RESUMEN
OBJECTIVE: Infliximab treatment results in a decrease in synovial cellularity as early as 48 hours after initiation of therapy in patients with rheumatoid arthritis (RA). This study was undertaken to investigate whether infliximab induces apoptosis within the first 24 hours after infusion. METHODS: The percentage of apoptotic cells was determined by flow cytometry in blood drawn from 21 patients directly before, 1 hour after, and 24 hours after infliximab infusion. Synovial tissue samples obtained before, 1 hour after (n = 5), or 24 hours after (n = 5) initiation of therapy were subjected to immunohistochemistry to detect active caspase 3 and to TUNEL assay and electron microscopy to detect apoptosis. In addition, plasma levels of nucleosomes (generated during apoptosis) and C4b/c (an indicator of complement activation) were measured. RESULTS: There were no signs of apoptosis induction in peripheral blood monocytes or lymphocytes after infliximab treatment. Circulating lymphocyte counts were increased within 1 hour after infusion (P < 0.05). There was no definite evidence of apoptosis induction in the synovium, except in 1 patient 24 hours after the infliximab infusion. Consistent with these results, there was no increase in nucleosome levels nor were there signs of complement activation. CONCLUSION: Our findings indicate that the rapid decrease in synovial cellularity observed after initiation of anti-tumor necrosis factor antibody therapy cannot be explained by apoptosis induction at the site of inflammation. It is tempting to speculate that the striking effects on synovial inflammation may be explained by other mechanisms, such as decreased migration toward the synovial compartment and reduced retention in the inflamed synovium.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Antirreumáticos/farmacología , Apoptosis/efectos de los fármacos , Artritis Reumatoide/tratamiento farmacológico , Células Sanguíneas/efectos de los fármacos , Membrana Sinovial/efectos de los fármacos , Anticuerpos Monoclonales/uso terapéutico , Antirreumáticos/uso terapéutico , Células Sanguíneas/citología , Caspasa 3/análisis , Complemento C4b , Femenino , Citometría de Flujo , Humanos , Inmunohistoquímica , Etiquetado Corte-Fin in Situ , Infliximab , Recuento de Linfocitos , Linfocitos/citología , Masculino , Microscopía Electrónica , Persona de Mediana Edad , Monocitos/citología , Nucleosomas/efectos de los fármacos , Membrana Sinovial/citologíaRESUMEN
Dendritic cells (DCs) have been proposed to play a pivotal role in the initiation and perpetuation of rheumatoid arthritis (RA) by presentation of arthritogenic antigens to T cells. We investigated the in vivo characteristics of two major DC subsets, myeloid DCs (mDCs) and plasmacytoid DCs (pDCs), in RA synovial tissue (ST) by measuring their frequency, phenotype, distribution, and cytokine expression. ST was obtained by arthroscopy from 20 RA, 8 psoriatic arthritis, and 10 inflammatory osteoarthritis patients. Levels of CD1c(+) mDCs and CD304(+) pDCs present in ST were quantified by digital image analysis, and their distribution was assessed by double immunolabeling with antibodies against CD3 and CD8. The maturation status and cytokine profile of mDCs and pDCs were quantified by double-immunofluorescence microscopy. In RA patients, the number of CD304(+) pDCs exceeded that of CD1c(+) mDCs, with the majority of infiltrating DCs being CD83(-) or DC-LAMP(-). Synovial pDC numbers were especially increased in RA patients who were positive for rheumatoid factor and anti-citrullinated peptide antibody. mDCs and pDCs were localized adjacent to lymphocyte aggregates. In ST from RA patients, both mDCs and pDCs expressed interleukin (IL)-15. IL-18 and interferon (IFN)-alpha/beta were mainly expressed by pDCs whereas IL-12p70 and IL-23p19 expression was predominant in mDCs. These data characterize the phenotypes of mDCs and pDCs in inflammatory synovitis and define for the first time the cytokine expression profile of these DC subsets.
