Synovial Analysis Research Articles

Effects of intra-articular injection of an acellular equine liquid amniotic allograft in healthy equine joints.

Evaluate effects of acellular equine liquid amnion allograft (ELAA) injected into healthy equine joints. Randomized, blinded, controlled experiment. Eight healthy adult horses. One intercarpal joint (ICJ) of each horse was randomly assigned to be injected with 1.5ml of ELAA (treatment) while the contralateral ICJ was injected with 1.5ml of 0.9% NaCl (control). Subjective lameness evaluation, force plate analysis, and synovial fluid analysis, including interleukin-1 receptor antagonist (IL-1ra) analysis, were performed before (day 0) and at days 1, 3, 5, and 10. Synovial fluid analysis was also performed on days 20 and 30. No difference in subjective lameness (P=.75) and no decrease in peak vertical force or vertical impulse were seen in any limb on any day. Total nucleated cell count (TNCC) was increased in treatment joints on days 1 (P=.0007; T: 6039 cells/μl, C: 240 cells/μl) and 3 (P < .0001; T: 1119 cells/μl, C: 240 cells/μl). Log-10 transformed values for IL-1ra were higher in treated joints on days 1 (P=.0005; T: 3553.7pg/ml, C: 1890.1pg/ml) and 3 (P=.01; T: 2283.2pg/ml, C: 1250.7pg/ml). Injection of ELAA into the ICJ caused an increase in synovial fluid TNCC in comparison with saline control but no lameness was observed. There was increased IL-1ra on days 1 and 3 after ELAA injection. Intra-articular injection of ELAA into healthy equine joints results in no significant safety concerns. The observed increase in IL-1ra may provide beneficial effects in inflamed joints.

Ultrasound-guided temporomandibular joint aspiration: technique and results in six cases of suspected septic arthritis.

The aim of this study is to describe an ultrasound (US)-guided temporomandibular joint (TMJ) arthrocentesis technique and determine its microbial yield in the workup of suspected TMJ septic arthritis. A retrospective review of US-guided TMJ arthrocentesis for the work-up of septic arthritis performed by radiologists at two institutions was performed. Patient demographics, risk factors for septic arthritis, blood culture results, and pre-procedural imaging findings were recorded. Procedural data included fluid aspirate quantity, needle gauge and length, and any immediate complications. Post-procedural data included synovial fluid analysis including culture, final diagnosis of TMJ disease, type of treatment, and any delayed complications from arthrocentesis. A total of six US-guided TMJ arthrocenteses were identified, all of which yielded at least 1mL of synovial fluid. Five patients were subsequently diagnosed with septic arthritis, and one patient was diagnosed with GVHD arthritis. The synovial fluid in four out of five patients with a final diagnosis of septic arthritis produced positive cultures. There were no immediate or delayed complications from arthrocentesis. Basic US-guided procedural skills are transferrable to TMJ arthrocentesis, which is a low-risk procedure with a high microbial yield in our small series of patients with septic arthritis.

Autologous Adipose-Derived Tissue Stromal Vascular Fraction (AD-tSVF) for Knee Osteoarthritis.

