Joint Fluid Of Patients Research Articles

Inadequate anticoagulation and hyperuricemia cause knee pain after platelet-rich plasma injection: A retrospective study.

Platelet-rich plasma treatment delays the need for total knee replacement in patients with knee osteoarthritis. However, its use and preparation remain controversial. The aim of this study was to investigate the relationship between anticoagulant use in the preparation of platelet-rich plasma and post-treatment pain in patients with knee osteoarthritis. Additionally, we explored the efficacy of platelet-rich plasma over medium- and long-term follow-up periods and identified other factors that may affect treatment outcomes. In this retrospective study, 225 patients with knee osteoarthritis, who underwent knee platelet-rich plasma treatment from June 2021 to January 2022, were examined at three study centres. Patients were categorised, based on the type and amount of anticoagulant used during platelet-rich plasma preparation, into 4% sodium citrate (SC) 0.6mL, 4% SC 1mL, 4% SC 2mL, heparin 0.1mL, and heparin 0.2mL groups. We analysed the patients' basic information, pain after treatment, and inflammatory markers (i.e., interleukin 6, tumour necrosis factor-α, and hypersensitive C-reactive protein) in the joint fluid via enzyme-linked immunosorbent assay and joint fluid crystallisation. Additionally, we assessed the patients' Western Ontario and McMaster University scores and minimal clinically significant differences after treatment. Patients in the 4% SC 0.6mL and heparin 0.1mL groups experienced less pain after platelet-rich plasma treatment than did patients in the high-dose anticoagulant group. The joint fluid of patients with pain in these groups had lower levels of inflammatory markers. Patients treated with SC had slightly better medium- and long-term therapeutic outcomes than did patients treated with heparin. Patients with poorly controlled hyperuricemia also experienced pain after platelet-rich plasma treatment. The results suggest that platelet-rich plasma prepared using high-dose anticoagulants or administered to patients with poorly controlled hyperuricaemia may lead to moderate-to-severe knee pain and joint effusion after joint puncture therapy. Platelet-rich plasma had a therapeutic effect on knee osteoarthritis; however, its efficacy gradually decreased over time. SC anticoagulant is more suitable for platelet-rich plasma preparation than is heparin. Further studies are needed to understand the safety and the various factors influencing platelet-rich plasma therapy.

Copper metabolism in osteoarthritis and its relation to oxidative stress and ferroptosis in chondrocytes.

Ferroptosis, an iron-ion-dependent process of lipid peroxidation, damages the plasma membrane, leading to non-programmed cell death. Osteoarthritis (OA), a prevalent chronic degenerative joint disease among middle-aged and older adults, is characterized by chondrocyte damage or loss. Emerging evidence indicates that chondrocyte ferroptosis plays a role in OA development. However, most research has concentrated on ferroptosis regulation involving typical iron ions, potentially neglecting the significance of elevated copper ions in both serum and joint fluid of patients with OA. This review aims to fill this gap by systematically examining the interplay between copper metabolism, oxidative stress, ferroptosis, and copper-associated cell death in OA. It will provide a comprehensive overview of copper ions' role in regulating ferroptosis and their dual role in OA. This approach seeks to offer new insights for further research, prevention, and treatment of OA.

Gram staining of the preoperative joint aspiration for the diagnosis of infection after total knee arthroplasty