Asunto(s)
Antígenos CD/metabolismo , Artritis Reumatoide/patología , Citocinas/metabolismo , Células Dendríticas/patología , Inmunoglobulinas/metabolismo , Proteínas de Membrana de los Lisosomas/metabolismo , Glicoproteínas de Membrana/metabolismo , Membrana Sinovial/patología , Adulto , Anciano , Anciano de 80 o más Años , Artritis Reumatoide/inmunología , Autoanticuerpos/inmunología , Agregación Celular , Recuento de Células , Movimiento Celular , Células Dendríticas/metabolismo , Femenino , Humanos , Inflamación , Masculino , Persona de Mediana Edad , Células Mieloides/patología , Fenotipo , Membrana Sinovial/metabolismo , Linfocitos T/citología , Antígeno CD83Asunto(s)
Artritis Reumatoide/patología , Artritis Reumatoide/terapia , Biomarcadores , Macrófagos/patología , Membrana Sinovial/patología , Anticuerpos/uso terapéutico , Artritis Reumatoide/inmunología , Biopsia , Quimiocina CCL2/inmunología , Humanos , Inmunoterapia , Proteínas de la Membrana/inmunología , Receptor de Anafilatoxina C5a , Receptores de Complemento/inmunología , Membrana Sinovial/inmunologíaRESUMEN
OBJECTIVE: The transforming growth factor beta superfamily member macrophage inhibitory cytokine 1 (MIC-1) is expressed upon macrophage activation, regulated by the p53 pathway, and linked to clinical events in atherosclerosis and cancer. Since rheumatoid arthritis (RA) shares similar etiopathologic mechanisms with the above diseases, we sought to determine the clinical utility of determining MIC-1 serum levels and MIC-1 genotype in the management of RA. METHODS: Ninety-one RA patients were recruited. Serum was collected from 83 of these patients and synovial biopsy samples were collected from the remaining 8 patients. Of the 83 patients from whom serum was collected, 61 were treated on an outpatient basis (defined as having nonsevere disease), and 22 patients went on to undergo hemopoietic stem cell transplantation (HSCT) (defined as having severe disease). RESULTS: Serum levels of MIC-1 were higher in RA patients and reflected disease severity independently of classic disease markers. MIC-1 was detected in rheumatoid synovial specimens, and allelic variation of MIC-1 was associated with earlier erosive disease and severe treatment-resistant chronic RA. Additionally, algorithms including serum and/or allelic variation in MIC-1 predicted response to HSCT, the presence of severe disease, and joint erosions. CONCLUSION: Determination of serum levels of MIC-1 and MIC-1 genotype may be clinically useful in the management of RA as well as in selection of patients for HSCT, since they predict disease course and response to therapy. The data indicate a potential role for MIC-1 in RA pathogenesis. These results warrant larger prospective studies to fully delineate and confirm a role for MIC-1 genotyping and serum estimation in patient selection for HSCT and in the management of RA.
Asunto(s)
Artritis Reumatoide/sangre , Proteínas Morfogenéticas Óseas/sangre , Articulaciones/fisiopatología , Adulto , Anciano , Artritis Reumatoide/fisiopatología , Biomarcadores/sangre , Proteínas Morfogenéticas Óseas/genética , Proteína C-Reactiva/metabolismo , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Regulación de la Expresión Génica , Factor 15 de Diferenciación de Crecimiento , Trasplante de Células Madre Hematopoyéticas , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Membrana Sinovial/metabolismo , Membrana Sinovial/patología , Factor de Necrosis Tumoral alfa/sangreRESUMEN
Successive studies from one academic center (Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands) have consistently suggested that synovial tissue expression of sublining macrophages may be a biomarker of clinical response to therapeutic intervention in rheumatoid arthritis (RA) clinical trials. A proof-of-concept, randomized clinical trial was completed at a second academic center (St. Vincent's University Hospital, Dublin, Ireland), and the relationship between the change in disease activity and the change in sublining macrophages in distinct treatment cohorts was determined. The preliminary findings were not conclusive, but appeared to support a role for sublining CD68+ macrophages as a biomarker of clinical response to therapeutic intervention in cohorts of patients with RA.