Adipose tissue contains adult mesenchymal stem cells that may modulate the metabolism when applied to other tissues. Stromal vascular fraction (SVF) can be isolated from adipose tissue mechanically and/or enzymatically. SVF was recently used to decrease the pain and improve the function of knee osteoarthritis (OA) patients. Primary and/or secondary OA causes inflammation and degeneration in joints, and regenerative approaches that may modify the natural course of the disease are limited. SVF may modulate inflammation and initiate regeneration in joint tissues by initiating a paracrine effect. Chemokines released from SVF may slow down degeneration and stimulate regeneration in joints. In this review, we overviewed articular joint cartilage structures and functions, OA, and macro-, micro-, and nano-fat isolation techniques. Mechanic and enzymatic SVF processing techniques were summarized. Clinical outcomes of adipose tissue derived tissue SVF (AD-tSVF) were evaluated. Medical devices that can mechanically isolate AD-tSVF were listed, and publications referring to such devices were summarized. Recent review manuscripts were also systematically evaluated and included. Transferring adipose tissues and cells has its roots in plastic, reconstructive, and aesthetic surgery. Micro- and nano-fat is also transferred to other organs and tissues to stimulate regeneration as it contains regenerative cells. Minimal manipulation of the adipose tissue is recently preferred to isolate the regenerative cells without disrupting them from their natural environment. The number of patients in the follow-up studies are recently increasing. The duration of follow up is also increasing with favorable outcomes from the short- to mid-term. There are however variations for mean age and the severity of knee OA patients between studies. Positive outcomes are related to the higher number of cells in the AD-tSVF. Repetition of injections and concomitant treatments such as combining the AD-tSVF with platelet rich plasma or hyaluronan are not solidified. Good results were obtained when combined with arthroscopic debridement and micro- or nano-fracture techniques for small-sized cartilage defects. The optimum pressure applied to the tissues and cells during filtration and purification of the AD-tSVF is not specified yet. Quantitative monitoring of articular joint cartilage regeneration by ultrasound, MR, and synovial fluid analysis as well as with second-look arthroscopy could improve our current knowledge on AD-tSVF treatment in knee OA. AD-tSVF isolation techniques and technologies have the potential to improve knee OA treatment. The duration of centrifugation, filtration, washing, and purification should however be standardized. Using gravity-only for isolation and filtration could be a reasonable approach to avoid possible complications of other methodologies.

Immunometabolic Analysis of Synovial Fluid from Juvenile Idiopathic Arthritis Patients.

Juvenile idiopathic arthritis (JIA) is an inflammatory rheumatic disorder. Polymorphonuclear neutrophils (PMNs) are present in JIA synovial fluid (SF), but with variable frequency. SF PMNs in JIA were previously shown to display high exocytic but low phagocytic and immunoregulatory activities. To further assess whether the degree of SF neutrophilia associated with altered immune responses in JIA, we collected SF and blood from 16 adolescent JIA patients. SF and blood leukocytes were analyzed by flow cytometry. SF and plasma were used for immune mediator quantification and metabolomics. Healthy donor blood T cells were cultured in SF to evaluate its immunoregulatory activities. PMN and T cell frequencies were bimodal in JIA SF, delineating PMN high/T cell low (PMNHigh) and PMN low/T cell high (PMNLow) samples. Proinflammatory mediators were increased in SF compared with plasma across patients, and pro- and anti-inflammatory mediators were further elevated in PMNHigh SF. Compared to blood, SF PMNs showed increased exocytosis and programmed death-1/programmed death ligand-1 expression, and SF PMNs and monocytes/macrophages had increased surface-bound arginase-1. SPADE analysis revealed SF monocyte/macrophage subpopulations coexpressing programmed death-1 and programmed death ligand-1, with higher expression in PMNHigh SF. Healthy donor T cells showed reduced coreceptor expression when stimulated in PMNHigh versus PMNLow SF. However, amino acid metabolites related to the arginase-1 and IDO-1 pathways did not differ between the two groups. Hence, PMN predominance in the SF of a subset of JIA patients is associated with elevated immune mediator concentration and may alter SF monocyte/macrophage phenotype and T cell activation, without altering immunoregulatory amino acids.

Cytologie des liquides articulaires

AbstractCytological analysis of synovial fluid is an important step in orienting the diagnosis of arthropathy with effusion. The nucleated elements count allows orientation towards a mechanical or inflammatory origin. The presence of crystals confirms microcrystalline arthritis. In order to obtain a reliable result, the pre- analytical and analytical steps must be respected. Review key steps of cytological analysis and diagnostic orientation according to the result.

Synovial Fluid Analysis to Identify Osteoarthritis.