PurposeGram staining of joint fluid for the diagnosis of postoperative joint infection after total knee arthroplasty is considered to have limited efficacy because of the low sensitivity. However, the specificity of the gram staining is reported to be high in most reports. This study aimed to evaluate the sensitivity and specificity of the gram staining when used on the aspirated joint fluid in patients with suspected postoperative knee joint infection after total knee arthroplasty. MethodsWe retrospectively reviewed the reports of synovial fluid samples retrieved from suspected infected joints at eight hospitals between 2012 and 2019. A total of 179 samples of aspirated joint fluid from knee joints (80 culture-positive samples and 99 culture-negative samples) were evaluated in this study. ResultsOf the 80 gram stains performed on samples from infected patients, there were 60 true positives and 20 false negatives. In contrast, of the 99 stains performed on samples from aseptic knees, there were 99 true negatives and no false positives. The sensitivity and specificity for detecting periprosthetic knee infections were 75.0% and 100.0%, respectively. Further, we divided infected samples into the early aspiration group (within 14 days) and the late aspiration group (15 days or more) based on the duration between the onset of symptoms and aspiration. The sensitivity of the gram staining was 84.2% and 41.2% in the first and second groups, respectively. ConclusionsIn this study, gram staining of preoperatively aspirated joint fluid for the infected periprosthetic knee joint with short-lived symptoms showed high sensitivity.

Single-cell RNA sequencing of immune cells in patients with acute gout

Cell subpopulations in the blood and joint fluid of patients with gout are poorly understood. Single-cell RNA sequencing and bioinformatic tools were used to identify cell subsets and their gene signatures in blood and synovial fluid (SF) cells, determine their relationships, characterize the diversity, and evaluate interactions among specific cell types. We identified 34 subpopulations (5 types of B cells, 16 types of T and natural killer cells, 9 types of monocytes, and 4 other cell types) in the blood of five healthy subjects and seven patients with acute gouty, and the SF of three patients with acute gout. We found that naïve CD4 T cells and classical monocytes cell populations were enriched in patients with gout, whereas plasmacytoid dendritic cells and intermediate monocytes were more abundant in healthy subjects. SF was enriched in Th1/Th17 cells, effector memory CD8 T cells, mucosal-associated invariant T cells, and macrophages. Subclusters of these cell subpopulations showed different compositions between healthy subjects and those with acute gout, according to blood and SF samples. At the cellular level, the inflammation score of a subpopulation or subcluster was highest in SF, following by the blood of acute gout patients and healthy person, whereas energy score showed the opposite trend. We also detected specific cell–cell interactions for interleukin-1, tumor necrosis factor-α, and transforming growth factor-β1 expression in the cells of patients with acute gout. Our study reveals cellular and molecular insights on inflammatory responses to hyperuricemia or uric crystal and may provide therapeutic guidance to improve treatments for gout.

The Effects of Ozone Therapy on the Expression of IL-8, IL-10, CXCL9 and CXCL11 in Joint Fluid in Patients with Knee Osteoarthritis

Knee joint is one of the common sites of osteoarthritis (OA) with manifestation of localized joint swelling, pain and deformity, often seriously affecting daily work and life. It was found that the activation of Janus kinase / signal transducer and activator of transcription 3 (JAK / STAT3) signal pathway can lead to osteoarthritis. JAK-STAT signal transduction pathway is closely related to painful diabetic peripheral neuropathy and participates in neuropathic pain. Ozone therapy is often used for alleviating pain in neck, shoulder, waist and leg due to its oxidative, anti-inflammatory and analgesic effects. In recent years, ozone therapy is promising in treating knee osteoarthritis, which can significantly reduce the pain and swelling of the joints. The mechanism of ozone for knee osteoarthritis remains unclear and might associated with inhibition of inflammatory factors and matrix metalloproteinase activity, and intervention of free radical metabolism. In this study, the efficacy of ozone in the treatment of OA and its effect on inflammatory factors were evaluated by knee joint cavity ozone injection and detecting the expression of inflammatory factors IL-8, IL-10, CXCL9 and CXCL11 in joint fluid.

Screening of Fv Antibodies with Specific Binding Activities to Monosodium Urate and Calcium Pyrophosphate Dihydrate Crystals for the Diagnosis of Gout and Pseudogout.

