Caspase-1 Level in Synovial Fluid Is High in Patients with Spondyloarthropathy but Not in Patients with Gout

Activation of caspase-1 by NALP3 inflammasomes has been shown to be important in initiating acute gouty arthritis. The objectives of this study were to measure the levels of caspase-1 in synovial fluid in gout and various arthritides, and to elucidate the clinical significance of caspase-1 levels in synovial fluid. Caspase-1, IL-1beta, IL-18, and uric acid were measured in synovial fluid from 112 patients with gout and other arthritides, such as rheumatoid arthritis, osteoarthritis, and spondyloarthropathy. Caspase-1 in synovial fluid from patients with crystal-induced arthritis, inflammatory arthritis, osteoarthritis, and spondyloarthropathy was 35.9 +/- 86.7, 49.7 +/- 107.7, 2.1 +/- 7.0, and 152.6 +/- 155.7 pg/mL, respectively. The mean level and the frequency of high levels (> or =125 pg/mL) of caspase-1 in spondyloarthropathy were significantly higher than those in the other arthritides including gout. Caspase-1 was detectible in the synovial fluid of patients with the various arthritides. Contrary to our hypothesis, the caspase-1 level in the synovial fluid of patients with gout was not higher than in that of other arthritides. High levels of caspase-1 may be helpful in differentiating spondyloarthropathy from other arthritides.

Over-expression of extracellular superoxide dismutase in mouse synovial tissue attenuates the inflammatory arthritis

Oxidative stress such as reactive oxygen species (ROS) within the inflamed joint have been indicated as being involved as inflammatory mediators in the induction of arthritis. Correlations between extracellular-superoxide dismutase (EC-SOD) and inflammatory arthritis have been shown in several animal models of RA. However, there is a question whether the over-expression of EC-SOD on arthritic joint also could suppress the progression of disease or not. In the present study, the effect on the synovial tissue of experimental arthritis was investigated using EC-SOD over-expressing transgenic mice. The over-expression of EC-SOD in joint tissue was confirmed by RT-PCR and immunohistochemistry. The degree of the inflammation in EC-SOD transgenic mice was suppressed in the collagen-induced arthritis model. In a cytokine assay, the production of pro-inflammatory cytokines such as, IL-1beta, TNFalpha, and matrix metalloproteinases (MMPs) was decreased in fibroblast-like synoviocyte (FLS) but not in peripheral blood. Histological examination also showed repressed cartilage destruction and bone in EC-SOD transgenic mice. In conclusion, these data suggest that the over-expression of EC-SOD in FLS contributes to the activation of FLS and protection from joint destruction by depressing the production of the pro-inflammatory cytokines and MMPs. These results provide EC-SOD transgenic mice with a useful animal model for inflammatory arthritis research.

Biomarkers for identifying the early phases of osteoarthritis secondary to medial patellar luxation in dogs

The levels of tartrate resistant acid phosphatase (TRAP), matrix metalloproteinase-2 (MMP-2), and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in synovial fluid (SF) and serum in cases of canine osteoarthritis (OA) were measured. OA was induced by a surgically-created medial patellar luxation in the left stifle of 24 dogs. SF and blood samples were collected at 1.5- and 3-month intervals, respectively. Every 3 months, one dog was euthanatized to collect tissue samples from both stifles. TRAP levels in SF and serum were measured using a spectrophotometer, and TRAP-positive cells in joint tissues were identified by enzyme histochemistry. MMP-2 and TIMP-2 in SF and serum were detected by Western blotting and ELISA, respectively. TRAP in SF from the stifles and serum was significantly increased (p < 0.05) after 3 months. TIMP-2 in SF and serum was significantly decreased (p < 0.05), whereas MMP-2 in SF was significantly increased (p < 0.05) during the progression of OA. Histochemistry revealed an increased number of TRAP-positive cells in tissues from OA-affected joints. Assays measuring TRAP, MMP-2, and TIMP-2 in SF and serum, and methods that detect increased numbers of TRAP-positive cells in the joint tissues can play an important role in identifying the early phases of degenerative changes in canine joint components.