Synovial fluid (SF) analysis is important in diagnosing osteoarthritis (OA). Macroscopic and microscopic features, including total and differential white blood cell (WBC) count, help define the non-inflammatory nature of SF, which is a hallmark of OA. In patients with OA, WBC in SF samples usually does not exceed 2000 cells per microliter, and the percentage of inflammatory cells, such as neutrophils, is very low or absent. Calcium crystals are frequent in SF collected from OA patients. Although their role in the pathogenesis of OA remains unclear, they have been associated with a mild inflammatory process and a more severe disease progression. Recently, calcium crystals have been described in both the early and late stages of OA, indicating that they may play a vital role in diagnosing different clinical subsets of OA and pharmacological treatment. The overall goal of SF analysis in OA is two-fold: to ascertain the non-inflammatory degree of SF and to highlight the presence of calcium crystals.

Neuroartropatía de Charcot: Diagnóstico diferencial de monoartritis de rodilla en pacientes con diabetes mellitus 2

A 46-year-old man with long-standing, poorly controlled diabetes is hospitalized for right knee monoarthritis after trauma. His clinical evaluation found joint deformity, synovitis in the right knee and absence of multiple toes due to a history of amputation. With the radiological evaluation that showed bone destruction and the synovial fluid analysis that ruled out infectious causes and microcrystal arthritis, the diagnosis of Charcot neuroarthropathy of the knee was made. Conservative management was indicated with the use of a felt insole for unloading and the use of a walker, the case being followed up to define behavior according to evolution. Despite being rare, it is important to consider Charcot neuroarthropathy in all diabetic patients with monoarthritis of the knee, in order to make an early diagnosis and avoid important complications and sequelae, always ruling out infectious causes and arthritis due to microcrystals.

Acute joint swelling in psoriatic arthritis: Flare or "psout"-A 10-year-monocentric study on synovial fluid.

Psoriatic arthritis (PsA) is a multifaceted inflammatory disease associated with psoriasis that can affect peripheral joints, entheses, and the axial skeleton with a variable clinical course. Acute episodes of joint swelling in PsA patients can have different causes and require specific treatments. We aimed to describe the acute joint swelling in PsA patients via synovial fluid (SF) analyses, assessing in particular the presence of pathogenic crystals, to determine whether it is a flare or an acute episode of gout ("psout") during the course of the disease. This retrospective study was based on the results of SF analysis of samples collected from unselected adult PsA patients referred to our clinic for acute joint swelling. Demographic characteristics, disease involvement, laboratory findings on SF, and treatment options were recorded and reviewed. Among 5,478 SF samples analyzed in a 10-year time span, 213 complete SF records from PsA patients were evaluated. Overall, after adjustment for the degree of synovial inflammation, significant differences were observed in term of sex (p = 0.0017) and ongoing therapy (p = 0.0246). Non-inflammatory SFs, indeed, were mainly described for female PsA patients under therapy. Regarding serum uric acid levels, there were 19/213 (8.9%) PsA with hyperuricemia (HU), who were older, mostly male, patients with mild articular involvement and rare pathogenic crystals in their SF. Although it is known that the risk of gout is higher among patients with PsA ("psout"), monosodium urate crystals were reported only in 5/213 SFs (2.4%) of our cohort and in 2/19 SFs (10.5%) of HU PsA patients. Moreover, hyperuricemia seems not to modify the SF features in PsA patients. This study results seem to suggest that the convergence of gout and PsA, involving the role of urate crystals, is a more intricate relationship, which needs further insights to be unraveled.

Cell-free Deoxyribonucleic Acid: A Potential Biomarker of Chronic Periprosthetic Knee Joint Infection

