Effects of Biological Therapies on Molecular Features of Rheumatoid Arthritis

Personalized cardiovascular risk assessment in Rheumatoid Arthritis patients using circulating molecular profiles and their modulation by TNFi, IL6Ri, and JAKinibs

BACKGROUND & OBJECTIVES

This study aimed to: 1) analyze the inflammatory profile of Rheumatoid Arthritis (RA) patients, identifying clinical phenotypes associated with cardiovascular (CV) risk; 2) evaluate biologic and targeted-synthetic disease-modifying antirheumatic drugs (b-DMARDs and ts-DMARDs': TNFi, IL6Ri, JAKinibs) effects; and 3) characterize molecular mechanisms in immune-cell activation and endothelial dysfunction.

PATIENTS & METHODS

A total of 387 RA patients and 45 healthy donors were recruited, forming three cohorts: i) 208 RA patients with established disease but without previous CV events; ii) RA-CVD: 96 RA patients with CV events, and iii) 83 RA patients treated with b-DMARDs/ts-DMARDs for 6 months. Serum inflammatory profiles (cytokines/chemokines/growth factors) and NETosis/oxidative stress-linked biomolecules were evaluated. Mechanistic in vitro studies were performed on monocytes, neutrophils and endothelial cells (EC).

RESULTS

In the first RA-cohort, unsupervised clustering unveiled three distinct groups: cluster 3 (C3) displayed the highest inflammatory profile, significant CV-risk score, and greater atheroma plaques prevalence. In contrast, cluster 1 (C1) exhibited the lowest inflammatory profile and CV risk score, while cluster 2 (C2) displayed an intermediate phenotype. Notably, 2nd cohort RA-CVD patients mirrored C3's inflammation. Treatment with b-DMARDs or ts-DMARDs effectively reduced disease-activity scores (DAS28) and restored normal biomolecules levels, controlling CV risk. In vitro, serum from C3-RA or RA-CVD patients increased neutrophils activity and CV-related protein levels in cultured monocytes and EC, which were partially prevented by pre-incubation with TNFi, IL6Ri, and JAKinibs.

CONCLUSIONS

Overall, analyzing circulating molecular profiles in RA patients holds potential for personalized clinical management, addressing CV risk and assisting healthcare professionals in tailoring treatment, ultimately improving outcomes.

Peptidyl Arginine Deiminases in Chronic Diseases: A Focus on Rheumatoid Arthritis and Interstitial Lung Disease

Protein citrullination is accomplished by a broad enzyme family named Peptidyl Arginine Deiminases (PADs), which makes this post-translational modification in many proteins that perform physiological and pathologic mechanisms in the body. Due to these modifications, citrullination has become a significant topic in the study of pathological processes. It has been related to some chronic and autoimmune diseases, including rheumatoid arthritis (RA), interstitial lung diseases (ILD), multiple sclerosis (MS), and certain types of cancer, among others. Antibody production against different targets, including filaggrin, vimentin, and collagen, results in an immune response if they are citrullinated, which triggers a continuous inflammatory process characteristic of autoimmune and certain chronic diseases. PAD coding genes (PADI1 to PADI4 and PADI6) harbor variations that can be important in these enzymes' folding, activity, function, and half-life. However, few studies have considered these genetic factors in the context of chronic diseases. Exploring PAD pathways and their role in autoimmune and chronic diseases is a major topic in developing new pharmacological targets and valuable biomarkers to improve diagnosis and prevention. The present review addresses and highlights genetic, molecular, biochemical, and physiopathological factors where PAD enzymes perform a major role in autoimmune and chronic diseases.

