Occurrence Of Rheumatoid Arthritis Research Articles

Infrared thermogram image guided discontinuous appearances of hyaluronic acid for classification of arthritic knee joints

The liveliness of a human potentially depends on his/her smooth movability. To accomplish the work of daily life, the joints of the body need to be healthy. However, the occurrence of Rheumatoid arthritis and Osteoarthritis has a significant prevalence towards the immovability of humankind. Rheumatoid arthritis (RA) and Osteoarthritis (OA) mostly affect the joints of the hand and knee which result in lifelong pain, inability to climb, walk, etc. In the early stages, these diseases attack the synovial membrane and synovial fluid, and further it destroys the soft tissues and bone structure. By early diagnosis, we can start the treatment in the early stage which may cure these diseases with such extreme consequences. As per clinical studies of previous literature, it is observed that synovial fluid imbalance appears in the early stage of such diseases and Hyaluronic Acid (HA) concentration also decreases for that. Therefore, estimation of HA is a significant key to arthritis disease classification and grading. In this paper, we proposed a hybrid framework for classification of arthritic knee joints based on the analysis of the discontinuous appearances of the HA concentration using infrared imaging technology. To meet up the specific necessities, firstly we have proposed a modified K-Means clustering algorithm for extraction of the region of interest (ROI) i.e., the knee joint surface. Secondly, a mathematical formulation is proposed to calculate the concentration of HA from the segmented ROIs. This experimental process was implemented on the publicly available IR (Infrared) Knee Joint Dataset and for further evaluation of the novelty of mathematical formulation, we have extended the proposed work to the classification of healthy and arthritis affected knee joints depending on significant discriminative characteristics of the HA concentration with respect to the existing significant imaging features. Experimental results and analysis demonstrates that concentration of HA has the dominant potential for classifying healthy and arthritic knee joints using infrared holistic images. Our experimental analysis reveals that estimation and combination of the HA concentration features with conventional handcrafted and deep features increases the classification performance with an average accuracy of 91% and 97.22% respectively as compared to the each individual feature sets.

High fat diet increases the severity of collagen-induced arthritis in mice by altering the gut microbial community

ObjectivesResearch has demonstrated that obesity may be associated with rheumatoid arthritis (RA). In addition, gut microbiota and its metabolites contribute to the occurrence and development of RA and obesity. However, the mechanism by which obesity affects RA remains unclear. In this study, we aimed to investigate whether gut microbiota and their metabolites alter the effects of high fat diet (HFD) on the severity of collagen-induced arthritis (CIA) in mice.MethodsBriefly, mice were divided into normal group (N), CIA model group (C), HFD group (T), and HFD CIA group (CT). Hematoxylin and Eosin staining(HE) and Safranin O-fast green staining were conducted, and levels of blood lipid and inflammatory cytokines were measured. 16S rDNA sequencing technique and liquid chromatography-mass spectrometry (LC-MS)-based metabolomics were performed to explore changes in the microbiota structure to further reveal the pathomechanism of HFD on CIA.ResultsHFD aggravated the severity of CIA in mice. The CT group had the highest proportion of microbial abundance of Blautia, Oscillibacter, Ruminiclostridium-9, and Lachnospiraceae UCG 006 at the genus level, but had a lower proportion of Alistipes. Additionally, the fecal metabolic phenotype of the combined CT group shows significant changes, with differential metabolites enriched in 9 metabolic pathways, including primary bile acid biosynthesis, arginine biosynthesis, sphingolipid metabolism, purine metabolism, linoleic acid metabolism, oxytocin signaling pathway, aminoacyl-tRNA biosynthesis, the pentose phosphate pathway, and sphingolipid signaling pathway. Correlation analysis revealed that some of the altered gut microbiota genera were strongly correlated with changes in fecal metabolites, total cholesterol (TC), triglyceride (TG), and inflammatory cytokine levels.ConclusionsThis study shows that HFD may aggravate inflammatory reaction in CIA mice by altering the gut microbiota and metabolic pathways.

Clinical characteristics and risk factors of connective tissue disease complicated with bronchiectasis and pulmonary infection.