BackgroundThe correct diagnosis of a chronic periprosthetic joint infection (PJI) is a major challenge in clinical practice, with the “gold standard” for diagnosis yet to be established. Synovial fluid analysis has been proven to be a useful tool for that purpose. Cell-free DNA (cf-DNA) levels have been shown to be increased in several conditions such as cancer, trauma, and sepsis. Therefore, this study was designed to evaluate the potential of synovial fluid cf-DNA quantification for the diagnosis of chronic periprosthetic infections following total knee arthroplasty. MethodsA prospective study with patients undergoing total knee arthroplasty revision surgery for any indication was performed. PJI diagnosis was defined according to the Second International Consensus Meeting on Musculoskeletal Infection (2018) criteria. The study cohort consisted of 26 patients classified as infected and 40 as noninfected. Synovial fluid cf-DNA direct quantification by fluorescent staining was made. Sensitivity, specificity, and receiver operating characteristic curve were calculated. ResultsThe cf-DNA levels were significantly higher in patients who had PJIs (122.5 ± 57.2 versus 4.6 ± 2.8 ng/μL, P < .0001). With a cutoff of 15 ng/μL, the area under the receiver operating characteristic, sensitivity, and specificity of cf-DNA were 0.978, 96.2%, and 100%, respectively. ConclusionThe present study has shown that cf-DNA is increased in synovial fluid of patients who have chronic PJIs. It is a promising biomarker for knee PJI diagnosis and further studies are needed to confirm its utility.

Disease-specific expansion of CD29+IL-17RA+ T effector cells possessing multiple signalling pathways in spondyloarthritis.

T cells adhere to enthesis fibrocartilage via integrins and intrinsically require IL-17RA-mediated signals to maintain their effector function. We analysed CD29+IL-17RA+ T cells in inflamed lesions and peripheral blood in patients with SpA and investigated their association with disease activity and therapeutic response. Transcriptome analysis of synovial fluid T cells from PsA was performed using publicly available bulk cell RNA sequencing data. Blood samples were obtained from healthy controls (n = 37), RA (n = 12), IgG4-related disease (IgG4-RD; n = 12), large vessel vasculitis (LVV; n = 12) and SpA (n = 28) and were analysed by flow cytometry. T cells in the inflamed joints of PsA showed CD29 and IL-17RA expression. CD29+IL-17RA+ T cells showed enriched CXCR3+CD45RA+ effector cells and activation of spleen tyrosine kinase (Syk), nuclear factor κB (NF-κB) and Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathways. The proportion of peripheral blood CD29+IL-17RA+ T cells was significantly increased in patients with SpA compared with patients with RA, IgG4-RD or LVV and in healthy controls. Based on the ASDAS-CRP scores, the proportion of CD29+IL-17RA+ T cells was positively correlated with disease activity in treatment-naïve patients with active SpA. Anti-IL-17 but not anti-TNF monoclonal antibodies reduced CD29+IL-17RA+ T cells. CD29+IL-17RA+ T effector cells with enhanced Syk, NF-κB and JAK-STAT pathways were specifically increased in SpA and were correlated with disease activity, implicating a role of this newly identified T cell population in the pathogenesis. Anti-IL-17 monoclonal antibodies may be effective for patients by reducing this pathogenic T cell population.

Function of arthroscopy for early diagnosis and early therapeutic intervention in knee synovitis compared to histopathology

Background and Aim: Osteoarthritis (OA) is the most common form of arthritis and a major cause of joint pain and disability. Synovial fluid analysis and biopsy have been found to be a valuable adjunct to conventional investigations and are routinely advised in most cases of joint diseases. Needle arthroscopy of the knee has been advocated as it allows good macroscopic evaluation of synovial inflammation and selective sampling of the synovial membrane thereby overcoming the disadvantage of closed needle biopsy.Material and Methods: In the decided study period, total of 60 cases were selected as per the inclusion and exclusion criteria decided prior to the start of the study. The clinical examination with movements in knee joints, valgus stress test, lachman test amd McMurrays test was done. After initial arthroscopic inspection, the structures like anterior cruciate ligament, medial and lateral menisci, tested and seen for their integrity and consistency. The synovial fluid was sent for cytology, culture and for biochemistry. The data was analyzed using proportions.Results: Overall in 24 cases the clinical diagnosis differed from that of gold standard i.e. histopathology. In six cases the diagnosis was chronic non-specific synovitis but it turned out to be Osteoarthritis on histopathology. In two cases the clinical diagnosis was chronic non-specific synovitis but it turned out to be pyogenic synovitis on histopathology. In two cases the clinical diagnosis was chronic non-specific synovitis but it turned out to be Villonodular synovitis s on histopathology. In six cases the diagnosis was septic arthritis but it turned out to be gouty arthritis on histopathology.Conclusion: Thus arthroscopic diagnosis can be relied upon and treatment can be started on this basis in view of time consuming and costly histopathological tests.

