Platelets: emerging facilitators of cellular crosstalk in rheumatoid arthritis

Diagnostic accuracy of the neutrophil-to-lymphocyte ratio and the platelet-to-lymphocyte ratio in rheumatoid arthritis: a systematic review and meta-analysis

Existing challenges with the early diagnosis of rheumatoid arthritis (RA) and active disease, mainly by non-rheumatologists, have prompted the search for novel biomarkers. Elevations in indices derived from blood cell counts, e.g., the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR), have been reported in RA patients. However, their diagnostic accuracy has not been comprehensively assessed. Therefore, we conducted a systematic review and meta-analysis of studies reporting the sensitivity and specificity of the NLR and PLR, obtained by receiver operating characteristic (ROC) curve analysis, for the presence of RA and active disease. We searched electronic databases from inception to 15 March 2024 and assessed the risk of bias using the JBI Critical Appraisal Checklist (PROSPERO registration number: CRD42024533546). In 15 studies, the NLR exhibited acceptable accuracy for the presence of RA (area under the curve, AUC = 0.76, 95% CI 0.72 to 0.80) and active disease (AUC = 0.70, 95% CI 0.66 to 0.74). The PLR exhibited good accuracy for the presence of RA (AUC = 0.80, 95% CI 0.76 to 0.83). There were insufficient studies to assess the accuracy of the PLR for the presence of active disease. Our systematic review and meta-analysis suggests that the NLR and the PLR are promising biomarkers of RA (NLR and PLR) and active disease (NLR). Further research is required to investigate whether the NLR and PLR can significantly enhance the capacity to diagnose RA and active disease in clinical practice.

Nonlinear associations of systemic immune-inflammation index with all-cause and cardiovascular mortality in US adults with rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic systemic inflammatory autoimmune disease. However, the relationship between the systemic immune-inflammation index (SII) and the prognosis of RA patients remains unclear. This study aimed to investigate the association between inflammatory biomarker SII and all-cause and cardiovascular mortality in RA patients. A retrospective analysis was conducted using data from the National Health and Nutrition Examination Survey database spanning from 1999 to March 2020. We assessed the association between the SII and all-cause as well as cardiovascular mortality in RA patients employing multivariable Cox proportional hazards regression analysis and restricted cubic spline plots. Receiver operating characteristic curves were employed to evaluate the prognostic capacity of SII in predicting outcomes in both the RA patients and the general population, alongside its predictive performance compared to other markers. This study comprised 2247 RA patients and a control cohort of 29,177 individuals from the general population. Over a 20-year follow-up period, 738 all-cause deaths and 215 deaths attributable to cardiovascular disease were documented in RA patients. We observed a nonlinear positive correlation between the SII and both all-cause and cardiovascular mortality in RA patients. Of significance, at an SII level of 529.7, the hazard ratio reached 1, signifying a transition from low to high mortality risk. Moreover, subgroup analysis did not reveal any potential interactions. Our study findings indicate a nonlinear positive correlation between the inflammatory biomarker SII and both all-cause and cardiovascular mortality in patients with RA.

A Perspective on How Fibrinaloid Microclots and Platelet Pathology May be Applied in Clinical Investigations

Microscopy imaging has enabled us to establish the presence of fibrin(ogen) amyloid (fibrinaloid) microclots in a range of chronic, inflammatory diseases. Microclots may also be induced by a variety of purified substances, often at very low concentrations. These molecules include bacterial inflammagens, serum amyloid A, and the S1 spike protein of severe acute respiratory syndrome coronavirus 2. Here, we explore which of the properties of these microclots might be used to contribute to differential clinical diagnoses and prognoses of the various diseases with which they may be associated. Such properties include distributions in their size and number before and after the addition of exogenous thrombin, their spectral properties, the diameter of the fibers of which they are made, their resistance to proteolysis by various proteases, their cross-seeding ability, and the concentration dependence of their ability to bind small molecules including fluorogenic amyloid stains. Measuring these microclot parameters, together with microscopy imaging itself, along with methodologies like proteomics and imaging flow cytometry, as well as more conventional assays such as those for cytokines, might open up the possibility of a much finer use of these microclot properties in generative methods for a future where personalized medicine will be standard procedures in all clotting pathology disease diagnoses.

Revolutionizing rheumatoid arthritis therapy: harnessing cytomembrane biomimetic nanoparticles for novel treatment strategies

Rheumatoid arthritis (RA) is a systemic immune disease with severe implications for joint health. The issue of non-specific drug distribution potentially limits the therapeutic efficacy and increases the risk associated with RA treatment. Researchers employed cytomembrane-coated biomimetic nanoparticles (NPs) to enhance the targeting delivery efficacy to meet the demand for drug accumulation within the affected joints. Furthermore, distinct cytomembranes offer unique functionalities, such as immune cell activation and augmented NP biocompatibility. In this review, the current strategies of RA treatments were summarized in detail, and then an overview of RA's pathogenesis and the methodologies for producing cytomembrane-coated biomimetic NPs was provided. The application of cytomembrane biomimetic NPs derived from various cell sources in RA therapy is explored, highlighting the distinctive attributes of individual cytomembranes as well as hybrid membrane configurations. Through this comprehensive assessment of cytomembrane biomimetic NPs, we elucidate the prospective applications and challenges in the realm of RA therapy, and the strategy of combined therapy is proposed. In the future, cytomembrane biomimetic NPs have a broad therapeutic prospect for RA.

Association of Hematological and Biochemical Parameters and HLA-DRB1 Alleles With Anti-cyclic Citrullinated Peptide Autoantibodies in Sudanese Rheumatic Patients

Introduction Anti-citrullinated protein/peptide antibodies (ACPA) are crucial for the diagnosis and prognosis of rheumatoid arthritis (RA) and are associated with class II HLA-DRB1 alleles. The study's goal was to determine how DRB1 alleles and hematological and biochemical parameters affect ACPA production in RA patients from Sudan. Methods The study analyzed the hematological and biochemical parameters and the frequency of HLA-DRB1 alleles in 120 RA patients and 100 controls. Automated analyzers, ELISA, the latex agglutination test, and the Westergren method were utilized for hematological and biochemical testing. HLA class II alleles were genotyped using polymerase chain reaction-sequence-specific primers (PCR-SSP). The student's t-test and the chi-square (Χ2) test were employed to identify significant alterations between the examined parameters and allele frequencies. Results A total of 51.7% of 120 RA patients tested positive for ACPA (ACPA+). Among those patients, the DRB1*04 and *10 alleles were significantly more prevalent (22.2% vs. 8.9%, P = 0.048 and 23.8% vs. 8.9%, P = 0.030, respectively). RA patients had significantly higher counts of platelet count test (PLT; P = 0.011), lymphocytes (LY; P = 0.000), neutrophils (NE; P = 0.025), monocytes (MO; P = 0.000), eosinophils (EO; P = 0.000), neutrophil-to-lymphocyte ratio (NLR; P = 0.006), C-reactive protein (CRP; P = 0.000), and erythrocyte sedimentation rate (ESR; P = 0.000) than controls. Patients also showed low counts of red blood cells (RBC; P = 0.003), hemoglobin (Hb; P = 0.024), mean platelet volume (MPV; P = 0.000), and basophils (BA; P = 0.048). ACPA+ RA patients had elevated white blood cells (WBC; P = 0.046), PLT (P = 0.029), and low mean corpuscular hemoglobin concentration (MCHC; P = 0.022). The hematological and biochemical parameters of ACPA+ RA patients with the DRB1*04 or *10 alleles did not differ significantly. Conclusions We found significant differences in hematological and biochemical parameters between RA patients and controls that had nothing to do with ACPA positivity or the frequency of DRB1*04 or *10 alleles.

Repurposing the Fibrosis-4 Score in Rheumatoid Arthritis: Data from the ESPOIR Cohort

Background: We aimed to evaluate the value of the Fibrosis-4 (FIB-4) score as a prognostic factor in RA in the prospective ESPOIR cohort. Methods: We included patients from the ESPOIR cohort with a diagnosis of RA according to ACR/EULAR criteria. The formula for the FIB-4 score is as follows: [age (years) × aspartate transaminase level (U/L)]/[platelet count (109/L) × alanine aminotransferase level (U/L)1/2]. We used a linear mixed-effects model with a random effect of patient to account for repeated measures over time. Results: Overall, 647 of the 813 patients included met the ACR/EULAR criteria for RA, with no differential diagnosis during the first 10 years of follow-up. Of these patients, at baseline, 633 had a calculable FIB-4 score. Median FIB-4 score was 0.75 (interquartile range 0.53-0.99). On multivariate analysis, FIB-4 score was not independently associated with progression of Disease Activity Score in 28 joints over 10 years of follow-up, unlike baseline C-reactive protein level and SJC. Baseline FIB-4 score was not associated with the modified Sharp score at 5-year follow-up, unlike age and ACPAs. FIB-4 score was not associated with mortality (hazard ratio 1.1 [95% CI 0.46; 2.8], p = 0.77) or major adverse cardiovascular events (0.46 [0.13; 1.6], p = 0.22) over the 10-year follow-up. No significant change in FIB-4 score over time was related to treatments. Conclusions: The present prospective cohort study did not find a prognostic role of FIB-4 score in RA. Reassuringly, FIB-4 score was not increased with DMARD treatment after 10 years of follow-up.