The clinical data from 118 CTD patients with bronchiectasis were collected and categorized into two groups: pulmonary infection present (n = 67) and absent (n = 51), for comparative analysis of characteristics and risk factors. Then, we analyzed and compared their demographics, disease characteristics, and risk factors for infection. Among the whole cohort (n = 118), the incidence of pulmonary infections was 56.78%. The occurrence of rheumatoid arthritis, systemic lupus erythematosus, and vasculitis was found to be associated with an increased risk of pulmonary infection. Sputum culture identified Pseudomonas aeruginosa and Klebsiella pneumoniae as the predominant pathogens in the infected group. Notably, symptoms such as joint pains (p = 0.018) and morning stiffness (p = 0.017) were significantly more common in the infected group compared to the noninfected group. Moreover, our findings revealed that elevated levels of C-reactive protein and complement C3, along with bronchial expansion observed on high-resolution computed tomography (HRCT), were significant independent factors in the infection group. Conversely, pulmonary interstitial changes identified through HRCT (OR: 0.135, 95% CI: 0.030-0.612, p = 0.009) were significantly associated with the non-infection group. Overall, this study provides valuable insights into managing CTD patients with bronchiectasis, emphasizing early detection and tailored approaches to prevent and treat pulmonary infections for better outcomes.

P040 Obesity and rheumatoid arthritis among individuals with low education

Abstract Background/Aims Poor education is connected to many diseases including cardiovascular diseases (CVD) and some CVD-related risk factors such as obesity. However, precisely how this relationship occurs is unknown. In this research we will be exploring how the connection between obesity and overall mortality is modified by rheumatoid arthritis (RA). Methods Our study was conducted on participants that were aged 20 years or older living in the United States with a education level of only some high school. We assessed RA status by using the arthritis question in the National Health and Nutrition Examination Survey (NHANES) survey conducted by the National Center for Health Statistics (NCHS) for the years of 1999 to 2010 with mortality follow-up to December 2019. We determined obesity by calculating BMI and setting a cutpoint at 30 kg/m2. Education level was determined through self-reported data. Chronic Kidney Disease was determined using the Cockcroft-Gault equation. Prospective analysis was performed using complex samples Cox regression with adjustment for known confounders to determine the relationship of obesity and mortality, and if RA has an overall relationship in those with low education. Results Among individuals with low education and RA, percent mortality was 32.3% among males and 32.6% among females with mean follow-up of 9.3 years. For overall mortality, the age and sex-adjusted hazard ratio (HR) for obesity was 1.18 (95% confidence interval [CI], 1.05-1.34 p = 0.01). The adjusted HR was elevated, 1.56 (CI 1.06-2.32, p = 0.03), among people with obesity who also had RA but close to 1.0 (1.21 CI 0.99-1.47, p = 0.06) among individuals with obesity who had no RA, after adjusting for medical (chronic obstructive pulmonary disease, history of cancer, cardiovascular disease, chronic kidney disease, and diabetes) and demographic risk factors (poverty-income-ratio, age, military service, citizenship, and gender). Conclusion We found that among individuals with low education, not only does obesity lead to 18% higher overall mortality but also RA occurrence impacts the relationship between obesity and overall mortality even after controlling for potential confounders. Education and health literacy are especially important in the preventing and treating RA especially in those who have obesity. With cardiovascular disease having the highest rate of mortality, risk factors for CVD such as obesity must be prevented. Disclosure J. Khubchandani: None. S. Banerjee: None.

The Association of Chronic Periodontitis as a Potential Risk Factor with Rheumatoid Arthritis: A Nested Case-Control Study Using a Korean National Health Screening Cohort.

Growing research has proposed that rheumatoid arthritis (RA) and chronic periodontitis (CP) share similar pathophysiological mechanisms involving inflammation and tissue destruction. However, the potential correlation of CP as a contributing factor for the occurrence of RA warrants validation in the Korean population, where both diseases are prevalent, especially considering the increasingly aging demographic in Korea. This study examined 5139 RA cases and 509,727 matched controls from a Korean national cohort dataset (2002-2019) by carefully employing propensity score matching to ensure comparability between groups. Baseline characteristics were compared using standardized differences, and logistic regression was employed to estimate the impact of CP history on RA likelihood while controlling for covariates. We fully examined medical records documenting CP occurrences within the two-year period leading up to the index date, conducting comprehensive subgroup analyses. While a 1-year history of CP did not show a significant association with likelihood of RA, a 2-year history of CP increased RA likelihood by 12%, particularly among older adults, females, rural residents, and those with certain comorbidities such as hypercholesterolemia. Interestingly, this association persisted even among individuals with non-smoking habits, normal weight, and infrequent alcohol consumption. These findings suggest that chronic CP exposure for at least 2 years may independently elevate RA risk in Korean adults. The association in certain subgroups appears to suggest a predisposition toward genetic susceptibilities over lifestyle and environmental factors. Predicting RA in CP patients may be challenging, emphasizing the importance of regular RA screening, especially in high-risk subgroups.