Asunto(s)
Artritis Reumatoide/terapia , Macrófagos/citología , Membrana Sinovial/inmunología , Antígenos CD/análisis , Antígenos de Diferenciación Mielomonocítica/análisis , Biomarcadores , Humanos , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Membrana Sinovial/citologíaRESUMEN
Synovial tissue of rheumatoid arthritis (RA) patients is characterised by an influx and retention of CD97-positive inflammatory cells. The ligands of CD97, CD55, chondroitin sulfate B, and alpha5beta1 (very late antigen [VLA]-5) are expressed abundantly in the synovial tissue predominantly on fibroblast-like synoviocytes, endothelium, and extracellular matrix. Based upon this expression pattern, we hypothesise CD97 expression to result in accumulation of inflammatory cells in the synovial tissue of RA patients. To determine the therapeutic effect of blocking CD97 in an animal model of RA, collagen-induced arthritis was induced in a total of 124 DBA/J1 mice. Treatment was started on day 21 (early disease) or on day 35 (longstanding disease) with the blocking hamster anti-mouse CD97 monoclonal antibody (mAb) 1B2, control hamster immunoglobulin, or NaCl, applied intraperitoneally three times a week. The paws were evaluated for clinical signs of arthritis and, in addition, examined by radiological and histological analysis. Mice receiving 0.5 mg CD97 mAb starting from day 21 had significantly less arthritis activity and hind paw swelling. Furthermore, joint damage and inflammation were reduced and granulocyte infiltration was decreased. When treatment was started on day 35, CD97 mAb treatment had similar effects, albeit less pronounced. The results support the notion that CD97 contributes to synovial inflammation and joint destruction in arthritis.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Artritis Experimental/inmunología , Artritis Experimental/terapia , Inmunoterapia/métodos , Glicoproteínas de Membrana/inmunología , Animales , Artritis Experimental/patología , Modelos Animales de Enfermedad , Interleucina-6/sangre , Articulaciones/inmunología , Articulaciones/patología , Masculino , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos DBA , Receptores Acoplados a Proteínas G , Membrana Sinovial/inmunología , Membrana Sinovial/patología , Células TH1/inmunología , Células Th2/inmunologíaRESUMEN
OBJECTIVE: Chemokines such as CCL2/monocyte chemotactic protein 1 (MCP-1) play a key role in leukocyte migration and are potential targets in the treatment of chronic inflammatory disorders. The objective of this study was to evaluate the effects of human anti-CCL2/MCP-1 monoclonal antibody (ABN912) treatment in patients with rheumatoid arthritis (RA). METHODS: Patients with active RA were enrolled in a randomized, placebo-controlled, dose-escalation study of ABN912. Infusions were administered on day 1 and day 15. In the dose-escalation phase, 4 cohorts of 8 patients each underwent serial arthroscopic biopsy of synovial tissue. Immunohistochemistry and digital image analysis were used to characterize biomarkers in synovial tissue. Laboratory evaluation included pharmacokinetic analysis and immunotypic studies of peripheral blood mononuclear cells. To assess the clinical effects of treatment with ABN912, an additional 21 patients were treated with the highest dose tolerated. RESULTS: The total study population comprised 45 patients: 33 patients received ABN912, and 12 patients received placebo. ABN912 treatment was well tolerated. Unexpectedly, there was a dose-related increase in ABN912-complexed total CCL2/MCP-1 levels in peripheral blood, up to 2,000-fold. There was no detectable clinical benefit of ABN912 compared with placebo, nor did treatment with the study drug result in a significant change in the levels of biomarkers in synovial tissue and peripheral blood. CONCLUSION: ABN912 treatment did not result in clinical or immunohistologic improvement and may have been associated with worsening of RA in patients treated with the highest dose. The results might be related to the greatly increased level of total CCL2/MCP-1 in serum that was observed following treatment with ABN912. This observation may be relevant for a variety of antibody-based therapies.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Quimiocina CCL2/inmunología , Factores Inmunológicos/uso terapéutico , Adulto , Anciano , Anticuerpos Monoclonales/farmacocinética , Antirreumáticos/farmacocinética , Artritis Reumatoide/metabolismo , Artritis Reumatoide/fisiopatología , Biomarcadores/metabolismo , Biopsia , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Factores Inmunológicos/farmacocinética , Masculino , Persona de Mediana Edad , Membrana Sinovial/efectos de los fármacos , Membrana Sinovial/metabolismo , Membrana Sinovial/patología , Resultado del TratamientoRESUMEN
Analysis of biomarkers in synovial tissue is increasingly used in the evaluation of new targeted therapies for patients with rheumatoid arthritis (RA). This study determined the intrarater and inter-rater reliability of digital image analysis (DIA) of synovial biopsies from RA patients participating in clinical trials. Arthroscopic synovial biopsies were obtained before and after treatment from 19 RA patients participating in a randomized controlled trial with prednisolone. Immunohistochemistry was used to detect CD3+ T cells, CD38+ plasma cells and CD68+ macrophages. The mean change in positive cells per square millimetre for each marker was determined by different operators and at different times using DIA. Nonparametric tests were used to determine differences between observers and assessments, and to determine changes after treatment. The intraclass correlations (ICCs) were calculated to determine the intrarater and inter-rater reliability. Intrarater ICCs showed good reliability for measuring changes in T lymphocytes (R = 0.87), plasma cells (R = 0.62) and macrophages (R = 0.73). Analysis by Bland-Altman plots showed no systemic differences between measurements. The smallest detectable changes were calculated and their discriminatory power revealed good response in the prednisolone group compared with the placebo group. Similarly, inter-rater ICCs also revealed good reliability for measuring T lymphocytes (R = 0.68), plasma cells (R = 0.69) and macrophages (R = 0.72). All measurements identified the same cell types as changing significantly in the treated patients compared with the placebo group. The measurement of change in total positive cell numbers in synovial tissue can be determined reproducibly for various cell types by DIA in RA clinical trials.