Prodrug-based nanomedicines for rheumatoid arthritis

Most antirheumatic drugs with high toxicity exhibit a narrow therapeutic window due to their nonspecific distribution in the body, leading to undesirable side effects and reduced patient compliance. To in response to these challenges, prodrug-based nanoparticulate drug delivery systems (PNDDS), which combines prodrug strategy and nanotechnology into a single system, resulting their many advantages, including stability for prodrug structure, the higher drug loading capacity of the system, improving the target activity and bioavailability, and reducing their untoward effects. PNDDS have gained attention as a method for relieving arthralgia syndrome of rheumatoid arthritis in recent years. This article systematically reviews prodrug-based nanocarriers for rheumatism treatment, including Nano systems based on prodrug-encapsulated nanomedicines and conjugate-based nanomedicines. It provides a new direction for the clinical treatment of rheumatoid arthritis.

Evaluating the Diagnostic Performance of Systemic Immune-Inflammation Index in Childhood Inflammatory Arthritis: A Focus on Differentiating Juvenile Idiopathic Arthritis from Reactive Arthritis

In pediatric care, the range of potential diagnoses for arthritis can be relatively extensive, primarily involving infectious and inflammatory causes and, to a lesser extent, oncological conditions. Specifically, when addressing inflammatory causes, differentiating between Juvenile Idiopathic Arthritis (JIA) and Reactive Arthritis (ReA) can prove to be challenging during the first weeks, owing to the lack of specific antibodies in several JIA subtypes. This single-center retrospective study of 108 children with arthritis aimed to evaluate in greater detail the complete blood count (CBC) profiles of children with JIA and ReA in greater detail. The most significant differences were noted in terms of the Systemic Immune-Inflammation Index (SII), with higher values in the JIA group. Moreover, within the JIA group, SII displayed a significant positive correlation with conventional inflammatory biomarkers, specifically C-reactive protein (ρ = 0.579) and Erythrocyte Sedimentation Rate (ρ = 0.430). It was the only independent factor associated with the presence of JIA after adjusting for age (p = 0.030). Also, even with the moderate diagnostic value, the discriminating capacity of SII was superior to those of each of its component CBC parameters according to receiver operating characteristic (ROC) analysis. In summary, this study identified elevated SII values in the JIA group compared to the ReA group, indicating the potential utility of SII as an adjuvant discriminatory marker between these two arthritis forms.

Platelets-related signature based diagnostic model in rheumatoid arthritis using WGCNA and machine learning

Background and aim

Rheumatoid arthritis (RA) is an autoinflammatory disease that may lead to severe disability. The diagnosis of RA is limited due to the need for biomarkers with both reliability and efficiency. Platelets are deeply involved in the pathogenesis of RA. Our study aims to identify the underlying mechanism and screening for related biomarkers.

Methods

We obtained two microarray datasets (GSE93272 and GSE17755) from the GEO database. We performed Weighted correlation network analysis (WGCNA) to analyze the expression modules in differentially expressed genes identified from GSE93272. We used KEGG, GO and GSEA enrichment analysis to elucidate the platelets-relating signatures (PRS). We then used the LASSO algorithm to develop a diagnostic model. We then used GSE17755 as a validation cohort to assess the diagnostic performance by operating Receiver Operating Curve (ROC).

Results

The application of WGCNA resulted in the identification of 11 distinct co-expression modules. Notably, Module 2 exhibited a prominent association with platelets among the differentially expressed genes (DEGs) analyzed. Furthermore, a predictive model consisting of six genes (MAPK3, ACTB, ACTG1, VAV2, PTPN6, and ACTN1) was constructed using LASSO coefficients. The resultant PRS model demonstrated excellent diagnostic accuracy in both cohorts, as evidenced by area under the curve (AUC) values of 0.801 and 0.979.

Conclusion

We elucidated the PRSs occurred in the pathogenesis of RA and developed a diagnostic model with excellent diagnostic potential.

A Bird's Eye View of Various Cell-Based Biomimetic Nanomedicines for the Treatment of Arthritis

Arthritis is the inflammation and tenderness of the joints because of some metabolic, infectious, or constitutional reasons. Existing arthritis treatments help in controlling the arthritic flares, but more advancement is required to cure arthritis meticulously. Biomimetic nanomedicine represents an exceptional biocompatible treatment to cure arthritis by minimizing the toxic effect and eliminating the boundaries of current therapeutics. Various intracellular and extracellular pathways can be targeted by mimicking the surface, shape, or movement of the biological system to form a bioinspired or biomimetic drug delivery system. Different cell-membrane-coated biomimetic systems, and extracellular-vesicle-based and platelets-based biomimetic systems represent an emerging and efficient class of therapeutics to treat arthritis. The cell membrane from various cells such as RBC, platelets, macrophage cells, and NK cells is isolated and utilized to mimic the biological environment. Extracellular vesicles isolated from arthritis patients can be used as diagnostic tools, and plasma or MSCs-derived extracellular vesicles can be used as a therapeutic target for arthritis. Biomimetic systems guide the nanomedicines to the targeted site by hiding them from the surveillance of the immune system. Nanomedicines can be functionalized using targeted ligand and stimuli-responsive systems to reinforce their efficacy and minimize off-target effects. This review expounds on various biomimetic systems and their functionalization for the therapeutic targets of arthritis treatment, and discusses the challenges for the clinical translation of the biomimetic system.

ECM-Inspired Hydrogels with ADSCs Encapsulation for Rheumatoid Arthritis Treatment

Due to their intrinsic anti-inflammatory and immunomodulatory properties, adipose-derived stem cells (ADSCs) are explored as a promising alternative in treating rheumatoid arthritis (RA). To address the poor survival and function loss of directly injected stem cells, efforts in this area are focus on the generation of efficient cell delivery vehicles. Herein, a novel extracellular matrix (ECM)-inspired injectable hydrogel for ADSCs encapsulation and RA treatment is proposed. The hydrogel with dendritic polylysine and polysaccharide components is formed through the reversible Schiff base crosslinking. It possesses self-healing capability, superior mechanical properties, minimal toxicity, and immunomodulatory ability. When encapsulated with ADSCs, the hydrogel could recover chronic inflammation by directly reversing the dominant macrophage phenotype from M1 to M2 and inhibiting the migration of fibroblast-like synoviocytes. Through a collagen-induced arthritis rat model, the tremendous therapeutic outcomes of this ADSCs-laden hydrogel, including inflammation attenuation, cartilage protection, and bone mineral density promotion are demonstrated. These results make the ECM-inspired hydrogel laden with ADSCs an ideal candidate for treating RA and other autoimmune disorders.

Rheumatoid arthritis characteristics and classification of heat and cold patterns-an observational study

Introduction

Traditional Chinese medicine (TCM) has been proven to be an effective complementary therapy in treating rheumatoid arthritis (RA). The cold pattern and the heat pattern were the two main TCM patterns for RA, which is crucial for TCM treatment. The cold pattern is characterized by fear of cold and wind, joint pain with a thin white tongue coating which can be relieved by hot herbs. In contrast, heat pattern patients suffer from severe joint pain with a yellow coating, with red swelling of the skin and high skin temperature which can be relieved by cooling herbs.

Objective

We aimed to classify the heat and cold patterns in RA patients with cluster analysis and factor analysis. Moreover, we aimed to explore the association of RA characteristics between these two patterns.

Methods

and Design: A cross-sectional observational research method was used, and data was collected on 300 RA patients in Hangzhou in China. Signs and symptoms associated with RA were clustered using SPSS 22.0 software. In addition, factor analysis was also used for the classification. After classification of heat and cold patterns, characteristics and treatment of the RA participants between the two patterns were explored.

Results

RA patients in the study were divided into two categories using cluster analysis. Twenty-two symptoms in the first category were included in the heat pattern of RA patients. After factor analysis, nine principal components were extracted to heat pattern. The component with the highest eigenvalue (2.530) were mainly contributed by shortness of breath, palpitation, heavy limbs, chest tightness and yellow greasy tongue with high factor loading values (0.765, 0.703, 0.504, 0.429 and 0.402, respectively). Ten symptoms in the second category were included in the cold pattern of RA patients. Four principal components were extracted to cold pattern. The component with the highest eigenvalue (2.089) were mainly contributed by joint distension and pain, joint stiffness, fatigue and upset with high factor loading values (0.597, 0.590, 0.491 and 0.481, respectively). Although there were no statistical differences between the levels of rheumatoid factor and anti-cyclic peptide containing citrulline (anti-CCP), the levels of C-reactive protein, platelet count and the disease activity score using 28 joint counts were significantly higher in the heat pattern RA patients compared to the ones in cold pattern. Moreover, heat pattern RA patients were more likely to be prescribed two more disease-modifying anti-rheumatic drugs (DMARDS) combined with Methotrexate (MTX) (70.59% versus 49.72%; P = 0.000).

