C-reactive protein and implications in rheumatoid arthritis and associated comorbidities

Unveiling functionality and conducting two-sample mendelian randomization on WGCNA-identified oxidative stress-related hub genes in metabolic dysfunction-associated fatty liver disease

Metabolic dysfunction-associated fatty liver disease (MAFLD) shows accelerated development under the impact of oxidative stress (OS). There is an imperative to identify OS-related biomarkers in MAFLD and explore their potential mechanistic insights. The objective of this study was to identify OS-related biomarkers in MAFLD and explore their potential mechanisms. DEG analysis was performed using GSE17470 and GSE24807 datasets. An investigative exploration utilizing WGCNA was executed to elucidate hub OS-related genes. The intersection of OS-related hub genes identified by WGCNA and DEGs was systematically employed for thorough analyses. A mendelian randomization (MR) study examined the causal effect of C-reactive protein (CRP) on MAFLD. 59 OS-related DEGs were identified in MAFLD. WGCNA revealed 100 OS-related hub genes in MAFLD. Sixteen OS-related genes have been delineated as critical components in MAFLD. Enrichment analyses, employing GO and KEGG pathways, revealed pathways enriched with these genes. Following PPI analyses, the highest-ranking ten hub genes demonstrating abnormal expression were determined. Ultimately, a two-sample MR analysis demonstrated a causal link between the hub gene CRP and the occurrence of MAFLD. In this study, we harnessed WGCNA to formulate a co-expression network and identified hub OS-related DEGs in MAFLD. Additionally, the hub gene CRP exhibited a significant correlation with the predisposition to MAFLD. These findings offer innovative perspectives on the applications of OS-associated genes in individuals afflicted with MAFLD.

IL-4 polymorphisms (rs2227284, rs2243267, and rs2243270) are associated with reduced risk of rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disease, and understanding its genetic and molecular basis is crucial for early diagnosis, treatment, and prevention.

OBJECTIVE

This study aims to explore the association between IL-4 polymorphisms (rs2227284, rs2243267, rs2243270, and rs2243283) and RA risk.

METHODS

The four IL-4 polymorphisms were genotyped in 493 RA patients and 493 healthy controls using Agena MassARRAY. Logistic regression analysis calculated odds ratio (OR) and 95% confidence interval (CI) to estimate the relationship between IL-4 polymorphisms and RA risk.

RESULTS

Overall analysis revealed that rs2243267 (GG vs. CC: OR = 0.26, FDR-p = .032; Recessive: OR = 0.27, FDR-p = .048) and rs2243270 (AA vs. GG: OR = 0.26, FDR-p = .024; Recessive: OR = 0.27, FDR-p = .024) were associated with a decreased risk of RA. Stratified analysis indicated that rs2243267 and rs2243270 were correlated with reduced RA risk in female, smoking, BMI <24, and drinking population; rs2227284 was associated with a decreased RA risk in BMI <24 and drinking population. Moreover, rs2243267 and rs2243270 were significantly associated with reduced ACPA positivity.

CONCLUSIONS

Our findings suggest that IL-4 polymorphisms (rs2227284, rs2243267, and rs2243270) act as protective factors for RA in the Chinese Han population.

How to Distinguish Non-Inflammatory from Inflammatory Pain in RA?

PURPOSE OF THE REVIEW

Managing non-inflammatory pain in rheumatoid arthritis (RA) can be a huge burden for the rheumatologist. Pain that persists despite optimal RA treatment is extremely challenging for patient and physician alike. Here, we outline the latest research relevant to distinguishing non-inflammatory from inflammatory RA pain and review the current understanding of its neurobiology and management.

RECENT FINDINGS

Nociplastic pain is a recently introduced term by the international pain community. Its definition encompasses the non-inflammatory pain of RA and describes pain that is not driven by inflamed joints or compromised nerves, but that is instead driven by a functional reorganisation of the central nervous system (CNS). Insights from all areas of nociplastic pain research, including fibromyalgia, support a personalised pain management approach for non-inflammatory pain of RA, with evidence-based guidelines favouring use of non-pharmacological interventions. Future developments include novel CNS targeting pharmacotherapeutic approaches to treat nociplastic pain.

May high mobility group box protein-1 be a biomarker for major depressive disorder?

High Mobility Group Box Protein-1 (HMGB1), which has proinflammatory properties, is known to be involved in psychiatric disorders as far as we know, there are only one clinical studies investigating the role of HMGB1 in major depressive disorder (MDD). In this study, we aimed to investigate the role of HMGB1 in the etiopathogenesis of MDD and whether HMGB1 can be used as a biomarker in MDD by measuring the serum HMGB1 levels of depressed patients in the episode and remission periods. This study included 30 patients diagnosed with MDD in episode, 30 patients in remission and 30 healthy controls. Each group comprised 20 female and 10 male participants. In this study, serum HMGB1 levels were found to be lower in the patient group in the episode compared to the patient group in the remission period and the healthy control group. There was no significant difference between the patient group in remission and the healthy control group in terms of serum HMGB1 levels. The fact that serum HMGB1 levels were lower in the patient group in the episode compared to the patient group in the remission period and the control group may be related to the neuroprotective effects of HMGB1. HMGB1 may be used as a biomarker for MDD.

Risk factors for type 2 diabetes mellitus in Chinese rheumatoid arthritis patients from 2018 to 2022: a real-world, single-center, retrospective study

Introduction

In patients with rheumatoid arthritis (RA), the increased risk of concomitant type 2 diabetes mellitus (T2D) is an important contributor to increased mortality and decreased quality of life; however, the mechanisms and pathogenetic factors remain unknown.

Methods

In this study, we aimed to assess the risk factors for T2D in patients with RA. We recruited 206 healthy controls and 488 patients with RA, 160 of whom had comorbid T2D. General clinical information, disease characteristics, and circulating lymphocyte levels detected using modified flow cytometry were collected from all participants. Logistic regression models adjusted for confounders were fitted to estimate the risk factors of T2D in patients with RA.

Results

The incidence of RA in patients with T2D was 15.6%. Patients with RA and T2D had a longer disease duration, higher BMI, and a higher incidence of hypertension and a family history of diabetes than those with RA but no T2D. The absolute numbers of T helper 2 cell (Th2) and Regulatory T cells (Treg) decreased in patients with RA and T2D, which led to an increase in the ratios of Th1/Th2 and Th17/Treg cells. Multivariate logistic regression analysis showed that a family history of diabetes, a higher incidence of hypertension, higher neutrophil-lymphocyte ratio (NLR) levels, lower platelet-lymphocyte ratio (PLR) levels, and fewer circulating Th2 and Treg cells were associated with an increased risk of T2D in patients with RA.

Discussion

The levels of peripheral lymphocytes, especially Th2 and Treg cells, are closely related to the occurrence of T2D in patients with RA; however, the influence of body mass index (BMI), family history of diabetes, and systemic inflammation should not be ignored.

Association between blood Pentraxin-3 concentrations and rheumatic diseases: A systematic review and meta-analysis

BACKGROUND

Among the Pentraxins, the long Pentraxin-3 (PTX-3) is associated with several processes, particularly in the earliest phases of the innate humoral response. Increased blood PTX-3 concentrations have been observed in a wide range of conditions, from infectious to cardiovascular disorders. Since its increase is more rapid than C-reactive protein (CRP), PTX-3 can be useful to detect and monitor early inflammation. To dissect its pathophysiological role in rheumatic diseases (RD), we conducted a systematic review and meta-analysis comparing blood PTX-3 concentrations in RD patients and healthy individuals and investigating possible associations with clinical, demographic, and study characteristics.

METHODS

We performed a search of published evidence until April 2024 in PubMed, Web of Science and Scopus, which led to the selection of 60 relevant manuscripts from a total of 1072 records.

RESULTS

Our synthesis revealed a statistically significant difference in PTX-3 concentrations between RD patients and controls (standard mean difference, SMD = 1.02, 95% CI 0.77-1.26, p < .001), that correlated with CRP concentrations. The effect size was associated with geographical region of study conduction, RD type, with a reduction of the observed heterogeneity in patients with low LDL-cholesterol and triglycerides concentrations.

CONCLUSIONS

Our study has shown a significant increase in blood PTX-3 concentrations in RD patients, which was associated with specific patient characteristics. Nevertheless, additional studies are needed to better define the utility of measuring PTX-3 in the early phase of RD. Our study was conducted in compliance with the PRISMA 2020 statement (study protocol available at PROSPERO CRD42024516600).

Association of ultraprocessed food consumption with risk of rheumatoid arthritis: a retrospective cohort study in the UK Biobank

BACKGROUND

Limited studies explored the association between consumption of ultraprocessed food (UPF) and rheumatoid arthritis (RA).

OBJECTIVES

This study aimed to examine the association between UPF consumption and RA risk and explore the potential mediating effects of RA-related biomarkers.

METHODS

This retrospective cohort study included 207,012 participants without RA at recruitment and completed 24-h dietary recalls. UPF was defined based on the NOVA food classification system. Incident RA was ascertained using the International Classification of Diseases version 10. Cox regression models were used to examine the association between UPF consumption and the incidence of RA. Additionally, mediation analyses were conducted to evaluate the contribution of biomarkers related to the lipid profile, systemic inflammatory factors, serum liver enzymes, and glucose metabolism to the observed associations.

RESULTS

The participants' mean (standard deviation [SD]) age at recruitment was 56.08 (7.95) y. During a median follow-up of 12.24 (interquartile range: 11.66-13.03) y, 1869 RA events were recorded. Compared with the lowest quintile of UPF consumption (weight percentage of the UPF), the adjusted hazard ratio (HR) of RA in the highest quintile was 1.17 (95% confidence interval (CI): 1.01, 1.36). There was a 6% elevated risk of RA incidence per SD increase in UPF intake (HR: 1.06; 95% CI: 1.01, 1.11). In the mediation analyses, the biomarkers explained 3.07%-14.80% of the association between UPF intake and RA.