Association between serum antinuclear antibody and rheumatoid arthritis.

The relationship between serum antinuclear antibody (ANA) and rheumatoid arthritis (RA) remains unknown. Therefore, we aimed to evaluate whether serum ANA was associated with an increased risk of RA in a case-control study. Patients with rheumatoid arthritis hospitalized at Shandong Provincial Hospital from January 2018 to December 2022 were recruited as the case group, and patients with other types of arthritis and healthy people at the same time were taken as the control group. Antinuclear antibody (ANA) was detected by indirect immunofluorescence assays. Propensity score matching was employed to construct a cohort of patients exhibiting comparable baseline characteristics. The relationship between serum ANA and the risk of rheumatoid arthritis was analyzed by logistic regression analysis. A total of 1,175 patients with RA and 1,662 control subjects were included in this study. After adjusting for potential confounding factors in the propensity-score matched cohort, the risk of RA gradually increased with rising of ANA titers. When ANA titers were divided into three groups (1:100, 1:320, and 1:1,000), the OR (95% CI) for ANA titers from low to high was 3.95 (3.01, 5.18), 16.63 (9.44, 29.30), and 17.34 (9.53, 31.54), respectively, compared to those when ANA was negative. The ANA patterns closely related to the occurrence of RA include nuclear homogeneous, nuclear speckled, and cytoplasmic speckled. Among them, the positive rate of nuclear homogeneous was the highest, which accounted for 42.64%. The OR (95% CI) of ANA patterns including nuclear homogeneous, nuclear speckled, and cytoplasmic speckled was 16.81 (11.46, 24.65), 3.40 (2.49, 4.63), and 3.09 (1.77, 5.40), respectively. There was a curve relation between ANA titer and RA, and the higher the ANA titer, the higher the probability of RA. However, there was no statistical difference in probability of RA for 1:320 versus 1:1,000 ANA titers. The most important kind of ANA pattern in the blood of RA patients was nuclear homogeneous. These findings suggest that ANA may be a novel risk marker for RA.

MicroRNA-150 Deletion Reduces the Occurrence and Severity of Rheumatoid Arthritis by Inhibiting IL-17.

Understanding the effects of epigenetic factors on the pathogenesis of rheumatoid arthritis (RA) is important for the early diagnosis and therapeutic intervention of this disease. MicroRNA-150 (miR-150) exerts an important influence on the development and function of lymphocytes. However, the role of miR-150 in the pathogenesis of RA remains unclear. To explore the role of miR-150 in the pathogenesis of RA and the related immune mechanism. In this study, we used miR-150 knock-out (miR-150KO) and created animal models of RA. Flow cytometry, immunohistochemistry, and real-time RT-PCR were employed to assess the frequency of T cell subsets and cytokines expression. Compared to wild-type (WT) mice, the onset of RA was postponed and the incidence of RA was reduced in miR-150KO mice. The expression of IL-4 and IFN-γ significantly increased while the expression of IL-17 decreased significantly in NKT and CD4+ T cells of KO mice compared to that of WT mice after RA induction. In addition, the expression of IL-4 and IFN-γ increased while the expression of IL-17 decreased significantly in the joint tissues of KO mice compared to that of WT mice. Furthermore, the mRNA expression of TNF-α and IL-17 decreased significantly in the synovial fluid cells of KO mice compared to that of the WT mice after RA induction. MiR-150 deficiency decreases the expression of IL-17 in T cells and joint tissues, and alleviates the occurrence and progression of RA in mice.

Role of Platelet/Lymphocyte, Neutrophil/Lymphocyte, and Interleukin-37/Interleukin-17 Ratios in the Occurrence and Treatment of Rheumatoid Arthritis

