Active Juvenile Idiopathic Arthritis Patients Research Articles

NKG2D receptor regulates CD4+T cell differentiation via interaction with dendritic cells in patients with juvenile idiopathic arthritis

NKG2D provides a costimulatory signal for activation of CD4+ T cells. We explored its role in interactions of CD4+ T cells and dendritic cells (DCs) in juvenile idiopathic arthritis (JIA) patients by using NKG2D genetically modified CD4+ T cells. We found active JIA patients had significantly higher content of CD4 + NKG2D+ T cells than healthy controls. Expression of NKG2D on CD4+ T cells, and MICA and MICB on DCs were significantly greater in articular JIA than systemic JIA. NKG2D induced IL- 12 and suppressed IL-10 and TGF-β from CD4+ T cells, increased IFN-γ + CD4+ T and IL-17+ CD4+ T cells, RORc and T-bet, but reduced CD25+ Foxp3+ CD4+ T cells, IL-4+ CD4+ T cells, Foxp3, and GATA3 in JIA patients. NKG2D decreased IL-10 and increased CD83, MICA, and MICB of DCs in JIA and controls. So NKG2D regulates differentiation of CD4+ T cells directly and the maturation of DCs indirectly.

Increased histone citrullination in juvenile idiopathic arthritis.

ObjectivePosttranslational modifications (PTMs) of proteins are crucial for regulating various biological processes. However, protein alteration via PTMs, and consequently, the creation of new epitopes, can induce abnormal autoimmune responses in predisposed individuals. Immunopathogenesis of several rheumatic diseases, including the most common childhood form, juvenile idiopathic arthritis (JIA), is associated with the generation of autoantibodies against such modified proteins. Dysregulated generation of neutrophil extracellular traps (NETs) can be a source of post-translationally altered proteins. Thus, we investigated the role of PTMs and the presence of NET-associated markers in JIA patients.MethodsWe recruited 30 pediatric patients with JIA (20 with active disease and 10 in remission) and 30 healthy donors. The serum concentrations of citrullinated histone H3 (citH3), peptidyl arginine deiminases (PADs), and NET-related products were detected using ELISA, and the number of citH3+ neutrophils was assessed using flow cytometry.ResultsThe serum levels of citH3 and PADs were higher in active as well as in remission JIA patients than in healthy donors. Similarly, the number of citH3+ neutrophils was higher in the peripheral blood of patients with JIA, implying an enhanced process of NETosis. This was effectively reflected by elevated serum levels of NET-associated products, such as neutrophil elastase, LL37, and cell-free DNA-histone complexes. Additionally, 16.7% of active JIA patients were seropositive for carbamylated autoantibodies, the levels of which declined sharply after initiation of anti-TNFα therapy.ConclusionCollectively, our data suggest that the accelerated process of NETosis and PTMs in JIA may result in the generation of anti-citrullinated/carbamylated autoantibodies against various epitopes later in life, which could be prevented by effectively regulating inflammation using immune therapy.

Evidence of persistent glial cell dysfunction in the anterior cingulate cortex of juvenile idiopathic arthritis children: a proton MRS study

BackgroundThis study aims to investigate whether the neurometabolites of the anterior cingulate cortex (ACC) were distinct in patients with active and inactive juvenile idiopathic arthritis (JIA) using the proton magnetic resonance spectroscopy.MethodsWe measured the levels of total N-acetylaspartate (tNAA), choline (Cho), myo-inositol (ml), glutamate (Glu) and the complex of glutamate and glutamine (Glx) relative to total creatine (tCr) in ACC of each participant.ResultsCompared with the healthy controls, a significant decrease of total Cho/tCr and Glx/tCr ratio in ACC occurred in active and inactive JIA group. The tCho/Cr level was negatively associated with the serum level of ESR in active JIA patients. There was no difference in NAA/tCr ratio among the three groups, which may imply that no neuron and axonal losses occurred in either active or inactive JIA patients.ConclusionsThe abnormal neurometabolites in tCho/tCr and Glx/tCr in ACC may indicate that persistent dysfunction of glial cell, while neither neuron nor axonal losses occurred in active and inactive JIA patients.