CONCLUSIONS

Higher UPF consumption was associated with an increased risk of RA, which may be mediated by inflammation, lipids, and liver enzymes. Lower UPF consumption is recommended to reduce RA incidence.

Inflammatory Marker Changes Following Total Knee Arthroplasty for Rheumatoid Arthritis with Vancomycin-loaded Calcium Sulfate Bone Filling

Rheumatoid arthritis (RA) patients undergoing total knee arthroplasty (TKA) face infection risk. The study evaluates vancomycin-loaded calcium sulfate bone as infection prevention. Patients with RA treated with TKA who had their femoral canal filled using either vancomycin-loaded calcium sulfate bone (experimental group [n = 35]) or the patient's own excised autologous bone (control group [n = 30]) at the Qingdao University Affiliated Hospital, Qingdao, China from January 1, 2017, to March 1, 2023, were retrospectively enrolled in this study. An experienced surgeon used midvastus approach. Surgeries included disinfection, antibiotics, and femoral filling. The age, gender, body mass index (BMI), comorbidities, and intraoperative details were extracted from the patient's medical records. Preoperation and postoperation markers (C-reactive protein [CRP], erythrocyte sedimentation rate [ESR]), pain scale (Visual Analog Scale [VAS]), infection rate, and Knee Society Score (KSS) were collected. Groups matched in age, gender, and BMI. No preoperative inflammatory marker differences were observed. However, compared to the control group, the postoperative inflammatory markers were significantly lower in the experimental group at 1-week postsurgery (CRP: 40.80 ± 23.17 vs. 60.80 ± 43.12 mg/L, p = 0.021; ESR: 72.06 ± 17.52 vs. 83.87 ± 21.52 mm/h, p = 0.012) and at 1-month postsurgery (CRP: 15.63 ± 6.56 vs. 21.17 ± 13.16 mg/L, p = 0.032; ESR: 25.25 ± 20.44 vs. 38.40 ± 25.26 mm/h, p = 0.024). There were no significant differences in the VAS (2.79 ± 0.90 vs. 2.70 ± 0.84 score, p = 0.689) and KSS (64.31 ± 17.88 vs. 66.57 ± 12.36) at 1-month postsurgery. Experimental group: zero infections; control group: only one infection. Administering vancomycin and calcium sulfate during TKA in RA patients reduces postoperative inflammation, but does not significantly affect infection risk; further research may be necessary for validation.

A unified metric of human immune health

Immunological health has been challenging to characterize but could be defined as the absence of immune pathology. While shared features of some immune diseases and the concept of immunologic resilience based on age-independent adaptation to antigenic stimulation have been developed, general metrics of immune health and its utility for assessing clinically healthy individuals remain ill defined. Here we integrated transcriptomics, serum protein, peripheral immune cell frequency and clinical data from 228 patients with 22 monogenic conditions impacting key immunological pathways together with 42 age- and sex-matched healthy controls. Despite the high penetrance of monogenic lesions, differences between individuals in diverse immune parameters tended to dominate over those attributable to disease conditions or medication use. Unsupervised or supervised machine learning independently identified a score that distinguished healthy participants from patients with monogenic diseases, thus suggesting a quantitative immune health metric (IHM). In ten independent datasets, the IHM discriminated healthy from polygenic autoimmune and inflammatory disease states, marked aging in clinically healthy individuals, tracked disease activities and treatment responses in both immunological and nonimmunological diseases, and predicted age-dependent antibody responses to immunizations with different vaccines. This discriminatory power goes beyond that of the classical inflammatory biomarkers C-reactive protein and interleukin-6. Thus, deviations from health in diverse conditions, including aging, have shared systemic immune consequences, and we provide a web platform for calculating the IHM for other datasets, which could empower precision medicine.

Combating Prozone Effects and Predicting the Dynamic Range of Naked-Eye Nanoplasmonic Biosensors through Capture Bioentity Optimization

Accurately quantifying high analyte concentrations poses a challenge due to the common occurrence of the prozone or hook effect within sandwich assays utilized in plasmonic nanoparticle-based lateral flow devices (LFDs). As a result, LFDs are often underestimated compared to other biosensors with concerns surrounding their specificity and sensitivity toward the target analyte. To address this limitation, here we develop an analytical model capable of predicting the prozone effect and subsequently the dynamic range of the biosensor based on the concentration of the capture antibody. To support our model, we conduct a sandwich immunoassay to detect C-reactive protein (CRP) in a phosphate-buffered saline (PBS) buffer using an LFD. Within the experiment, we investigate the relationship between the CRP dynamic range and the prozone effect as a function of the capture antibody concentration, which is increased from 0.1 to 2 mg/mL. The experimental results, while supporting the developed analytical model, show that increasing the capture antibody concentration increases the dynamic range. The developed model therefore holds the potential to expand the measurable range and reduce costs associated with quantifying biomarkers in diverse diagnostic assays. This will ultimately allow LFDs to have better clinical significance before the prozone effect becomes dominant.

Jin-Gu-Lian Capsule Did Not Significantly Improve Clinical Value in Rheumatoid Arthritis Therapy: A Real-World Study

Purpose

To investigate the clinical value of adding Jin-gu-lian (JGL) capsules into rheumatoid arthritis (RA) treatment by examining its impact on disease activity and quality of life (QoL) through a real-world study (RWS).

Patients and methods

RWS was conducted to compare the inflammatory markers, including IgM-RF, ESR, and CRP, between RA patients treated with only Western medicine (reference group) and Western medicine plus JGL (study group) during one-year follow-up. The clinical data was acquired from the hospital information system (HIS). Telephone call-based follow-up on QoL (SF-36) and accompanying symptoms, including gastrointestinal complaints, attacks of pneumonia, herpes zoster, URTIs, UTIs, and LTBIs. Finally, the anti-rheumatic drugs given to both groups were also compared. RWS was further validated for its feasibility by performing studies with hydroxychloroquine (HCQ) treatment, which is a commonly used anti-rheumatic drug for RA with mild effect.

Results

The study group failed to show a significant effect on inflammatory markers, especially on the CRP levels, indicating no additional clinical value of supplementing with JGL. Similarly, at the endpoint, no significant differences between the two groups on QoL and related symptoms were observed. Our study suggests that the patients in the study group might need more anti-rheumatic drugs to fill the treatment insufficiency, and the application ratio of NSAIDs would be significantly higher than the reference group. By conducting this study on HCQ treatment, the positive aspects of controlling disease activity and reducing NSAIDs application were found, which demonstrates the utility of performing the RWS to evaluate the effect of JGL.

Conclusion

Adding JGL did not significantly improve the clinical efficacy of RA treatment by this RWS. Folk herbal prescriptions such as JGL are suggested to underwent strict clinical trials before application.

Intestinal Dysbiosis, Tight Junction Proteins, and Inflammation in Rheumatoid Arthritis Patients: A Cross-Sectional Study

Recent studies point to intestinal permeability as an important factor in the establishment and development of rheumatoid arthritis (RA). Tight junctions (TJs) play a major role in intestinal homeostasis. The alteration of this homeostasis is related to RA. Furthermore, RA patients present dysbiosis and a lower microbiota diversity compared to healthy individuals. A cross-sectional study including RA patients and sex- and age-matched healthy controls was performed. The quantification of TJ proteins was carried out by ELISA. Gut microbiota was evaluated by NGS platform Ion Torrent S. The inflammatory variables included were DAS28, CRP, inflammatory cytokines (IL-6, IL-1, TNF-α) and oxidised LDL. Claudin-1 levels showed significant differences between groups. Results evidenced a correlation between claudin-1 values and age (r: -0.293; p < 0.05), IL6 (r: -0.290; p < 0.05) and CRP (r: -0.327; p < 0.05), and between zonulin values and both age (r: 0.267; p < 0.05) and TNFα (r: 0.266; p < 0.05). Moreover, claudin-1 and CRP levels are related in RA patients (β: -0.619; p: 0.045), and in patients with high inflammatory activity, the abundance of the genus Veillonella is positively associated with claudin-1 levels (β: 39.000; p: 0.004).

Nanomaterials in the treatment and diagnosis of rheumatoid arthritis: Advanced approaches

Rheumatoid arthritis (RA), a chronic inflammatory condition that affects persons between the ages of 20 and 40, causes synovium inflammation, cartilage loss, and joint discomfort as some of its symptoms. Diagnostic techniques for RA have traditionally been split into two main categories: imaging and serological tests. However, significant issues are associated with both of these methods. Imaging methods are costly and only helpful in people with obvious symptoms, while serological assays are time-consuming and require specialist knowledge. The drawbacks of these traditional techniques have led to the development of novel diagnostic approaches. The unique properties of nanomaterials make them well-suited as biosensors. Their compact dimensions are frequently cited for their outstanding performance, and their positive impact on the signal-to-noise ratio accounts for their capacity to detect biomarkers at low detection limits, with excellent repeatability and a robust dynamic range. In this review, we discuss the use of nanomaterials in RA theranostics. Scientists have recently synthesized, characterized, and modified nanomaterials and biomarkers commonly used to enhance RA diagnosis and therapy capabilities. We hope to provide scientists with the promising potential that nanomaterials hold for future theranostics and offer suggestions on further improving nanomaterials as biosensors, particularly for detecting autoimmune disorders.

Body mass index stratification enables cytokine-based prediction of ACPA status and Power-Doppler disease activity in rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis can be classified according to ACPA and RF status. ACPA status may be associated with other pathophysiological differences, e.g., the cytokines driving inflammation. Obesity influences the course of RA, likely involving leptin; the exact mechanisms are not completely understood. This study investigates BMI influence on RA cytokine profiles and the possibility of predicting ACPA status and disease activity measured by Power-Doppler sonography (PDS).