Asunto(s)
Artritis Reumatoide/patología , Interpretación de Imagen Asistida por Computador/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Membrana Sinovial/patología , Artritis Reumatoide/tratamiento farmacológico , Humanos , Prednisolona/farmacología , Prednisolona/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Reproducibilidad de los Resultados , Estadísticas no Paramétricas , Membrana Sinovial/efectos de los fármacosRESUMEN
Synovial fluid from patients with various arthritides contains procoagulant, cell-derived microparticles. Here we studied whether synovial microparticles modulate the release of chemokines and cytokines by fibroblast-like synoviocytes (FLS). Microparticles, isolated from the synovial fluid of rheumatoid arthritis (RA) and arthritis control (AC) patients (n = 8 and n = 3, respectively), were identified and quantified by flow cytometry. Simultaneously, arthroscopically guided synovial biopsies were taken from the same knee joint as the synovial fluid. FLS were isolated, cultured, and incubated for 24 hours in the absence or presence of autologous microparticles. Subsequently, cell-free culture supernatants were collected and concentrations of monocyte chemoattractant protein-1 (MCP-1), IL-6, IL-8, granulocyte/macrophage colony-stimulating factor (GM-CSF), vascular endothelial growth factor (VEGF) and intracellular adhesion molecule-1 (ICAM-1) were determined. Results were consistent with previous observations: synovial fluid from all RA as well as AC patients contained microparticles of monocytic and granulocytic origin. Incubation with autologous microparticles increased the levels of MCP-1, IL-8 and RANTES in 6 of 11 cultures of FLS, and IL-6, ICAM-1 and VEGF in 10 cultures. Total numbers of microparticles were correlated with the IL-8 (r = 0.91, P < 0.0001) and MCP-1 concentrations (r = 0.81, P < 0.0001), as did the numbers of granulocyte-derived microparticles (r = 0.89, P < 0.0001 and r = 0.93, P < 0.0001, respectively). In contrast, GM-CSF levels were decreased. These results demonstrate that microparticles might modulate the release of chemokines and cytokines by FLS and might therefore have a function in synovial inflammation and angiogenesis.
Asunto(s)
Artritis Reumatoide/metabolismo , Quimiocinas/metabolismo , Citocinas/metabolismo , Líquido Sinovial/metabolismo , Adulto , Anciano , Artritis Reumatoide/patología , Células Cultivadas , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Líquido Sinovial/citología , Líquido Sinovial/fisiologíaRESUMEN
OBJECTIVE: Given the heterogeneity of gene expression patterns and cellular distribution between rheumatoid arthritis (RA) synovial tissues, we sought to determine whether this variability was also reflected at the level of the fibroblast-like synoviocyte (FLS) cultured from RA synovial tissues. METHODS: Gene expression profiles in FLS cultured from synovial tissues obtained from 19 RA patients were analyzed using complementary DNA microarrays and hierarchical cluster analysis. To validate the subclassification, we performed prediction analysis and principal components analysis. Genes that differed significantly in their expression between FLS cultures were selected using Statistical Analysis of Microarrays software. Real-time quantitative polymerase chain reaction was performed to validate the microarray data. Immunocytochemistry was applied to study the expression of the genes of interest in FLS and synovial tissues. RESULTS: Hierarchical clustering identified 2 main groups of FLS characterized by distinctive gene expression profiles. FLS from high-inflammation synovial tissues revealed increased expression of a transforming growth factor beta/activin A-inducible gene profile that is characteristic of myofibroblasts, a cell type considered to be involved in wound healing, whereas increased production of growth factor (insulin-like growth factor 2/insulin-like growth factor binding protein 5) appeared to constitute a characteristic feature of FLS derived from low-inflammation synovial tissues. The molecular feature that defines the myofibroblast-like phenotype was reflected as an increased proportion of myofibroblast-like cells in the heterogeneous FLS population. Myofibroblast-like cells were also found upon immunohistochemical analysis of synovial tissue. CONCLUSION: Our findings support the notion that heterogeneity between synovial tissues is reflected in FLS as a stable trait, and provide evidence of a possible link between the behavior of FLS and the inflammation status of RA synovium.