Conclusions

In conclusion, heat and cold patterns in RA patients could be classified well using cluster analysis and factor analysis. Most of RA patients with heat pattern were active and likely to be prescribed two more DMARDs combined with MTX.

Deposition of platelet-derived microparticles in podocytes contributes to diabetic nephropathy

BACKGROUND

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in the developed world. Podocyte injury is a critical cellular event involved in the progression of DN. Our previous studies demonstrated that platelet-derived microparticles (PMPs) mediated endothelial injury in diabetic rats. This study aimed to investigate whether PMPs are deposited in podocytes and to assess their potential effects on podocyte injury in DN.

METHODS

The deposition of PMPs in podocytes was assessed by immunofluorescent staining and electron microscopy. The changes in renal pathology and ultra-microstructure were assessed by periodic acid-Schiff staining and electron microscopy, respectively. The expression of inflammatory cytokines and extracellular matrix proteins was measured by immuno-histochemical staining and western blot.

RESULTS

PMPs were widely deposited in podocytes of glomeruli in diabetic patients and animal models and closely associated with DN progression. Interestingly, aspirin treatment significantly inhibited the accumulation of PMPs in the glomeruli of diabetic rats, alleviated mesangial matrix expansion and fusion of foot processes, and decreased the protein expression of inflammatory cytokines and extracellular matrix secretion. An in vitro study further confirmed the deposition of PMPs in podocytes. Moreover, PMP stimulation induced the phenotypic transition of podocytes through decreased podocin protein expression and increased protein expression of α-SMA and fibronectin, which was correlated with increased production of inflammatory cytokines.

CONCLUSION

Our findings demonstrated for the first time that the deposition of PMPs in podocytes contributed to the development of DN.

Association between Novel Hematological Indices and Measures of Disease Activity in Patients with Rheumatoid Arthritis

Background and Objectives: Hematological indices have been known to be available markers used for evaluating disease activity in rheumatoid arthritis (RA). This study serves to verify the association between four different hematological indices and disease activity measures in patients with RA. Materials and Methods: The study included 257 female RA patients and 71 age-matched female controls. Four hematological indices, namely systemic immune-inflammation index (SII), neutrophil-to-hemoglobin and lymphocyte (NHL) score, neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), were evaluated. Composite measures of RA included Disease Activity Score 28 joints (DAS28), the simplified disease activity index (SDAI), and the clinical disease activity index (CDAI). Results: Patients with RA showed statistically higher SII, NHL score, NLR, and PLR compared with controls. SII and NHL score were significantly associated with DAS28 erythrocyte sedimentation rate (DAS28-ESR), DAS28 C-reactive protein (DAS28-CRP), CDAI, and SDAI, whereas NLR was related to DAS28-CRP, CDAI, and SDAI. SII, NHL score, and NLR tended to increase as disease activity based on DAS28-ESR, DAS28-CRP, and CDAI worsened. In the analysis using receiver operating characteristic curve of hematological indices for diagnostic accuracy, the area under the curve was 0.703 (95% confidence interval, CI 0.637−0.769, p < 0.001) for SII and 0.705 (95% CI 0.639−0.770, p < 0.001) for NHL score, which showed acceptable potential for the diagnosis of RA. Four hematological indices showed weak potential for the detection of remission. Conclusions: The present study results showed that SII and NHL scores might be useful markers that adequately reflect disease activity and lead to more accurate diagnosis in RA.

Serum serotonin levels are elevated in patients with increased risk of rheumatoid arthritis

Background

Even though serotonin (5-HT) has been ascribed immunomodulatory features, very little is known about its role in chronic inflammatory diseases. Serotonin is implicated in inflammation and increased levels have been associated with progression of bone erosions in RA.

Objective

To investigate serum serotonin levels in patients with increased risk of rheumatoid arthritis (RA) and patients with recent-onset disease. Moreover, we aimed to determine the prognostic value of serotonin for arthritis development and the disease course.

Methods

Two prospective observational patient cohorts were studied; anti-citrullinated protein antibody (ACPA) -positive patients with musculoskeletal pain without clinical arthritis (n = 82) and patients with early RA (n = 412). Serotonin levels were measured by enzyme-linked immunosorbent assay (ELISA) in baseline serum samples from both cohorts, and longitudinally in at-risk individuals.

Results

Compared to healthy controls (median 65 ng/ml), serotonin levels were significantly higher in both at-risk individuals (median 111 ng/ml, p < 0.0001) and patients with early RA (median 135 ng/ml, p < 0.0001). No significant differences were found between at-risk individuals and patients with early RA. At-risk individuals progressing to arthritis had similar levels as those not progressing, and no significant differences were seen over time. Baseline levels in early RA did not associate with mean 28-joint disease activity scores during 3 years follow-up.

Conclusion

Serum serotonin levels are elevated both at, and prior to, onset of RA. However, increased serotonin is not prognostic for arthritis development or disease course.

Association Between Platelet Indices and Preoperative Deep Vein Thrombosis in Elderly Patients Undergoing Total Joint Arthroplasty: A Retrospective Study

To investigate the association between platelet (PLT) indices and preoperative deep vein thrombosis (DVT) in elderly patients undergoing total joint arthroplasty (TJA). A total of 1391 patients were enrolled. We created receiver operator characteristic (ROC) curve using the ratio of PLT indices to DVT before TJA, divided the enrolled patients into groups based on the cut-off value, and then analyzed risk factors for DVT before TJA in the multivariate binary logistic regression analysis. Preoperative DVT occurred in 103 cases. Based on the ROC curve, we determined that the cut-off values for PLT, mean platelet volume (MPV), platelet distribution width (PDW), platelet large cell ratio (P-LCR), and plateletcrit (PCT) were 202 × 109/L, 11.4 fL, 13.2 fL, 34.6%, and 0.228%. And the areas under the curve were 0.606, 0.605, 0.617, 0.616, and 0.598. Multivariate binary regression analysis revealed that the risk of preoperative DVT in TJA patients with PLT≥202 × 109/L, MPV≤11.4 fL, PDW≤13.2 fL, P-LCR≤34.6%, and PCT≥0.228% increased by 2.32 (P < .001, 95% confidence interval [CI] [1.50-3.60]), 1.86 (P < .001, 95% CI [1.22-2.83]), 2.17 (P < .001, 95% CI [1.43-3.31]), 2.27 (P < .001, 95% CI [1.50-3.45]), and 1.76 times (P = .013, 95% CI [1.13-2.76]), respectively. Age, P < .001, odds ratio (OR) = 1.08, 95% CI [1.04-1.11]; corticosteroid use, P = .011, OR = 3.66, 95% CI [1.34-9.96]. We found that increased PLT count and PCT, decreased MPV, PDW, and P-LCR, old age, and corticosteroid use were independent risk factors for preoperative DVT in elderly TJA patients.

Nanomaterial-assisted theranosis of bone diseases

Bone-related diseases refer to a group of skeletal disorders that are characterized by bone and cartilage destruction. Conventional approaches can regulate bone homeostasis to a certain extent. However, these therapies are still associated with some undesirable problems. Fortunately, recent advances in nanomaterials have provided unprecedented opportunities for diagnosis and therapy of bone-related diseases. This review provides a comprehensive and up-to-date overview of current advanced theranostic nanomaterials in bone-related diseases. First, the potential utility of nanomaterials for biological imaging and biomarker detection is illustrated. Second, nanomaterials serve as therapeutic delivery platforms with special functions for bone homeostasis regulation and cellular modulation are highlighted. Finally, perspectives in this field are offered, including current key bottlenecks and future directions, which may be helpful for exploiting nanomaterials with novel properties and unique functions. This review will provide scientific guidance to enhance the development of advanced nanomaterials for the diagnosis and therapy of bone-related diseases.

Deciphering the role of platelets in severe allergy by an integrative omics approach

BACKGROUND

Mechanisms causing the onset and perpetuation of inflammation in severe allergic patients remain unknown. Our previous studies suggested that severe allergic inflammation is linked to platelet dysfunction.

METHODS

Platelet-rich plasma (PRP) and platelet-poor plasma (PPP) samples were obtained by platelet-apheresis from severe (n = 7) and mild (n = 10) allergic patients and nonallergic subjects (n = 9) to perform platelet lipidomics by liquid chromatography coupled to mass spectrometry (LC-MS) and RNA-seq analysis. Significant metabolites and transcripts were used to identify compromised biological pathways in the severe phenotype. Platelet and inflammation-related proteins were quantified by Luminex.