METHODS

Patients were examined using a multi-biomarker disease assay and PDS examination of wrists and MCP and PIP joints and stratified according to ACPA status and BMI, using prediction precision to determine BMI cutoff. Analysis was performed using elastic net regularization of logistic and multiple regression. We then attempted to predict ACPA status/PDS activity based on a bootstrap approach.

RESULTS

A total of 120 measurements from 95 patients were performed. ACPA status prediction peaked at BMI 26 kg/m2, with AUC 0.82. PDS activity prediction had a mean average error of < 1.6 PDS points for all groups. In obese patients, cytokine profiles appear to align in ACPA-positive and -negative patients, with leptin playing a greater role in predicting PDS activity, but with some remaining differences.

CONCLUSION

When stratified according to BMI, cytokine patterns can predict ACPA status and PDS activity in RA with a high degree of precision. This indicates that studies into the pathophysiology of RA should take BMI into account, to differentiate between disease- and obesity-associated phenomena. The underlying pathological processes of ACPA-negative and -positive RA appear different. Multi-cytokine evaluations may provide a deeper understanding of disease processes. Key Points • A multi-cytokine approach combined with ultrasonography and modern mathematical methods can contribute to a deeper understanding of the relationship between systemic and joint inflammation. • BMI influences cytokine profiles in rheumatoid arthritis and appears to "override" disease-specific processes. • Using cytokines only, and adjusting for BMI, it is possible to predict the ACPA status and joint inflammation with considerable precision.

A tale of two functions: C-reactive protein complement-ary structures and their role in rheumatoid arthritis

C-reactive protein (CRP) is an inflammatory biomarker with associated clinical utility in a wide number of inflammatory disorders, including rheumatoid arthritis (RA). The interaction of CRP with pro-inflammatory cytokines has been explored before, however its role in complement regulation is more subtle, where CRP is capable of both up and downregulating the complement cascade. CRP is produced in a pentameric form and can dissociate to a monomeric form in circulation which has significant implications for its ability to interact with receptors and binding partners. This dichotomy of CRP structure could have relevance in patients with RA who have significant dysfunction in their complement cascade and also widely varying CRP levels including at the time of flare. This review aims to bring together current knowledge of CRP in its various forms, its effects on complement function and how this could influence pathology in the context of RA.

Low-grade systemic inflammation links heavy metal exposures to mortality: A multi-metal inflammatory index approach

Certain heavy metals have been correlated to an elevated risk of inflammation-related diseases and mortality. Nevertheless, the intricate relationships between metal exposure, inflammation and mortality remain unknown. We included 3741 adults with measurements of ten urinary heavy metals in the National Health and Nutritional Examination Survey (NHANES) 2005-2010, followed up to December 31, 2019. Low-grade systemic inflammation was evaluated by various markers, including C-reactive protein (CRP) and ratios derived from regular blood tests. We assessed associations between heavy metal and all-cause mortality using multivariate COX regressions. Then we assessed the mediation effect of low-grade systemic inflammation on the associations via Sobel Test. To gauge the systemic inflammatory potential of the multi-metal mixture and its correlation with all-cause mortality, a Metal Mixture Inflammatory Index (MMII) was developed using reduced rank regression (RRR) models. The association between MMII and all-cause mortality was explored via multivariate COX regressions. Cadmium, antimony and uranium displayed positive associations with mortality, with hazard ratios (HR) ranging from 1.18 to 1.46 (all P-FDR < 0.05). Mediation analyses revealed that the associations between specific heavy metals (cadmium and antimony) and mortality risk were slightly mediated by the low-grade systemic inflammation markers, with mediation proportions ranging from 3.11 % to 5.38 % (all P < 0.05). MMII, the weighted sum of 9 heavy metals, significantly predicted platelet-to-lymphocyte ratio (PLR) and CRP (β = 0.10 and 1.16, all P < 0.05), was positively associated with mortality risk (HR 1.28, 95 % CI 1.14 to 1.43). Exposure to heavy metals might increase all-cause mortality, partly mediated by low-grade systemic inflammation. MMII, designed to assess the potential systemic inflammatory effects of exposure to multiple heavy metals, was closely related to the all-cause mortality risk. This study introduces MMII as an approach to evaluating co-exposure and its potential health effects comprehensively.

No evidence for causal effects of C-reactive protein (CRP) on chronic pain conditions: a Mendelian randomization study

Objective

We conducted a Mendelian randomization (MR) study to examine causal associations of C-reactive protein (CRP) with (1) spinal pain; (2) extent of multisite chronic pain; and (3) chronic widespread musculoskeletal pain.

Design

Two-sample MR study.

Setting/Subjects

We used summary statistics from publicly available genome-wide association studies (GWAS) conducted in multiple cohorts and biobanks. Genetic instrumental variables were taken from an exposure GWAS of CRP (n=204,402). Outcome GWASs examined spinal pain (n=1,028,947), extent of multisite chronic pain defined as the number of locations with chronic pain (n=387,649), and chronic widespread pain (n=249,843).

Methods

We examined MR evidence for causal associations using inverse-variance weighted (IVW) analysis and sensitivity analyses using other methods. We calculated odds ratios (ORs), 95% confidence intervals (95% CIs), and p-values, using a Bonferroni correction (p<0.0166) to account for 3 primary comparisons.

Results

Greater serum CRP (mg/L) was not significantly causally associated with spinal pain (OR=1.04, 95% CI 1.00-1.08; p=0.07) in IVW analysis. Greater serum CRP also showed no significant causal association with extent of multisite chronic pain in IVW analysis (beta coefficient= 0.014, standard error=0.011; p=0.19). CRP also showed no significant causal association with chronic widespread pain in IVW analysis (OR=1.00, 95% CI 1.00-1.00; p=0.75). All secondary and sensitivity analyses also showed no significant associations.

Conclusions

This MR study found no causal association of CRP on spinal pain, the extent of chronic pain, or chronic widespread pain. Future studies examining mechanistic biomarkers for pain conditions should consider other candidates besides CRP.

Monocyte chemoattractant protein-1 detection in wound tissue fluids for the assisted diagnosis of wound infection

BACKGROUND

Infections are commonly seen in wounds. The overall infection rate is 1.8% to 4.2%. Improper infection management can lead to serious conditions and may progress to life-threatening sepsis. Because there is a need for assistance in predicting wound infection before obvious clinical symptoms, the measurement of cytokines in wound tissue fluids has attracted our attention for determining the overall status of wound infection. Our intent was to assess the potential biomarkers in the diagnosis of wound infection.

METHODS

We collected 146 tissue fluids (acute: 59, chronic: 61, and normal: 26) for analysis of biomarkers using a human cytokine array. Serum C-reactive protein was also measured from 104 patients. The sensitivity and specificity of significant wound cytokines and serum C-reactive protein for the diagnosis of wound infection were evaluated.

RESULTS

Among biomarkers examined, serum C-reactive protein and tissue C-reactive protein were highly expressed in acute infection wounds, whereas monocyte chemoattractant protein-1 was significantly expressed in chronic infection wounds. Because the expression of wound biomarkers varied in different types of wounds, relationships among them were studied. A high correlation between tissue C-reactive protein and interleukin-8 (R2 = 0.7) and a moderate correlation between systemic and local C-reactive protein (R2 = 0.47) were observed. In addition, tissue monocyte chemoattractant protein-1 had better sensitivity (74%) and specificity (65%) in the diagnosis of wound infection. Moreover, combined serum C-reactive protein with monocyte chemoattractant protein-1 examination provided a higher area under the curve in the receiver operator characteristic curve (0.75).

CONCLUSION

We found that tissue monocyte chemoattractant protein-1 is a superior diagnostic marker for assistance with the diagnosis of wound infection.

The efficacy of curcumin supplementation on serum total antioxidant capacity, malondialdehyde, and disease activity in women with rheumatoid arthritis: A randomized, double-blind, placebo-controlled clinical trial

Oxidative stress plays a crucial role in the physiopathology of rheumatoid arthritis (RA), which is associated with impaired antioxidant defenses. This study aimed to investigate the effects of curcumin supplementation on serum levels of total antioxidant capacity (TAC), malondialdehyde (MDA), and disease activity in women with RA. In this clinical trial, 48 women with RA were treated with one capsule of curcumin (500 mg daily) or placebo for 8 weeks. Anthropometric measurements and fasting blood samples were collected at baseline and end of the study. Finally, we assessed the Disease Activity Score in 28 joints (DAS-28), dietary intake, and physical activity levels. While curcumin supplementation for 8 weeks significantly increased the serum levels of TAC (p < 0.05), it decreased tender joint counts, swollen joint counts, visual analog scale (VAS) for pain, and DAS-28 compared to the placebo at the end of the study (p < 0.001 for all). MDA levels significantly decreased in the curcumin group (p < 0.05). However, changes in MDA concentration were not significant between groups at the end of the trial (p = 0.145). Curcumin supplementation had a beneficial effect on increasing the serum levels of TAC and decreased DAS-28 in women with RA.

Associations of C reactive protein to albumin ratio, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio with disease activity in patients with juvenile idiopathic arthritis

INTRODUCTION

Recent works in the scientific literature reported the role of C reactive protein to albumin ratio (CAR), neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) as biomarkers of disease activity in rheumatic diseases.

OBJECTIVES

To investigate the role of CAR, PLR and NLR as potential markers of disease activity in children with non-systemic JIA (nsJIA) and their correlation with the risk of persistent disease activity of flare during follow up.

METHODS

Our prospective, cross-sectional study involved 130 nsJIA patients (74 with active disease and 56 with inactive disease according to Wallace criteria) and 62 healthy controls. Demographic, clinical and laboratory data were collected at baseline (T0) and at 3 (T1), 6 (T2), 12 (T3) and 18 months (T4) during follow up. Disease activity was evaluated through Juvenile Arthritis Disease Activity Score (JADAS-27).