Cell Cultures as a Versatile Tool in the Research and Treatment of Autoimmune Connective Tissue Diseases

Cell cultures are an important part of the research and treatment of autoimmune connective tissue diseases. By culturing the various cell types involved in ACTDs, researchers are able to broaden the knowledge about these diseases that, in the near future, may lead to finding cures. Fibroblast cultures and chondrocyte cultures allow scientists to study the behavior, physiology and intracellular interactions of these cells. This helps in understanding the underlying mechanisms of ACTDs, including inflammation, immune dysregulation and tissue damage. Through the analysis of gene expression patterns, surface proteins and cytokine profiles in peripheral blood mononuclear cell cultures and endothelial cell cultures researchers can identify potential biomarkers that can help in diagnosing, monitoring disease activity and predicting patient's response to treatment. Moreover, cell culturing of mesenchymal stem cells and skin modelling in ACTD research and treatment help to evaluate the effects of potential drugs or therapeutics on specific cell types relevant to the disease. Culturing cells in 3D allows us to assess safety, efficacy and the mechanisms of action, thereby aiding in the screening of potential drug candidates and the development of novel therapies. Nowadays, personalized medicine is increasingly mentioned as a future way of dealing with complex diseases such as ACTD. By culturing cells from individual patients and studying patient-specific cells, researchers can gain insights into the unique characteristics of the patient's disease, identify personalized treatment targets, and develop tailored therapeutic strategies for better outcomes. Cell culturing can help in the evaluation of the effects of these therapies on patient-specific cell populations, as well as in predicting overall treatment response. By analyzing changes in response or behavior of patient-derived cells to a treatment, researchers can assess the response effectiveness to specific therapies, thus enabling more informed treatment decisions. This literature review was created as a form of guidance for researchers and clinicians, and it was written with the use of the NCBI database.

Intra-articular delivery of AAV vectors encoding PD-L1 attenuates joint inflammation and tissue damage in a mouse model of rheumatoid arthritis

Objective

Rheumatoid arthritis (RA) is the most common form of autoimmune inflammatory arthritis. Intra-articular gene delivery to block proinflammatory cytokines has been studied in pre-clinical models and human clinical trials. It has been demonstrated that the level of programmed death-ligand 1 (PD-L1) is associated with rheumatoid arthritis (RA). This study examined the therapeutic role of PD-L1 by intra-articular delivery via adeno-associated virus (AAV) vectors in the mouse collagen-induced arthritis (CIA) model.

Methods

Mice were intra-articularly injected with AAV5 vectors encoding human PD-L1 on day 0 and immunized with bovine type II collagen to induce CIA simultaneously. On day 49 post AAV administration, joints were collected for histo-pathological and cytokine analysis. Additionally, the systemic impacts of intra-articular injection of AAV5/PD-L1 vectors were also studied. To study the therapeutic effect of PD-L1, AAV5/PD-L1 vectors were administered into the joints of RA mice on day 21.

Results

After administration of AAV5/PD-L1 vectors, strong PD-L1 expression was detected in AAV transduced joints. Joints treated with PD-L1 at the time of arthritis induction exhibited significantly less swelling and improved histopathological scores when compared to untreated joints. Additionally, the infiltration of T cells and macrophages was decreased in joints of CIA mice that received AAV5/PD-L1 vectors (P<0.05). The levels of pro-inflammatory cytokines, including IL-1, IL-6, IL-17 and TNFα, were lower in AAV5/PD-L1 treated than untreated joints (P<0.05). Furthermore, the administration of AAV5/PD-L1 vectors into the joints of CIA mice did not impact serum cytokine levels and the antibody titers to type II collagen. Biodistribution of AAV vectors after intra-articular injection showed undetectable AAV genomes in other tissues except for a low level in the liver. Similar to the results of AAV5/PD-L1 vector administration on day 0, decreased joint swelling and lower histopathological damage were observed in joints treated with AAV5/PD-L1 vectors on day 21.

Conclusion

The results from this study demonstrate that local AAV mediated PD-L1 gene delivery into the joints is able to prevent the development and block the progression of arthritis in CIA mice without impacting systemic immune responses. This study provides a novel strategy to effectively treat inflammatory joint diseases using local AAV gene therapy by interference with immune checkpoint pathways.