ABSTRACT This study was designed to investigate the correlation of neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and interleukin (IL)-37/IL-17 ratio with the incidence/treatment of rheumatoid arthritis (RA). Firstly, fifty-eight patients with RA treated at the first affiliated hospital of Xinjiang Medical University from January 2018 to January 2019 were selected as the RA group; forty-nine healthy volunteers were enrolled in the control group. RA patients were treated with disease-modifying anti-rheumatic drugs (DMARDs). Next, the NLR, PLR, IL-37, IL-17 and 28-joint disease activity score using erythrocyte sedimentation rate (DAS28-ESR) were deleted in two groups. Subsequently, Spearman correlation analysis was adopted for the correlations of various indicators before and after treatment in two groups. According to the analysis results, the levels of NLR, PLR, IL-37, and IL-17 before treatment in the RA group were higher than those in the control group (P < .05), but the difference in the IL-37/IL-17 level between the two groups was not significant (P > .05). After treatment, NLR, PLR, and IL-37/IL-17 levels were significantly reduced in RA patients (P < .05). NLR and PLR were significantly positively correlated with DAS28-ESR, ESR and C-reactive protein (CRP), of which represented the disease activity of RA. NLP was strongly correlated with IL-37/IL-17. Collectively, NLR, PLR, IL-37, and IL-17 are closely related to the occurrence of RA. In addition, NLR and IL-37/IL-17 are more suitable than PLR in reflecting the therapeutic effect. Therefore, IL-37/IL-17 can be considered as a new indicator for reflecting the treatment effectiveness of RA.

Potential association of genetically predicted lipid and lipid-modifying drugs with rheumatoid arthritis: A Mendelian randomization study.

Past studies have demonstrated that patients diagnosed with rheumatoid arthritis (RA) often exhibit abnormal levels of lipids. Furthermore, certain lipid-modifying medications have shown effectiveness in alleviating clinical symptoms associated with RA. However, the current understanding of the causal relationship between lipids, lipid-modifying medications, and the risk of developing RA remains inconclusive. This study employed Mendelian randomization (MR) to investigate the causal connection between lipids, lipid-modifying drugs, and the occurrence of RA. We obtained genetic variation for lipid traits and drug targets related to lipid modification from three sources: the Global Lipids Genetics Consortium (GLGC), UK Biobank, and Nightingale Health 2020. The genetic data for RA were acquired from two comprehensive meta-analyses and the R8 of FINNGEN, respectively. These variants were employed in drug-target MR analyses to establish a causal relationship between genetically predicted lipid-modifying drug targets and the risk of RA. For suggestive lipid-modified drug targets, we conducted Summary-data-based Mendelian Randomization (SMR) analyses and using expression quantitative trait loci (eQTL) data in relevant tissues. In addition, we performed co-localization analyses to assess genetic confounders. Our analysis revealed no significant causal relationship between lipid and RA. We observed that the genetically predicted 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) -mediated low density lipoprotein cholesterol (LDL-C) (OR 0.704; 95% CI 0.56, 0.89; P = 3.43×10-3), Apolipoprotein C-III (APOC3) -mediated triglyceride (TG) (OR 0.844; 95% CI 0.77, 0.92; P = 1.50×10-4) and low density lipoprotein receptor (LDLR) -mediated LDL-C (OR 0.835; 95% CI 0.73, 0.95; P = 8.81×10-3) were significantly associated with a lowered risk of RA. while Apolipoprotein B-100 (APOB) -mediated LDL-C (OR 1.212; 95%CI 1.05,1.40; P = 9.66×10-3) was significantly associated with an increased risk of RA. Our study did not find any supporting evidence to suggest that lipids are a risk factor for RA. However, we observed significant associations between HMGCR, APOC3, LDLR, and APOB with the risk of RA.

Exploratory analysis on the relationship between dietary live microbe intake and arthritis: a national population based cross-sectional study.

The pathogenesis of arthritis such as rheumatoid arthritis (RA) and osteoarthritis (OA) remains unclear. This study aims to investigate whether the intake of live dietary microbes can be used as an auxiliary means for the treatment of arthritis. Data used in the present research were originated from the US National Health and Nutrition Examination Survey (NHANES) from 2003-2018. Participants involved in the present study were categorized into three groups based on the dietary live microbe classification system, namely low, medium, and high dietary live microbe groups. The analyses utilized weighted univariate and multivariate logistic regression. The restricted cubic spline plot was used to explore the relationship between the high dietary live microbe group and the odds of arthritis. 12,844 participants were included in the present study. The intake of high live dietary microbes in RA group was lower than that in healthy control group and OA group. The proportion of RA patients in the high live dietary microbe group was lower than that in the low and medium live dietary microbe group. Following the comprehensive adjustment for covariates, it was observed that participants in both the high and medium dietary live microbe groups exhibited lower odds of RA compared to those in the low dietary live microbe group (High OR: 0.71, 95% CI: 0.53-0.96; Medium OR: 0.77, 95% CI: 0.59-1.00, p = 0.02). A restricted cubic spline plot indicates a negative correlation between the quantity of dietary live microbes and the occurrence of RA within the high dietary live microbe group. The results of our study revealed a significant difference in dietary live microbe intake between healthy and RA patients. Higher dietary intake was correlated with a decreased odds of RA. However, no significant association was found between the occurrence of OA and the quantity of dietary live microbes.