RESULTS

At baseline, CRP and CAR were higher in patients than in controls (p = 0.046), while no differences were found for NLR and PLR. However, there was no positive correlation between CAR, NLR, PLR and JADAS-27 in JIA patients. To better investigate the role of CAR, NLR and PLR as markers of disease activity, we used a generalized estimating equation (GEE) model, applied to all patients either with or without active disease. According to this analysis, CAR and NLR baseline levels were predictive of higher risk of disease activity at 6 months follow up (p < 0.001).

CONCLUSIONS

CAR and NLR could indicate persistent disease activity in patients with JIA. Their predictive value could be increased by their combined use and by the observation of their trend during follow up, since increasing CAR values over time could predict a disease flare in the brief time.

Association of C-reactive protein with all-cause and cause-specific mortality in people with gout

AIMS

To test the association of C-reactive protein (CRP) with all-cause and cause-specific mortality in people with gout.

METHODS

This cohort study included 502 participants with gout from the National Health and Nutrition Examination Survey. Multivariate Cox regression analysis, subgroup analysis, and restricted cubic spline (RCS) analyses were utilized to examine the association of CRP levels with all-cause, cardiovascular, and cancer mortality.

RESULTS

After adjusting for multiple variables, Cox regression analysis showed that compared with individuals in the lowest tertile of CRP levels, those in the middle and highest tertiles experienced increases in all-cause mortality risk of 74.2% and 149.7%, respectively. Similarly, the cancer mortality risk for individuals in the highest tertile of CRP levels increased by 283.9%. In addition, for each standard deviation increase in CRP, the risks of all-cause and cancer mortality increased by 25.9% and 35.4%, respectively (P < 0.05). Subgroup analyses demonstrated that the association between CRP levels and all-cause mortality remained significant across subgroups of age (≤ 60 and > 60 years), gender (male), presence or absence of hypertension, non-diabetes, cardiovascular disease, non-cardiovascular disease and non-cancer. Furthermore, the association with cancer mortality was significant in subgroups including males, those without hypertension and cancer, and those with or without diabetes. However, the association with cardiovascular mortality was only significant in the non-hypertension subgroup (P < 0.05). Nonlinear association of CRP with all-cause mortality and linear association with cancer mortality were also confirmed (P for nonlinearity = 0.008 and 0.135, respectively).

CONCLUSIONS

CRP levels were associated with increased all-cause and cancer mortality among individuals with gout.

Investigating the therapeutic potential of sinomenine in rheumatoid arthritis: anti-inflammatory, antioxidant, and immunomodulatory mechanisms

An autoimmune disease, rheumatoid arthritis (RA) is characterized by the onset of inflammation and subsequent damage to the joints. Although several therapies are available for RA, none are effective, and many have undesirable side effects. The roots of Sinomenium acutum produce an alkaloid called Sinomenine (SIN), which has been used for centuries in Chinese medicine to treat arthritis due to its anti-inflammatory properties. This study aimed to explore the potential therapeutic benefits of SIN through oral administration following RA induction using Freund's complete adjuvant (FCA) injections. The study monitored changes in the arthritic index, hind paw volume, inflammation and oxidative stress markers. Results demonstrated that SIN effectively inhibited the activity of NF-κB and IKKβ in knee joint tissues, which led to a decrease in tissue levels of TNF-α, IL-6, IL-1β, and iNOS in RA-induced rats. The production of anti-inflammatory cytokines such as IL-10, Arg-1, and Fizz1 also increased. In rat knee joints, SIN elevated the expression of TIMP-1 and TIMP-3 and decreased the expression of MMP-2 and MMP-9. Additionally, SIN modulated the RANK/RANKL/OPG pathway in RA-induced rat knee joint tissues, reducing RANKL expression and increasing OPG. SIN also effectively decreased MDA, NO, and elevated antioxidant enzymes (SOD, CAT, GPx, and GSH) in RA-induced rats via Nrf2/Keap 1 signaling pathway activation. In conclusion, this study suggests that SIN possesses potential therapeutic benefits for treating RA by modulating the RANK/RANKL/OPG pathway, which may impact osteoclast activity, oxidative stress, and inflammation in knee joint tissues.

A narrative review of the comparative safety of disease-modifying anti-rheumatic drugs used for the treatment of rheumatoid arthritis

INTRODUCTION

Disease-modifying anti-rheumatic drugs (DMARDs) have improved the outcomes of patients with rheumatoid arthritis (RA). DMARDs are classified into three categories: conventional synthetic DMARDs, biological DMARDs (including biosimilars), and targeted synthetic DMARDs. DMARDs, by way of their effect on the immune system, are associated with increased risk of adverse events, including infections, malignancies, cardiovascular disease, gastrointestinal perforations, and other less common events.

AREAS COVERED

In this narrative literature review performed with searches of the PubMed database from 1 January 2010 through 1 January 2023, we compare the risk of safety events between DMARDs using data from both randomized clinical trials and observational studies.

EXPERT OPINION

DMARD use in RA is associated with higher rates of serious infections, tuberculosis reactivation, opportunistic infections, and possibly malignancies. Specific biologic DMARDs and higher doses are associated with elevated risks of various adverse events (gastrointestinal perforations, thromboembolism, serious infection). Shared decision-making is paramount when choosing a treatment regimen for patients based on their own comorbidities. JAKi are the newest class of medications used for RA with robust safety data provided in clinical trials. However, more real-world evidence and phase-IV pharmacovigilance data are needed to better understand comparative safety profile of DMARDs in RA.

The first involved joints and associated factors in patients with rheumatoid arthritis

Objectives

This study aimed to investigate the first involved joints and associated factors in Turkish patients with rheumatoid arthritis (RA).

Patients and methods

This retrospective cross-sectional study included 300 newly diagnosed and disease-modifying antirheumatic drug-naïve RA patients (240 females, 60 males; mean age: 54±1.2 years; range, 18 to 82 years). Baseline demographic, clinical, and laboratory data were evaluated between January 2022 and December 2022. The patients were divided into four groups according to autoantibody profile: antibody-negative patients (Group 1; both RF and anti-CCP were negative in this group of patients), RF-positive patients (Group 2), anti-CCP-positive patients (Group 3), and patients with dual seropositivity with RF and antiCCP (Group 4). The patients were also divided into two groups according to the size of the first affected joint: patients with SJI at diagnosis and patients without SJI involvement at diagnosis.

Results

Rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) antibody positivity rates were 40.3% and 35.6%, respectively. The mean lag time to diagnosis was 25±36 months. At the disease onset, 20% of patients did not have small joint involvement (SJI). Seronegative patients tended to be female (p=0.001), had longer lag time (p=0.001), and had lower levels of C-reactive protein (p=0.025), white blood count (p=0.005), and neutrophil/lymphocyte ratio (p=0.001) compared to the dual seropositive group. Patients presenting with SJI had a younger age (p=0.002), tended to be female (p=0.001), and had lower RF (p=0.034) and anti-CCP (p=0.031) positivity. Only age (p=0.005) and dual seronegativity (RF and anti-CCP; p=0.035) were the independent predictors of SJI in multivariate analysis.

Conclusion

The decreasing age and seronegative status were defined as independent risk factors of SJI at the onset of RA. Population-based, prospective studies are needed for earlier diagnosis.

Decoding the Correlation Between Inflammatory Response Marker Interleukin-6 (IL-6) and C-reactive Protein (CRP) With Disease Activity in Rheumatoid Arthritis

BACKGROUND

Excessive interleukin-6 (IL-6) production in rheumatoid arthritis (RA) leads to joint destruction, inflammation, and systemic symptoms. IL-6 inhibitors alleviate symptoms. C-reactive protein (CRP), an inflammation biomarker, correlates with RA activity. In this study, we assess IL-6 and CRP levels in RA patients to understand their association with disease activity.

MATERIALS AND METHODS

This cross-sectional study was conducted at a tertiary care hospital in central India for 15 months, from July 2022 to September 2023. The study involved 75 participants diagnosed with RA and receiving outpatient treatment. Exclusion criteria included anti-IL-6 drug treatment, bedridden individuals, proxy patients, and those without consent. Disease activity was assessed using the 28-joint disease activity score (DAS28), while IL-6 and CRP levels were measured following the standard procedures.

RESULTS

The average CRP levels were found to be 51.67 ± 47.49 mg/L, while IL-6 levels averaged 65.16 ± 43.67 pg/ml. The results revealed a substantial positive correlation between IL-6 levels and DAS28 (r = 0.603, p value < 0.001), indicating a significant association. Additionally, a moderate correlation between CRP levels and DAS28 (r = 0.493, p value < 0.001) highlighted a significant relationship between these variables.

CONCLUSIONS

The analysis showed that higher IL-6 levels were associated with increased disease activity and suggested IL-6 as a valuable indicator for assessing RA severity. Also, CRP levels had a moderate correlation with disease activity. Overall, IL-6 is a better marker for disease activity when compared to CRP levels in patients with RA.

Impact of adding Mediterranean diet to aerobic and strengthening exercise program on pain, inflammation, and muscle performance in females with rheumatoid arthritis: a randomized controlled trial

BACKGROUND

People with rheumatoid arthritis (RA) frequently use dietary interventions such as Mediterranean diet (MedDiet) and exercises to complement pharmacotherapy.

OBJECTIVE

To investigate the effect of adding MedDiet to a designed exercise program on quadriceps and hamstrings muscles performance, pain, C-reactive protein (CRP), handgrip strength, bodyweight, and function in females with RA.

METHODS

Sixty females were allocated randomly to the MedDiet plus exercise program (n = 30) or exercise program only (n = 30). The interventions continued for 6 months followed by 6 months of follow-up with no intervention. The primary outcome was the quadriceps and hamstrings muscles performance (agonist-antagonist ratio). The secondary outcomes were visual analog scale (VAS) for pain, CRP blood marker for inflammation, handheld dynamometer for handgrip strength, Health AssessmentQuestionnaire disability index (HAQ-DI) for function, and body weight. All outcomes were measured at baseline, 6-month post-intervention, and 12 months from baseline as a follow-up.