New developments in the biology of fibroblast growth factors

The fibroblast growth factor (FGF) family is composed of 18 secreted signaling proteins consisting of canonical FGFs and endocrine FGFs that activate four receptor tyrosine kinases (FGFRs 1-4) and four intracellular proteins (intracellular FGFs or iFGFs) that primarily function to regulate the activity of voltage-gated sodium channels and other molecules. The canonical FGFs, endocrine FGFs, and iFGFs have been reviewed extensively by us and others. In this review, we briefly summarize past reviews and then focus on new developments in the FGF field since our last review in 2015. Some of the highlights in the past 6 years include the use of optogenetic tools, viral vectors, and inducible transgenes to experimentally modulate FGF signaling, the clinical use of small molecule FGFR inhibitors, an expanded understanding of endocrine FGF signaling, functions for FGF signaling in stem cell pluripotency and differentiation, roles for FGF signaling in tissue homeostasis and regeneration, a continuing elaboration of mechanisms of FGF signaling in development, and an expanding appreciation of roles for FGF signaling in neuropsychiatric diseases. This article is categorized under: Cardiovascular Diseases > Molecular and Cellular Physiology Neurological Diseases > Molecular and Cellular Physiology Congenital Diseases > Stem Cells and Development Cancer > Stem Cells and Development.

Analysis of Risk Factors for Rheumatoid Arthritis in Yunnan: A Small-Scale Case-Control Study

Objective

To study the risk factors of rheumatoid arthritis (RA) in Yunnan and provide reference for its clinical prevention and treatment.

Methods

From January 2014 to February 2022, a total of 249 RA patients who were admitted to the First People's Hospital of Yunnan Province were selected and 149 healthy people were selected as the controls. The medical records, clinical data of blood test results of anticyclic citrullinated polypeptide (anti-CCP) antibody, antikeratin antibody (AKA), and antiperinuclear factor (APF) were collected. Logistic regression and receiver operating curve (ROC) were used to analyze the correlation between blood anti-CCP antibody, AKA, and APF and the occurrence of RA.

Results

Univariate analysis showed that the age, proportion of hypertension, and diabetes patients in RA patients were significantly different from those in the control group (p < 0.05), but there was no statistical difference in sex (p > 0.05). The area under the curve (AUC) of the serum anti-CCP antibody level in the diagnosis of RA was 0.76 (95% CI: 0.72-0.81, p < 0.01), the sensitivity was 85.23%, the specificity was 61.45%, and the cutoff value was 18.07AU/mL. The positive rates of AKA (33.73%) and APF (43.37%) in the RA patients were significantly higher than those in the controls (4.03% and 6.04%), and the differences were statistically significant (p < 0.001). After adjusting for age, sex, hypertension, and diabetes, logistic regression analysis showed that anti-CCP positivity, AKA positive, and APF positive were all independent risk factors for RA (OR = 20.24, 95% CI: 9.36-43.77, p < 0.01; OR = 4.33, 95% CI: 1.62-11.60, p < 0.01; OR = 5.28, 95% CI: 2.33-11.99, p < 0.01).

Conclusion

Anti-CCP positive, AKA positive, and APF positive are independent risk factors for the occurrence of RA. Serum anti-CCP level has high sensitivity but low specificity in the diagnosis of RA.

Circ_0088036 mediated progression and inflammation in fibroblast-like synoviocytes of rheumatoid arthritis by miR-1263/REL-activated NF-κB pathway

BACKGROUND

Rheumatoid arthritis (RA) is a common joint disease with abnormal development of human fibroblast-like synoviocytes (HFLS). Circular RNAs (circRNAs) have essential regulation in the disease progression, and this study was to explore the regulatory mechanism of circ_0088036 in RA.

METHODS

RNA expression analysis was performed through reverse transcription-quantitative polymerase chain reaction assay. Cell experiments were conducted by Cell Counting Kit-8 assay for cell viability, EdU (5-ethynyl-2'-deoxyuridine) assay for proliferation and flow cytometry for cell cycle or apoptosis. The protein detection was conducted using western blot. Enzyme-linked immunosorbent assay (ELISA) was used to examine the inflammatory cytokines. The binding identification was carried out through dual-luciferase reporter assay, RNA immunoprecipitation assay and pull-down assay.