Evaluating microRNA-499 expression and serum IL-17, ACCP and PADI4 cytokine levels in rheumatoid arthritis patients undergoing anti-TNF alpha therapy

Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by joint inflammation and damage. While anti-TNF-alpha therapies like infliximab have revolutionized RA, treatment response varies among patients. Identifying reliable biomarkers for treatment response is crucial for optimizing therapy and patient outcomes. MicroRNA-499 has been implicated in autoimmune diseases, and IL-17 is a key mediator in RA pathogenesis. Additionally, PADI4 and ACCP are linked to RA autoimmunity. This study aimed to investigate the potential of microRNA-499 expression, serum levels of IL-17, PADI4 and ACCP as biomarkers for predicting and monitoring treatment response in RA patients undergoing anti-TNF-alpha (infliximab) therapy. Methodology: In this case-control research, blood samples from 100 Iraqi patients with RA and 100 controls were collected. RNA was extracted and the levels of miRNA499 were quantified using real-time PCR. The serum IL-17, PADI4 and ACCP levels were determined using ELISA. Patients were sub-grouped as responders and non-responders based on their responses to anti-TNF-alpha (infliximab) treatment. Results: The mean age of the patients in this study was 46.22 years. The occurrence of RA was higher in age group (31-45) years. There was a significant association between RA, smoking and BMI. miRNA-499 expression was significantly higher in RA patients versus controls (1.1 folds in patients compared to 0.52 in control group). The serum levels of IL-17, PADI4 and ACCP was significantly higher in RA patients than controls (54.3ng/L, 2.52 ng/ml and 2.15 U/ml) vs (40.35ng/ L, 1.78 ng/ml and 1.06 U/ml) respectively. Subdividing of patients showed that miRNA-499 expression and serum IL-17, PADI4 and ACCP to be significantly higher in non-responders patients than responders. Conclusion: MicroRNA-499 expression, serum levels of IL-17, PADI4 and ACCP were found to be significantly higher in RA patients compared to control group as well as in non-responding than responding patients.

An Updated Review on Rheumatoid Arthritis (RA): Epidemiology, Pathophysiology, Diagnosis, and the Current Approaches for Its Treatment

Rheumatoid arthritis (RA) is a systemic self-inflicted inflammatory disease that primarily affects middle-aged women. Globally, 1% of people live with RA. This review aims to provide updated information on the different aspects of RA, including its epidemiology, pathophysiology, diagnosis, treatment, and management. A web-based literature search was conducted through various databases, including PubMed, Google Scholar, and Science Direct, to identify the most relevant studies. Epidemiological studies have suggested that the prevalence and occurrence of RA have remained inconsistent across geographical areas in different periods. Many factors such as age, gender, inheritances, and environmental exposure can contribute to the severity of the disease. The acute form of RA usually presents with pain, and if left untreated, it can result in joint deformities and influence a patient’s quality of life (QoL). RA diagnosis is usually based on the manifestation of pain with inflammation. Currently, many therapeutic strategies are available for the cure of RA. The management of daily routine activities is required with treatment to curtail the damage, avoid future deformities, and ultimately minimize the aching trouble of the patient.

Rheumatoid arthritis and gastroesophageal reflux disease: a bidirectional and multivariable two-sample Mendelian randomization study.