Early combination therapy with etanercept and methotrexate in JIA patients shortens the time to reach an inactive disease state and remission: results of a double-blind placebo-controlled trial

BackgroundRemission is the primary objective of treating juvenile idiopathic arthritis (JIA). It is still debatable whether early intensive treatment is superior in terms of earlier achievement of remission. The aim of this study was to evaluate the effectiveness of early etanercept+methotrexate (ETA+MTX) combination therapy versus step-up MTX monotherapy with ETA added in refractory disease.MethodsA multi-centre, double-blind, randomized study in active polyarticular JIA patients treated with either ETA+MTX (n = 35) or placebo+MTX (n = 33) for up to 24 weeks, followed by a 24-week open-label phase. The efficacy endpoints included pedACR30 criteria improvement at week 12, inactive disease at week 24, and remission at week 48. Patients who failed to achieve the endpoints at week 12 or at week 24 escaped to open-label ETA+MTX. Safety was assessed at each visit.ResultsBy intention-to-treat analysis, more patients in the ETA+MTX group reached the pedACR30 response at week 12 (33 (94.3%)) than in the placebo+MTX group (20 (60.6%); p = 0.001). At week 24, comparable percentages of patients reached inactive disease (11 (31.4%) vs 11 (33.3%)). At week 48, 11 (31.4%) and eight (24.2%) patients achieved remission. The median (+/−IQR) times to achieve an inactive disease state in the ETA+MTX and placebo+MTX groups were 24 (14–32) and 32 (24–40) weeks, respectively. Forty-four (74/100 patient-years) adverse events (AEs) were reported, leading to treatment discontinuation in 6 patients.ConclusionsEarly combination therapy with ETA+MTX proved to be highly effective compared to the standard step-up regimen. Compared to those treated with the standard regimen, more patients treated with a combination of ETA+MTX reached the pedACR30 response and achieved inactive disease and remission more rapidly.

Procalcitonin Differs in Children With Infection and Children With Disease Flares in Juvenile Idiopathic Arthritis.

Patients with juvenile idiopathic arthritis (JIA) often present with signs and symptoms suggestive of serious bacterial infection (SBI). Procalcitonin (PCT) is a biomarker that is elevated in SBI. We conducted a comparative cohort study to test the hypothesis that PCT levels will differ between active JIA, quiescent JIA, and bacteremic patients and healthy controls. From October 2016 to May2018, consecutive children 6 months to 18 years of age with (a) active untreated JIA, (b) quiescent JIA, and (c) healthy elective presurgical candidates were recruited from clinics at a musculoskeletal specialty hospital. Juvenile idiopathic arthritis was defined according to the International League of Associations for Rheumatology criteria. Clinical data and serum samples meeting the same criteria were included from a prior study. Consecutive bacteremic patients were identified over the same period. Procalcitonin and other common measures of inflammation were measured. Descriptive statistics and univariate logistic analyses were performed. Ninety-two study subjects were recruited. Erythrocyte sedimentation rate, C-reactive protein (CRP), and PCT levels were all elevated in bacteremic patients in comparison to the other groups. Erythrocyte sedimentation rate and CRP both had wide ranges that overlapped between groups; however, the PCT concentration was 0.15 μg/mL or greater in 1 of 59 patients with JIA, whereas it was 0.15 μg/mL or less in only 1 bacteremic patient. Our study indicates that serum erythrocyte sedimentation rate, CRP, and PCT levels are all biomarkers that can be used to distinguish SBI versus active JIA at presentation. However, PCT is the most accurate, with the least overlap between patients with infection and noninfectious inflammatory arthritis. This finding can help clinicians direct therapy.

Frequency of CD19+CD24hiCD38hi regulatory B cells is decreased in peripheral blood and synovial fluid of patients with juvenile idiopathic arthritis: a preliminary study

BackgroundTo understand the relationship between regulatory B cells (Bregs) and juvenile idiopathic arthritis (JIA), we analyzed the percentages of Bregs and their function in peripheral blood (PB) and synovial fluid (SF) of JIA patients.MethodsTwenty-one JIA patients and 11 children with growing pain but without known rheumatic diseases as controls were included. The B cell phenotype and intracellular production of IL-10 of Bregs were assessed by flow cytometry. Mononuclear cells from PB and SF were stimulated to produce IL-10 in vitro for the identification of IL-10- producing regulatory B cells.ResultsThe percentage of CD24hiCD38hi Bregs in the PB of JIA patients was significantly decreased compared to that in controls, and it was even lower in the SF of JIA patients compared to that in the PB. CD24hiCD38hi Bregs frequency was significantly lower in the PB of RF-positive patients than in RF-negative patients. Frequency of IL-10-producing regulatory B cells (B10 cells) was significantly lower in active JIA patients than that in inactive patients.ConclusionsThe inability of the host to produce enough regulatory B cells in PB and especially in SF of JIA patients may contribute to the disease, especially the local inflammation.