STRUCTURAL AND FUNCTIONAL CONDITION OF THE KNEE JOINT IN PATIENTS WITH MONOGONARTHROSIS IN THE STAGE OF EXACERBATION

The goal is to study the structural changes of the elements of the knee joint and their functional consequences in patients with monogonarthrosis of the 1st-2nd grade in the stage of exacerbation according to the data of a complex clinical and arthroscopic study.&#x0D; Materials and Methods. Materials - protocols of clinical, radiological and arthroscopic examination of 125 patients (54 (43.2%) men; 71 (57.8%) women), aged 18 - 79 years, with a previous diagnosis: Monoarthrosis of the knee joint in the stage of exacerbation. Research methods: questionnaire, orthopedic examination, X-ray diagnostics, arthroscopy, laboratory diagnostics of blood (determination of C-reactive protein (CRP) as a serological marker of inflammation), synovial fluid (analyses of physical properties, biochemical, cytological, bacteriological), statistical.&#x0D; Results and Discussion. According to the results of the comprehensive examination, the presence of primary monoarthrosis was confirmed in 118 (94.4%) patients (group A). Based on the definition of CRP, subgroups were distinguished: A1 (n=71; 56.8%) with a normal level and A2 (n=47; 37.6%) with elevated CRP. In 7 (5.6%) patients diagnosed seropositive unspecified rheumatoid monoarthritis with hypertrophic synovitis (group B). A significant predominance of women compared to men insubgroup A2 was revealed (p&lt;0.05). It was investigated that the features of complaints, nature of pain sensations and indicators of orthopedic status in patients from subgroups A1 and A2 did not reliably differ in groups of patients with different levels of CRP. A significant predominance of normal contours of the affected knee joint was found in subgroups A1 (p&lt;0.001) and A2 (p&lt;0.01). Structural changes in knee joint elements according to X-ray and arthroscopic examination have no significant differences in subgroups of patients A1 and A2.&#x0D; Conclusions. The structural and functional state of the knee joints in patients with monogonarthrosis of the 1st-2nd grade according to the Kellgren-Lawrence classification is characterized by degenerative changes in almost all elements of the knee joint with moderate pain syndrome and functional disorders.

Quo vadis reactive arthritis?

We provide an overview of recent articles which describe new thinking regarding HLA-B27-associated reactive arthritis (ReA), including those additional infection-related arthritides triggered by microbes that often are grouped under the term ReA. With the advent and continuation of the pandemic, an increasing number of cases and case series of post-COVID-19 arthritis have been reported and classified as ReA. Further, arthritis after COVID-19 vaccination is a new entity included within the spectrum of ReA. New causative microorganisms identified in case reports include Clostridium difficile, Mycoplasma pneumoniae, Giardia lamblia, Leptospira , and babesiosis. SARS-CoV-2 is emerging as a significant etiologic agent for apparent ReA. It is now clear that comprehensive clinical and laboratory investigations, synovial fluid analyses, and close follow-up of patients all are essential to differentiate ReA from diseases that may present with similar clinical attributes. Further, and importantly, additional research is required to define the wide diversity in causative agents, epidemiology, and rare case presentations of these arthritides. Finally, new classification and diagnostic criteria, and updated treatment recommendations, are essential to the advancement of our understanding of ReA.