Comparison of xanthine oxidase levels in synovial fluid from patients with rheumatoid arthritis and other joint inflammations

To search whether xanthine oxido-reductase [XOR] present in the synovium is also liberated, to determine its activity in synovial fluid and to establish a possible relationship between XOR levels in rheumatoid arthritis [RA] and non-RA patients. This study was carried out in the Laboratory of Immunology, University Ferhat Abbas, Setif, Algeria from 2001-2008. This study is a retrospective controlled study matching cases with RA to non rheumatoid joint inflammations. Synovial fluid [SF] samples were collected with consent of the patients, at Setif University Hospital, from adults suffering from RA [n=36] or only with joint inflammations [n=52]. After its detection in SF with indirect enzyme-linked immunosorbent assay [ELISA] and dot-immunobinding, using anti-bovine XOR as first antibodies, XOR was assayed with capture ELISA. Xanthine oxidoreductase is found in all studied SF. Capture ELISA showed levels up to 0.762 and 0.143 mg/mL in SF of RA and other joint inflammations patients, respectively. In most cases, more than 50% of synovial XOR is present as oxidase form. Positive correlation was observed between enzyme level and the disease severity since RA patients had a significantly high enzyme amount compared to patients with other less severe arthritic pathologies. These results suggest that the enzyme could well be involved in joint inflammation probably by producing reactive oxygen species

Expresión de neuropéptidos en la articulación temporomandibular, 1: GGRP y articulación temporomandibular / Neuropeptides expression in the temporomandibular joint, 1: CGRP and temporomandibular joint

Antecedentes: neuropéptidos como el péptido relacionado con el gen de la calcitonina (CGRP), sustancia P (SP) y neurokinina A (NKA) se relacionan con desarrollo y progresión de enfermedad degenerativa articular. Estudios previos mostraron su rol en respueta vascular y nociceptiva en artritis y su papel modulardor en hiperalgesia y dolor de tipo artrítico, comprobando su presencia en líquido sinovial de articulación temporomandibular. Propósito: evaluar presencia y contenido de neuropéptidos en tejidos retrodiscal hiperplásico de la articulación temporomandibular en pacientes con enfermedad degenerativa articular mediante radioinmunoensayo. Métodos: ocho pacientes de sexo femenino (15 articulaciones), premenopáusicas, no embarazadas ni lactando por un año, fueron diagnosticadas con enfermedad articular degenerativa (osteoartrosis). Se registraron niveles de dolor en escala visual análoga, donde 0 es ausencia de dolor y 16 dolor agudo; se clasificó la degeneración ósea entre leve, moderada y severa, de acuerdo con hallazgos de resonanacia nuclear magnética. Las pacientes fueron sometidas a cirugía abierta de ATM donde se tomaron las muestras. Los especímenes se colocaron en bloques plásticos con medio congelante y se almacenaron a -700C hasta la extracción de los neuropéptidos por radioinmunoensayo con el estuche específico para cada uno. Resultados: se estableció una relacion directamente proporcional entre grado de degeneración ósea y expresión de CGRP, y entre clasificación de osteoartrosis con escala visual análoga. Los hallazgos mostraron correlación definitiva entre niveles de dolor y expresión del péptido relacionado con el gen de la calcitonina. Conclusiones: CGRP, SP y NKA, si se expresan en tejido retrodiscal de ATM en humanos con enfermedad degenerativa articular, relacionándose CGRP directamente con niveles de osteoartrosis y dolor

Incremento en la produccion de colagenasa en incubado de sinoviocitos de pacientes com artritis reumatoidea y osteoartrosis / Collagenase production increases in rheumatoid arthritis and ostheoarthritis synoviocytes incubated