RESULTS

The MedDiet group showed statistically significant improvements in all the measured outcomes than the control group (p < .05) after 6 and 12 months. After 6 months of intervention, the mean±SD for agonist-antagonist ratio, pain, and HAQ-DI were 84.59 ± 5.33 and 69.92 ± 5.56 (p < .001, ƞ2 = 0.65), 42.33 ± 8.98 and 54.33 ± 10.06 (p < .001, ƞ2 = 0.3), 1.13 ± 0.48 and 1.9 ± 0.59 (p < .001, ƞ2 = 0.34) in the MedDiet and control groups, respectively.

CONCLUSION

Adding MedDiet to aerobic and strengthening exercise program improved quadriceps and hamstrings muscles performance, pain, functional ability, CRP, handgrip strength, and body weight. Consequently, Mediterranean diet should be considered as adjunctive therapy in treating females with RA.

Lipid profile alterations in non-infectious uveitis: correlation with quantitative optical coherence tomography angiography parameters

BACKGROUND/AIMS

Lipid profiles have been changed in numerous chronic conditions. The impact of uveitis on lipid metabolism remains unclear.

METHODS

This is a cross-sectional study included 416 patients with non-infectious uveitis (NIU) and 416 healthy subjects. Standard techniques were used to measure total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol (HDLc), low-density lipoprotein-cholesterol (LDLc) levels. Quantitative optical coherence tomography angiography (OCTA) parameters were obtained from 500 eyes in each group. Correlation analysis examined the relationship between lipid profile and OCTA parameters.

RESULTS

Patients with NIU exhibited significantly elevated TC, TG and LDLc levels compared with controls (p=0.003; p<0.001; p<0.001, respectively). Subgroup analysis revealed that HDLc was significantly lower in Behçet's disease (p=0.024) compared with controls. Vascular density (VD) in the superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris and optic disk were significantly decreased in NIU eyes (p<0.05, respectively) compared with controls. HDLc exhibited a significant negative correlation with VDs in the whole and parafovea SCP (r=-0.489, p=0.008; r=-0.480, p=0.0026, respectively), while LDLc showed a significant positive correlation with VDs in the whole and parafovea DCP in NIU patients (r=0.576, p=0.032; r=0.267, p=0.034, respectively).

CONCLUSIONS

The lipid profile is altered in NIU, and there are correlations between HDLc and LDLc levels and VD as measured by OCTA. Lipid profile analysis may offer valuable insights into evaluating vascular and metabolic aspects of NIU.

Comparison of Adenosine Deaminase, C-reactive Protein, Uric Acid, and Rheumatoid Arthritis Levels in Patients With Rheumatoid Arthritis and Those Without Arthritis: A Review

One of the hallmarks of rheumatoid arthritis (RA) is inflammation of the synovial membrane, and oxidative stress is a mediator of tissue damage. RA is characterized by persistent joint inflammation, which leads to pain, edema, and finally joint destruction. Numerous biochemical markers can cause RA because of their impact on systemic and local inflammation. Numerous biomarkers have been investigated for their potential application in the diagnosis and prognosis of RA. In this review article, we evaluate the role of RA factor or rheumatoid factor (RF), uric acid, C-reactive protein (CRP), and adenosine deaminases (ADAs) as biomarkers in patients with and without arthritis. Studies that analyze and compare the levels of uric acid, ADAs, CRP, and RF in patients with and without arthritis. Although recent research has shown higher levels of uric acid, ADA, CRP, and RA in patients with RF compared to healthy controls, these findings may indicate a role for these markers in reflecting inflammation and disease activity. In the metabolism of purines, the enzyme ADA is involved. The liver produces CRP, which is then released into the bloodstream. In inflammatory situations, there is a rise in CRP levels. This biomarker is frequently used for systemic inflammatory assessment in RA. The pathophysiology and severity of RA have both been connected to uric acid, which has historically been linked to gout. One particular biomarker for RA is RF. When compared to a healthy control group of individuals with arthritis, this review provides valuable insights into the diagnostic and prognostic use of uric acid, CRP, ADAs, and RF.

Disease-specific plasma protein profiles in patients with fever after traveling to tropical areas

Fever is common among individuals seeking healthcare after traveling to tropical regions. Despite the association with potentially severe disease, the etiology is often not determined. Plasma protein patterns can be informative to understand the host response to infection and can potentially indicate the pathogen causing the disease. In this study, we measured 49 proteins in the plasma of 124 patients with fever after travel to tropical or subtropical regions. The patients had confirmed diagnoses of either malaria, dengue fever, influenza, bacterial respiratory tract infection, or bacterial gastroenteritis, representing the most common etiologies. We used multivariate and machine learning methods to identify combinations of proteins that contributed to distinguishing infected patients from healthy controls, and each other. Malaria displayed the most unique protein signature, indicating a strong immunoregulatory response with high levels of IL10, sTNFRI and II, and sCD25 but low levels of sCD40L. In contrast, bacterial gastroenteritis had high levels of sCD40L, APRIL, and IFN-γ, while dengue was the only infection with elevated IFN-α2. These results suggest that characterization of the inflammatory profile of individuals with fever can help to identify disease-specific host responses, which in turn can be used to guide future research on diagnostic strategies and therapeutic interventions.

Effects of Selenium Supplementation on the Indices of Disease Activity, Inflammation and Oxidative Stress in Patients with Rheumatoid Arthritis: a Randomized Clinical Trial

The aim of study was to evaluate the effect of selenium supplementation on disease activity, inflammation, and oxidative stress in patients with rheumatoid arthritis (RA). This study was a randomized double-blind placebo-controlled trial on 59 patients with RA. Participants were randomly divided to receive 200 μg/day of selenium or a placebo for 12 weeks. The disease activity score (DAS.CRP and DAS.ESR), erythrocyte sedimentation rate (ESR), serum levels of C-reactive protein (CRP), fasting blood glucose, lipids, antibodies to cyclic citrullinated protein (anti-CCP), nitric oxide, glutathione, and total antioxidant capacity were assessed. The mean of DAS.CRP and DAS.ESR decreased significantly within both study groups after the intervention. However, the between-group comparisons revealed no significant differences. The CRP levels decreased significantly in the selenium group, and this decrease was near the significance level compared to the placebo (P = 0.05). However, after adjusting for baseline values, the observed difference between groups did not remain significant. In addition, the values of ESR and anti-CCP decreased significantly within the selenium group. Although, between-group comparison did not statistically significant, the change in ESR and anti-CCP in the selenium group was small clinically relevant compared to the placebo [the effect size (95% CI) for ESR: 0.38 (- 0.14, 0.89), and for anti-CCP: 0.32 (- 0.2, 0.83)]. Our study showed that selenium caused a small clinically relevant improvement in some RA biomarkers such as ESR and anti-CCP. Future studies that evaluate the effects of novel forms of supplements such as selenium nanoparticles on the clinical symptoms and biomarkers of RA are suggested. Trial Registration: At www.irct.ir as IRCT20190924044869N1 on 2020-06-14.

Metabolic Syndrome Is Associated With an Increased Risk of Rheumatoid Arthritis: A Prospective Cohort Study Including 369,065 Participants

OBJECTIVE

To explore the associations between metabolic syndrome (MetS) and its individual components and the risk of rheumatoid arthritis (RA).

METHODS

A total of 369,065 individuals were included in the present study based on the UK Biobank. Multivariable Cox proportional hazards regression models were applied to estimate the associations between MetS and its individual components and the risk of RA. Mediation analysis was performed to further assess the potential mediating role of C-reactive protein (CRP) in the relationship between MetS and RA.

RESULTS

During a median follow-up period of 12.04 years, a total of 4901 incident RA cases were documented. MetS (hazard ratio [HR] 1.22, 95% CI 1.14-1.30) and 4 of its 5 components (elevated waist circumference [WC; HR 1.21, 95% CI 1.12-1.32], elevated triglyceride [TG] level [HR 1.12, 95% CI 1.05-1.19], reduced high-density lipoprotein cholesterol [HDL-C] level [HR 1.31, 95% CI 1.23-1.39], and hyperglycemia [HR 1.15, 95% CI 1.05-1.25]) were associated with an increased risk of RA. In addition, the risk of RA increased as the number of diagnosed MetS components increased, with the highest risk in participants with all 5 components. Mediation analysis showed that CRP might mediate the association between MetS and RA, accounting for 9.27% of the total effect.

CONCLUSION

These findings indicated positive associations between MetS and 4 of its components (WC, TG, HDL-C, and hyperglycemia) and the risk of RA, highlighting the importance of MetS management in the prevention of RA.

Cost-consequence analysis of tocilizumab versus adalimumab and etanercept among rheumatoid arthritis patients in Saudi Arabia: a single-center study

BACKGROUND

The study aimed to examine the direct medical cost and impact of tocilizumab (TOZ) versus adalimumab (ADM) and etanercept (ETC) on reducing the levels of two inflammatory markers (e.g., C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)) among patients with rheumatoid arthritis (RA) using real-world data from Saudi Arabia.

METHOD

This was a single-center retrospective cohort study in which data for biologic-naïve RA patients aged ≥ 18 years and treated with TOZ, ADM, ETC were retrieved from the electronic medical records (EMRs) of a university-affiliated tertiary care center in Riyadh, Saudi Arabia. Patients were followed up at least one year after the treatment initiation. Bottom-up microcosting was utilized to estimate the direct medical costs. Additionally, inverse probability treatment weighting and bootstrapping with 10,000 replications were conducted to generate 95% confidence levels for costs and the mean reductions in CRP and ESR levels.

RESULTS

The number of patients who met the inclusion criteria and were included in the analysis was 150 patients (TOZ (n = 56), ADM (n = 41), ETC (n = 53)). Patients on TOZ had 3.96 mg/L (95% CI: -0.229-4.95) and 11.21 mm/hr (95% CI: 10.28-18.11) higher mean reductions in the CRP and ESR levels compared to their counterparts on ADM, ETC, respectively. However, this was associated with mean annual incremental costs of USD 10,087.88 (95% CI: 9494.50-11,441.63) in all cost-effectiveness bootstrap distributions.