To date, medical diagnosis of gout and pseudogout has been performed by observing the crystals in the joint fluid of patients under a polarized microscope. Conventional diagnostic methods using a polarized microscope have disadvantages, such as time-consuming analysis, a high false negative rate, and difficulty in distinguishing gout with monosodium urate (MSU) crystals and pseudogout with calcium pyrophosphate dihydrate (CPPD) crystals in synovial fluids. In this study, a chromogenic assay for the diagnosis of gout and pseudogout, without the requirement of a polarized microscope and trained experts, was proposed using Fv antibodies with specific binding activities to MSU and CPPD crystals. The IgG VH chain Fv library with randomized complementarity-determining region 3 (CDR3) region was expressed on the outer membrane of Escherichia coli using autodisplay technology. The target Fv antibodies with binding activity to MSU and CPPD crystals were screened from the autodisplayed Fv library on the E. coli outer membrane, and five clones were selected. On the basis of the binding properties of the screened Fv antibodies, peptides with the selected clone of amino acid sequences of the CDR3 region (15 residues) were chemically synthesized. The binding properties of the synthetic peptides with amino acid sequences of CDR3 regions from the selected clones were analyzed using fluorescence imaging and flow cytometry, and the affinity constants (Kd) of each peptide for binding to MSU and CPPD crystals were calculated by fitting based on the isotherm model. A chromogenic assay configuration for gout and pseudogout was developed using synthetic peptides. In this chromogenic assay, synthetic peptides labeled with biotin and streptavidin-horseradish peroxidase (HRP) complex were used, and crystal detection was possible using a chromogenic reaction between HRP and a chromogenic substrate (TMB). Finally, gout and pseudogout were diagnosed by detecting MSU and CPPD crystals in the synovial fluid in the concentration range of 0-300 μg/mL.

Expression changes and clinical significance of TLR-4 and IL-1β in serum and knee joint fluid of patients with knee osteoarthritis

Objective: To investigate the expression changes and clinical significance of Toll-like receptor-4 (TLR-4) and interleukin-1β (IL-1β) in the serum and knee joint fluid in patients with knee osteoarthritis (KOA).Methods: From June 2017 to December 2018, 220 cases of patients with KOA who were admitted in Department of Orthopedics of the Third Affiliated Hospital of Inner Mongolia Medical University (“our hospital” for short) were selected as the observation group. According to the severity of KOA, they were divided into the mild subgroup (n = 98), the moderate subgroup (n = 80) and the severe subgroup (n = 42). In addition, 60 cases of volunteers who received the physical examination in Health Medical Center of our hospital were selected as the control group. The levels of TLR-4 and IL-1β in the serum and knee joint fluid were detected by enzyme-linked immunosorbent assay, in order to analyze the correlation of TLR-4 and IL-1β levels with the severity of KOA.Results: The levels of TLR-4 and IL-1β in the serum and knee joint fluid of the observation group were significantly higher than those of the control group, and the differences were statistically significant (all p < .05). The levels of TLR-4 and IL-1β in the serum and knee joint fluid of the severe subgroup were significantly higher than those of the mild subgroup and the moderate subgroup, and the levels of TLR-4 and IL-1β in the serum and knee joint fluid of the moderate subgroup were higher than those of the mild group. The differences were statistically significant (all p < .05). The levels of TLR-4 and IL-1β in the serum and knee joint fluid were positively correlated to the severity of KOA (r = .706, .729, .741, .715, all p < .05); in the serum, the level of TLR-4 was positively correlated to the level of IL-1 (r = .720, p < .05); in the joint fluid, the level of TLR-4 was positively correlated to the level of IL-1 (r = .736, p < .05).Conclusions: The levels of TLR-4 and IL-1β in the serum and knee joint fluid of KOA patients are abnormally increased, which is closely related with the severity of KOA. It can be used for clinical prediction, diagnosis and treatment of KOA.

Content of distinct metals in periprosthetic tissues and pseudosynovial joint fluid in patients with total joint arthroplasty.