RESULTS

The level of circ_0088036 RNA was significantly upregulated in sera and in HFLS cells of RA patients. Targeted silencing of circ_0088036 restrained proliferation, cell cycle progression and inflammatory reaction through promoted the apoptosis of HFLS-RA cells via inhibiting the NF-κB pathway. The miR-1263 was identified as a target of circ_0088036. MiR-1263 was found to be down-regulated in sera and in HFLS cells of RA patients. The regulatory effects of circ_0088036 on HFLS-RA cells were attributed to inhibit the miR-1263 level. REL is a susceptibility locus for certain autoimmune diseases. MiR-1263 directly targeted REL, which was discovered to be elevated in sera and HFLS cells of RA patients, and circ_0088036 interacted with miR-1263 to affect REL expression. Functionally, overexpression of miR-1263 suppressed the development of HFLS-RA by blocking the NF-κB pathway, and this phenomenon was reversed by the upregulation of REL.

CONCLUSION

These findings suggested that circ_0088036/miR-1263/REL/NF-κB pathway was involved in the functional development of HFLS-RA cells, indicating a novel molecular network in RA progression in vitro.

Cyclic Citrullinated Peptide Aptamer Treatment Attenuates Collagen-Induced Arthritis

We describe the study of a novel aptamer-based candidate for treatment of seropositive rheumatoid arthritis. The candidate is a nanoparticle-formulated cyclic citrullinated peptide aptamer, which targets autoantibodies and/or the immune reactions leading to antibody production. Due to its specificity, the peptide aptamer nanoparticles might not interfere with normal immune functions as seen with other disease-modifying antirheumatic drugs. Over a 3-week course of treatment, joint swelling and arthritis score in collagen-induced rats were significantly decreased compared with animals treated with phosphate-buffered saline, unloaded nanoparticles, or nanoparticles with a noncitrullinated control peptide. The reduction in joint swelling was associated with decreased anticitrullinated peptide autoantibody levels in the blood. Treatment with aptamer nanoparticles also increased interleukin-10 levels. The effect seen with the proposed treatment candidate could be mediated by upregulation of anti-inflammatory mediators and decreased levels of anticitrullinated peptide antibodies.

Effectiveness and safety of aerobic exercise for rheumatoid arthritis: a systematic review and meta-analysis of randomized controlled trials

Background

Rheumatoid arthritis (RA) can cause severe physical impairment and a reduced quality of life, and there is limited evidence for any effective intervention. Aerobic exercise may be beneficial for improving symptoms. Therefore, the purpose of this meta-analysis was to evaluate the effectiveness and safety of aerobic exercise for rheumatoid arthritis patients.

Methods

PubMed, The Cochrane Library, Web of Science, EMBASE, CNKI, WanFang Data and VIP databases were searched. Randomized controlled trials of the effectiveness and safety of aerobic exercise for rheumatoid arthritis were included. Risks of bias were assessed by two independent reviewers using the methods described in the RevMan 5.3, GRADEpro and the Cochrane Handbook. Meta-analyses were performed to investigate the effects of aerobic exercise on rheumatoid arthritis.

Results

A total of 13 RCTs were included, including 967 rheumatoid arthritis patients. The Meta-analysis results showed that aerobic exercise can improve functional ability [MD = − 0.25, 95% CI (− 0.38, − 0.11), P = 0.0002], relieve pain [SMD = − 0.46, 95% CI (− 0.90, − 0.01), P = 0.04], increase aerobic capacity [MD = 2.41, 95% CI (1.36, 3.45), P < 0.00001] and improve the Sit to Stand test score[MD = 1.60, 95% CI (0.07, 3.13), P = 0.04] with statistically significant differences.