Aims/hypothesis: The association between gastroesophageal reflux disease (GERD) and rheumatoid arthritis (RA) has been reported by many observational studies in the Asian population. This study aimed to examine the bidirectional causal effects between GERD and RA by two-sample Mendelian randomization (MR) analyses using genetic evidence. Methods: Two-sample Mendelian randomization analyses were performed to determine the causal effect of GERD (129,080 cases vs. 602,604 control participants) on RA (6,236 cases vs. 147,221 control participants) and RA on GERD, respectively. The inverse-variance weighted (IVW) method was used as the primary analysis. Weighted median and MR-Egger regression were taken as supplementary analyses. Cochran's Q test evaluated the heterogeneity. Horizontal pleiotropy was detected by estimating the intercept term of MR-Egger regression. Furthermore, multivariable MR analyses were performed to exclude the influence of confounding factors, including the years of schooling, BMI, and time spent watching television, between GERD and RA. Result: Both univariate MR (UVMR) and multivariable MR (MVMR) provided valid evidence that RA was causally and positively influenced by GERD (UVMR: OR = 1.49, 95% CI = 1.25-1.76, p = 6.18*10-6; MVMR: OR = 1.69, 95% CI = 1.24-2.31, p = 8.62*10-4), whereas GERD was not influenced by RA (UVMR: OR = 1.03, 95% CI = 1.00-1.06, p = 0.042; MVMR: OR = 1.04, 95% CI = 1.00-1.07, p = 0.0271). Conclusion: Our comprehensive bidirectional MR analysis found that for the European population, GERD can induce the occurrence of RA (OR = 1.69, p < 0.00125), whereas RA only has no significant influence on GERD. In particular, patients with GERD are suffering a 69% increased risk of RA occurrence, which means GERD is a substantial risk factor for RA.

Prolonged administration of total glucosides of paeony improves intestinal immune imbalance and epithelial barrier damage in collagen-induced arthritis rats based on metabolomics-network pharmacology integrated analysis.

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by synovial inflammation and joint damage with complex pathological mechanisms. In recent years, many studies have shown that the dysregulation of intestinal mucosal immunity and the damage of the epithelial barrier are closely related to the occurrence of RA. Total glucosides of paeony (TGP) have been used clinically for the treatment of RA in China for decades, while the pharmacological mechanism is still uncertain. The purpose of this study was to investigate the regulatory effect and mechanism of TGP on intestinal immunity and epithelial barrier in RA model rats. The results showed that TGP alleviated immune hyperfunction by regulating the ratio of CD3+, CD4+ and CD8+ in different lymphocyte synthesis sites of the small intestine, including Peyer's patches (PPs), intraepithelial lymphocytes (IELs), and lamina propria lymphocytes (LPLs). Specially, TGP first exhibited immunomodulatory effects on sites close to the intestinal lumen (IELs and LPLs), and then on PPs far away from the intestinal lumen as the administration time prolonged. Meanwhile, TGP restores the intestinal epithelial barrier by upregulating the ratio of villi height (V)/crypt depth (C) and expression of tight junction proteins (ZO-1, occludin). Finally, the integrated analysis of metabolomics-network pharmacology was also used to explore the possible regulation mechanism of TGP on the intestinal tract. Metabolomics analysis revealed that TGP reversed the intestinal metabolic profile disturbance in CIA rats, and identified 32 biomarkers and 163 corresponding targets; network pharmacology analysis identified 111 potential targets for TGP to treat RA. By intersecting the results of the two, three key targets such as ADA, PNP and TYR were determined. Pharmacological verification experiments showed that the levels of ADA and PNP in the small intestine of CIA rats were significantly increased, while TGP significantly decreased their ADA and PNP levels. In conclusion, purine metabolism may play an important role in the process of TGP improving RA-induced intestinal immune imbalance and impaired epithelial barrier.

Postbiotics in rheumatoid arthritis: emerging mechanisms and intervention perspectives.

Rheumatoid arthritis (RA) is a prevalent chronic autoimmune disease that affects individuals of all age groups. Recently, the association between RA and the gut microbiome has led to the investigation of postbiotics as potential therapeutic strategies. Postbiotics refer to inactivated microbial cells, cellular components, or their metabolites that are specifically intended for the microbiota. Postbiotics not only profoundly influence the occurrence and development of RA, but they also mediate various inflammatory pathways, immune processes, and bone metabolism. Although they offer a variety of mechanisms and may even be superior to more conventional "biotics" such as probiotics and prebiotics, research on their efficacy and clinical significance in RA with disruptions to the intestinal microbiota remains limited. In this review, we provide an overview of the concept of postbiotics and summarize the current knowledge regarding postbiotics and their potential use in RA therapy. Postbiotics show potential as a viable adjunctive therapy option for RA.