RESULTS

Platelets from severe allergic patients were characterized by high levels of ceramides, phosphoinositols, phosphocholines, and sphingomyelins. In contrast, they showed a decrease in eicosanoid precursor levels. Biological pathway analysis performed with the significant lipids revealed the alteration of phospholipases, calcium-dependent events, and linolenic metabolism. RNAseq confirmed mRNA overexpression of genes related to platelet activation and arachidonic acid metabolism in the severe phenotypes. Pathway analysis indicated the alteration of NOD, MAPK, TLR, TNF, and IL-17 pathways in the severe phenotype. P-Selectin and IL-17AF proteins were increased in the severe phenotype.

CONCLUSIONS

This study demonstrates that platelet lipid, mRNA, and protein content is different according to allergy severity. These findings suggest that platelet load is a potential source of biomarkers and a new chance for therapeutic targets in severe inflammatory pathologies.

LC-MS/MS-based serum proteomics reveals a distinctive signature in a rheumatoid arthritis mouse model after treatment with mesenchymal stem cells

Mesenchymal stem cells (MSCs) are known to be able to modulate immune responses, possess tissue-protective properties, and exhibit healing capacities with therapeutic potential for various diseases. The ability of MSCs to secrete various cytokines and growth factors provides new insights into autoimmune-diseases such as rheumatoid arthritis (RA). RA is a systemic autoimmune disease that affects the lining of synovial joints, causing stiffness, pain, inflammation, and joint erosion. In recent years, MSCs-based therapies have been widely proposed as promising therapies in the treatment of RA. However, the mechanism involved in disease-specific therapeutic effects of MSCs on RA remains unclear. To clarify the mechanism involved in effects of MSCs on RA, proteomic profiling was performed using an RA mouse model before and after treatment with MSCs. In this study, treatment efficacy of human umbilical cord blood-mesenchymal stem cells (hUCB-MSCs) was confirmed using a type II collagen-induced arthritis (CIA) mouse model. Results of measuring incidence rates of arthritis and clinical arthritis index (CAI) revealed that mice administrated with hUCB-MSCs had a significant reduction in arthritis severity. Proteins that might affect disease progression and therapeutic efficacy of hUCB-MSC were identified through LC-MS/MS analysis using serum samples. In addition, L-1000 analysis was performed for hUCB-MSC culture medium. To analysis data obtained from LC–MS/MS and L-1000, tools such as ExDEGA, MEV, and DAVID GO were used. Results showed that various factors secreted from hUCB-MSCs might play roles in therapeutic effects of MSCs on RA, with platelet activation possibly playing a pivotal role. Results of this study also suggest that SERPINE1 and THBS1 among substances secreted by hUCB-MSC might be key factors that can inhibit platelet activation. This paper is expected to improve our understanding of mechanisms involved in treatment effects of stem cells on rheumatoid arthritis.

Flavored Food Additives on the Leaves of Piper betle L.: A Human Health Perspective

Natural products and traditional ethnomedicines are of great effect in therapeutics. Such types of medicine have been practiced in certain areas of the world to treat different health conditions. This pilot investigation aims to review the cumulative health effect of addendums used in betel quid such as areca nut, lime, and tobacco-associated betel quid chewing and without tobacco-associated chewing. This review shows that betel leaf extract and its essential oil could inhibit growth of microbes and damage different gram-positive and gram-negative bacteria as well as various fungus species. Some studies concluded that the combination of Piper leaves essential oil with antibiotics have potential effect on oral microorganisms. Long-term consumption of betel quid with tobacco is known to cause cancer, chromosomal aberrations, and pharynx tumors. However, consumption of betel leaf without tobacco has health benefits because of ethnomedicinal properties. Its essential is oil utilized as raw material for perfumes and mouth fresheners manufacturing. Scientific researches on this plant revealed that it possesses many beneficial activities to be used for developing novel drugs. However, compounds of betel leaves have beneficial natural antioxidant. Chewing and intake of leaves have effect on moving parts of salivary gland which is the main step of digestion. Its components also act as heartbeat regulators in relaxing the blood vessels to reduce hypertension. So this review discussed the natural compounds of betel leaves which is used as traditional medicine to further develop drug discovery.

Anti-inflammatory protective effect of ADAMTS-13 in murine arthritis models

BACKGROUND

Patients with rheumatoid arthritis (RA) have frequent thrombotic events with endothelial dysfunction. Von Willebrand factor (VWF) has been shown to bind neutrophil extracellular traps (NETs) and NETs are part of RA etiology.

OBJECTIVES

This study aims to elucidate whether this prothrombotic status exacerbates inflammation in arthritis. Here we focus on the involvement of A Disintegrin And Metalloprotease with ThromboSpondin type 1 motif, member 13 (ADAMTS-13), an enzyme cleaving VWF and its effect on NET deposition and RA development.

METHODS

We evaluated the influence of the Adamts13 gene and recombinant human ADAMTS-13 (rhADAMTS-13) on arthritis in the mouse models of collagen-induced arthritis (CIA). We also assessed VWF and NETs in synovial tissue.

RESULTS

Several Adamts13-/- mice developed arthritis, while Adamts13+/+ siblings did not. Synovial tissue from Adamts13-/- showed accumulation of NETs. Treatment of DBA/1 J mice, an arthritis-susceptible strain, with well-tolerated doses of rhADAMT13 reduced arthritis incidence and alleviated the severity of arthritis. Mice treated with rhADAMT13 presented less serum interleukin 6 and less bone erosion determined by micro-computed tomography. The effects on arthritis severity were observed both when administering rhADAMTS-13 prophylactically and also when given after arthritis has developed. In both conditions, rhADAMTS-13 reduced VWF and NET deposition on proliferated synovial tissue evaluated by immunoblotting.

CONCLUSIONS

Our results demonstrate the inhibitory role of Adamts13 in murine arthritis and the effectiveness of rhADAMTS-13 treatment. Additionally, this study suggests that deposition of VWF in the synovium and subsequent pathogenic NET retention promotes arthritis. Treatment with rhADAMTS-13 provides a potential therapeutic approach targeting inflammation and pro-thrombotic state in arthritis.

The potential role of ischaemia-reperfusion injury in chronic, relapsing diseases such as rheumatoid arthritis, Long COVID, and ME/CFS: evidence, mechanisms, and therapeutic implications

Ischaemia-reperfusion (I-R) injury, initiated via bursts of reactive oxygen species produced during the reoxygenation phase following hypoxia, is well known in a variety of acute circumstances. We argue here that I-R injury also underpins elements of the pathology of a variety of chronic, inflammatory diseases, including rheumatoid arthritis, ME/CFS and, our chief focus and most proximally, Long COVID. Ischaemia may be initiated via fibrin amyloid microclot blockage of capillaries, for instance as exercise is started; reperfusion is a necessary corollary when it finishes. We rehearse the mechanistic evidence for these occurrences here, in terms of their manifestation as oxidative stress, hyperinflammation, mast cell activation, the production of marker metabolites and related activities. Such microclot-based phenomena can explain both the breathlessness/fatigue and the post-exertional malaise that may be observed in these conditions, as well as many other observables. The recognition of these processes implies, mechanistically, that therapeutic benefit is potentially to be had from antioxidants, from anti-inflammatories, from iron chelators, and via suitable, safe fibrinolytics, and/or anti-clotting agents. We review the considerable existing evidence that is consistent with this, and with the biochemical mechanisms involved.

The protective effect of the spleen in sickle cell patients. A comparative study between patients with asplenia/hyposplenism and hypersplenism

Sickle cell disease (SCD) is caused by a point mutation in the beta-globin gene. SCD is characterized by chronic hemolytic anemia, vaso-occlusive events leading to tissue ischemia, and progressive organ failure. Chronic inflammatory state is part of the pathophysiology of SCD. Patients with SCD have extremely variable phenotypes, from mild disease to severe complications including early age death. The spleen is commonly injured in SCD. Early splenic dysfunction and progressive spleen atrophy are common. Splenomegaly and hypersplenism can also occur with the loss of the crucial splenic function. Acute, life-threatening spleen-related complications in SCD are well studied. The association of laboratory parameters with the spleen status including hyposplenism, asplenia, and splenomegaly/hypersplenism, and their implication in vaso-occlusive crisis and long-term complications in SCD remain to be determined. We evaluated the association between the spleen status with clinical and laboratory parameters in 31 SCD patients: Group a) Patients with asplenia/hyposplenism (N = 22) (including auto-splenectomy and splenectomized patients) vs. Group b) patients with splenomegaly and or hypersplenism (N = 9). Laboratory studies included: Complete Blood Count, reticulocyte count, iron metabolism parameters, C Reactive Protein (CRP), Hb variant distribution, and D-dimer. Metabolic and morphological red blood cell (RBC) studies included: density gradient (by Percoll), glucose consumption, lactate release, and K⁺ leakage, fetal RBC (F-Cells) and F-Reticulocytes, annexinV+, CD71⁺, oxidative stress measured by GSH presence in RBC and finally Howell Jolly Bodies count were all analyzed by Flow Cytometry. Scanning electron microscopy analysis of RBC was also performed. Patients with asplenia/hyposplenism showed significantly higher WBC, platelet, Hematocrit, hemoglobin S, CRP, D-dimer, Gamma Glutamyl Transferase (GGT), cholesterol, transferrin, annexin V+ RBCs, CD71⁺ RBCs, together with a markedly lower F Reticulocyte levels in comparison with splenomegaly/hypersplenism patients. In summary, important differences were also found between the groups in the studied RBCs parameters. Further studies are required to elucidate the effect of the spleen including hyper and hypo-splenia on laboratory parameters and in clinical manifestations, vascular pathology, and long-term complications of SCD. The benefits and risks of splenectomy compared to chronic transfusion need to be evaluated in clinical trials and the standard approach managing hypersplenism in SCD patients should be re-evaluated.

