benefit from early treatment with DMARDs). It also has a high level of specificity (and hence a low risk of falsely diagnosing somebody with RA who may suffer adverse effects of DMARD therapy). US is already widely available and well accepted by clinicians and patients. It does not involve exposure to radiation and can be readily delivered by appropriately trained staff.

CONCLUSION

This review of relevant studies indicates that US should become accepted as the investigation with the most favourable balance of benefits to risks in the early diagnosis of RA. Given the continuing controversy surrounding studies of different imaging techniques in RA, further research into the diagnostic role of US in RA is indicated.

Radiographic changes in TMJ in relation to serology and disease activity in RA patients

OBJECTIVES

This study was undertaken as an attempt to assess radiographic temporomandibular joint (TMJ) changes in relation to rheumatoid factor (RF), anticitrullinated protein (ACCP) antibodies and disease activity score 28 (DAS28) in rheumatoid arthritis (RA) patients to find the best predictor of rheumatoid affection of the TMJ with the ultimate goal of maintaining TMJ function and preventing joint damage.

METHODS

20 Rheumatoid Arthritis patients as well as 20 volunteers were included in this study. RA group were assessed for RF, ACCP, DAS28. Both groups were assessed by CBCT for TMJ dimensions and radiographic osteoarthritic changes. All data were statistically analyzed.

RESULTS

Rheumatoid Arthritis group showed significantly less condylar height and more radiographic osteoarthritic changes than the control group. RF showed no significant correlation with either TMJ measurements or TMJ radiographic osteoarthritic changes. ACCP showed significant inverse correlation with condylar height and anteroposterior (AP) dimensions, but non-significant relation with mediolateral dimension and radiographic osteoarthritic changes. DAS28 showed significant inverse correlation with condylar AP and mediolateral dimensions. It also showed significant correlation with flattening of the TMJ condylar head and flattening of the articular fossa. Patients with high and moderate disease activity showed significantly smaller AP TMJ dimension than patients with low disease activity. Disease activity showed statistically significant direct correlation with all osteoarthritic changes except for erosions of the glenoid fossa and condyle.

CONCLUSION

Disease Activity Score28 score and disease activity are strong indicators of TMJ affection in RA patients when compared to RF and ACCP. ACCP is a better indicator of changes in condylar measurements than TMJ osteoarthritic changes. While RF is the least efficient indicator of TMJ involvement in RA patients.

The folate receptor β as a macrophage-mediated imaging and therapeutic target in rheumatoid arthritis

Macrophages play a key role in the pathophysiology of rheumatoid arthritis (RA). Notably, positive correlations have been reported between synovial macrophage infiltration and disease activity as well as therapy outcome in RA patients. Hence, macrophages can serve as an important target for both imaging disease activity and drug delivery in RA. Folate receptor β (FRβ) is a glycosylphosphatidyl (GPI)-anchored plasma membrane protein being expressed on myeloid cells and activated macrophages. FRβ harbors a nanomolar binding affinity for folic acid allowing this receptor to be exploited for RA disease imaging (e.g., folate-conjugated PET tracers) and therapeutic targeting (e.g., folate antagonists and folate-conjugated drugs). This review provides an overview of these emerging applications in RA by summarizing and discussing properties of FRβ, expression of FRβ in relation to macrophage polarization, FRβ-targeted in vivo imaging modalities, and FRβ-directed drug targeting.

The application value of MRI in the diagnosis of subclinical inflammation in patients with rheumatoid arthritis in remission

Background

To explore the value of MRI in the diagnosis of subclinical inflammation in patients with early rheumatoid arthritis (RA) in remission and to predict the radiographic progression.

Methods

A total of 76 of 156 patients with early RA in remission at 1 year and with available magnetic resonance imaging (MRI) data at baseline and at 12 months were included. Complete clinical and laboratory evaluations were conducted for the patients. MRI images were assessed according to the Rheumatoid Arthritis Magnetic Resonance Imaging Scoring (RAMRIS) system. Progression of bone erosions was defined as an increase of 1 or more units in annual RAMRIS score for erosions compared to baseline.

Results

At 1 year, the majority of patients with RA in sustained remission showed some inflammatory activity on MRI (43.4% synovitis, 39.5% bone marrow edema (BME), and 9.2% tenosynovitis), and 25 of the 76 patients (32.9%) showed MRI progression of bone erosions. A significant difference was observed in MRI BME and bone erosion at 1 year, with higher mean score in patients with progression compared to non-progression of erosions (BME, 4.8 ± 3.6 vs 3.1 ± 2.1, P = 0.01; bone erosion, 13.5 ± 9.6 vs 4.4 ± 3.6, P < 0.001).