CONCLUSION

Tocilizumab has shown better effectiveness in reducing the levels of CRP and ESR but with higher costs. Future studies should examine whether the reduction of these two inflammatory markers is associated with quality-adjusted life years (QALYs) gains.

Inflammatory mediators, oxidative stress and genetic disturbance in rheumatoid arthritis rats supported by alfalfa seeds metabolomic constituents via blocking interleukin-1receptor

Rheumatoid arthritis (RA) is an autoimmune disease characterized by aggressive cartilage and bone erosion. This work aimed to evaluate the metabolomic profile of Medicago sativa L. (MS) (alfalfa) seeds and explore its therapeutic impact against RA in rats. Arthritis was induced by complete Freund's adjuvant (CFA) and its severity was assessed by the arthritis index. Treatment with MS seeds butanol fraction and interlukin-1 receptor antagonist (IL-1RA) were evaluated through measuring interlukin-1 receptor (IL-1R) type 1 gene expression, interlukin-1 beta (IL-1β), oxidative stress markers, C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), prostaglandin E2 (PGE2), caspase-3 (Cas-3), intracellular adhesion molecule-1 (ICAM-1), DNA fragmentation, and chromosomal damage. Total phenolics/ flavonoids content in the ethyl acetate, butanol fraction and crude extract of MS seeds were estimated. The major identified compounds were Quercetin, Trans-taxifolin, Gallic acid, 7,4'-Dihydroxyflavone, Cinnamic acid, Kudzusaponin SA4, Isorhamnetin 3-O-beta-D-2'',3'',4''-triacetylglucopyranoside, Apigenin, 5,7,4'-Trihydroxy-3'-methoxyflavone, Desmethylxanthohumol, Pantothenic acid, Soyasapogenol E, Malvidin, Helilandin B, Stigmasterol, and Wairol. Treatment with MS seeds butanol fraction and IL-1RA enhanced all the biochemical parameters and the histopathological features of the ankle joint. In conclusion, Trans-taxifolin was isolated for the first time from the genus Medicago. MS butanol fraction seeds extract and IL-1 RA were considered as anti-rheumatic agents.

Mendelian randomization analysis identifies a genetic casual association between circulating C-reactive protein and intracerebral hemorrhage

BACKGROUND

The causal effect of C-reactive protein (CRP) on intracerebral hemorrhage (ICH) remains controversial. We discussed the causal association of CRP with ICH based on two-sample Mendelian randomization.

METHODS

The data from two genome-wide association studies (GWAS) of European ancestry was extracted, including circulating CRP levels (204,402 individuals) and ICH (1,687 cases and 201,146 controls). The inverse variance weighted (IVW) method was primary tool to evaluate the causal relationship of circulating CRP levels on ICH risk. MR-Egger regression and MR-PRESSO global test were utilized to identify pleiotropy. Heterogeneity was discussed with Cochran's Q test. The leave-one-out analysis explored the reliability of the results.

RESULTS

54 SNPs were identified as instrumental variables (IVs) for circulating CRP levels, and these IVs had no significant horizontal pleiotropy, heterogeneity, or bias. MR analysis demonstrated a causal relationship between elevated circulating CRP levels and decreased risk of ICH (ORIVW = 0.828, 95% CI 0.692-0.992, P = 0.040).

CONCLUSION

Elevated circulating CRP levels demonstrated a significant potentially protective causal relationship with risk of ICH.

C-Reactive Protein (CRP) is Associated With Chronic Pain Independently of Biopsychosocial Factors

Inflammation is linked with chronic pain but the extent to which this relationship is associated with biopsychosocial factors is not known. We investigated relationships between blood C-reactive protein (CRP) and regional chronic pain conditions adjusting for a large range and number of potential confounders. We performed cross-sectional analyses using the UK Biobank (N = 415,567) comparing CRP in people reporting any of 9 types of regional chronic pain with pain-free controls. Using logistic regression modelling, we explored relationships between CRP and the presence of chronic pain, with demographic, socioeconomic, psychological/lifestyle factors, and medical comorbidities as covariates. CRP was higher in chronic pain at any site compared with controls (Females: median [interquartile range] 1.60 mg/L [2.74] vs 1.17 mg/L [1.87], P < .001; Males: 1.44 mg/L [2.12] vs 1.15 mg/L [1.65], P < .001). In males, associations between CRP and all types of chronic pain were attenuated but remained significant after adjustment for biopsychosocial covariates (OR range 1.08-1.49, P ≤ .001). For females, adjusted associations between CRP and pain remained significant for most chronic pain types (OR range 1.07-1.34, P < .001) except for facial pain (OR 1.04, P = .17) and headache (OR 1.02, P = .07)-although these non-significant findings may reflect reduced sample size. The significant association between CRP and chronic pain after adjustment for key biopsychosocial confounders implicates an independent underlying biological mechanism of inflammation in chronic pain. The presence of yet unknown or unmeasured confounding factors cannot be ruled out. Our findings may inform better-targeted treatments for chronic pain. PERSPECTIVE: Using a large-scale dataset, this article investigates associations between chronic pain conditions and blood C-reactive protein (CRP), to evaluate the confounding effects of a range of biopsychosocial factors. CRP levels were higher in those with chronic pain versus controls after adjusting for confounders-suggesting a possible independent biological mechanism.

Analysis of Potential Vitamin D Molecule Biomarkers: Association of Calcitriol and Its Hydroxylation Efficiency Ratio with Cardiovascular Disease Risk in Rheumatoid Arthritis Patients

Rheumatoid arthritis (RA) is a multifactorial autoimmune disease in which hypovitaminosis D by calcidiol quantification has been associated with disease severity. However, other vitamin D molecules could be implicated in RA pathophysiology and its comorbidities such as cardiovascular disease (CVD), which impacts the severity and mortality of RA patients. This study aimed to assess the relationship between calcidiol, calcitriol, its hydroxylation efficiency ratio, and the soluble vitamin D receptor (sVDR) and clinical and CVD risk variables to propose potential vitamin D molecule biomarkers for RA. A cross-sectional study of females was conducted on 154 RA patients and 201 healthy subjects (HS). Calcidiol, calcitriol, and the sVDR were measured in blood serum, and vitamin D hydroxylation efficiency was estimated using the calcitriol/calcidiol ratio score. CVD risk was calculated by the high-sensitivity C-reactive protein (hs-CRP) cutoff values. Disease activity was evaluated with the Disease Activity Score for 28 standard joints (DAS28-CRP). Results: The hydroxylation efficiency ratio and calcitriol serum levels were higher in RA patients with hypovitaminosis D (p < 0.001). Moreover, RA patients had a higher probability of a high hydroxylation efficiency ratio (OR = 2.02; p = 0.02), calcitriol serum levels (OR = 2.95; p < 0.001), and sVDR serum levels (OR = 5.57; p < 0.001) than HS. This same pattern was also observed in RA patients with high CVD risk using CRP serum levels; they showed a higher hydroxylation efficiency ratio (OR = 4.51; p = 0.04) and higher calcitriol levels (OR = 5.6; p < 0.01). Calcitriol correlates positively with the sVDR (r = 0.21, p = 0.03), CRP (r = 0.28, p < 0.001), and cardiometabolic indexes (p < 0.001) also showed discrimination capacity for CVD risk in RA patients with CRP ≥ 3 mg/L (AUC = 0.72, p < 0.01). In conclusion, hypovitaminosis D in RA patients was characterized by a pattern of a higher hydroxylation efficiency ratio and higher calcitriol and sVDR serum levels. Notably, higher calcitriol serum levels and a higher vitamin D hydroxylation efficiency ratio were associated with higher CVD risk in RA patients.

A Review of Proposed Mechanisms in Rheumatoid Arthritis and Therapeutic Strategies for the Disease

Rheumatoid arthritis (RA) is characterized by synovial edema, inflammation, bone and cartilage loss, and joint degradation. Patients experience swelling, stiffness, pain, limited joint movement, and decreased mobility as the condition worsens. RA treatment regimens often come with various side effects, including an increased risk of developing cancer and organ failure, potentially leading to mortality. However, researchers have proposed mechanistic hypotheses to explain the underlying causes of synovitis and joint damage in RA patients. This review article focuses on the role of synoviocytes and synoviocytes resembling fibroblasts in the RA synovium. Additionally, it explores the involvement of epigenetic regulatory systems, such as microRNA pathways, silent information regulator 1 (SIRT1), Peroxisome proliferatoractivated receptor-gamma coactivator (PGC1-α), and protein phosphatase 1A (PPM1A)/high mobility group box 1 (HMGB1) regulators. These mechanisms are believed to modulate the function of receptors, cytokines, and growth factors associated with RA. The review article includes data from preclinical and clinical trials that provide insights into potential treatment options for RA.

CXCL9 and NT-proBNP, a notable link between inflammatory mediator and cardiovascular disease biomarker in rheumatoid arthritis

INTRODUCTION

Cardiovascular disease (CVD) is the most critical extra-articular manifestation of rheumatoid arthritis, and inflammatory molecules contribute to its pathogenesis. Recently, CXCL9 has been considered an inflammatory chemokine associated with the pathogenesis of CVD. Here, we evaluated the association of plasma CXCL9 with well-established cardiac biomarkers, including HS-CRP (High sensitivity C-reactive protein) and NT-ProBNP (N-terminal pro-B-type natriuretic peptide), in newly diagnosed and under-treatment RA patients.

METHODS

Thirty newly diagnosed patients, 30 under-treatment RA patients, and 30 healthy subjects were recruited. The plasma concentration of CXCL9 and NT-ProBNP was measured using the ELISA method. The HS-CRP levels was measured in plasma samples using latex-enhanced immunoturbidimetric test.