Diagnostic Value of Neutrophil-to-Lymphocyte, Platelet-to-Lymphocyte, and Monocyte-to-Lymphocyte Ratios for the Assessment of Rheumatoid Arthritis in Patients with Undifferentiated Inflammatory Arthritis

Background: To investigate the diagnostic performance of the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) in the diagnosis of rheumatoid arthritis (RA) in subjects with undifferentiated inflammatory arthritis (UIA). Methods: This retrospective cohort study investigated 201 female patients with UIA (≥1 swollen joint) and 280 age-matched, healthy female controls. “Clinical RA” was defined based on the clinical judgment of a rheumatologist and “disease-modifying anti-rheumatic drugs (DMARDs) RA” was defined as a case of initiating DMARDs treatment within 6 months after the first visit. “Classified RA” was defined as fulfilling the 2010 classification criteria for RA. Receiver operating characteristics were used to determine the optimal cut-off value. Results: UIA patients had a significantly higher NLR, PLR, and MLR than the controls. Among the 201 UIA patients, 65 (32.3%), 63 (31.3%), and 61 (30.3%) subjects were classified as clinical RA, DMARDs RA, and classified RA, respectively. At a cut-off of 0.24, MLR showed moderate accuracy for the diagnosis of DMARDs RA (sensitivity, 65.1%; specificity, 62.3%; area under the curve [AUC], 0.701; p < 0.001). However, the diagnostic accuracies of NLR and PLR were low. Conclusions: MLR may be used as a complementary diagnostic indicator for RA diagnosis in patients with UIA.

Fibrin deposition associates with cartilage degeneration in arthritis

Background

Cartilage damage in inflammatory arthritis is attributed to inflammatory cytokines and pannus infiltration. Activation of the coagulation system is a well known feature of arthritis, especially in rheumatoid arthritis (RA). Here we describe mechanisms by which fibrin directly mediates cartilage degeneration.

Methods

Fibrin deposits were stained on cartilage and synovial tissue of RA and osteoarthritis (OA) patients and in murine adjuvant-induced arthritis (AIA) in wild-type or fibrinogen deficient mice. Fibrinogen expression and procoagulant activity in chondrocytes were evaluated using qRT-PCR analysis and turbidimetry. Chondro-synovial adhesion was studied in co-cultures of human RA cartilage and synoviocytes, and in the AIA model. Calcific deposits were stained in human RA and OA cartilage and in vitro in fibrinogen-stimulated chondrocytes.

Findings

Fibrin deposits on cartilage correlated with the severity of cartilage damage in human RA explants and in AIA in wild-type mice, whilst fibrinogen deficient mice were protected. Fibrin upregulated Adamts5 and Mmp13 in chondrocytes. Chondro-synovial adhesion only occurred in fibrin-rich cartilage areas and correlated with cartilage damage. In vitro, autologous human synoviocytes, cultured on RA cartilage explants, adhered exclusively to fibrin-rich areas. Fibrin co-localized with calcification in human RA cartilage and triggered chondrocyte mineralization by inducing pro-calcification genes (Anx5, Pit1, Pc1) and the IL-6 cytokine. Similar fibrin-mediated mechanisms were observed in OA models, but to a lesser extent and without pseudo-membranes formation.

Interpretation

In arthritis, fibrin plaques directly impair cartilage integrity via a triad of catabolism, adhesion, and calcification.

Funding

None.

Hematological markers and ultrasound 7-joint inflammation score as add-on tools in the assessment of inflammation in rheumatoid arthritis patients

Background

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation and joint destruction that eventually induces severe disability. Inflammation is the key determinant and primary underlying mechanism leading to disability and increased mortality in patients with RA. This study aimed to correlate the hematological markers and ultrasound 7-joint inflammation score to disease activity in rheumatoid arthritis patients.

Results

The current study involved 54 RA patients diagnosed according to the 2010 ACR/EULAR classification criteria for RA and thirty healthy control subjects. There were 48 females (88.9%) and 6 males (11.1%). The age of patients ranged from 32 to 60 years, with a mean of 46.04 ± 5.65 years. Using disease activity score 28-ESR, total white blood cell count and absolute lymphocytic count were significantly lower in RA patients with high disease activity. Neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, mean platelet volume, ESR, and CRP were significantly higher in patients with high disease activity using disease activity score 28 CRP. Also, a statistically significant positive correlation was detected between neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio and both clinical disease activity scores. Red cell distribution width but not platelet distribution width was significantly higher in RA patients but both parameters had no association or correlation with clinical disease activity scores. Neutrophil-to-lymphocyte ratio was found to have a statistically significant positive correlation with the tenosynovitis score by powered Doppler ultrasound. There were statistically significant positive correlations between disease activity score 28 ESR and CRP and synovitis and tenosynovitis scores by greyscale and powered Doppler ultrasound using the ultrasound 7 score.

Conclusion

Neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and mean platelet volume could be potential inflammatory markers for follow-up of disease activity in RA patients. The ultrasound 7 score is a simple and practical scoring system for use in the detection of inflammation, even subclinically in RA patients, which may help the physician in his clinical decisions. The combined use of both hematological markers and the ultrasound 7 score may be of great value.

Preliminary study on the involvement of platelets in mouse experimental periodontitis

Background/purpose

Although some studies have taken an interest in the participation of platelets in periodontitis, so far, we know very little about the roles of platelets in periodontitis. The objective of this study is to explore the involvement of platelets in the development of experimental periodontitis in mice.

Materials and methods

Twenty C57BL/6 male mice were used for this study. Experimental periodontitis models of mice were constructed by ligating for 1, 3, 7, and 14 days, respectively. Morphological changes in the alveolar bone were assessed by micro-computed tomography (Micro-CT). The gingival crevicular fluid samples of ligation sites were collected and stained by immunocytochemistry. Immunohistochemistry was used to detect platelets infiltration in gingival tissues of mice.

Results

The results of Micro-CT showed that with the extension of ligation time, alveolar bone resorption increased, suggesting that the experimental periodontitis models were established. Immunochemical staining showed that there were almost no platelets in the gingival crevicular fluid of mice ligated for 1 and 3 days. And at 7 and 14 days of ligation, a large number of platelets were present in the gingival crevicular fluid and formed complexes with neutrophils. And with the extension of ligation time, the extent of platelet infiltration increased in mice gingival tissues.

Conclusion

Platelets were infiltrated increasedly in the gingival sulcus and gingival tissues following the experimental time, and may participate in the development of mouse experimental periodontitis.

Role of Platelets in Osteoarthritis-Updated Systematic Review and Meta-Analysis on the Role of Platelet-Rich Plasma in Osteoarthritis

Platelets are an essential component of hemostasis, with an increasing role in host inflammatory processes in injured tissues. The reaction between receptors and vascular endothelial cells results in the recruitment of platelets in the immune response pathway. The aim of the present review is to describe the role of platelets in osteoarthritis. Platelets induce secretion of biological substances, many of which are key players in the inflammatory response in osteoarthritis. Molecules involved in cartilage degeneration, or being markers of inflammation in osteoarthritis, are cytokines, such as tumor necrosis factor α (TNFα), interleukins (IL), type II collagen, aggrecan, and metalloproteinases. Surprisingly, platelets may also be used as a treatment modality for osteoarthritis. Multiple randomized controlled trials included in our systematic review and meta-analyses prove the effectiveness of platelet-rich plasma (PRP) as a minimally invasive method of pain alleviation in osteoarthritis treatment.

Platelet Indices Are the Promising Biomarkers in Monitoring Disease Activities in Patients with Syphilis

OBJECTIVE

To uncover the role of the platelet indices in patients with syphilis.

METHODS

A total of 2061 syphilis patients and 528 healthy controls were enrolled in this retrospective cohort study. The data of platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW) and indicators of syphilis activities were collected. The correlations between the platelet indices and disease activities were analyzed.