Conclusion

Generally, aerobic exercise is beneficial and safe for RA patients and has a certain alleviating effect on the disease, such as functional ability improvement, pain relief and aerobic capacity increase. Limited by the quantity and quality of the included studies, future research with higher-quality studies needs to be conducted to verify the above conclusions.

Trial registration: PROPERO registration number: CRD42021242953.

MicroRNA-4423-3p inhibits proliferation of fibroblast-like synoviocytes by targeting matrix metalloproteinase 13 in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that is increasing in incidence worldwide. RA is regulated by a variety of microRNAs (miRNAs/miR). Moreover, analysis of public data has revealed that miR-4423-3p is significantly downregulated in peripheral blood mononuclear cells of RA patients. This study investigated the role of miR-4423-3p in RA. The levels of miR-4423-3p and matrix metalloproteinase 13 (MMP13) in RA patients and the regulatory relationship between miR-4423-3p and MMP13 were analyzed using public data. A dual-luciferase reporter assay was performed to verify that miR-4423-3p targets MMP13 in human fibroblast-like synoviocyte (HFLS) RA cells (HFLS-RA). Following the overexpression of miR-4423-3p, miR-4423-3p inhibitor, and MMP13 in HFLS-RA, viability, proliferation, cell cycle, apoptosis, and invasion/migration assays were used to detect the effects of miR-4423-3p targeting MMP13 on cell biological processes. The results revealed that miR-4423-3p was downregulated in peripheral blood mononuclear cells of RA patients and MMP13 was upregulated in synovial tissue of RA patients. miR-4423-3p targets the 3' untranslated region of MMP13 and downregulates MMP13 expression. After overexpression of miR-4423-3p, cell proliferation, migration, and invasion were inhibited, the cell cycle was prevented and cell apoptosis was promoted. Overexpression of MMP13 promoted cell proliferation, migration, and invasion, while accelerating the cell cycle process and suppressing apoptosis. The findings indicate that in HFLS-RA cells, overexpression of miR-4423-3p inhibited proliferation, migration, and invasion, and promoted apoptosis by negatively regulating MMP13. The overexpression of miR-4423-3p might be a novel strategy for the treatment of RA.

Mechanosensitive pathways are regulated by mechanosensitive miRNA clusters in endothelial cells

Shear stress is known to affect many processes in (patho-) physiology through a complex, multi-molecular mechanism, termed mechanotransduction. The sheer complexity of the process has raised questions how mechanotransduction is regulated. Here, we comprehensively evaluate the literature about the role of small non-coding miRNA in the regulation of mechanotransduction. Regulation of mRNA by miRNA is rather complex, depending not only on the concentration of mRNA to miRNA, but also on the amount of mRNA competing for a single mRNA. The only mechanism to counteract the latter factor is through overarching structures of miRNA. Indeed, two overarching structures are present miRNA families and miRNA clusters, and both will be discussed in details, regarding the latest literature and a previous conducted study focussed on mechanotransduction. Both the literature and our own data support a new hypothesis that miRNA-clusters predominantly regulate mechanotransduction, affecting 65% of signalling pathways. In conclusion, a new and important mode of regulation of mechanotransduction is proposed, based on miRNA clusters. This finding implicates new avenues for treatment of mechanotransduction and atherosclerosis.

NOX2-Deficient Neutrophils Facilitate Joint Inflammation Through Higher Pro-Inflammatory and Weakened Immune Checkpoint Activities