RESULTS

We found increased plasma levels of CXCL9, HS-CRP, and NT-proBNP in RA patients compared to healthy subjects, besides that the concentration of CXCL9, HS-CRP, and NT-ProBNP showed elevated levels in newly diagnosed RA patients compared to under-treatment group. The mean plasma concentration of CXCL9, NT-proBNP, and HS-CRP were statistically different among healthy subjects, newly diagnosed, and under-treatment RA patients (p < 0.001, p = 0.016, and p < 0.001, respectively). We also found a significant positive correlation between CXCL9 and DAS-28 (p = 0.0005, r = 0.436) in the patients' group (new-case + under-treatment). There was a significantly positive correlation between CXCL9 and NT-proBNP in newly diagnosed and under-treatment patients (p = 0.020, r = 0.424; p < 0.0001, r = 0.853, respectively). In the patient's group (new-case + under-treatment), there was a significantly positive correlation between CXCL9 with NT-proBNP (p < 0.001, r = 0.703) and CXCL9 with HS-CRP (p = 0.015, r = 0.313).

CONCLUSION

CXCL9 correlates significantly with well-established cardiovascular biomarkers, including HS-CRP and NT-ProBNP in RA patients. Key Points • CXCL9 is an inflammatory marker in RA. • CXCL9 has correlated with DAS-28. • There is a strong correlation between CXCL9 with NT-proBNP and HS-CRP.

Chronic stress predisposes to the aggravation of inflammation in autoimmune diseases with focus on rheumatoid arthritis and psoriasis

The global incidence of autoimmune diseases is on the rise, and many healthcare professionals believe that chronic stress plays a prominent role in both the aggravation and remission of these conditions. It is believed that prolonged exposure to stress is associated with neuroimmune axis malfunction, which eventually dysregulates multiple immunological factors as well as deregulates autoimmune responses that play a central role in various autoimmune diseases, including rheumatoid arthritis and psoriasis. Herein, we performed validation of an 8-week long rat model of chronic unpredictable stress (CUS) which consisted of exposing groups of rats to random stressors daily for 8 weeks. Additionally, we developed a novel rat model combining 8-week long random stressor-induced CUS with CIA-triggered arthritis and IMQ-triggered psoriasis and have successfully used both these models to assess the role of chronic stress in the aggravation of arthritis and psoriasis, respectively. Notably, the 8-week CUS protocol extensively aggravated and prolonged both arthritis and psoriasis condition in the rat model by upregulating the release of different pro-inflammatory cytokines, dysregulation of immune cell responses and oxidative stress system, which were all related to severe inflammation. Further, CUS aggravated macroscopic features and the increase in destruction of joint tissue and epidermal thickness induced by CIA and IMQ, respectively, in rats. In conclusion, this study suggests that exposure to an 8-week long CUS paradigm aggravates the distinctive characteristics of rheumatoid arthritis and psoriasis in rats via amplifying the inflammatory circuits and immune cell responses linked to these autoimmune diseases.

A study on the therapeutic potential of graphene titanate nanocomposite for treating chemically induced arthritis in rats

Nanotechnology holds substantial promise in the innovative therapies for rheumatoid arthritis (RA). The current study was designed to synthesize and characterize a new graphene titanate nanocomposite (GTNc) and explore its anti-arthritic, anti-inflammatory, and antioxidant potencies against Complete Freund's adjuvant (CFA)-induced arthritis in rats, as well as investigate the underlying molecular mechanisms. Our characterization methods included XRD, FT-IR, SEM, EDX, zeta potential, practical size, and XRF to characterize the novel GTNc. Our findings revealed that arthritic rats treated with GTNc exhibited lower levels of RF, CRP, IL-1β, TNF-α, IL-17, and ADAMTS-5, and higher levels of IL-4 and TIMP-3. In arthritic rats, GTNc reduced LPO levels while increasing GSH content and GST antioxidant activity. Additionally, GTNc decreased the expression of the TGF-β mRNA gene in arthritic rats. Histopathological investigation showed that GTNc reduced inflammatory cell infiltration, cartilage degradation, and bone destruction in joint injuries caused by CFA in the arthritic rats. Collectively, the anti-arthritic, anti-inflammatory, and antioxidant properties of GTNc appear promising for future arthritis treatments and bone disability research.

Anti-inflammatory and anti-oxidant activities of mesenchymal stem cells in chemically induced arthritic rats

BACKGROUND

Mesenchymal stem cells (MSCs) have been extensively used as cell-based treatments for decades due to their anti-inflammatory, immunomodulatory, and healing abilities. The intent of our study was to determine the efficacy of MSCs in alleviating rheumatoid arthritis (RA) induced by Complete Freund's adjuvant (CFA) and to investigate the anti-inflammatory and antioxidant characteristics of MSCs.

METHODS AND RESULTS

Intrapedally injecting 0.1 ml of CFA directly into the footpad of the right hind paw daily for 2 days was used to induce RA. Arthritic rats received four doses of MSCs (1 × 106 cells/rat/dose) intravenously through the lateral tail vein. Our results showed that arthritic rats treated with MSCs exhibited reduced levels of paw edema. Furthermore, arthritic rats treated with MSCs exhibited a significant decrease in the levels of RF, CRP, IL-1β, TNF-α, IL-17 and ADAMTS-5, along with a significant increase in the levels of IL-4 and TIMP-3. Additionally, MSCs significantly reduced the expression of TGF-β. Both the glutathione (GSH) content and antioxidant activity of GST were enhanced by MSCs, while LPO levels were suppressed.

CONCLUSION

These findings provide further evidence that MSCs are valuable in treating RA, possibly due to their anti-inflammatory and anti-oxidative properties. Thus, MSCs have potential as a more effective therapeutic strategy for treating RA.

Anti-GM-CSF otilimab versus sarilumab or placebo in patients with rheumatoid arthritis and inadequate response to targeted therapies: a phase III randomised trial (contRAst 3)

OBJECTIVES

To investigate the efficacy and safety of otilimab, an anti-granulocyte-macrophage colony-stimulating factor antibody, in patients with active rheumatoid arthritis and an inadequate response to conventional synthetic (cs) and biologic disease-modifying antirheumatic drugs (DMARDs) and/or Janus kinase inhibitors.

METHODS

ContRAst 3 was a 24-week, phase III, multicentre, randomised controlled trial. Patients received subcutaneous otilimab (90/150 mg once weekly), subcutaneous sarilumab (200 mg every 2 weeks) or placebo for 12 weeks, in addition to csDMARDs. Patients receiving placebo were switched to active interventions at week 12 and treatment continued to week 24. The primary end point was the proportion of patients achieving an American College of Rheumatology ≥20% response (ACR20) at week 12.

RESULTS

Overall, 549 patients received treatment. At week 12, there was no significant difference in the proportion of ACR20 responders with otilimab 90 mg and 150 mg versus placebo (45% (p=0.2868) and 51% (p=0.0596) vs 38%, respectively). There were no significant differences in Clinical Disease Activity Index, Health Assessment Questionnaire-Disability Index, pain Visual Analogue Scale or Functional Assessment of Chronic Illness Therapy-Fatigue scores with otilimab versus placebo at week 12. Sarilumab demonstrated superiority to otilimab in ACR20 response and secondary end points. The incidence of adverse or serious adverse events was similar across treatment groups.

CONCLUSIONS

Otilimab demonstrated an acceptable safety profile but failed to achieve the primary end point of ACR20 and improve secondary end points versus placebo or demonstrate non-inferiority to sarilumab in this patient population.

TRIAL REGISTRATION NUMBER

NCT04134728.

Platelet-to-lymphocyte ratio and serum hsCRP levels in third trimester and adverse pregnancy outcomes in women with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) is a major complication of pregnancy. GDM is associated with a higher risk of adverse pregnancy outcomes (APO). The purpose of this study was to assess the association between third-trimester platelet to lymphocyte ratio (PLR) and high-sensitivity C-reactive protein (hsCRP) concentration and the risk of APO in GDM pregnant women. This study selected 406 non-elderly gestational diabetes patients diagnosed in the Renmin Hospital of Wuhan University from May 2021 to February 2023 as the research objects. According to the presence or absence of APO, they were divided into an APO group (n = 171) and a non-APO group (n = 235). Logistic regression model to evaluate the correlation between PLR and hsCRP and APO in women with GDM; Restricted cubic spline analyses was used to explore nonlinear correlations between PLR or hsCRP and the risk of APO; ROC curve analysis of the diagnostic performance of PLR and hsCRP for APO in women with GDM. APO occurred in 171 of the 406 included participants. Compared with the non-APO group, patients in the APO group had higher PLR and hsCRP levels. The incidence of APO was positively associated with PLR and the hsCRP level in each logistic regression model (P < 0.05). After adjusting for all the risk factors included in this study, restricted cubic spline analyses found that the PLR and the hsCRP level were positively associated with the risk of APO. The levels of PLR and hsCRP in the third trimester are related to the occurrence of APO in women with GDM, and high levels of PLR and hsCRP may indicate the occurrence of APO.

Ranking as a Procedure for Selecting a Replacement Variable in the Score Predicting the Survival of Patients Treated with Curative Intent for Colorectal Liver Metastases

Background and Objectives: The issue of a missing variable precludes the external validation of many prognostic models. For example, the Liverpool score predicts the survival of patients undergoing surgical therapy for colorectal liver metastases, but it includes the neutrophil-lymphocyte ratio, which cannot be measured retrospectively. Materials and Methods: We aimed to find the most appropriate replacement for the neutrophil-lymphocyte ratio. Survival analysis was performed on data representing 632 liver resections for colorectal liver metastases from 2000 to 2020. Variables associated with the Liverpool score, C-reactive protein, albumins, and fibrinogen were ranked. The rankings were performed in four ways: The first two were based on the Kaplan-Meier method (log-rank statistics and the definite integral IS between two survival curves). The next method of ranking was based on univariate and multivariate Cox regression analyses. Results: The ranks were as follows: the radicality of liver resection (rank 1), lymph node infiltration of primary colorectal cancer (rank 2), elevated C-reactive protein (rank 3), the American Society of Anesthesiologists Classification grade (rank 4), the right-sidedness of primary colorectal cancer (rank 5), the multiplicity of colorectal liver metastases (rank 6), the size of colorectal liver metastases (rank 7), albumins (rank 8), and fibrinogen (rank 9). Conclusions: The ranking methodologies resulted in almost the same ranking order of the variables. Elevated C-reactive protein was ranked highly and can be considered a relevant replacement for the neutrophil-lymphocyte ratio in the Liverpool score. These methods are suitable for ranking variables in similar models for medical research.