RESULTS

425 (20.6%) of all the 2061 patients were of primary and secondary syphilis, 433 (21.0%) latent, 463 (22.5%) serofast, 350 (17.0%) asymptomatic neurosyphilis and 390 (18.9%) symptomatic neurosyphilis. Compared with the healthy controls, PLT was significantly increased in the primary and secondary syphilis group. Whereas, MPV and PDW were significantly decreased in all stages of syphilis. These changes of platelets indices were reversed after anti-treponemal therapy. Further correlation analysis showed PLT was positively associated with the syphilis activity indicators [rapid plasma reagin (RPR) titer, cerebrospinal fluid white blood cell (CSF-WBC), CSF-protein, and CSF-VDRL (venereal disease research laboratory)] and inflammatory markers [WBC, C-reaction protein (CRP), and erythrocyte sedimentation rate (ESR)]. Conversely, PDW was negatively correlated with all of these parameters. MPV had an inverse relationship with RPR, ESR, and CRP.

CONCLUSIONS

Platelet indices are associated with syphilis activities.

Association Between Blood PLT and RBC Related Indices and Disease Activity in Patients with Rheumatoid Arthritis

Background

Platelet (PLT) and red blood cell (RBC) have been demonstrated to play a critical role in inflammatory processes. This study aimed to evaluate the association of blood PLT and RBC related parameters with the disease activity in rheumatoid arthritis (RA) patients, and also to investigate the role of these indices in differentiating among RA patients with different disease activity.

Methods

Clinical data from RA patients were retrospectively analyzed. RA patients were divided into inactive group and active group according to DAS28-CRP. The relationship between blood PLT and RBC counts-related indices and DAS28-CRP was detected by Spearman correlation. ROC curve was used to assess the diagnostic value of these indices in differentiating active RA from inactive RA.

Results

Active RA patients exhibited higher level of PLT counts but significantly lower levels of RBC counts, hemoglobin (Hb), red blood cells-platelet ratio (RPR) and hemoglobin-platelet ratio (HPR) compared with inactive RA. PLT counts were positively but RBC counts, Hb, RPR and HPR were negatively related with DAS28-CRP.

Conclusion

Blood PLT and RBC related indices were significantly associated with RA disease activity. These indices may be used to distinguish active RA from inactive RA.

Blood tests for prediction of deep endometriosis: A case-control study

BACKGROUND

Deep endometriosis (DE) is the most aggressive subtype of endometriosis. The diagnosis may be challenging, and no biomarkers that can discriminate women with DE from those without DE have been developed.

AIM

To evaluate the role of blood hemostatic parameters and inflammatory indices in the prediction of DE.

METHODS

This case-control study was performed at the Women’s Hospital, Zhejiang University School of Medicine between January 2015 and December 2016. Women with DE and women with benign gynecologic disease (control group) eligible for gynecological surgery were enrolled. Routine plasma hemostatic parameters and inflammatory indices were obtained before surgery. Univariate and multivariate analysis were performed. Receiver operating characteristic (ROC) curves were generated, and areas under the curve (AUC) were calculated to assess the predictive values of the selected parameters.

RESULTS

A total of 126 women were enrolled, including 31 with DE and 95 controls. Plasma fibrinogen (Fg, P < 0.01), international normalized ratio (P < 0.05), and C-reactive protein levels (P < 0.01) were significantly higher in women with DE compared with controls. Plasma hemoglobin (HB) levels (P < 0.05) and shortened thrombin time (P < 0.05) were significantly lower in women with DE than in controls. Plasma Fg levels [adjusted OR (aOR) 2.12, 95%confidence interval (CI): 1.31-3.75] and plasma HB levels (aOR 0.48, 95%CI: 0.29-0.78) were significantly associated with DE (both P < 0.05). ROC analysis showed that the diagnostic value of Fg or HB alone for DE was limited. The AUC of the combination of both markers as a dual marker index was 0.773 with improved sensitivity (67.7%) and specificity (78.9%) at cutoffs of 3.09 g/L and 126 g/L, respectively.

CONCLUSION

The combination of Fg and HB was a reliable predictor of DE. A larger study is needed to confirm the findings.

"Platelet-rich plasma holds promise in management of rheumatoid arthritis"-systematic review

The treatment of rheumatoid arthritis (RA) has been closely evolving with an understanding of disease pathogenesis with disease modifying anti-rheumatoid drugs (DMARDS) and Biologic DMARDS being the main stay. platelet rich plasma (PRP) has been the center of research in many specialties in the past decade. Its ability to stop and reverse inflammation have attracted researchers to try PRP in RA. A systematic review of studies on PRP in RA is lacking. The study protocol was prospectively registered in PROSPERO. Detailed search of Cochrane, Scopus, Medline, Embase, and Web of science databases were made to identify the relevant articles till Sep 2020 following Cochrane and PRISMA guidelines. Number of subjects, Animal model used, cell lines used for the study, method of induction of arthritis, PRP dose, concentration used, frequency of administration and clinical, histologic, and molecular changes from baseline following PRP use were extracted and analysed. Eight studies were included for the review. Four of these were in-vitro studies. Two were exclusive animal studies. One study analysed the effects of PRP in RA in both animal models (mice) and Hela cell lines. One study was a report of a series of patients of resistant RA treated with PRP. In the in vitro studies while platelets increase the migration and invasion of RA-FLS, they suppressed the inflammation on the whole. Available animal studies and the Human study have shown encouraging results. There has been no evidence of exacerbation of inflammation in these studies. The quantity and quality of literature on the effects of PRP in treating joint pathologies in RA is limited. Preclinical studies show decrease in disease activity with good safety profile. Invitro studies show suppression of inflammation. Thus, the available literature is encouraging towards the use of PRP in RA. Larger trials and molecular studies to understand the exact role of platelets in disease pathogenesis and treatment mechanisms are needed to decide the future course of PRP in RA.

Platelet Behavior Contributes to Neuropathologies: A Focus on Alzheimer's and Parkinson's Disease

The functions of platelets are broad. Platelets function in hemostasis and thrombosis, inflammation and immune responses, vascular regulation, and host defense against invading pathogens, among others. These actions are achieved through the release of a wide set of coagulative, vascular, inflammatory, and other factors as well as diverse cell surface receptors involved in the same activities. As active participants in these physiological processes, platelets become involved in signaling pathways and pathological reactions that contribute to diseases that are defined by inflammation (including by pathogen-derived stimuli), vascular dysfunction, and coagulation. These diseases include Alzheimer's and Parkinson's disease, the two most common neurodegenerative diseases. Despite their unique pathological and clinical features, significant shared pathological processes exist between these two conditions, particularly relating to a central inflammatory mechanism involving both neuroinflammation and inflammation in the systemic environment, but also neurovascular dysfunction and coagulopathy, processes which also share initiation factors and receptors. This triad of dysfunction-(neuro)inflammation, neurovascular dysfunction, and hypercoagulation-illustrates the important roles platelets play in neuropathology. Although some mechanisms are understudied in Alzheimer's and Parkinson's disease, a strong case can be made for the relevance of platelets in neurodegeneration-related processes.

Platelet-derived extracellular vesicles promote the migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes via CXCR2 signaling

Platelet-derived extracellular vesicles (PEVs), which are generated from the plasma membrane during platelet activation, may be involved in the inflammatory processes of rheumatoid arthritis (RA). The motility of RA fibroblast-like synoviocytes (RA-FLS) plays a key role in the development of synovial inflammation and joint erosion. However, the effects of PEVs on the motility of RA-FLS remain unclear. Thus, the present study aimed to investigate the active contents and potential molecular mechanisms underlying the role of PEVs in regulating the migration and invasion of RA-FLS. The results demonstrated that PEVs contain certain chemokines associated with cell migration and invasion, including C-C motif chemokine ligand 5, C-X-C motif chemokine ligand (CXCL)4 and CXCL7. Furthermore, SB225002, an antagonist of C-X-C motif chemokine receptor 2 (CXCR2; a CXCL7 receptor), partially prevented the migration and invasion of RA-FLS induced by PEVs, suggesting that PEVs may activate a CXCR2-mediated signaling pathway in RA-FLS. In addition, SB225002 antagonized the phosphorylation of IκB and NF-κB in RA-FLS induced by PEVs. Taken together, the results of the present study suggested that PEVs may promote the migration and invasion of RA-FLS by activating the NF-κB pathway mediated by the CXCR2 signaling pathway.

Selectins impair regulatory T cell function and contribute to systemic lupus erythematosus pathogenesis

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by a loss of tolerance toward self-nucleic acids, autoantibody production, interferon expression and signaling, and a defect in the regulatory T (T_reg) cell compartment. In this work, we identified that platelets from patients with active SLE preferentially interacted with T_reg cells via the P-selectin/P-selectin glycoprotein ligand-1 (PSGL-1) axis. Selectin interaction with PSGL-1 blocked the regulatory and suppressive properties of T_reg cells and particularly follicular T_reg cells by triggering Syk phosphorylation and an increase in intracytosolic calcium. Mechanistically, P-selectin engagement on T_reg cells induced a down-regulation of the transforming growth factor-β axis, altering the phenotype of T_reg cells and limiting their immunosuppressive responses. In patients with SLE, we found an up-regulation of P- and E-selectin both on microparticles and in their soluble forms that correlated with disease activity. Last, blocking P-selectin in a mouse model of SLE improved cardinal features of the disease, such as anti-dsDNA antibody concentrations and kidney pathology. Overall, our results identify a P-selectin-dependent pathway that is active in patients with SLE and validate it as a potential therapeutic avenue.