Early diagnosis and treatment of acute brucellosis knee arthritis complicated by acute osteomyelitis: two cases report

BackgroundBrucellosis is an endemic systemic infectious disease, the most common complication is bone and joint involvement. Sacroiliac joint and spinal joint are the most frequently involved sites in adults, but knee joint infection is rare, and acute infectious knee arthritis complicated by acute osteomyelitis is even extremely uncommon in adults. Here, we report two cases of acute septic knee arthritis complicated by acute osteomyelitis caused by Brucella melitensis (B. melitensis).Case presentationBoth patients had a history of traveling in animal husbandry areas within three months. On clinical examination, their right knee joint was tender, swollen, had limited movement and an effusion was present. Imaging examination showed effusion and synovial thickening of the right knee joint, as well as subchondral bone edema of the distal femur and proximal tibia. Laboratory examination showed that the serum agglutination test (SAT) in both patients were positive (1: 640 and 1: 320) without leukocytosis, although the proportion of lymphocytes, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) significantly increased. Both patients underwent knee joint aspiration. Real-time polymerase chain reaction (Real-time PCR) analysis of synovial fluid showed that there was B. melitensis, and blood bacterial culture was negative. We determined that two patients had acute brucellosis knee arthritis complicated by acute osteomyelitis. Antibiotic treatment was given during hospitalization consisting of doxycycline (0.1 g po bid) and rifampicin (0.6 g po qd) for six weeks, and the changes of inflammatory indexes were closely monitored. At discharge, the symptoms had completely resolved, imaging abnormalities disappeared, and inflammatory indexes returned to normal. There was no recurrence of the disease at 1-year follow-up.ConclusionAcute brucellosis knee arthritis complicated by acute osteomyelitis is a rare but serious complication of brucellosis in adults. There is no obvious specificity of clinical manifestation and imaging examination. Early diagnosis and treatment can prevent the occurrence of knee joint deformity and even pathological fracture. Clinicians should fully consider the possibility of brucellosis where the travel or occupational history is suggestive.

Isolation and Characterization of Synovial Mesenchymal Stem Cells Derived From Patients With Chronic Lateral Ankle Instability: A Comparative Analysis of Synovial Fluid, Adipose Synovium, and Fibrous Synovium of the Ankle Joint.

Background:Synovial mesenchymal stem cells (MSCs) have high proliferative potential and are considered an excellent source for stem cell therapy.Purposes:To isolate MSCs from the synovium of ankle joints in patients with chronic lateral ankle instability (CLAI) and to compare the characteristics of MSCs derived from the synovium anterior to the talus with those from the surrounding anterior talofibular ligament (ATFL) synovium.Study Design:Controlled laboratory study.Methods:The synovium was harvested from 2 locations in the ankle, the synovium anterior to the talus and the surrounding ATFL synovium, of 14 patients who underwent arthroscopic ATFL repair for CLAI without osteochondral lesions of the talus (OLTs). Synovial fluid was also harvested. MSCs were isolated from both types of synovial tissue, as well as synovial fluid. The number of MSCs in the synovium and their viability, proliferation, colony-forming units, and potential to differentiate into adipose, bone, and cartilage tissues were determined and compared between groups. Additionally, real-time polymerase chain reaction was used to assess the differentiation capacity of adipose, bone, and cartilage tissues from both samples. The Wilcoxon signed rank test was used to compare the sample weight, number of colonies, number of nucleated cells per colony, yield obtained, and phenotypic characteristics of MSCs derived from different locations of the synovium.Results:No significant differences were observed in the sample weight (P = .051), number of nucleated cells per milligram (P = .272), number of colonies (P = .722), and yield obtained (P = .099) between the 2 groups. MSCs could not be isolated from synovial fluid. The frequency of oil red O–positive adipogenic colonies (P = .028) and the expression of the adipsin gene (P < .05) were significantly increased in the cells from the synovium anterior to the talus compared to those in the cells from the surrounding ATFL synovium. However, chondrogenic and osteogenic potentials were not significantly different between the 2 groups.Conclusion:Synovial MSCs obtained from the ankle joint had self-renewal and multilineage differentiation potential, although the adipogenesis potential of MSCs from the synovium anterior to the talus was superior to that from the surrounding ATFL synovium.Clinical Relevance:Both the adipose synovium and fibrous synovium in the ankle joints of patients with CLAI may be a good source of MSCs for stem cell therapy applications, whereas synovial fluid appeared unsuitable.

Production of Cytotoxic Antibodies After Intra-Articular Injection of Allogeneic Synovial Membrane Mesenchymal Stem Cells With and Without LPS Administration.