This prospective study examined the content of metals released from total joint arthroplasty into joint fluid, whole blood and periprosthetic tissues. We determined the levels of Ti, V, Nb, Co, Cr, and Mo, using inductively coupled plasma mass spectrometry, in samples from patients who underwent reoperation of total hip or knee arthroplasty. All of the patients (n = 117) included in the study had either metal on polyethylene or ceramic on polyethylene-bearing pairs. First, our results conclusively showed that the majority of released metals were deposited in periprosthetic tissues. In this context, the bloodstream turned out to be an ineffective biomarker of the effects occurring in local tissues. Second, there was a clear time-dependent nature of metallic accumulation. Based on our extensive dataset, we found significantly elevated levels of the released metals in joint fluid and periprosthetic tissues originating from loosened implants compared to stable ones, as well as recognizable differences between the groups with stable implants and aseptic loosening. Finally, it was proved that the concentrations of metals decreased dependent on the distance of the tissue from the implant. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 454-462, 2019.

THU0549 Decoy Receptor 3 Regulates the Expression of Tryptophan Hydroxylase TPH1 in Rheumatoid Synovial Fibroblasts

BackgroundTryptophan hydroxylase (TPH) which catalyzes the hydroxylation of L-tryptophan is the rate-limiting enzyme involved in the synthesis of serotonin. TPH has two isoforms; TPH1 expresses in peripheral and central nerve...

FRI0006 Decoy receptor 3 regulates the expression of tryptophan hydroxylase tph1 in rheumatoid synovial fibroblasts

BackgroundTryptophan hydroxylase (TPH) which catalyzes the hydroxylation of L-tryptophan is the rate-limiting enzyme involved in the synthesis of serotonin. TPH has two isoforms; TPH1 expresses in peripheral and central nerve...

Bruton's Tyrosine Kinase mediates platelet receptor-induced generation of microparticles: A potential mechanism for amplification of inflammatory responses in rheumatoid arthritis synovial joints

Platelet microparticles (pMPs) are small membrane-coated vesicles that are released from the plasma membrane upon platelet activation. In the joint fluid of patients with rheumatoid arthritis, pMP can interact with and activate fibroblast-like synoviocytes (FLS), which are important effector cells that mediate both immune activation and joint destruction. The signaling process by which engagement of glycoprotein VI (GPVI), a surface glycoprotein receptor for collagen which is expressed on platelets, triggers pMP generation is poorly understood, but has been suggested to involve Spleen Tyrosine Kinase (SYK), best known as an upstream activator of Bruton's Tyrosine Kinase (BTK) in B cells. In this study, we showed that activation of human platelets triggered by convulxin or collagen, specific ligands for GPVI receptor, or alternatively by antibody-mediated cross-linking of another platelet receptor, C type lectin-like receptor 2 (CLEC2), resulted in phosphorylation of BTK and downstream effector, phospholipase Cγ2 (PLCγ2). A potent and selective BTK inhibitor, RN486, inhibited GPVI- or CLEC2-mediated PLCγ2 phosphorylation and pMP production in a dose-dependent manner. BTK is also an essential effector of B cell receptor (BCR)-induced B cell signaling. Consistent with the biology, the IC50s of BTK inhibitors with varying potencies in a BCR-dependent B cell activation marker assay correlated with those in the GPVI-mediated PLCγ2 phosphorylation. In a co-culture system consisting of human primary synovial FLS and activated human platelets, convulxin stimulation resulted in elevated production of pro-inflammatory cytokines, IL-6 and IL-8, an effect which was dose-dependently blocked by RN486. The effects are specific as RN486 abrogated platelet aggregation induced by GPVI ligands but not by other platelet surface receptor agonists. Taken together, our data further support the potential therapeutic utility of BTK inhibitors in RA therapy, by inhibiting GPVI-mediated platelet activation and thus subsequent amplification of inflammation driven by pMP-induced FLS cytokines production.