Quantification of bone marrow edema in rheumatoid arthritis by using high-speed T2-corrected multiecho acquisition of 1H magnetic resonance spectroscopy: a feasibility study

OBJECTIVE

To determine whether high-speed T2-corrected multiecho (HISTO) sequences can quantify bone marrow edema (BME) in the capitate bone in rheumatoid arthritis (RA), and whether the HISTO fat fraction (FF) reflects therapeutic effectiveness.

METHODS

In this prospective study, 25 RA patients (19 women; average age, 45.08 ± 13.48 years) underwent 3.0-T MRI with HISTO at the baseline and after 4, 8, and 12 weeks of treatment. Rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), platelet (PLT) count, and 28-joint Disease Activity Score using ESR (DAS28-ESR) were recorded on the day of each MRI examination by a rheumatologist blinded to the MRI findings. In addition, 21 healthy subjects (15 women; age, 49.17 ± 6.56 years) underwent only the HISTO sequence at a single time point.

RESULTS

HISTO FF values were significantly higher in the control group (74.5% ± 3.1%; range, 68.6-79.3%) than in the patient group (55.8% ± 17.7%; range, 15.6-79.0%) at the baseline (independent-samples t-test: t = 5.257, P = 0.000). The changes in HISTO FF and DAS28-ESR showed moderate negative correlations with each other at 4, 8, and 12 weeks, and all of them were statistically significant (P < 0.05). As the HISTO FF increased, the DAS28-ESR decreased.

CONCLUSION

The HISTO sequence can measure the bone marrow FF of the wrist joint bones in RA patients. The HISTO FF value increased as the DAS28-ESR decreased. The HISTO sequence may help quantify BME in RA and help monitor the effectiveness of RA treatment. Key Points •The HISTO sequence could measure the bone marrow FF of the wrist joint bones. •FF value increased as the DAS28-ESR decreased in RA patients. •The HISTO sequence can monitor the therapeutic effect of RA.

Metabolically engineered stem cell–derived exosomes to regulate macrophage heterogeneity in rheumatoid arthritis

Despite the remarkable advances in therapeutics for rheumatoid arthritis (RA), a large number of patients still lack effective countermeasures. Recently, the reprogramming of macrophages to an immunoregulatory phenotype has emerged as a promising therapeutic strategy for RA. Here, we report metabolically engineered exosomes that have been surface-modified for the targeted reprogramming of macrophages. Qualified exosomes were readily harvested from metabolically engineered stem cells by tangential flow filtration at a high yield while maintaining their innate immunomodulatory components. When systemically administered into mice with collagen-induced arthritis, these exosomes effectively accumulated in the inflamed joints, inducing a cascade of anti-inflammatory events via macrophage phenotype regulation. The level of therapeutic efficacy obtained with bare exosomes was achievable with the engineered exosomes of 10 times less dose. On the basis of the boosted nature to reprogram the synovial microenvironment, the engineered exosomes display considerable potential to be developed as a next-generation drug for RA.

Platelets in HIV: A Guardian of Host Defence or Transient Reservoir of the Virus?

The immune and inflammatory responses of platelets to human immunodeficiency virus 1 (HIV-1) and its envelope proteins are of great significance to both the treatment of the infection, and to the comorbidities related to systemic inflammation. Platelets can interact with the HIV-1 virus itself, or with viral membrane proteins, or with dysregulated inflammatory molecules in circulation, ensuing from HIV-1 infection. Platelets can facilitate the inhibition of HIV-1 infection via endogenously-produced inhibitors of HIV-1 replication, or the virus can temporarily hide from the immune system inside platelets, whereby platelets act as HIV-1 reservoirs. Platelets are therefore both guardians of the host defence system, and transient reservoirs of the virus. Such reservoirs may be of particular significance during combination antiretroviral therapy (cART) interruption, as it may drive viral persistence, and result in significant implications for treatment. Both HIV-1 envelope proteins and circulating inflammatory molecules can also initiate platelet complex formation with immune cells and erythrocytes. Complex formation cause platelet hypercoagulation and may lead to an increased thrombotic risk. Ultimately, HIV-1 infection can initiate platelet depletion and thrombocytopenia. Because of their relatively short lifespan, platelets are important signalling entities, and could be targeted more directly during HIV-1 infection and cART.

The molecular basis of immune-based platelet disorders

Platelets have a predominant role in haemostasis, the maintenance of blood volume and emerging roles as innate immune cells, in wound healing and in inflammatory responses. Platelets express receptors that are important for platelet adhesion, aggregation, participation in inflammatory responses, and for triggering degranulation and enhancing thrombin generation. They carry a cargo of granules bearing enzymes, adhesion molecules, growth factors and cytokines, and have the ability to generate reactive oxygen species. The platelet is at the frontline of a host of cellular responses to invading pathogens, injury, and infection. Perhaps because of this intrinsic responsibility of a platelet to rapidly respond to thrombotic, pathological and immunological factors as part of their infantry role; platelets are susceptible to targeted attack by the adaptive immune system. Such attacks are often transitory but result in aberrant platelet activation as well as significant loss of platelet numbers and platelet function, paradoxically leading to elevated risks of both thrombosis and bleeding. Here, we discuss the main molecular events underlying immune-based platelet disorders with specific focus on events occurring at the platelet surface leading to activation and clearance.

A bioavailable form of curcumin, in combination with vitamin-D- and omega-3-enriched diet, modifies disease onset and outcomes in a murine model of collagen-induced arthritis

OBJECTIVE

Curcumin (CUR), vitamin D₃ (D3), and omega-3-fatty acids (O3FA) individually modulate inflammation and pain in arthritis. Although these supplements are widely used, their combinatorial effects have not been defined. In this study, we examined the effects of a D3 and O3FA (VO)-enriched diet in conjunction with a highly bioavailable form of CUR (Cureit/Acumin™) in a collagen-induced arthritis (CIA) murine model.

METHODS

Male DBA/1J mice were acclimatized to VO-enriched diet and challenged with bovine collagen II (CII). Bioavailable CUR was administered daily by oral gavage from the onset of CII challenge. Disease severity was determined by monitoring joint thickness and standardized clinical score. Cellular infiltration and cartilage degradation in the joints were assessed by histology, serum cytokines profiled by Meso Scale Discovery multiplex assay, and joint matrix metalloproteinases examined by western blots.

RESULTS

CUR by itself significantly decreased disease severity by ~ 60%. Administration of CUR in CIA mice taking a VO-enriched diet decreased disease severity by > 80% and maximally delayed disease onset and progression. Some of the disease-modifying effects was mediated by CUR alone, e.g., suppression of serum anti-collagen antibodies and decrease of cellular infiltration and MMP abundance in the joints of CIA mice. Although CUR alone suppressed inflammatory cytokines in serum of CIA mice, the combination of CUR and VO diet significantly enhanced the suppression (> 2-fold compared to CUR) of TNF, IFN-γ, and MCP-1, all known to be associated with RA pathogenesis.

CONCLUSION

This study provides proof-of-concept that the combination of bioavailable CUR, vitamin D₃, and O3FA substantially delays the development and severity of CIA. These findings provide a rationale for systematically evaluating these widely available supplements in individuals at risk for developing future RA.

Activated Platelets Convert CD14+CD16- Into CD14+CD16+ Monocytes With Enhanced FcγR-Mediated Phagocytosis and Skewed M2 Polarization

Monocytes are important cellular effectors of innate immune defense. Human monocytes are heterogeneous and can be classified into three distinct subsets based on CD14 and CD16 expression. The expansion of intermediate CD14⁺CD16⁺ monocytes has been reported in chronic inflammatory diseases including rheumatoid arthritis (RA). However, the mechanism underlying induction of CD16 and its role in monocytes remains poorly understood. Here, we demonstrate that activated platelets are important for induction of CD16 on classical CD14⁺CD16^- monocytes by soluble factors such as cytokines. Cytokine neutralization and signaling inhibition assays reveal that sequential involvement of platelet-derived TGF-β and monocyte-derived IL-6 contribute to CD16 induction on CD14⁺CD16^- monocytes. Activated platelet-induced CD16 on monocytes participates in antibody-dependent cellular phagocytosis (ADCP) and its level is positively correlated with phagocytic activity. CD14⁺CD16^- monocytes treated with activated platelets preferentially differentiate into M2 macrophages, likely the M2c subset expressing CD163 and MerTK. Lastly, the amount of sCD62P, a marker of activated platelets, is significantly elevated in plasma of RA patients and positively correlates with clinical parameters of RA. Our findings suggest an important role of activated platelets in modulating phenotypical and functional features of human monocytes. This knowledge increases understanding of the immunological role of CD14⁺CD16⁺ cells in chronic inflammatory diseases.