Identification of HHT-9041P1: A novel potent and selective JAK1 inhibitor in a rat model of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic systemic disease associated with long-term disability and premature mortality. If left untreated, it can seriously affect patients’ quality of life. The JAK-STAT signal transduction process is known to affect the occurrence and development of RA, and small molecule JAK inhibitors, such as tofacitinib, have been identified as treatments for RA. However, tofacitinib is a non-selective JAK inhibitor that was found to be associated with dose-limiting tolerability and safety issues, such as anemia in phase 2 dose-ranging studies. Therefore, we developed a selective JAK1 inhibitor, HHT-9041P1, to overcome target-related adverse reactions. We used enzyme and cytokine potency assays in vitro as well as the collagen-induced arthritis (CIA) model in vivo to explore the efficacy and mechanism. In vitro, HHT-9041P1 was diluted (0.017 nM–1 mM) in DMSO) and mixed with JAK1, JAK2, JAK3 or TYK2 kinases for use in the respective assays for inhibitory activity and selectivity evaluation. Fresh human PBMCs were activated and incubated with 100 ng/mL cytokine IL-6 or 20 ng/mL GM-CSF for use in the investigation of the immune mechanism. In vivo, HHT-9041P1 (1 mg/kg, 3 mg/kg and 10 mg/kg) was administered by oral gavage twice daily to CIA model Lewis rats from Day 8 to Day 29 for paw swelling and arthritis score evaluation. At the end of the experiment, the rats were sacrificed before collection of the hind ankle joint, spleen and blood for analysis of inflammation, arthritis phenotypes, inflammatory cytokine expression and Th1 cell proportions. As expected, HHT-9041P1 showed 10-fold greater selectivity for JAK1 over JAK2, and 23-fold greater selectivity over JAK3 in cellular assays. The high selectivity of HHT-9041P1 was also validated by in vivo safety studies. HHT-9041P1 demonstrated significant efficacy in a rat model of collagen-induced arthritis (CIA) and was associated with reduced helper T Cell 1 (Th1) cell differentiation. HHT-9041P1 also exhibited excellent pharmacokinetics properties. Thus, HHT-9041P1 was identified as a candidate for clinical development with many options for the treatment of RA.

Identification of potential ferroptosis key genes and immune infiltration in rheumatoid arthritis by integrated bioinformatics analysis

ObjectiveFerroptosis is of vital importance in the development of Rheumatoid arthritis (RA). The purpose of this project is to clarify the potential ferroptosis-related genes, pathways, and immune infiltration in RA by bioinformatics analysis. MethodsWe acquired ferroptosis-related genes (FRGs) from Ferroptosis database (FerrDb). We obtained the Gene dataset of RA (GSE55235) from the Gene Expression Omnibus (GEO) Database, screened the differentially expressed genes (DEGs) in RA and control samples, and then took the intersection of it and FRGs. Aiming to construct the protein-protein interaction (PPI) networks of the FRGs-DEGs, STRING database and Cytoscape software 3.7.0 would be used. Furthermore, hub genes were identified by CytoNCA, a Cytoscape plug-in. The gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment of FRGs-DEGs were performed. ResultsWe identified 34 FRGs-DEGs, including 7 upregulated and 27 downregulated genes by taking the intersection of the FRGs and DEGs. PPI analysis identified a total of 3 hub genes(VEGFA, PTGS2, and JUN). GO enrichment analyses and KEGG Pathway enrichment displayed that the FRGs-DEGs are involved in the response to oxidative stress and corticosteroid, heme binding, FoxO-signal pathway. Results of immune infiltration displayed that increased infiltration of T cells, while Macrophages M2 less may be related to the occurrence of RA. ConclusionThe hub genes involved in ferroptosis in RA may be VEGFA, PTGS2, and JUN, which are mainly involved in FoxO-signal pathway. T cell, Mac, and plasma cells may be involved in the regulation of RA-joints-synovial-inflammation.

Appraising causal risk and protective factors for rheumatoid arthritis.

Mendelian randomization (MR) is considered to overcome the bias of observational studies, but there is no current meta-analysis of MR studies on rheumatoid arthritis (RA). The purpose of this study was to summarize the relationship between potential pathogenic factors and RA risk based on existing MR studies. PubMed, Web of Science, and Embase were searched for MR studies on influencing factors in relation to RA up to October 2022. Meta-analyses of MR studies assessing correlations between various potential pathogenic factors and RA were conducted. Random-effect and fixed-effect models were used to synthesize the odds ratios of various pathogenic factors and RA. The quality of the study was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology using Mendelian Randomization (STROBE-MR) guidelines. A total of 517 potentially relevant articles were screened, 35 studies were included in the systematic review, and 19 studies were eligible to be included in the meta-analysis. Pooled estimates of 19 included studies (causality between 15 different risk factors and RA) revealed that obesity, smoking, coffee intake, lower education attainment, and Graves' disease (GD) were related to the increased risk of RA. In contrast, the causality contribution from serum mineral levels (calcium, iron, copper, zinc, magnesium, selenium), alcohol intake, and chronic periodontitis to RA is not significant. Obesity, smoking, education attainment, and GD have real causal effects on the occurrence and development of RA. These results may provide insights into the genetic susceptibility and potential biological pathways of RA.