Association of a Toll‐like receptor 1 polymorphism with heightened Th1 inflammatory responses and antibiotic‐refractory Lyme arthritis

Single-nucleotide polymorphisms (SNPs) that alter immune function, inflammatory responses, and disease susceptibility have been identified in several genes encoding Toll-like receptors (TLRs). The TLR SNPs with the best evidence of an effect on immune function are those in TLR1 (1805GG), TLR2 (2258GA), and TLR5 (1174CT). This study was undertaken to assess the frequency and functional outcomes of these polymorphisms in patients with Lyme disease. SNP frequencies and functional outcomes were assessed in 248 patients with Lyme disease. Cytokine and chemokine levels were determined using multiplex assays in the serum of patients with erythema migrans (EM), joint fluid of patients with Lyme arthritis, and supernatants of Borrelia burgdorferi-stimulated peripheral blood mononuclear cells (PBMCs) from patients with Lyme arthritis. The frequency of the TLR1-1805GG polymorphism was greater in patients with antibiotic-refractory arthritis compared with patients with EM or those with antibiotic-responsive arthritis. Early in the illness, patients with EM carrying 1805GG, primarily those infected with B burgdorferi 16S-23S ribosomal spacer RNA intergenic type 1 (RST1) strains, had higher serum levels of interferon-γ (IFNγ), CXCL9, and CXCL10 and had more severe infection than EM patients carrying the 1805TG/TT polymorphism. These inflammatory responses were amplified in patients with Lyme arthritis, and the highest responses were observed in patients with 1805GG in the antibiotic-refractory group who had been infected with RST1 strains. When PBMCs from patients with Lyme arthritis were stimulated with a B burgdorferi RST1 strain, the 1805GG group had a significantly larger fold increase in the levels of IFNγ, CCL2, CXCL9, and CXCL10 compared to the 1805TG/TT group. In contrast, the TLR2 and TLR5 polymorphisms did not vary in frequency or function among the groups. The TLR1-1805GG polymorphism in B burgdorferi RST1-infected patients was associated with stronger Th1-like inflammatory responses, an environment that may set the stage for antibiotic-refractory arthritis.

Effects of Ankaferd hemostat on the synovial fluid of patients with osteoarthritis

Ankaferd Blood Stopper (ABS) is a novel topical hemostatic agent with antiinfective, wound healing, and antineoplastic properties. In this study, we evaluated the macroscopic and biochemical effects of ABS in the joint fluid of patients with osteoarthritis. Materials and methods: Synovial fluid samples were obtained from 10 patients with osteoarthritis (5 women, 5 men; mean age 57.6 ± 11.2 years). From each patient, 4 mL of synovial fluid was drawn and put into 2 different serum separator tubes, and 1 mL of ABS was added to the first sample and 1 mL of 0.9% saline was added to the second sample. Macroscopic evaluation and biochemical analyses for glucose, protein, albumin, and lactate dehydrogenase (LDH) were performed. Results: The addition of ABS into synovial fluid revealed a rapid and apparent reaction resulting in dense coagulation within seconds in all of the samples. No reaction was observed in the saline group. Total protein, albumin, globulin, and LDH levels significantly decreased in the ABS group, while glucose levels remained unchanged. Conclusion: ABS can work in the synovial fluid, causes rapid frozen gel-like solidification, and decreases the protein component of the synovial fluid. This observation, together with hemostatic and wound healing properties of ABS, might provide an important starting point for testing its actions on distinct hemorrhagic, neoplastic, or inflammatory joint disorders.

Expression levels and association of gelatinases MMP-2 and MMP-9 and collagenases MMP-1 and MMP-13 with VEGF in synovial fluid of patients with arthritis

This study was performed to provide evidence, albeit indirectly, as to which matrix metalloproteinases (MMPs), among the gelatinases MMP-2 and MMP-9 and the collagenases MMP-1 and MMP-13, play a more proactive role in the angiogenic process in arthritic joint. Joint fluid was collected from 33 patients with rhuematoid arthritis (RA) and osteoarthritis (OA), and protein (MMPs and vascular endothelial growth factor (VEGF)) levels were measured by ELISA, and the association of MMPs with VEGF was evaluated in joint fluid of patients with RA or OA. The levels of collagenases (total MMP-1 and total MMP-13) and gelatinases (total MMP-2 and total MMP-9) in RA joint fluid were significantly higher than those in OA fluid. Total MMP-9 levels were significantly associated with VEGF levels in RA fluids, but not in OA fluid, while total MMP-13 levels were strongly associated with VEGF levels in both RA and OA fluid. However, total MMP-2 and total MMP-1 levels were not associated with VEGF levels in either RA or OA joint fluid. Our results indirectly suggest that in RA and OA, MMP-9 and MMP-13 may play a more important role in angiogenesis than MMP-2 and MMP-1.