Rheumatoid arthritis disease activity and adverse events in patients receiving tofacitinib or tumor necrosis factor inhibitors: a post hoc analysis of ORAL Surveillance

Background

In patients with rheumatoid arthritis (RA), persistent inflammation and increasing disease activity are associated with increased risk of adverse events (AEs).

Objectives

To assess relationships between RA disease activity and AEs of interest in patients treated with tofacitinib or tumor necrosis factor inhibitors (TNFi).

Design

This was a post hoc analysis of a long-term, postauthorization safety endpoint trial of tofacitinib versus TNFi.

Methods

In ORAL Surveillance, 4362 patients aged ⩾50 years with active RA despite methotrexate, and ⩾1 additional cardiovascular (CV) risk factor, were randomized 1:1:1 to tofacitinib 5 or 10 mg twice daily or TNFi for up to 72 months. Post hoc time-dependent multivariable Cox analysis evaluated the relationships between disease activity [Clinical Disease Activity Index (CDAI)], inflammation [C-reactive protein (CRP)], and AEs of interest. The AEs included major adverse CV events (MACE), malignancies excluding nonmelanoma skin cancer (NMSC), venous thromboembolism (VTE), serious infections, herpes zoster (HZ), nonserious infections excluding HZ (NSI), and death.

Results

Across treatments, risk for NSI was higher when patients had CDAI-defined active disease versus remission; MACE and VTE risks trended higher, but did not reach significance. Hazard ratios for MACE, malignancies excluding NMSC, VTE, infections, and death rose by 2-9% for each 5-mg/L increment in serum CRP. The interaction terms evaluating the impact of treatment assignment on the relationship between disease activity and AEs were all p > 0.05.

Conclusion

In ORAL Surveillance, higher NSI risk was observed in the presence of active RA versus remission. The risk of MACE and VTE directionally increased in active disease versus remission, although statistical power was limited due to small event numbers in these categories. The relationship between active disease and AEs was not impacted by treatment with tofacitinib versus TNFi.

Registration

NCT02092467.

The pentraxin family in autoimmune disease

The pentraxins represent a family of multifunctional proteins composed of long and short pentamers. The latter includes serum amyloid P component (SAP) and C-reactive protein (CRP) whereas the former includes neuronal PTX1 and PTX2 (NPTX1 and NPTX2, respectively), PTX3 and PTX4. These serve as a bridge between adaptive immunity and innate immunity and a link between inflammation and immunity. Similarities and differences between long and short pentamers are examined and their roles in autoimmune disease are discussed. Increased CRP and PTX3 could indicate the activity of rheumatoid arthritis, systemic lupus erythematosus or other autoimmune diseases. Mechanistically, CRP and PTX3 may predict target organ injury, regulate bone metabolic immunity and maintain homeostasis as well as participate in vascular endothelial remodeling. Interestingly, PTX3 is pleiotropic, being involved in inflammation and tissue repair. Given the therapeutic potential of PTX3 and CRP, targeting these factors to exert a beneficial effect is the focus of research efforts. Unfortunately, studies on NPTX1, NPTX2, PTX4 and SAP are scarce and more research is clearly needed to elaborate their potential roles in autoimmune disease.

Ratiometric Fluorescence and Afterglow Lifetime Dual-Channel Nanoprobe for Simultaneous Imaging of HOCl and Temperature in Arthritis

Arthritis is a joint disorder that potentially causes permanent joint damage and eventual disability without effective treatment. Clinical detection methods, including in vitro blood tests and anatomical imaging, still have limitations in achieving real-time in situ early detection of arthritis. In this work, a dual-channel luminescence nanoprobe (AGNPs-Cy7) is reported, which combines a cyanine dye and a photochemical reaction-based afterglow system for real-time in vivo imaging of arthritis. AGNPs-Cy7 simultaneously detect hypochlorous acid (HOCl) and temperature, two important indicators associated with the early development of arthritis, by monitoring the respective changes in independent ratiometric fluorescence and afterglow lifetime signals. The anti-interference properties of both the ratiometric fluorescence signal and afterglow lifetime signal enhance sensing accuracy compared to the single luminescence intensity. The developed probe successfully reveals the simultaneous increase in HOCl concentration and temperature in an arthritis mouse model.

A systematic review and meta-analysis of the kynurenine pathway of tryptophan metabolism in rheumatic diseases

There is an increasing interest in the pathophysiological role of the kynurenine pathway of tryptophan metabolism in the regulation of immune function and inflammation. We sought to address the link between this pathway and the presence rheumatic diseases (RD) by conducting a systematic review and meta-analysis of studies reporting the plasma or serum concentrations of tryptophan, kynurenine, and other relevant metabolites in RD patients and healthy controls. We searched electronic databases for relevant articles published between inception and the 30th of June 2023. Risk of bias and certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and the Grades of Recommendation, Assessment, Development and Evaluation Working Group system. In 24 studies selected for analysis, compared to controls, RD patients had significantly lower tryptophan (standard mean difference, SMD= -0.71, 95% CI -1.03 to -0.39, p<0.001; I2 = 93.6%, p<0.001; low certainty of evidence), and higher kynurenine (SMD=0.69, 95% CI 0.35 to 1.02, p<0.001; I2 = 93.2%, p<0.001; low certainty), kynurenine to tryptophan ratios (SMD=0.88, 95% CI 0.55 to 1.21, p<0.001; I2 = 92.9%, p<0.001; moderate certainty), 3-hydroxykynurenine (SMD=0.74, 95% CI 0.30 to 1.18, p=0.001; I2 = 87.7%, p<0.001; extremely low certainty), and quinolinic acid concentrations (SMD=0.71, 95% CI 0.31 to 1.11, p<0.001; I2 = 88.1%, p<0.001; extremely low certainty). By contrast, there were non-significant between-group differences in kynurenic acid, 3-hydroxyanthranilic acid, kynurenic acid to kynurenine ratio, or quinolinic acid to kynurenine acid ratio. In meta-regression, the SMD of tryptophan, kynurenine, and kynurenine to tryptophan ratio were not associated with age, publication year, sample size, RD duration, C-reactive protein, or use of anti-rheumatic drugs and corticosteroids. In subgroup analysis, the SMD of tryptophan, kynurenine, and kynurenine to tryptophan ratio was significant across different types of RD, barring rheumatoid arthritis. Therefore, we have observed significant alterations in tryptophan, kynurenine, 3-hydroxykynurenine, and quinolinic acid concentrations in RD patients. Further research is warranted to determine whether these biomarkers can be useful for diagnosis and management in this patient group. (PROSPERO registration number: CRD CRD42023443718).

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD CRD42023443718.

Plasma Expression of Carotid Plaque Presence-Related MicroRNAs Is Associated with Inflammation in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is associated with problems beyond the joints such as cardiovascular (CV) disease. MicroRNA-24, -146 and -Let7a are associated with carotid plaque presence in RA patients. We evaluated whether these microRNAs were involved in the inflammatory state of RA, and we studied their gene targets to understand their role in inflammation and atherosclerosis. A total of 199 patients with RA were included. Inflammatory variables such as disease activity score 28 (DAS28) and erythrocyte sedimentation rate (ESR) were quantified. MicroRNAs were extracted from plasma and quantified with qPCR. Multivariate models and classification methods were used for analysis. The multivariate models showed that diminished expression of microRNA-146 was associated with inferior levels of DAS28-ESR, and the decreased expression of microRNA-24, -146 and -Let7a were associated with lowered ESR in the overall cohort. When microRNAs were evaluated globally, a global increase was associated with increased DAS28-ESR and ESR in the overall cohort. Sex-stratified analyses showed different associations of these microRNAs with the inflammatory variables. Finally, random forest models showed that microRNAs have a pivotal role in classifying patients with high and low inflammation. Plasmatic expressions of microRNA-24, -146 and -Let7a were associated with inflammatory markers of RA. These microRNAs are associated with both inflammation and atherosclerosis and are potential therapeutic targets for RA.

Biological Applications of Synthetic Binders Isolated from a Conceptually New Adhiron Library

BACKGROUND

Adhirons are small (10 kDa) synthetic ligands that might represent an alternative to antibody fragments and to alternative scaffolds such as DARPins or affibodies.

METHODS

We prepared a conceptionally new adhiron phage display library that allows the presence of cysteines in the hypervariable loops and successfully panned it against antigens possessing different characteristics.

RESULTS

We recovered binders specific for membrane epitopes of plant cells by panning the library directly against pea protoplasts and against soluble C-Reactive Protein and SpyCatcher, a small protein domain for which we failed to isolate binders using pre-immune nanobody libraries. The best binders had a binding constant in the low nM range, were produced easily in bacteria (average yields of 15 mg/L of culture) in combination with different tags, were stable, and had minimal aggregation propensity, independent of the presence or absence of cysteine residues in their loops.

DISCUSSION

The isolated adhirons were significantly stronger than those isolated previously from other libraries and as good as nanobodies recovered from a naïve library of comparable theoretical diversity. Moreover, they proved to be suitable reagents for ELISA, flow cytometry, the western blot, and also as capture elements in electrochemical biosensors.