Decreased PD-1 expression on circulating CD4+T cell and PD-L1 expression on myeloid dendritic cell correlate with clinical manifestations in systemic juvenile idiopathic arthritis.

Programmed cell death-1 (PD-1) and its ligand (PD-L1) mediate negative signal in autoimmune diseases. While little is known about its role in juvenile idiopathic arthritis (JIA). The study aimed to reveal the circulating cell profile and the relative PD-1/PD-L1 expression of JIA subsets, elucidating their underlying immunomodulatory mechanisms. We detected the circulating cells and the relative PD-1/PD-L1 signaling in 101 JIA patients and 50 controls by flow cytometry and analyzed their association with disease activity and clinical manifestations. Different from other JIA types, active systemic JIA (sJIA) patients had lower percentage and count of CD4+T cells and lower PD-1 expression on them compared with healthy controls (P<0.05), active polyarthritis (P<0.05) and enthesitis-related arthritis (ERA) patients (P<0.05). Also, they had higher percentage and count of myeloid dendritic cell (mDC) and lower PD-L1 expression on mDC compared with healthy controls (P<0.05). Both PD-1 on CD4+T cell and PD-L1 on mDC were negatively correlated with JADAS-27 in sJIA patients (P<0.05). In addition, PD-1 expression on CD4+T cell was negatively associated with the number of involved joints (P<0.05) and PD-L1 on mDC was lower in patients with fever (P<0.01), which could further divide patients into two groups of different manifestations. Our finding displayed decreased CD4+T cell, increased mDC and reduced PD-1/PD-L1 signal in sJIA PBMC comparing with other JIA subsets, which might be helpful in JIA differential diagnosis and responsible for distinct clinical manifestations via different mechanisms.

Normal MRI findings of the knee in patients with clinically active juvenile idiopathic arthritis

ObjectiveIn a number of patients with clinically active juvenile idiopathic arthritis (JIA), contrast-enhanced MRI shows no signs of synovitis. The objective of this study was to assess the frequency and the patient characteristics in clinically active JIA patients in which MRI showed no signs of synovitis. MethodsFrom our cohort of 313 patients in which contrast-enhanced MRI of the knee had been performed, we selected 72 JIA patients with clinically active disease involving the target joint. The validated Juvenile Arthritis MRI Scoring (JAMRIS) system was used to evaluate synovial thickening. Patients were divided into two groups based on MRI outcome: Group 1: thickened synovium on MRI (JAMRIS score ≥1) or Group 2: normal synovium on MRI (JAMRIS score 0). Patient characteristics and disease activity parameters were then compared. ResultsIn 35% (25/72) of these patients, MRI results contrasted with the clinical assessment (Group 2). In comparison to Group 1, the patients with discrepant findings were significantly older at the date of examination and JIA had been diagnosed at later age (median age of 13.2 vs. 10.9 and median age 10.0 vs. 8.0 respectively). In Group 2 there were significantly more patients with RF-negative polyarticular disease. ConclusionPatients with RF-negative polyarticular JIA who had been diagnosed at a later age and were older at the time of MRI were most likely to be considered clinically active while MRI showed no signs of synovitis. These particular JIA patients may benefit from monitoring of disease activity by MRI to prevent overtreatment.

Contrast-enhanced MRI of the knee in children unaffected by clinical arthritis compared to clinically active juvenile idiopathic arthritis patients.