Decoy receptor 3 is highly expressed in patients with rheumatoid arthritis

Decoy receptor 3 (DcR3), a member of the tumor necrosis factor receptor (TNFR) superfamily, is a soluble receptor that binds to the TNF family including Fas ligand (Fas-L), LIGHT, and TL1A. DcR3 is mostly expressed in tumor cells and competitively inhibits the TNF family. We previously demonstrated that overexpressed DcR3 in rheumatoid synovial cells protects the cells from apoptosis in vitro. The objective of the study was to investigate DcR3 expression in serum and joint fluids of patients with rheumatoid arthritis (RA) and osteoarthritis (OA), and to analyze the correlations with disease activities and TNFα expression. Sera and joint fluids were collected from patients with RA and OA. Expression of DcR3 in sera and joint fluids was measured by ELISA. The concentration of DcR3 in sera and joint fluids of RA patients was significantly higher than that in sera and joint fluids of OA patients. A correlation between serum DcR3 concentration and disease activity was not observed, but the serum DcR3 concentration was strongly correlated with the TNFα concentration. DcR3 was highly expressed in serum and joint fluids of RA patients.

Decoy receptor 3 is highly expressed in patients with rheumatoid arthritis

Decoy receptor 3 (DcR3), a member of the tumor necrosis factor receptor (TNFR) superfamily, is a soluble receptor that binds to the TNF family including Fas ligand (Fas-L), LIGHT, and TL1A. DcR3 is mostly expressed in tumor cells and competitively inhibits the TNF family. We previously demonstrated that overexpressed DcR3 in rheumatoid synovial cells protects the cells from apoptosis in vitro. The objective of the study was to investigate DcR3 expression in serum and joint fluids of patients with rheumatoid arthritis (RA) and osteoarthritis (OA), and to analyze the correlations with disease activities and TNFalpha expression. Sera and joint fluids were collected from patients with RA and OA. Expression of DcR3 in sera and joint fluids was measured by ELISA. The concentration of DcR3 in sera and joint fluids of RA patients was significantly higher than that in sera and joint fluids of OA patients. A correlation between serum DcR3 concentration and disease activity was not observed, but the serum DcR3 concentration was strongly correlated with the TNFalpha concentration. DcR3 was highly expressed in serum and joint fluids of RA patients.

Analysis of Borrelia burgdorferi genotypes in patients with lyme arthritis: High frequency of ribosomal RNA intergenic spacer type 1 strains in antibiotic‐refractory arthritis

Most of the Borrelia burgdorferi genotypes have been isolated from erythema migrans (EM) skin lesions in patients with Lyme disease. OspC type K strains, which are 16S-23S ribosomal RNA intergenic spacer type 2 (RST2) strains, are most commonly recovered, but a higher percentage of OspC type A strains (RST1), the next most commonly recovered type, is detectable in blood. The goal of this study was to determine the B burgdorferi genotypes in the joints of patients with Lyme arthritis. Joint fluid samples from 124 patients seen over a 30-year period were analyzed for OspC types by semi-nested polymerase chain reaction (PCR) and sequencing, and for RSTs by nested PCR and restriction fragment length polymorphism analysis. These results were correlated with clinical outcome. OspC and RST genotypes were identified in 49 of the 124 joint fluid samples (40%). In these 49 samples, OspC type K strains (RST2) were identified in 21 samples (43%), OspC type A strains (RST1) were identified in 11 samples (22%), and 8 other OspC types and all 3 RSTs were identified among the remaining 17 samples (35%). However, among the 17 patients who had been treated with antibiotics according to current guidelines, all 7 patients who were infected with RST1 strains had antibiotic-refractory arthritis, compared with 4 of 6 patients infected with RST2 strains and only 1 of 4 infected with RST3 strains (P = 0.03). Most of the B burgdorferi genotypes, particularly OspC type K (RST2), were identified in the joint fluid of patients with Lyme arthritis, and the genotype frequencies found in joints reflected those in EM skin lesions. However, RST1 strains were most frequent in patients with antibiotic-refractory arthritis. Our results help to further the understanding of the differential pathogenicity of strains of B burgdorferi.

