Emerging Role of Eosinophils in Resolution of Arthritis

Revealing the mechanism and efficacy of natural products on treating the asthma: Current insights from traditional medicine to modern drug discovery

Asthma remains a significant global health challenge, demanding innovative approaches to treatment. Traditional medicine has a rich history of using natural products to alleviate asthmatic symptoms. However, transitioning from these traditional remedies to modern drug discovery approaches has provided fresh insights into the mechanisms and effectiveness of these natural products. This study provides our comprehensive review, which examines the current state of knowledge in the treatment of asthma. It delves into the mechanisms through which natural products ameliorate asthma symptoms, and it discusses their potential in the development of novel therapeutic interventions. Our analysis reveals that natural products, traditionally employed for asthma relief, exhibit diverse mechanisms of action. These include anti-inflammatory, bronchodilatory, immunomodulatory effects, and reducing gene expression. In the context of modern drug discovery, these natural compounds serve as valuable candidates for the development of novel asthma therapies. The transition from traditional remedies to modern drug discovery represents a promising avenue for asthma treatment. Our review highlights the substantial efficacy of natural products in managing asthma symptoms, underpinned by well-defined mechanisms of action. By bridging the gap between traditional and contemporary approaches, we contribute to the growing body of knowledge in the field, emphasizing the potential of natural products in shaping the future of asthma therapy.

Causal association between genetically predicted circulating immune cell counts and frailty: a two-sample Mendelian randomization study

Background

Despite the recognized link between immune responses and frailty, the association between immune cell counts and frailty based on previous observational studies remains disputed, with uncertain causal nexus. This study aimed to elucidate causal association between genetically predicted circulating immune cell counts and frailty.

Methods

We conducted the two-sample Mendelian randomization (MR) study with independent genetic variants associated with six immune cell subtype counts from genome-wide association studies in 563,946 European individuals. Frailty summary data, assessed via frailty index (FI), was obtained from study comprising 175,226 subjects. Univariate MR, reverse MR and multivariate MR were conducted to comprehensive investigate the association between immune cell counts and FI, with two-step MR analysis for mediation analysis.

Results

Univariate MR evidence indicated that among six leukocyte subtype counts, only elevated eosinophil count was significantly correlated with higher FI (β = 0.059, 95% confidence interval [CI], 0.042-0.078, P=5.63E-11), with no reverse causal relationship identified in reverse MR. In multivariate MR, the causal effect of eosinophil count retained statistical significance (β = 0.063, 95% CI, 0.021-0.104, P = 0.003). Ultimately, the two-step MR analysis demonstrated two mediators in this causal pathway: asthma (β= 0.019, 95% CI, 0.013-0.025, P = 35.84E-10, mediated proportion, 31.732%) and rheumatoid arthritis (β= 0.004, 95% CI, 0.001-0.006, P=1.75E-03, mediated proportion, 6.411%).

Conclusions

Within immune cell subtypes, MR evidence indicated only genetically predicted circulating eosinophil count had irreversible and independent causal effect on frailty, with asthma and rheumatoid arthritis possibly serving as partial mediators. The finding stressed the need for further exploring physiological functions of eosinophils in order to develop effective strategies against frailty.

Genetic evidence for causal effects of leukocyte counts on risk for rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by the accumulation of leukocytes and inflammatory mediators within the synovial tissue. Leukocyte counts are proposed to play a role in the pathogenesis of RA. However, the causality remains unclear. To investigate the causal relationship between various leukocytes and RA by implementing two-sample univariable Mendelian Randomization (MR) and multivariable MR. MR analysis was performed using respective genome-wide association study (GWAS) summary statistics for the exposure traits (eosinophil counts, neutrophil counts, lymphocyte counts, monocyte counts, basophil counts, and white blood cell counts) and outcome trait (RA). Summary statistics for leukocytes were extracted from the Blood Cell Consortium meta-analysis and INTERVAL studies. Public GWAS information for RA included 14,361 cases and 43,923 controls. Inverse variance weighted, weighted median, MR-Egger regression, MR pleiotropy residual sum and outlier, and multivariable MR analyses were performed in MR analysis. Univariable MR found elevated eosinophil counts (OR 1.580, 95% CI 1.389-2.681, p = 1.30 × 10-7) significantly increased the risk of RA. Multivariable MR further confirmed that eosinophil counts were a risk factor for RA. Increased eosinophils were associated with higher risk of RA. Further elucidations of the causality and mechanisms underlying are likely to identify feasible interventions to promote RA prevention.

Efficacy of montelukast as an adjuvant therapy in rheumatoid arthritis patients: A randomized controlled study

OBJECTIVE

This study aimed to evaluate the efficacy of montelukast in conjunction with non-biologic disease modifying anti-rheumatic drugs (nDMARDs) in rheumatoid arthritis (RA) patients.

METHODS

This study was a single-center randomized double-blinded placebo-controlled study. Adult RA patients were included if they had moderate to severe disease activity and were receiving monotherapy or combination of nDMARDs. Eligible patients were randomized, in 1:1 ratio, to receive either 10 mg montelukast or placebo, once daily for 16 weeks. The primary endpoint was the change in the 28-joints disease activity score (DAS28) 16 weeks after treatment. The patients' quality of life (QoL) was assessed by the Arabic version of the Health Assessment Questionnaire-Disability Index. Moreover, serum levels of vascular adhesion molecule-1 (VCAM-1) were measured.