Asunto(s)
Artritis Reumatoide/patología , Fibroblastos/patología , Membrana Sinovial/patología , Células Cultivadas , Expresión Génica , Humanos , Inmunohistoquímica , Inflamación/patología , Análisis de Secuencia por Matrices de Oligonucleótidos , FenotipoRESUMEN
OBJECTIVE: EMR2 and CD97 are closely related members of the epidermal growth factor (EGF)-TM7 family of adhesion class 7-span transmembrane (TM7) receptors. Chondroitin sulfates (CS) have recently been identified as ligands for EMR2 and CD97. CS have been implicated in the pathogenesis of rheumatoid arthritis (RA). We undertook this study to determine the expression of EMR2 and the distribution of EMR2 and CD97 ligands within RA synovial tissue (ST). METHODS: ST samples were obtained by arthroscopy from 19 patients with RA, 13 patients with inflammatory osteoarthritis (OA), and 13 patients with reactive arthritis (ReA). Immunohistochemistry was performed with a monoclonal antibody against EMR2, and stained STs were analyzed by digital image analysis. Coexpression of EMR2 with cell lineage- and activation-specific markers was determined by double immunofluorescence microscopy. To evaluate the expression of EMR2 and CD97 ligands in RA synovium, binding assays were performed using EMR2- and CD97-specific multivalent fluorescent probes. RESULTS: EMR2 expression in the synovial sublining was found to be significantly higher in RA patients compared with OA and ReA control patients. Most EMR2+ cells were macrophages and dendritic cells expressing costimulatory molecules and tumor necrosis factor alpha. Dermatan sulfate was shown to be the ligand of the largest isoforms of EMR2 and CD97 in rheumatoid synovium. In addition, the smaller isoforms of CD97, but not those of EMR2, bound CD55 on fibroblast-like synoviocytes. CONCLUSION: The EGF-TM7 receptors EMR2 and CD97 are abundantly expressed on myeloid cells in ST of RA patients where their cognate ligands dermatan sulfate and CD55 are detected. These results suggest that these interactions may facilitate the retention of activated macrophages in the synovium.
Asunto(s)
Artritis Reumatoide/metabolismo , Dermatán Sulfato/análisis , Factor de Crecimiento Epidérmico/análisis , Receptores Acoplados a Proteínas G/análisis , Membrana Sinovial/química , Anciano , Antígenos CD , Antígenos CD55/análisis , Femenino , Colorantes Fluorescentes , Humanos , Inmunohistoquímica , Ligandos , Masculino , Glicoproteínas de Membrana/análisis , Microscopía de Interferencia , Persona de Mediana Edad , Osteoartritis/metabolismo , ProhibitinasRESUMEN
OBJECTIVE: To create greater understanding of the changes in synovial tissue parameters that occur in conjunction with clinical response by using an effective therapy, in order to facilitate the planning of future studies with therapeutic agents for rheumatoid arthritis (RA). METHODS: Twenty-one patients with active RA were randomized to receive either oral prednisolone (n = 10) or placebo (n = 11) for 2 weeks. In all patients, synovial tissue biopsy specimens were obtained by arthroscopy directly before treatment and after 14 days of treatment. Immunohistochemical analysis was performed to characterize the cell infiltrate and vascularity. Stained tissue sections were analyzed by digital imaging. Statistical analysis was performed using an analysis of covariance model. RESULTS: After treatment, the mean Disease Activity Score in 28 joints (DAS28) was 2.0 units lower (95% confidence interval [95% CI] 1.0-3.0) in patients who received prednisolone than in those who received placebo. In the prednisolone group, the mean (+/-SD) DAS28 decreased from 6.27 +/- 0.95 to 4.11 +/- 1.43 after therapy; minimal change was observed in the placebo group. For macrophages, the estimated effect of prednisolone was large. Patients receiving active treatment had fewer (mean 628 cells/mm(2) [95% CI 328-927]) macrophages after therapy compared with those receiving placebo. A reduction in the total number of CD68+ macrophages, from 1,038 +/- 283 cells/mm(2) before treatment to 533 +/- 248 cells/mm(2) after treatment, was observed in the prednisolone group. There were clear trends toward decreased infiltration by T cells, plasma cells, and fibroblast-like synoviocytes after active treatment. We observed a trend toward a reduction in alphavbeta3+ newly formed blood vessels and expression of vascular growth factors after prednisolone therapy. CONCLUSION: Prednisolone therapy in RA is associated with a marked reduction in macrophage infiltration in synovial tissue, suggesting that synovial macrophage numbers could be used as a biomarker for clinical efficacy.