Detection of calcium phosphate crystals in the joint fluid of patients with osteoarthritis - analytical approaches and challenges.

Clinically, osteoarthritis (OA) is characterised by joint pain, stiffness after immobility, limitation of movement and, in many cases, the presence of basic calcium phosphate (BCP) crystals in the joint fluid. The detection of BCP crystals in the synovial fluid of patients with OA is fraught with challenges due to the submicroscopic size of BCP, the complex nature of the matrix in which they are found and the fact that other crystals can co-exist with them in cases of mixed pathology. Routine analysis of joint crystals still relies almost exclusively on the use of optical microscopy, which has limited applicability for BCP crystal identification due to limited resolution and the inherent subjectivity of the technique. The purpose of this Critical Review is to present an overview of some of the main analytical tools employed in the detection of BCP to date and the potential of emerging technologies such as atomic force microscopy (AFM) and Raman microspectroscopy for this purpose.

Rapid leukocyte activation following intraarticular bleeding

The study aims at elucidating the leukocyte activation in the joint fluid of patients with acute traumatic hemarthrosis. Paired samples of peripheral blood and articular effusions after an acute hemorrhage were obtained from 22 patients. Leukocytes were separated and stained with fluorescein isothiocyanate (FITC)-conjugated mouse anti-human CD11a, CD18, and CD97 monoclonal antibodies for flow cytometry. The reactive oxygen species (ROS) production of leukocytes in corresponding samples of peripheral blood and joint effusion was measured via luminol dependent whole blood chemiluminometry. Significant decrease of CD11a density on monocytes, but markedly enhanced expression of CD97 and CD18 on polymorphonuclear neutrophil granulocytes (PMN), and significantly increased proportion of CD97 positive lymphocytes were found in the joint fluids as compared to the corresponding peripheral blood samples. Moreover, significantly decreased lag time and elevated rate of ROS production were revealed by chemiluminometry in case of joint derived leukocytes. Our results provide good evidence for intraarticular leukocyte activation during acute hemarthrosis. Since the activation precedes synovial inflammation, it is suggested that the leukocytes play an important role as an initiator in the pathogenesis of acute hemarthrosis.

The activity of exoglycosidases in the synovial membrane and knee fluid of patients with rheumatoid arthritis and juvenile idiopathic arthritis

Objective: To determine the activities of the five exoglycosidases that catabolize glycoconjugates (proteoglycans, glycoproteins, and glycolipids) in the synovial membrane and knee joint fluid of patients with rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA).Methods: The following exoglycosidases were analysed with the p‐nitrophenyl derivatives of appropriate sugars as substrates: hexosaminidase (HEX) and its isoenzymes A and B, β‐glucuronidase, β‐galactosidase, α‐mannosidase, and α‐fucosidase.Results: Our results show that the activity of all exoglycosidases tested in the synovial membrane of patients with RA and JIA was significantly higher than in synovial fluid. We demonstrated that only the enzymatic activity of HEX was significantly higher in the tissue of patients with inflammatory diseases in comparison to the activity in the control group.Conclusion: These data support the concept that the synovial cells of patients with RA and JIA are the main source of exoglycosidases, which catabolize glycoconjugates of cartilage.