Immune-mediated arthritis is an important chronic inflammatory disease of joints causing debilitating morbidity in affected patients. The mechanisms underlying immune-mediated arthritis have been intensively investigated, however the cellular and molecular factors contributing to the joint inflammation in different redox conditions have not been clearly elucidated. Previous research showed that phagocyte-produced reactive oxygen species (ROS) plays an anti-inflammatory role in K/BxN serum-transfer arthritis and NOX2-deficient mice tend to have more severe arthritis. Although many leukocytes play critical roles in the development of immune-mediated arthritis, the role of neutrophils, which are the main producers of ROS in inflammation, is still controversial. We hence assessed the immunomodulatory function of neutrophils from arthritic joints of NOX2-deficient and wild type mice in this study. We found more neutrophils accumulation in NOX2-deficient inflamed joints. RNA-sequencing and quantitative PCR revealed significantly increased expression of acute inflammation genes including IL1b, Cxcl2, Cxcl3, Cxcl10 and Mmp3 in activated neutrophils from the inflamed joints of NOX2-deficient mice. Moreover, gene set enrichment analysis (GSEA) showed enriched gene signatures in type I and II IFN responses, IL-6-JAK-STAT3 signaling pathway and TNF-α signaling pathway via NF-κB in NOX2-deficient neutrophils. In addition, we found that NOX2-deficient neutrophils expressed lower levels of PD-L1 and were less suppressive than WT neutrophils. Moreover, treatment of PD-L1-Fc decreased cytokine expression and ameliorated the severity of inflammatory arthritis. Our results suggest that NOX2-derived ROS is critical for regulating the function and gene expression in arthritic neutrophils. Both the strong pro-inflammatory and weakened anti-inflammatory functions of neutrophils due to abnormal redox regulation may be targets of treatment for immune-mediated arthritis.

Upregulation of MicroRNA-937 Predicts a Poor Prognosis and Promotes Hepatocellular Carcinoma Cell Proliferation, Migration, and Invasion

Hepatocellular carcinoma (HCC) has a high dead rate partly due to late diagnosis. This study aimed to investigate the prognostic value of miR-937 in HCC and its role in the HCC progression. HCC tissue and adjacent non-cancerous tissues (NCT) (n = 125) were detected about the expression level of miR-937 via real-time quantitative PCR. The relationship between miR-937 expression and each important clinical characteristic was evaluated. And the prognostic significance of miR-937 was assessed by Kaplan-Meier curve and Cox regression analysis. CCK-8 and Transwell assays were conducted to observe the effects of miR-937 on HCC cell proliferation, migration, and invasion. The miR-937 expression was upregulated in HCC tissues, as well as in HCC cell lines. The upregulation of miR-937 showed a significant association with lymph node metastasis and TNM stage. Upregulation of miR-937 predicted poor prognosis of HCC patients. Overexpression of miR-937 promoted HCC cell ability of proliferation, migration, and invasiveness, while knockdown of miR-937 inhibited these cellular behaviors. miR-937 expression was upregulated in HCC and may serve as a promising prognostic factor and treated target for HCC patients. miR-937 might exert a promoter role in HCC through accelerated tumor cell proliferation, migration, and invasion.

CS-semi5 Inhibits NF-κB Activation to Block Synovial Inflammation, Cartilage Loss and Bone Erosion Associated With Collagen-Induced Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease that affects 1% of the population. CS-semi5 is a semisynthetic chondroitin sulfate. In this study, CS-semi5 was shown to have positive effects on a model of collagen-induced arthritis (CIA). CS-semi5 treatment had obvious effects on weight loss and paw swelling in CIA mice. Post-treatment analysis revealed that CS-semi5 alleviated three main pathologies (i.e., synovial inflammation, cartilage erosion and bone loss) in a dose-dependent manner. Further study showed that CS-semi5 could effectively reduce TNF-α and IL-1β production in activated macrophages via the NF-κB pathway. CS-semi5 also blocked RANKL-trigged osteoclast differentiation from macrophages. Therefore, CS-semi5 may effectively ameliorate synovial inflammation, cartilage erosion and bone loss in RA through NF-κB deactivation.