Regulatory effect of zinc finger protein A20 on rheumatoid arthritis through NLRP3/Caspase-1 signaling axis mediating pyroptosis of HFLS- RA cells.

As a chronic inflammatory autoimmune disease, rheumatoid arthritis (RA) causes significant destruction to joints and cartilage. So far, from RA patients, the synovial cells and subsynovial tissues reflected the positive expression of IL-18, IL-1β, Caspase-1 and NLRP3, with the synovial tissues of those patients also expressing the zinc finger protein A20 at a significantly lower level compared with osteoarthritis (OA) ones. Thus, the inhibition of the NLRP3/caspase-1 signaling pathway can effectively down-regulate the expression of IL-1β, but when NLRP3 inflammasomes are activated, they can also shear GSDMD and induce pyroptosis. These suggest that the Gasdermin family of proteins, downstream of the NLRP3 inflammasome, could be involved in pyroptosis. Previous studies have shown that A20 contributes largely as an anti-inflammatory factor in many inflammatory diseases, but it remains unclear whether zinc finger protein A20, as an inhibitor of NLRP3 inflammasomes, can play a protective role against RA by inhibiting NLRP3 inflammasome-mediated pyroptosis. Therefore, this study aimed to verify the effects of zinc finger protein A20 on NLRP3/ Caspase-1-mediated pyroptosis in rheumatoid arthritis synovial fibroblasts (HFLS-RA) cells through cell experiments and clinical bidirectional verification, aim to understand the regulatory mechanism of A20 on RA. The results of clinical trials showed that NLRP3, Caspase-1, IL-1β and IL-18 were positively scattered in RA synovial cells and subsynovial tissue. The expression level of the zinc finger protein A20 in RA synovial tissues was significantly lower than that in OA synovial tissue and was negative, while zinc finger protein A20 was strongly positive in OA synovial tissue. In addition, HFLS-RA cells with siRNA-interfering zinc finger protein A20 were constructed at the cellular level, with the results also confirming that zinc finger protein A20 can play a protective role against RA by inhibiting NLRP3 inflammasome-mediated pyroptosis. In conclusion, this study is of great significance for understanding the role of the NLRP3-caspase-1-IL-1β/ pyroptosis signaling pathway in the occurrence and development of RA. It is expected that the results will provide a theoretical basis for the immune regulation of innate immunity in the occurrence and development of RA, while providing a new therapeutic target for the clinical treatment of RA.

Association between weight-adjusted-waist index and the prevalence of rheumatoid arthritis and osteoarthritis: a population-based study

IntroductionThe weight-adjusted-waist Index (WWI), an innovative metric for assessing obesity, exhibits superior efficacy in appraising lean muscle and adipose tissue mass relative to both the Body Mass Index (BMI) and Waist Circumference (WC). The objective of this research paper is to investigate the correlation between WWI and the incidence of Rheumatoid Arthritis (RA) and Osteoarthritis (OA).MethodsIn this population-based study, we collected data from adult participants aged 20–80 years using the National Health and Nutrition Examination Survey (NHANES) conducted between 2011 and 2020 to analyze the association between WWI and the occurrence of RA and OA. NHANES, a nationally representative cross-sectional survey, is designed to evaluate the health and nutritional status of the U.S. population. The current research incorporates an extensive, nationally representative sample of U.S. adults, utilizing weighted multivariate linear regression and smoothed curve fitting techniques to examine linear and non-linear relationships. Threshold effects were determined through a two-part linear regression model. Additionally, subgroup analyses and interaction tests were conducted to explore the connection between WWI and the incidence of RA and OA.ResultsOur findings reveal a linear positive correlation between WWI and OA prevalence, indicating that an increase in WWI is linked to a heightened risk of OA. Conversely, a non-linear relationship was observed between WWI and RA prevalence, exhibiting a significant threshold effect with a saturation value of 11.21 cm/√kg. A positive association was detected to the left of the saturation point, while no significant association was present between the two variables to the right of the saturation point, suggesting a complex non-linear relationship between RA prevalence and WWI.ConclusionsThis investigation demonstrates a positive linear association between WWI and OA prevalence, as well as a complex non-linear relationship with RA prevalence in U.S. adults aged 20–80 years.