El cartílago articular es un tejido paucicelular, con colágeno y proteoglicanos en la matriz extracelular. Su degradación es función de los sinoviocitos, que segregan metaloproteasas que catabolizan a los proteoglicanos. Se distinguen los sinoviocitos A o macrofágicos y los sinoviocitos B o fibroblásticos. La destrucción de proteoglicanos puede ser LT- dependiente o independiente. Nuestro objetivo fue estudiar ex vívo el rol de los sinoviocitos, sin la influencia del sistema inmune. Líquido sinovial de pacientes de ambos sexos, 70ñ2años, con OA(6) y AR(6), vírgenes de tratamiento, se centrifugó 30 minutos a 1500 g, para aislar sinoviocitos. El sedimento se incubó 6 hs en medio Dulbecco-Eagles, con 26 mM de HEPES Gibco, NaHCO3 ( 0.5g/l), glutamina (2 mM), estreptomicina (100mg/l), penicilina (1 U/ml) y anfotericina B (2.5mg/l). Identidad y viabilidad celulares se determinaron con técnicas citopatológicas. Las muestras control provinieron de artritis traumática o patología osteoarticular no-inflamatoria. Con anticuerpos monoclonales anti-MMPs(10mg/ml), previo bloqueo de producción de proteínas inespecíficas con albúmina sérica bovina, se midió actividad colagenasa (MMP-1) antes y después de incubar con ELISA-doble-sandwich. Con streptavidin-peroxidasa se desarrolló color y por absorbancia a 410 nm, se leyó la complejación de los anticuerpos marcados. La secreción de MMP-1 por sinovio-citos AR fue 1373ñ115 ng/ml. Con 6 hs de incubado aumentó hasta 2143ñ132ng/l (-56 por ciento)(p<0.0001), probablemente por la hipercelularidad. Los sinoviocitos OA secretaron 276 ñ 23 ng/ml , y 542 ñ 47 ng/ml tras la incubación (96 por ciente)(p<0.001). Hay paralelismo entre la producción de MMP-1 y la observación microscópica. Sinoviocitos con abundante citoplasma corresponden a altos niveles de enzima. La baja secreción de MMPs responde a escasa población celular y núcleos picnóticos. Aunque en AR la producción de MMPs fue 4.6 veces mayor que en OA, en cambio el incremento porcentual tras la incubación fue casi el doble en OA que en AR. Esos resultados confirman que la producción enzimática varía con la inflamación, que es mayor en los procesos agudos, y que la incubación de sinoviocitos permite detectar cambios patológicos locales

Source and significance of raised serum and synovial fluid enzymes in rheumatoid arthritis

Fifty four patients with RA were included in the study. Blood samples were obtained from all cases and synovial fluid [SF] samples were obtained from 24 patients presenting with knee effusion. Besides routine tests of rheumatoid activity ESR, CRP, the following enzymes were analyzed in serum and SF samples: alkaline phosphatase [ALP], LDH, 5'-nucleotidase [5'NT] and adenosine deaminase [ADA], quantitative determination of LDH isoenzymes and qualitative determination of ALP isoenzymes. Cytological examination of SF was also carried out. Results revealed elevated serum levels of ALP, LDH, 5'NT and ADA in 81%, 27.77%, 23.8% and 50% of cases, respectively. Significantly higher SF levels were found for LDH, 5'NT and ADA when compared with serum levels. The values were 240.5 +/- 149.6 U/l, 10.72 +/- 9.05 U/l, 52.79 +/- 27.78 U/l for SF and 182.75 +/- 97.46, 5.46 +/- 3.57 and 23.6 +/- 12.36 for serum enzymes, respectively. SF serum ratio demonstrated a value less than one for ALP, but greater than one for LDH, 5'NT and ADA, this signifies that ALP originates mainly from the liver and passes to joint fluid due to increased permeability of synovial membrane, while the other three enzymes most probably originate from the joint itself and diffuse to blood stream. Serum LDH isoenzyme pattern was predominantly of LD1 and LD2 25.1 +/- 5.44% and 33.42 +/- 8.72%, respectively, while SF LDH isoenzyme pattern was predominantly of LD4 and LD5 20.95 +/- 5.25 and 35.57 +/- 5.78, respectively. This shift of LDH isoenzyme pattern towards the slowly migrating form is probably due to increased demands of the highly cellular SF in RA for anaerobic glycolysis to supply its energy requirements. Serum LDH was significantly elevated in active RA than inactive cases, values being 311.85 +/- 97.86 and 208.12 +/- 104.53, respectively. A positive correlation was found between SF LDH and PMN cell count indicating the value of LDH as a marker of disease activity better than ESR