Asunto(s)
Antiinflamatorios/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Prednisolona/uso terapéutico , Membrana Sinovial/efectos de los fármacos , Sinovitis/tratamiento farmacológico , Administración Oral , Adulto , Anciano , Antiinflamatorios/administración & dosificación , Antiinflamatorios/farmacología , Artritis Reumatoide/complicaciones , Artritis Reumatoide/patología , Biomarcadores/metabolismo , Recuento de Células , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Articulaciones/efectos de los fármacos , Articulaciones/patología , Macrófagos/efectos de los fármacos , Macrófagos/patología , Masculino , Persona de Mediana Edad , Prednisolona/administración & dosificación , Prednisolona/farmacología , Índice de Severidad de la Enfermedad , Membrana Sinovial/metabolismo , Sinovitis/etiología , Sinovitis/patologíaRESUMEN
OBJECTIVE: Antibodies directed toward citrullinated proteins (e.g., anti-cyclic citrullinated peptide antibodies) are highly specific for rheumatoid arthritis (RA) and are produced locally at the site of inflammation. Although the presence of citrullinated proteins in rheumatoid synovium has been described in the literature, it is uncertain whether their presence is specific for RA. The present study was undertaken to investigate this. METHODS: The local production of the anti-citrullinated protein antibodies was investigated by comparing the concentration of the antibodies (corrected for the total amount of IgG present) in paired samples of serum and synovial fluid from RA patients. The presence of citrullinated proteins in the synovial tissue was investigated by immunohistochemical analysis of synovial tissue from RA patients and from patients with other arthropathies, using a variety of specific antibodies to citrullinated proteins. RESULTS: In RA patients, anti-citrullinated protein antibodies constituted a 1.4-fold higher proportion of IgG in synovial fluid compared with serum, which is indicative of a local production of the antibodies. Immunohistochemical staining of citrullinated proteins was observed in the lining layer, the sublining layer, and in extravascular fibrin deposits in inflamed synovial tissue from RA as well as non-RA patients. CONCLUSION: The presence of citrullinated proteins in the inflamed synovium is not specific for RA, but rather, it may be an inflammation-associated phenomenon. The high specificity of the anti-citrullinated protein antibodies is, therefore, most likely the result of an abnormal humoral response to these proteins.
Asunto(s)
Artritis Reumatoide/metabolismo , Péptidos Cíclicos/metabolismo , Membrana Sinovial/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos/sangre , Anticuerpos/metabolismo , Artritis Reumatoide/sangre , Artritis Reumatoide/inmunología , Estudios de Casos y Controles , Citrulina/inmunología , Citrulina/metabolismo , Femenino , Humanos , Inmunoglobulinas/metabolismo , Inmunohistoquímica/métodos , Artropatías/sangre , Artropatías/metabolismo , Masculino , Persona de Mediana Edad , Péptidos Cíclicos/sangre , Péptidos Cíclicos/inmunología , Coloración y Etiquetado , Membrana Sinovial/inmunologíaRESUMEN
We investigated the therapeutic potential and mechanism of action of IFN-beta protein for the treatment of rheumatoid arthritis (RA). Collagen-induced arthritis was induced in DBA/1 mice. At the first clinical sign of disease, mice were given daily injections of recombinant mouse IFN-beta or saline for 7 days. Disease progression was monitored by visual clinical scoring and measurement of paw swelling. Inflammation and joint destruction were assessed histologically 8 days after the onset of arthritis. Proteoglycan depletion was determined by safranin O staining. Expression of cytokines, receptor activator of NF-kappaB ligand, and c-Fos was evaluated immunohistochemically. The IL-1-induced expression of IL-6, IL-8, and granulocyte/macrophage-colony-stimulating factor (GM-CSF) was studied by ELISA in supernatant of RA and osteoarthritis fibroblast-like synoviocytes incubated with IFN-beta. We also examined the effect of IFN-beta on NF-kappaB activity. IFN-beta, at 0.25 microg/injection and higher, significantly reduced disease severity in two experiments, each using 8-10 mice per treatment group. IFN-beta-treated animals displayed significantly less cartilage and bone destruction than controls, paralleled by a decreased number of positive cells of two gene products required for osteoclastogenesis, receptor activator of NF-kappaB ligand and c-Fos. Tumor necrosis factor alpha and IL-6 expression were significantly reduced, while IL-10 production was increased after IFN-beta treatment. IFN-beta reduced expression of IL-6, IL-8, and GM-CSF in RA and osteoarthritis fibroblast-like synoviocytes, correlating with reduced NF-kappaB activity. The data support the view that IFN-beta is a potential therapy for RA that might help to diminish both joint inflammation and destruction by cytokine modulation.