Allogeneic mesenchymal stem cells (MSC) are widely used in clinical routine due to the shorter expansion time and reliability of its quality. However, some recipients can produce alloantibodies that recognize MSCs and activate the immune system, resulting in cell death. Although antibody production was already described after MSC injection, no previous studies described the immune response after intra-articular MSC injection in acute synovitis. This study aimed to evaluate the influence of inflammation on immune response after single and repeated intra-articular injections of synovial membrane MSC (SMMSC). Horses were divided in three groups: control group (AUTO) received autologous synovial membrane MSCs; whereas group two (ALLO) received allogeneic SMMSCs and group three (ALLO LPS) was submitted to acute experimental synovitis 8 h before SMMSCs injection. The procedure was repeated for all groups for 28 days. Physical and lameness evaluations and synovial fluid analysis were performed. Sera from all animals were obtained before and every 7 days after each injection up to 4 weeks, to perform microcytotoxicity assays incubating donor SMMSCs with recipients’ sera. The first injection caused a mild and transient synovitis in all groups, becoming more evident and longer in ALLO and ALLO LPS groups after the second injection. Microcytotoxicity assays revealed significant antibody production as soon as 7 days after SMMSC injection in ALLO and ALLO LPS groups, and cytotoxicity scores of both groups showed no differences at any time point, being equally different from AUTO group. Although inflammation is capable of inducing MHC expression in MSCs, which enhances immune recognition, cytotoxicity scores were equally high in ALLO and ALLO LPS groups, making it difficult to determine the potentiation effect of inflammation on antibody production. Our findings suggest that inflammation does not display a pivotal role in immune recognition on first allogeneic MSC injection. In a translational way, since specific antibodies were produced against MSCs, patients that need more than one MSC injection may benefit from a first allogeneic injection followed by subsequent autologous injections.

Predictive Variables for Interventional Angiography among Patients with Knee Hemarthrosis.

Studies regarding the variables that could predict the success of conservative treatment for knee hemarthrosis are lacking. This retrospective study evaluated the laboratory variables of patients who had unsatisfactory results from conservative treatment for knee hemarthrosis. Twenty-nine patients conservatively treated for knee hemarthrosis were included and divided into two groups: group A comprised 14 patients who underwent interventional angiography and selective embolization due to failed conservative treatment, and group B comprised 15 patients with successful results after conservative treatment. The results of the serological and synovial fluid tests were evaluated. The mean number of synovial red blood cells (RBCs) was 1,905,857 cells/µL and 7730 cells/µL in groups A and B, respectively (p = 0.01), while the mean number of RBCs per high-power field (HPF) was 68.9 and 3.2, respectively (p < 0.01). Patients who underwent interventional angiography and selective embolization after failed conservative treatment for knee hemarthrosis had higher synovial RBC counts and RBC counts per HPF than those with successful outcomes after conservative treatment. It is necessary to carefully interpret the results of the synovial fluid analysis in patients with knee hemarthrosis; if the synovial fluid analysis shows a synovial RBC count greater than 81,500 and RBC count per HPF greater than 16.3, we recommend immediate interventional angiography rather than continuing conservative treatment.

Chronic Tropheryma whipplei infection: an important differential diagnosis of refractory polyarthritis

Refractory arthritis is acommon problem in routine rheumatology practice, and can be adiagnostic challenge. In these cases, chronic Tropheryma whipplei (T.whipplei) infection is an important differential diagnosis that should be considered. Based on five clinical cases, this case-based review describes the diagnostic and therapeutic principles in the management of chronic T.whipplei infection. Whipple's disease is amultisystemic infectious disease caused by the bacterium T.whipplei. The disease typically manifests with arthralgia, weight loss and diarrhoea. Joint involvement often develops years before gastrointestinal symptoms occur. In addition to systemic manifestations ("classic Whipple's disease"), T.whipplei can also lead to localized joint infections without gastrointestinal involvement. Articular manifestations of systemic and localized T.whipplei infections are commonly misdiagnosed as a sign of various forms of autoimmmune arthritis. Whipple's disease and localized T.whipplei joint infection should be considered in the diagnostic work-up of refractory arthritis. Synovial fluid analysis by means of specific polymerase chain reaction-based testing for T.whipplei is diagnostically ground-breaking.