ObjectivesTo evaluate enhancing synovial thickness upon contrast-enhanced magnetic resonance imaging (MRI) of the knee in children unaffected by clinical arthritis compared with clinically active juvenile idiopathic arthritis (JIA) patients. A secondary objective was optimization of the scoring method based on maximizing differences on MRI between these groups.MethodsTwenty-five children without history of joint complaints nor any clinical signs of joint inflammation were age/sex-matched with 25 clinically active JIA patients with arthritis of at least one knee. Two trained radiologists, blinded for clinical status, independently evaluated location and extent of enhancing synovial thickness with the validated Juvenile Arthritis MRI Scoring system (JAMRIS) on contrast-enhanced axial fat-saturated T1-weighted MRI of the knee.ResultsEnhancing synovium (≥2 mm) was present in 13 (52 %) unaffected children. Using the total JAMRIS score for synovial thickening, no significant difference was found between unaffected children and active JIA patients (p = 0.091). Additional weighting of synovial thickening at the JIA-specific locations enabled more sensitive discrimination (p = 0.011).ConclusionsMild synovial thickening is commonly present in the knee of children unaffected by clinical arthritis. The infrapatellar and cruciate ligament synovial involvement were specific for JIA, which—in a revised JAMRIS—increases the ability to discriminate between JIA and unaffected children.Key Points• Synovial inflammation is the primary disease feature in juvenile idiopathic arthritis (JIA).• Appearance of the synovium on contrast-enhanced MRI in unaffected children is unknown.• Validation of existing scoring methods requires comparison between JIA and unaffected children.• Mild enhancing synovial thickening was detected in half of the unaffected children.• Location-weighting for JIA-specific locations increased discriminative value of the scoring methods (p = 0.011).Electronic supplementary materialThe online version of this article (doi:10.1007/s00330-015-3912-z) contains supplementary material, which is available to authorized users.

Persistent improper upregulation of Th17 and TReg cells in patients with juvenile idiopathic arthritis.

Juvenile idiopathic arthritis (JIA) is the most common childhood rheumatic disease. A break in the balance between Th17 and TReg cells has been reported as an important factor in the development of autoimmune diseases. This study aimed to analyze peripheral Th17 and TReg cell levels in patients with JIA. The balance of Th17 and TReg cells among active and inactive JIA patients and normal control subjects were compared. Human peripheral blood mononuclear cells were isolated from the patients and controls. Surface and intracellular staining for CD4, CD25, Foxp3, IL-17, Th17, and TReg were analyzed. Twenty-eight JIA patients, including 12 with active JIA and 16 with inactive JIA, and 20 health controls were analyzed. Patients with active JIA had higher Th17 (1.85±1.15 vs. 1.05±0.72, p = 0.008) and TReg cells (1.1±0.8 vs. 0.6±0.7, p = 0.04) levels than those with inactive JIA. Among active JIA patients, remission days were highly correlated with the CD4(+)IL17A(+) T cell percentage, 276.5 ± 137.40 days (range, 130 ∼ 525 days), p < 0.01. There were no differences in Th17/TReg percentage between JIA patients and controls in the peripheral blood. Th17 and TReg cell levels are elevated in patients with active JIA and there is no Th17/TReg imbalance. The higher Th17 level predicted longer period to reach disease inactive stage. Improper Th17 up-regulation might contribute to JIA activation.

Distribution pattern of MRI abnormalities within the knee and wrist of juvenile idiopathic arthritis patients: signature of disease activity.

The aim of this study in clinically active juvenile idiopathic arthritis (JIA) was to assess the frequency and distribution pattern of synovitis as hallmark of disease and additional soft-tissue and bony abnormalities on MRI in the knee and wrist as two target joints. MRI datasets of 153 clinically active JIA patients (110 with knee and 43 with wrist involvement) were evaluated independently by two readers for the presence of literature-based imaging features: "synovial hypertrophy," "bone marrow changes," "bone erosions," "tenosynovitis" (only in the wrist), and "cartilage lesions" (only in the knee) in accordance with validated definitions and scoring locations. Synovial hypertrophy was most frequently observed--both in the knee and in the wrist (61.8-65.1% of cases). For the knee, the most frequently involved locations were the cruciate ligaments (46/183 locations [25.1%] affected with synovial hypertrophy) and medial patella (18/62 locations [29.0%] with bone marrow changes). Cartilage lesions and bone erosions were rare (5.5-7.3% of cases). For the wrist, most frequently involved were the radiocarpal joint (21/64 locations [32.8%] with synovial hypertrophy), lunate (7/46 locations [15.2%] with bone marrow changes), and capitate or triquetrum (6/28 locations [21.4%] with bone erosions). Tenosynovitis was a common wrist-specific feature (46.5% of cases). MRI showed no abnormalities in a subgroup of patients with clinically active knee (23.6%) and wrist (16.3%) involvement. The distribution pattern of MRI abnormalities in the knee and wrist of active JIA patients provides a practical tool to detect a signature of JIA disease activity in target joints.

Pixel-by-pixel analysis of DCE-MRI curve shape patterns in knees of active and inactive juvenile idiopathic arthritis patients.