Asunto(s)
Artritis Experimental/inducido químicamente , Artritis Experimental/prevención & control , Artritis Reumatoide/patología , Colágeno Tipo II , Interferón Tipo I/uso terapéutico , Animales , Antirreumáticos/administración & dosificación , Antirreumáticos/uso terapéutico , Cartílago/efectos de los fármacos , Cartílago/patología , Enfermedades de los Cartílagos/prevención & control , Colágeno Tipo II/inmunología , Citocinas/metabolismo , Modelos Animales de Enfermedad , Esquema de Medicación , Fibroblastos/metabolismo , Fibroblastos/patología , Inflamación/prevención & control , Interferón Tipo I/administración & dosificación , Masculino , Ratones , Ratones Endogámicos DBA , Osteoartritis/patología , Osteoartritis/prevención & control , Proteínas Recombinantes , Membrana Sinovial/patologíaRESUMEN
OBJECTIVE: To generate a molecular description of synovial tissue from rheumatoid arthritis (RA) patients that would allow us to unravel novel aspects of pathogenesis and to identify different forms of disease. METHODS: We applied complementary DNA microarray analysis to profile gene expression, with a focus on immune-related genes, in affected joint tissues from RA patients and in tissues from osteoarthritis (OA) patients as a control. To validate microarray data, real-time polymerase chain reaction was performed on genes of interest. RESULTS: The gene expression signatures of synovial tissues from RA patients showed considerable variability, resulting in the identification of at least two molecularly distinct forms of RA tissues. One class of tissues revealed abundant expression of clusters of genes indicative of an involvement of the adaptive immune response. Detailed analysis of the expression profile provided evidence for a prominent role of an activated signal transducer and activator of transcription 1 pathway in these tissues. The expression profiles of another group of RA tissues revealed an increased tissue remodeling activity and a low inflammatory gene expression signature. The gene expression pattern in the latter tissues was reminiscent of that observed in the majority of OA tissues. CONCLUSION: The differences in the gene expression profiles provide a unique perspective for distinguishing different pathogenetic RA subsets based on molecular criteria. These data reflect important aspects of molecular variation that are relevant for understanding the biologic dysregulation underlying these subsets of RA. This approach may also help to define homogeneous groups for clinical studies and evaluation of targeted therapies.
Asunto(s)
Artritis Reumatoide/genética , Artritis Reumatoide/fisiopatología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Transducción de Señal/fisiología , Transactivadores/genética , Transactivadores/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Artritis Reumatoide/metabolismo , Femenino , Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis/genética , Osteoartritis/metabolismo , Osteoartritis/fisiopatología , Factor de Transcripción STAT1 , Membrana Sinovial/metabolismo , Membrana Sinovial/fisiopatologíaRESUMEN
OBJECTIVE: To determine whether treatment with the chimeric anti-tumor necrosis factor alpha antibody infliximab could reduce cellularity by the induction of apoptosis in synovial tissue. METHODS: Twenty-four rheumatoid arthritis patients with active disease were randomized to receive either infliximab (3 mg/kg) (n = 12) or placebo (n = 12) intravenously. All patients were subjected to arthroscopic synovial biopsy directly before initiation of treatment. A second arthroscopic synovial biopsy of the same index joint was performed 48 hours after the first arthroscopy. After the second arthroscopy, the patients who had initially received placebo were also treated with infliximab in an extension study. A third arthroscopy was performed in all patients on day 28. Immunohistologic analysis was performed to characterize the cell infiltrate. In situ detection of apoptotic cells was performed by TUNEL assay and electron microscopy. RESULTS: At 48 hours after initiation of infliximab treatment, there was a significant reduction in the number of intimal macrophages; this was not observed in the placebo group. The number of sublining macrophages, T cells, and plasma cells also tended to be decreased in infliximab-treated patients, but not in the placebo group. Of interest, we did not detect any increase in the number of apoptotic cells after infliximab treatment. CONCLUSION: Infliximab therapy may reduce the number of inflammatory cells in rheumatoid synovial tissue as soon as 48 hours after initiation of treatment, but apparently not by induction of apoptosis. Conceivably, decreased cell infiltration primarily results from early inhibition of cell migration.
Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Antirreumáticos/administración & dosificación , Apoptosis/inmunología , Artritis Reumatoide/tratamiento farmacológico , Membrana Sinovial/patología , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adulto , Anciano , Anciano de 80 o más Años , Artritis Reumatoide/patología , Linfocitos B/patología , Movimiento Celular/inmunología , Femenino , Humanos , Infliximab , Macrófagos/patología , Macrófagos/ultraestructura , Masculino , Microscopía Electrónica , Persona de Mediana Edad , Células Plasmáticas/patología , Membrana Sinovial/inmunología , Linfocitos T/patologíaRESUMEN
OBJECTIVE: To investigate whether alefacept (a fully human lymphocyte function-associated antigen 3 [LFA-3]/IgG1 fusion protein that blocks the LFA-3/CD2 interaction) is able to reduce the signs and symptoms of joint inflammation in patients with active psoriatic arthritis (PsA). METHODS: Eleven patients with active PsA were treated with alefacept for 12 weeks in an open-label and explorative study. Clinical joint assessment and laboratory assessments were performed at baseline and after 4, 9, 12, and 16 weeks of treatment. Serial synovial tissue (ST) biopsy specimens from an inflamed index joint (knee, ankle, wrist, or metacarpophalangeal joint) were obtained by arthroscopy at baseline and after 4 and 12 weeks of treatment. RESULTS: At the completion of treatment, 6 of 11 patients (55%) fulfilled the Disease Activity Score (DAS) response criteria. Nine patients (82%) fulfilled the DAS response criteria at any point during the study. There was a statistically significant reduction in CD4+ lymphocytes (P < 0.05), CD8+ lymphocytes (P = 0.05), and CD68+ macrophages (P < 0.02) in the ST after 12 weeks of treatment compared with baseline. The ST and peripheral blood of those patients fulfilling the DAS response criteria contained more CD45RO+ cells at baseline and displayed a significant reduction in these cells compared with nonresponding patients. CONCLUSION: The changes in ST, together with the improvement in clinical joint scores, after treatment with alefacept support the hypothesis that T cell activation plays an important role in this chronic inflammatory disease. Furthermore, since alefacept, a T cell-specific agent, led to decreased macrophage infiltration, the data indicate that T cells are highly involved in synovial inflammation in PsA.
Asunto(s)
Artritis Psoriásica/tratamiento farmacológico , Proteínas Recombinantes de Fusión/farmacología , Adulto , Anciano , Alefacept , Artritis Psoriásica/inmunología , Artritis Psoriásica/patología , Artroscopía , Antígenos CD4/análisis , Femenino , Humanos , Inmunohistoquímica , Antígenos Comunes de Leucocito/análisis , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Membrana Sinovial/citología , Membrana Sinovial/inmunología , Linfocitos T/química , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Resultado del TratamientoRESUMEN
OBJECTIVE: Serial synovial biopsy samples are increasingly being used for the evaluation of novel therapies for rheumatoid arthritis (RA). Most studies have used tissues from knee biopsies, but technical improvements have made serial small joint arthroscopy feasible as well. Theoretically, there could be differences in the features of synovial inflammation between various joints as a result of mechanical factors, differences in innervation, and other factors. We therefore undertook this study to compare the cell infiltrate in paired synovial biopsy samples from inflamed knee joints and paired inflamed small joints of patients with RA. METHODS: Nine RA patients with both an inflamed knee joint and an inflamed small joint (wrist or metacarpophalangeal joint) underwent an arthroscopic synovial biopsy of both joints on the same day. Multiple biopsy specimens were collected and stained for macrophages, T cells, plasma cells, fibroblast-like synoviocytes, and interleukin-6 (IL-6) by immunohistochemistry. Sections were evaluated by digital image analysis. RESULTS: There were no significant differences in mean cell numbers for all markers investigated in samples from the knee joint compared with samples from the small joints. We detected statistically significant correlations for the numbers of sublining macrophages, T cells, and plasma cells, as well as for IL-6 expression, between the knee joint and the small joints. However, there was no significant correlation between different joints for the numbers of intimal macrophages or fibroblast-like synoviocytes. CONCLUSION: The results of this study show that the inflammation in one inflamed joint is generally representative of that in other inflamed joints. Therefore, it is possible to use serial samples from the same joint, selecting either large or small joints, for the evaluation of antirheumatic therapies.