RESULTS

A total of 87 patients completed the study; 44 in the montelukast arm and 43 in the control arm. After 16 weeks of treatment, disease activity decreased significantly in the montelukast arm with mean change in DAS28 (95% CIs) of -1.5 (-1.7, -1.2) while the control arm showed no improvement (0.2 (0.0, 0.4), p < 0.01). The QoL of the patients improved significantly from baseline in the montelukast arm (p < 0.01) but not in the control arm (p = 0.08). The median (IQR) serum levels of VCAM-1 were significantly lower in the montelukast arm (22.8 (15.0-32.7)) than in the control arm (28.9 (15.4-42.8), p = 0.004).

CONCLUSION

The co-administration of montelukast with nDMARDs in RA patients enhanced the anti-rheumatic effect which was reflected clinically by decreased disease activity.

Collagenase-Induced Mouse Model of Osteoarthritis-A Thorough Flow Cytometry Analysis

OBJECTIVES

Osteoarthritis (OA) is a chronic degenerative disorder of the joint characterized by cartilage breakdown and synovial inflammation. A number of different cells of innate and adaptive immunity contribute to joint pathology during OA inflammation. The interaction between the local synovial and systemic inflammatory cellular response and the structural changes in the joint is still unknown. The objective of this study was to investigate the role of the different types of immune cells in the development of OA.

METHODS

Collagenase-induced osteoarthritis was induced in Balb/c mice; flow cytometry analysis; and histopathological damages were assessed in histological sections stained with H&E, Toluidine blue, and Safranin O.

RESULTS

Flow cytometry analysis showed B lymphocyte infiltration in the active phase of inflammation and an increase in the effector T cell population into the synovium. An increased activation state of cytotoxic T cells and of NK cell populations in the spleen and synovium was also found. The differentiation of NK cells from a cytotoxic phenotype in early OA to cells with an effector phenotype in the chronic phase of the disease followed.

CONCLUSIONS

A number of different cells contribute to inflammatory processes in OA. The correlation between their phenotype and the inflammatory pathophysiology could result in the development of novel approaches to suppress destructive changes in the joint.

Th2 Cytokines (Interleukin-5 and -9) Polymorphism Affects the Response to Anti-TNF Treatment in Polish Patients with Ankylosing Spondylitis

Ankylosing spondylitis (AS) is an inflammatory disease that belongs to the spondyloarthritis family. IL-5 and IL-9 belong to the group of Th2 cytokines of anti-inflammatory nature. Polymorphisms in their coding genes have been so far associated with various inflammatory diseases, but there are no reports regarding their involvement in AS pathogenesis to date. The purpose of the study was to investigate relationships between IL5 and IL9 genetic variants with AS susceptibility, clinical parameters as well as response to therapy with TNF inhibitors. In total 170 patients receiving anti-TNF therapy and 218 healthy controls were enrolled in the study. The genotyping of IL5 rs2069812 (A > G) and IL9 rs2069885 (G > A) single nucleotide polymorphisms was performed using the Real-Time PCR method based on LightSNiP kits assays. The present study demonstrated significant relationships between IL5 rs2069812 and IL9 rs2069885 polymorphisms and response to anti-TNF therapy. Presence of the IL5 rs2069812 A allele in patients positively correlated with better response to treatment (p = 0.022). With regard to IL9 rs2069885, patients carrying the A allele displayed better outcomes in anti-TNF therapy (p = 0.046). In addition, IL5 rs2069812 A and IL9 rs2069885 A alleles were associated with lower CRP and VAS values. The obtained results may indicate a significant role for IL-5 and IL-9 in the course of AS and response to anti-TNF therapy.

Obesity, Inflammation, and Immune System in Osteoarthritis

Obesity remains the most important risk factor for the incidence and progression of osteoarthritis (OA). The leading cause of OA was believed to be overloading the joints due to excess weight which in turn leads to the destruction of articular cartilage. However, recent studies have proved otherwise, various other factors like adipose deposition, insulin resistance, and especially the improper coordination of innate and adaptive immune responses may lead to the initiation and progression of obesity-associated OA. It is becoming increasingly evident that multiple inflammatory cells are recruited into the synovial joint that serves an important role in pathological changes in the synovial joint. Polarization of macrophages and macrophage-produced mediators are extensively studied and linked to the inflammatory and destructive responses in the OA synovium and cartilage. However, the role of other major innate immune cells such as neutrophils, eosinophils, and dendritic cells in the pathogenesis of OA has not been fully evaluated. Although cells of the adaptive immune system contribute to the pathogenesis of obesity-induced OA is still under exploration, a quantity of literature indicates OA synovium has an enriched population of T cells and B cells compared with healthy control. The interplay between a variety of immune cells and other cells that reside in the articular joints may constitute a vicious cycle, leading to pathological changes of the articular joint in obese individuals. This review addresses obesity and the role of all the immune cells that are involved in OA and summarised animal studies and human trials and knowledge gaps between the studies have been highlighted. The review also touches base on the interventions currently in clinical trials, different stages of the testing, and their shortcomings are also discussed to understand the future direction which could help in understanding the multifactorial aspects of OA where inflammation has a significant function.

Insights Into the Concept of Rheumatoid Arthritis Flare

Identification of a pathological change in the course of systemic chronic immune-inflammatory diseases is key to delivering effective treatment strategies. In this context, one of the most compelling issues is the concept of flare. The multifaceted expression of disease activity in rheumatoid arthritis (RA) makes it challenging to provide an omni-comprehensive definition of flare, encompassing the pathology's different objective and subjective domains. Our incomplete understanding of the pathophysiological mechanisms underlying this process contributes to the partial comprehension of its potential clinical expression. This review focuses on the proposed pathophysiological processes underlying disease recrudescence in RA and the variable definitions adopted to capture flare in clinical practice through its objective, subjective, and temporal domains. Overall, what emerges is a complex landscape far from being unraveled.