To compare DCE-MRI parameters and the relative number of time-intensity curve (TIC) shapes as derived from pixel-by-pixel DCE-MRI TIC shape analysis between knees of clinically active and inactive juvenile idiopathic arthritis (JIA) patients. DCE-MRI data sets were prospectively obtained. Patients were classified into two clinical groups: active disease (n = 43) and inactive disease (n = 34). Parametric maps, showing seven different TIC shape types, were created per slice. Statistical measures of different TIC shapes, maximal enhancement (ME), maximal initial slope (MIS), initial area under the curve (iAUC), time-to-peak (TTP), enhancing volume (EV), volume transfer constant (K(trans)), extravascular space fractional volume (V(e)) and reverse volume transfer constant (k(ep)) of each voxel were calculated in a three-dimensional volume-of-interest of the synovial membrane. Imaging findings from 77 JIA patients were analysed. Significantly higher numbers of TIC shape 4 (P = 0.008), median ME (P = 0.015), MIS (P = 0.001) and iAUC (P = 0.002) were observed in clinically active compared with inactive patients. TIC shape 5 showed higher presence in the clinically inactive patients (P = 0.036). The pixel-by-pixel DCE-MRI TIC shape analysis method proved capable of differentiating clinically active from inactive JIA patients by the difference in the number of TIC shapes, as well as the descriptive parameters ME, MIS and iAUC. • The pixel-by-pixel TIC shape method differentiates clinically active and inactive JIA patients • Significantly higher numbers of TIC shape 4 were observed in clinically active patients • DCE-MRI parameters ME, MIS and iAUC differ between active and inactive patients • The pixel-by-pixel analysis method allows direct visualization of the heterogeneously distributed disease • The DCE-MRI TIC shape method may serve as a quantitative outcome measure.

Contrast-enhanced MRI compared with the physical examination in the evaluation of disease activity in juvenile idiopathic arthritis

To assess the value of magnetic resonance imaging (MRI) in discriminating between active and inactive juvenile idiopathic arthritis (JIA) patients and to compare physical examination outcomes with MRI outcomes in the assessment of disease status in JIA patients. Consecutive JIA patients with knee involvement were prospectively studied using an open-bore MRI. Imaging findings from 146 JIA patients were analysed (59.6% female; mean age, 12.9 years). Patients were classified as clinically active or inactive. MRI features were evaluated using the JAMRIS system, comprising validated scores for synovial hypertrophy, bone marrow oedema, cartilage lesions and bone erosions. Inter-reader reliability was good for all MRI features (intra-class correlation coefficient [ICC] = 0.87-0.94). No differences were found between the two groups regarding MRI scores of bone marrow oedema, cartilage lesions or bone erosions. Synovial hypertrophy scores differed significantly between groups (P = 0.016). Nonetheless, synovial hypertrophy was also present in 14 JIA patients (35.9%) with clinically inactive disease. Of JIA patients considered clinically active, 48.6% showed no signs of MRI-based synovitis. MRI can discriminate between clinically active and inactive JIA patients. However, physical examination is neither very sensitive nor specific in evaluating JIA disease activity compared with MRI. Subclinical synovitis was present in >35% of presumed clinically inactive patients. • MRI is sensitive for evaluating juvenile idiopathic arthritis (JIA) disease activity. • Contrast-enhanced MRI can distinguish clinically active and inactive JIA patients. • Subclinical synovitis is present in 35.9 % of presumed clinically inactive patients. • Physical examination is neither sensitive nor specific in evaluating JIA disease activity.

THU0301 Neopterin (NPT) and soluble interleukin 2 receptor (SIL-2R) as useful markers of disease activity in juvenile idiopathic arthritis (JIA)

BackgroundJIA is the common chronic rheumatic disease in children that may continue to be active in adulthood. The new laboratory markers are needed to adjust therapy of JIA to the...

SAT0452 Distribution Pattern of MRI Abnormalities Within the Knee and Wrist of Juvenile Idiopathic Arthritis Patients; MRI made Easy

BackgroundMRI plays an increasingly important role in the assessment and monitoring of disease activity in juvenile idiopathic arthritis (JIA). Awareness of the incidence and distribution pattern of MRI abnormalities in...

Magnitude and clinical profile of juvenile idiopathic arthritis in a medical college hospital of a socio-economically disadvantaged country.