Expression of sterile-α and armadillo motif in rheumatoid arthritis monocytes correlates with TLR2 induced IL-1β and disease activity

OBJECTIVE

Cartilage and bone damage in rheumatoid arthritis (RA) are associated with elevated IL-1β. The effects of IL-1β can be reduced by biological therapies that target IL-1β or TNFα. However, the mechanisms responsible for increased IL-1β and the effect of anti-TNFα have not been fully elucidated. Recently, sterile-α and armadillo motif-containing protein (SARM) was identified as a negative regulator of toll-like receptor (TLR) induced IL-1β secretion through an interaction with the inflammasome. This study set out to investigate SARM during TLR induced IL-1β secretion in RA peripheral blood monocytes and in patients commencing anti-TNFα treatment.

METHODS

Monocytes were isolated from RA patients and healthy controls; disease activity was measured by DAS28. IL-1β secretion was measured by ELISA following TLR1/2, TLR4 and TLR7/8 stimulation. The mRNA expression of SARM, IL-1β and the components of the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome were measured by quantitative PCR. SARM protein expression was measured by western blotting.

RESULTS

TLR1/2 activation induced elevated IL-1β in RA monocytes compared with heathy controls (p= 0.0009), which negatively correlated with SARM expression (p = 0.0086). Lower SARM expression also correlated with higher disease activity (p = 0.0246). Additionally, patients responding to anti-TNFα treatment demonstrated a rapid upregulation of SARM, which was not observed in non-responders.

CONCLUSION

Together, these data highlight a potential contribution from SARM to RA pathophysiology where decreased SARM may lead to elevated IL-1β associated with RA pathogenesis. Furthermore, the data additionally present a potential mechanism by which TNFα blockade can modify IL-1β secretion.

Biologic therapies for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the synovial joints. If left untreated, persistent synovial inflammation can lead to cartilage and bone destruction, ultimately causing significant longterm disability and mortality. However, since the late 1990s, the combined use of methotrexate, a synthetic diseasemodifying antirheumatic drug (DMARD), and a biological DMARD has revolutionized the treatment of RA. As of 2021, the Korea Food and Drug Administration has approved seven biological DMARDs for RA treatment: four tumor necrosis factor-alpha inhibitors (infliximab, etanercept, adalimumab, and golimumab) and three non-tumor necrosis factor biological products (abatacept, rituximab, and tocilizumab). Although the use of biological products has allowed significant advances in the treatment of RA, there are certain drawbacks, such as high cost, increased infection risk, and the necessity for parenteral route product administration. Therefore, discontinuation of biological DMARD use without a resulting disease flare is the next treatment goal and a desirable result from the standpoint of risk reduction and cost-effectiveness, especially for patients with clinical remission. It is still unclear which biological product is the best. Clinicians must, therefore, personalize the sequence and strategy of treatment by considering patient characteristics, disease activity, comorbidity, and economic condition

Biologic Drugs for Rheumatoid Arthritis in the Context of Biosimilars, Genetics, Epigenetics and COVID-19 Treatment

Rheumatoid arthritis (RA) affects around 1.2% of the adult population. RA is one of the main reasons for work disability and premature retirement, thus substantially increasing social and economic burden. Biological disease-modifying antirheumatic drugs (bDMARDs) were shown to be an effective therapy especially in those rheumatoid arthritis (RA) patients, who did not adequately respond to conventional synthetic DMARD therapy. However, despite the proven efficacy, the high cost of the therapy resulted in limitation of the widespread use and unequal access to the care. The introduction of biosimilars, which are much cheaper relative to original drugs, may facilitate the achievement of the therapy by a much broader spectrum of patients. In this review we present the properties of original biologic agents based on cytokine-targeted (blockers of TNF, IL-6, IL-1, GM-CSF) and cell-targeted therapies (aimed to inhibit T cells and B cells properties) as well as biosimilars used in rheumatology. We also analyze the latest update of bDMARDs' possible influence on DNA methylation, miRNA expression and histone modification in RA patients, what might be the important factors toward precise and personalized RA treatment. In addition, during the COVID-19 outbreak, we discuss the usage of biologicals in context of effective and safe COVID-19 treatment. Therefore, early diagnosing along with therapeutic intervention based on personalized drugs targeting disease-specific genes is still needed to relieve symptoms and to improve the quality of life of RA patients.