Conclusion

Persistent subclinical inflammations were shown in patients with sustained remission; BME in MRI may be a strong predictor of future radiographic progression of bone erosions in patients with persistent clinical remission.

The role of imaging in early diagnosis and prevention of joint damage in inflammatory arthritis

INTRODUCTION

Inflammatory arthritis is characterized by chronic inflammation in the synovium, associated with degradation of cartilage and erosion of juxta-articular bone. The bone loss and joint destruction mediated by aberrant immunological responses resulting in proinflammatory cytokine release and various immune cell activation are known as osteoimmunology. Areas covered: A structured literature search including Medline and PubMed, Cochrane meta-analyses and abstracts of international congresses was performed to review joint damage in inflammatory arthritis in terms of pathogenesis, novel imaging assessment, and prevention. Expert commentary: Deeper understanding of the integration of the skeletal and immune as well as inflammatory system is paving the way to prevent bone loss and bone destruction in inflammatory arthritis. With the availability of various imaging modalities such as ultrasound, magnetic resonance imaging (MRI) and high-resolution peripheral quantitative computed tomography (HR-pQCT), we are now able to detect early joint damage, early diagnosis of inflammatory arthritis, monitor the progression or even ascertain whether the inflammatory process is effectively suppressed to allow repair of joint damage by novel therapeutic agents.

[Big data in imaging]

Until now, most major medical advancements have been achieved through hypothesis-driven research within the scope of clinical trials. However, due to a multitude of variables, only a certain number of research questions could be addressed during a single study, thus rendering these studies expensive and time consuming. Big data acquisition enables a new data-based approach in which large volumes of data can be used to investigate all variables, thus opening new horizons. Due to universal digitalization of the data as well as ever-improving hard- and software solutions, imaging would appear to be predestined for such analyses. Several small studies have already demonstrated that automated analysis algorithms and artificial intelligence can identify pathologies with high precision. Such automated systems would also seem well suited for rheumatology imaging, since a method for individualized risk stratification has long been sought for these patients. However, despite all the promising options, the heterogeneity of the data and highly complex regulations covering data protection in Germany would still render a big data solution for imaging difficult today. Overcoming these boundaries is challenging, but the enormous potential advances in clinical management and science render pursuit of this goal worthwhile.

Role of ultrasound imaging in individuals at risk of RA

Early diagnosis and treatment improves outcomes for patients with rheumatoid arthritis (RA). Studies have shown that musculoskeletal ultrasound is more sensitive than clinical examination in identifying synovitis. This review aims to address the role of ultrasound in identifying (1) patients with early inflammatory arthritis (IA) at risk of progression to RA and (2) those without clinical synovitis at risk of progression to early IA and therefore early RA.

Complexes of DNA with fluorescent dyes are effective reagents for detection of autoimmune antibodies

To date, there are multiple assays developed that detect and quantify antibodies in biofluids. Nevertheless, there is still a lack of simple approaches that specifically detect autoimmune antibodies to double-stranded DNA. Herein we investigate the potential of novel nucleic acid complexes as targets for these antibodies. This is done in a simple, rapid and specific immunofluorescence assay. Specifically, employing 3D nanostructures (DNA origami), we present a new approach in the detection and study of human antibodies to DNA. We demonstrate the detection of anti-DNA antibodies that are characteristic of systemic lupus erythematosus, a chronic autoimmune disease with multiple manifestations. We tested the most potent non-covalent pairs of DNA and fluorescent dyes. Several complexes showed specific recognition of autoimmune antibodies in human samples of lupus patients using a simple one-step immunofluorescence method. This makes the novel assay developed herein a promising tool for research and point-of-care monitoring of anti-DNA antibodies. Using this method, we for the first time experimentally confirm that the disease-specific autoimmune antibodies are sensitive to the 3D structure of nucleic acids and not only to the nucleotide sequence, as was previously thought.

Technetium-99m based small molecule radiopharmaceuticals and radiotracers targeting inflammation and infection

^99mTc-labeled antibiotics, antifungal drugs, antimicrobial peptides and COX-2 inhibitors are comprehensively reviewed.