A number of children with Juvenile Idiopathic Arthritis (JIA) got admitted in the pediatrics ward of a medical college hospital. However, burden and clinical pattern of JIA have not been studied in our country. To estimate the burden of JIA admitted in the pediatric department of medical college hospital of Bangladesh and to observe the status of active JIA in respect to magnitude, clinical profile and hematological changes. A prospective study was carried out among the patients admitted in pediatric ward of a medical college hospital, Bangladesh from 2008 to 2010. All active JIA patients admitted during this period were included in this study. JIA was diagnosed according to the ILAR criteria. Male/Female ratio, age, Total Leukocyte Count (TLC), Differential count (D/C), Platelet count, Erythrocyte Sedimentation Rate (ESR), C Reactive Protein (CRP), Rheumatoid Factor (RF) of JIA patients were recorded. These were statistically analyzed with the help of SPSS programme using chi-square test. Twenty five cases of active JIA were diagnosed during this period. Magnitude was 3.75 per 1000 admitted cases. Male/Female ratio was 1.08:1. 10 (40%) cases were between the ages of 8 to 11 years. Polyarticular seronegative JIA was found in 10 (40%) cases and oligoarticular JIA in the next order 6 (24%). High ESR, TLC, platelet count was observed in 21 (84%) [p <.001], 19 (76%) [p <.009], 3 (12%) [p <.000] cases respectively. Burden of JIA was similar to all the areas of the world. Polyarticular seronegative JIA was commonly observed in our study. High ESR, increased TLC and Platelet count was the reliable predictor of active JIA.

Low cortisol levels in active juvenile idiopathic arthritis

The aim of our study was to evaluate the neuroendocrine system in patients with juvenile idiopathic arthritis (JIA) regarding the activity of disease. Twenty-one JIA patients (mean age +/- standard deviation 10.5 +/- 4.1 years) were included. None of the patients was taking steroids or antitumor necrosis factor-alpha therapy during this study. Ten healthy volunteers and ten volunteers with upper respiratory tract infection composed the control groups. Furthermore, ten of the 21 JIA patients were also evaluated during the remission period. Erythrocyte sedimentation rate, C-reactive protein, adrenocorticotropic hormone (ACTH), cortisol, prolactin, insulin-like growth factor-1 (IGF-1), insulin-like growth factor-binding protein 3, free T3, free T4, thyroid-stimulating hormone, interleukin-6 (IL-6) levels, and 24-h urinary cortisol were evaluated both during the active period and remission. The median levels of ACTH and cortisol at 08:00 a.m. were significantly lower in patients with active JIA than patients in remission period and the control groups (p < 0.05). Furthermore, the median level of urine cortisol in active JIA patients was significantly lower than remission period and control groups (p < 0.05). The median level of IGF-1 was significantly lower in active patients than that of remission (p < 0.05). The median level of IL-6 in active JIA patients was significantly higher than those in remission and control groups (p < 0.05). Our preliminary study suggested that impaired secretion of adenohypophyseal hormones and distorted bilateral interactions between the immune and endocrine systems in JIA. Further studies are needed to clarify the consequences of the impaired hormone secretion in JIA.

Serum and synovial fluid concentration of vascular endothelial growth factor in juvenile idiopathic arthritides.

To evaluate the role of vascular endothelial growth factor (VEGF) in the pathogenesis of local joint inflammation in juvenile idiopathic arthritis (JIA). Sera from 50 patients affected with JIA and 10 age-matched healthy controls were tested with a commercial ELISA for VEGF. Corresponding synovial fluid (SF) concentrations of VEGF and p75 soluble tumour necrosis factor receptor (sTNFR) were evaluated in 20 active JIA patients. Serum concentrations of VEGF were significantly higher in patients with active polyarticular disease than in patients with active and inactive oligoarticular disease and healthy controls. In JIA patients, serum concentrations of VEGF displayed a significant correlation with a number of clinical and laboratory parameters of disease activity. VEGF concentrations in SF were significantly higher than those detected in corresponding sera. Moreover, a clear correlation was found between corresponding SF and serum VEGF concentrations. In SF, VEGF showed a strong positive correlation with p75 sTNFR. Concentrations of VEGF in SF in patients with JIA are higher than corresponding serum concentrations, suggesting that this pro-angiogenic factor may have a major role in the outgrowth of hyperplastic pannus and tissue damage at the site of tissue inflammation.