Associations of Platelet Count with Inflammation and Response to Anti-TNF-α Therapy in Patients with Ankylosing Spondylitis

Background: Increased platelet count has been reported in ankylosing spondylitis (AS) patients, but its clinical significance is still largely elusive. The objective of this study was to evaluate the clinical role of platelet count in AS patients, especially its impact on treatment outcomes.

Methods: A case-control study containing 35 AS patients receiving anti-tumor necrosis factor-α (anti-TNF-α) therapy and 45 healthy controls was performed, and AS patients were followed at least 6 months after anti-TNF-α therapy. A systematic review and meta-analysis of studies containing relevant data on outcomes of interest was also performed.

Results: AS patients had significantly higher platelet count than controls (p = 0.0001), and the significantly increased platelet count in AS patients was confirmed in a meta-analysis of 14 studies involving 1,223 AS patients and 913 controls (mean difference = 39.61, 95% CI 27.89–51.34, p < 0.001). Besides, platelet count was significantly correlated with ESR (p < 0.001) and was moderately correlated with ASDAS-CRP score (p = 0.002). Moreover, anti-TNF-α therapy could reduce platelet count in AS patients at the first month and the effect was maintained through the treatment duration. In the prospective follow-up study of those 35 AS patients, those responders to anti-TNF-α therapy had significantly lower platelet count than nonresponders (p = 0.015). Logistic regression analysis suggested that lower platelet count was associated with higher possibility of achieving good response to anti-TNF-α therapy in AS patients (odds ratio = 2.26; 95% CI = 1.06–4.82; p = 0.035).

Conclusion: This study suggested that platelet count was associated with inflammation severity and treatment outcomes in AS patients, and elevated platelet count was a promising biomarker of poorer response to anti-TNF-α therapy. The findings above need to be validated in more future studies.

Lung megakaryocytes display distinct transcriptional and phenotypic properties

Megakaryocytes (MKs) are responsible for platelet biogenesis, which is believed to occur canonically in adult bone marrow (BM) and in the fetal liver during development. However, emerging evidence highlights the lung as a previously underappreciated residence for MKs that may contribute significantly to circulating platelet mass. Although a diversity of cells specific to the BM is known to promote the maturation and trafficking of MKs, little investigation into the impact of the lung niche on the development and function of MKs has been done. Here, we describe the application of single-cell RNA sequencing, coupled with histological, ploidy, and flow cytometric analyses, to profile primary MKs derived from syngeneic mouse lung and hematopoietic tissues. Transcriptional profiling demonstrated that lung MKs have a unique signature distinct from their hematopoietic counterparts, with lung MKs displaying enrichment for maturation markers, potentially indicating a propensity for more efficient platelet production. Reciprocally, fetal lung MKs also showed the robust expression of cytokines and growth factors that are known to promote lung development. Lastly, lung MKs possess an enrichment profile skewed toward roles in immunity and inflammation. These findings highlight the existence of a lung-specific MK phenotype and support the notion that the lung plays an independent role in the development and functional maturation of MKs. The immune phenotype displayed by lung MKs also introduces their potential role in microbial surveillance and antigen presentation.

Erythrocyte, Platelet, Serum Ferritin, and P-Selectin Pathophysiology Implicated in Severe Hypercoagulation and Vascular Complications in COVID-19

Progressive respiratory failure is seen as a major cause of death in severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2)-induced infection. Relatively little is known about the associated morphologic and molecular changes in the circulation of these patients. In particular, platelet and erythrocyte pathology might result in severe vascular issues, and the manifestations may include thrombotic complications. These thrombotic pathologies may be both extrapulmonary and intrapulmonary and may be central to respiratory failure. Previously, we reported the presence of amyloid microclots in the circulation of patients with coronavirus disease 2019 (COVID-19). Here, we investigate the presence of related circulating biomarkers, including C-reactive protein (CRP), serum ferritin, and P-selectin. These biomarkers are well-known to interact with, and cause pathology to, platelets and erythrocytes. We also study the structure of platelets and erythrocytes using fluorescence microscopy (using the markers PAC-1 and CD62PE) and scanning electron microscopy. Thromboelastography and viscometry were also used to study coagulation parameters and plasma viscosity. We conclude that structural pathologies found in platelets and erythrocytes, together with spontaneously formed amyloid microclots, may be central to vascular changes observed during COVID-19 progression, including thrombotic microangiopathy, diffuse intravascular coagulation, and large-vessel thrombosis, as well as ground-glass opacities in the lungs. Consequently, this clinical snapshot of COVID-19 strongly suggests that it is also a true vascular disease and considering it as such should form an essential part of a clinical treatment regime.

Platelet indices in patients with chronic inflammatory arthritis: a systematic review and meta-analysis

Correlation between platelet indices and chronic inflammatory arthritis (CIA) remains a moot point today. This meta-analysis aimed to evaluate whether platelet (PLT) count, mean platelet volume (MPV) and platelet distribution width (PDW) associated with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA). A systematic literature search was performed in PubMed, EMBASE, and Web of Science up to August 2019. Pooled standardized mean differences (SMD) and 95% confidence interval (CI) were calculated using a random-effect model. As a result, 34 studies were included, encompassing 17 on RA, 12 on AS, 3 on PsA and 2 on both RA and AS. In these studies, PLT count was significantly higher in RA (SMD = 0.55, 95% CI = 0.36-0.73, P < .001), AS (SMD = 0.53, 95% CI = 0.36-0.70, P < .001) and PsA patients (SMD = 1.29, 95% CI = 0.82-1.77, P < .001) than that in healthy subjects, while MPV and PDW presented nonsignificant differences in these intergroup comparisons (P > .05), and similar results were observed in subgroup analyses. The meta-regression analysis demonstrated that there were strong positive correlations between erythrocyte sedimentation rate and PLT count, and weak correlation trend between the disease activity score and PLT count in both RA and AS subjects without statistically significant difference. The sensitivity analysis indicated that these results were not unduly influenced by any single study. In conclusion, this meta-analysis demonstrated that PLT count was elevated in CIA patients and could be suitable for evaluating the disease activity, whereas MPV and PDW were independent of CIA.

Evaluation of anti rheumatic activity of Piper betle L. (Betelvine) extract using in silico, in vitro and in vivo approaches

Rheumatoid Arthritis is a chronic, inflammatory, and systemic autoimmune disease, it affects elders worldwide. Herbal medicines have been used for the treatment of various ailments from ancient times. Betelvine (Piper betle L.) leaves have long been used in Asian countries as a medicine to relieve pain and some metabolic diseases. The present study of methanolic extract of phytochemical analysis confirms the presence of alkaloids, tannins, terpenoids, saponins, steroids, total flavonoids and total phenols. GC-MS analysis of MeOH extract of Piper betle (PBME) revealed the presence of 40 bioactive compounds. In vitro antioxidant and anti-inflammatory assays showed greater inhibitory effect. The anti-arthritic effects of PBME at 250 and 500 mg/kg concentration showed recovery from joint damage in in vivo rat model. Among the 40 GC-MS derived bioactives, 4-Allyl-1,2-Diacetoxybenzene exhibited the higher interactions with minimized binding energy to the RA targets of MMP 1 (-6.4 kcal/mol), TGF-β (-6.9 kcal/mol), IL-1β (-5.9 kcal/mol). Further, the effect of PBME extract against RA molecular disease targets (IL-1β, MMP1 and TGF- β) were studied using Real-time PCR. These results substantiate that P. betle leaves could be a source of therapeutics for the treatment of rheumatoid arthritis.

Innate immune receptors in platelets and platelet-leukocyte interactions

Platelets are chief cells in hemostasis. Apart from their hemostatic roles, platelets are major inflammatory effector cells that can influence both innate and adaptive immune responses. Activated platelets have thromboinflammatory functions linking hemostatic and immune responses in several physiological and pathological conditions. Among many ways in which platelets exert these functions, platelet expression of pattern recognition receptors (PRRs), including TLR, Nod-like receptor, and C-type lectin receptor families, plays major roles in sensing and responding to pathogen-associated or damage-associated molecular patterns (PAMPs and DAMPs, respectively). In this review, an increasing body of evidence is compiled showing the participation of platelet innate immune receptors, including PRRs, in infectious diseases, sterile inflammation, and cancer. How platelet recognition of endogenous DAMPs participates in sterile inflammatory diseases and thrombosis is discussed. In addition, platelet recognition of both PAMPs and DAMPs initiates platelet-mediated inflammation and vascular thrombosis in infectious diseases, including viral, bacterial, and parasite infections. The study also focuses on the involvement of innate immune receptors in platelet activation during cancer, and their contribution to tumor microenvironment development and metastasis. Finally, how innate immune receptors participate in platelet communication with leukocytes, modulating leukocyte-mediated inflammation and immune functions, is highlighted. These cell communication processes, including platelet-induced release of neutrophil extracellular traps, platelet Ag presentation to T-cells and platelet modulation of monocyte cytokine secretion are discussed in the context of infectious and sterile diseases of major concern in human health, including cardiovascular diseases, dengue, HIV infection, sepsis, and cancer.