Discovery proteomics for the detection of putative markers for eradication of infection in an experimental model of equine septic arthritis using LC-MS/MS

Septic arthritis (SA) is a life-threatening condition in horses, and identifying eradication of infection in equine SA is challenging. This study explored the discovery of putative biomarkers for the eradication of joint infection in horses. We performed proteomics analysis of synovial fluid (SF) and plasma from horses with experimental SA, non-septic lipopolysaccharide-induced arthritis, and controls. The point of eradication of infection in horses with SA was determined previously. We compared spectral intensities between groups as well as before and after the eradication of infection. Twenty-six differentially abundant proteins were identified, which were upregulated in SF of horses with SA compared to the other groups, as well as compared to the same horses post-eradication of infection. In plasma, we did not identify differentially abundant proteins. Differentially abundant proteins in SF were of cellular origin and their biological functions included ubiquitination, signal transduction, apoptosis etc. The difference in their relative abundance between experimental groups was ≥10-fold compared to the abundance expected based on the difference in cell count alone (2-fold). Since most of cells in joints with bacterial infection are neutrophils, we suggest that the variable abundance of neutrophil- and cell-associated proteins represent potential biomarkers of eradication of infection in equine SA. SignificanceSeptic arthritis is an important condition in horses, which can be life-threatening. At present, identifying eradication of infection in cases of equine septic arthritis is challenging. In this study, we performed a global proteomics analysis of synovial fluid and plasma in horses with experimental septic arthritis and identified 26 differentially abundant proteins compared to non-septic arthritis and post eradication of infection. The results of this study provide the basis for further characterization of the differentially abundant proteins and identification of clinically relevant biomarkers of septic arthritis in horses.

Amniotic suspension allograft improves pain and function in a rat meniscal tear-induced osteoarthritis model

BackgroundOsteoarthritis is a degenerative disease of the knee that affects 250 million people worldwide. Due to the rising incidence of knee replacement and revision surgery, there is a need for a nonsurgical treatment to reduce pain and improve function in patients with knee osteoarthritis. Placental-derived allografts, such as an amniotic suspension allograft (ASA), provide growth factors and cytokines that could potentially modulate the inflammatory environment of osteoarthritis. The purpose of this study was to evaluate the efficacy of ASA in a rat medial meniscal tear (MMT) induced osteoarthritis model through histology, microCT, synovial fluid biomarkers, and behavioral testing.MethodsRats underwent MMT surgery at day − 7; at day 0, rats were injected with either ASA, vehicle control, or fibroblast growth factor-18 (FGF18). Behavioral testing, including gait analysis, pain threshold, incapacitance, and knee swelling were evaluated in-life, along with histology, microCT analysis of cartilage, and synovial fluid testing post-sacrifice. One MMT cohort was sacrificed at day 10, the other at day 21. A third cohort acted as a safety arm and did not receive MMT surgery; these rats were injected with either vehicle control or ASA and evaluated at day 3 and day 21.ResultsBehavioral testing showed a significant improvement in pain threshold, incapacitance, and gait following an injection of ASA. MicroCT showed significant improvements in cartilage thickness and attenuation at day 10 only, and histology showed no detrimental effects compared to the vehicle control at day 21. Synovial fluid analysis showed a significant increase in anti-inflammatory IL-10. The safety cohort showed no significant differences except for an increase in synovitis at day 21, which could be evidence of a xenogeneic response in this model.ConclusionsIn this study, an injection of ASA was well tolerated with no adverse events. Improvements in pain and function, along with cartilage properties at day 10, were observed. Increases in anti-inflammatory cytokines was also seen, along with no significant cartilage degeneration at day 21 compared to the vehicle control. This study provides evidence for the use of ASA as a nonsurgical treatment for knee OA.