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ID PMID Title PublicationDate abstract
18304942 New resting energy expenditure prediction equations for patients with rheumatoid arthritis 2008 Apr OBJECTIVES: Resting energy expenditure (REE), one of the main components of total energy expenditure, can be measured via indirect calorimetry and/or predicted from equations. The latter may be misleading in RA, as they do not take into account the metabolic alterations occurring in RA. The objectives of this study are to evaluate the accuracy of widely used REE-predictive equations in RA patients against measured REE and to develop RA-specific equations. METHODS: We assessed REE (via indirect calorimetry and several predictive equations), fat-free mass (FFM; via bioelectrical impedance) and disease activity (CRP) in RA patients and healthy controls. Data from 60 RA patients (experimental group) were used to assess the accuracy of existing REE equations and to develop new equations. The new equations were validated in an independent cross-validation group of 22 RA patients. These two groups were merged and two final equations were developed. RESULTS: All equations significantly under-predicted measured REE (from 15% to 18.2%, all at P < 0.001) in the RA experimental group, but not in the control group. After both equations demonstrated a high validity in the cross-validation group, the new final REE prediction equations developed from the total RA sample (n = 82) were: Model 1: REE (kcal/day) = 126.1 x FFM(0.638) x CRP(0.045) (R(2) = 0.70) and Model 2: REE (kcal/day) = 598.8 x weight(0.47) x age(-0.29) x CRP(0.066) (R(2) = 0.62). CONCLUSION: The new equations provide an accurate prediction of REE in RA patients and could be used for clinical monitoring of resting metabolism of these patients without the requirement for specialized personnel.
17642251 [Economic evaluation of a new treatment for rheumatoid arthritis]. 2007 Jul In recent years, new biologic agents have been approved for the treatment of rheumatoid arthritis. These agents may yield clear clinical benefits but impose greater costs than standard treatment. Economic evaluations have been used to provide evidence for the cost-effectiveness of treatment. We described two approaches to the cost-effectiveness analysis of the treatment of rheumatoid arthritis-micro-level economic evaluation based on quality-adjusted life years (QALYs) and macro-level economic evaluation based on disability-adjusted life years (DALYs).
18465661 Herpesviruses and autoimmunity. 2008 May Herpesvirus infection, in particular EBV infection, has been implicated in several major autoimmune diseases, including systemic lupus erythematosus (SLE), multiple sclerosis (MS) and rheumatoid arthritis (RA). Herpesvirus infection has potential roles in both initiating the autoimmune process and exacerbating disease progression. In particular, EBV has a proposed role in initiating the anti-nucleoprotein antibodies that are characteristic of SLE through molecular mimicry. There is also evidence to suggest that there is productive infection with EBV in the brain lesions of MS patients and in the synovium of RA patients. Research has been conducted in a mouse gamma-herpesvirus model, as it serves as a useful model for productive infection within autoimmune target tissues. The novel mechanisms by which EBV could contribute bystander effects by amplification of innate immune responses, along with preclinical and epidemiological studies into the role of herpesviruses in SLE, MS and RA, and clinical studies into the potential benefit of antiviral therapy, are discussed in this review.
17650648 [Influence of moxibustion on JAK-STAT signal transduction pathways of synovial cells in rh 2007 Apr OBJECTIVE: To observe the effect of moxibustion on Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway of synovial cells in rheumatoid arthritis (RA) rabbits for revealing the underlying mechanism of moxibustion in the treatment of RA. METHODS: A total of 30 rabbits (Japanese Big-ear White species) were randomized (stratified random) into control, model and moxibustion groups with 10 cases in each. RA model was established by injection of Freund's Complete Adjuvant (FCA, 0.5 mL/kg) into the animal's bilateral joint cavities. Moxibustion was applied to bilateral "Shenshu" (BL 23), 5 cones every time, once daily (except Sundays), 3 weeks altogether. The synovial tissue of joint was sampled for analyzing the expression of signal molecules associated with JAK-STAT pathway with gene chip and bioinformation analytical techniques. RESULTS: Compared with normal control group, the perimeters of both knee joints in model group increased significantly from the 3rd day to 21st day after injection of FCA (P < 0.01), while compared with model group, those in moxibustion group decreased considerably from the 6th day on (P < 0.05, 0.01). In comparison with control group, JAK-STAT pathway-associated genes with up-regulated expression in model group were C/EBP beta, CBP, CRP, GATA3, IFNAR1, IFNAR2, IFNGR2, IL-10Rb, INDO, SH2B, STAT3, STAT6, JAK3 and GP130, and those with down-regulated expression were A2M, MIG and IL-2Rr, suggesting an abnormal activation of JAK-STAT pathway; while in comparison with model group, the related gene up-regulated in moxibustion group in the expression was IL22R and those down-regulated were Cyclin D1, C/EBP beta, CRP, GATA3, IFNAR2, INDO, JAK2, JAK3, V-JUN, STAT3, STAT5, SH2B and OSM, showing that moxibustion had an apparent inhibitory effect on AR-induced abnormal activation of some genes as C/EBP beta, GATA3, IFNAR2, INDO, etc. CONCLUSION: Moxibustion can resist inflammation and eliminate swelling in RA rabbits, which may be closely with its effect in inhibiting abnormal activation of JAK-STAT pathway in synovial cells.
17806035 The relationship between physical function, knowledge of disease, social support and self- 2007 Sep The purposes of this study were to explore the relationships between physical function, knowledge of disease, social support, and self-care behavior in patients with rheumatoid arthritis and to examine the predictive variables of self-care behavior. A cross-sectional design was developed and implemented in which 115 subjects with rheumatoid arthritis were recruited from two hospitals located in southern Taiwan. Findings demonstrated a significantly positive correlation between self-care behavior and age, physical function and social support. Age and social support represented the effective predictors of self-care behavior, explaining 13.4% of total self-care behavior variance. Study results suggest that healthcare providers should better understand the predictive factors of self-care behavior, design effective interventions and provide therapeutic information in order to facilitate better self-care behavior in patients with rheumatoid arthritis.
16973113 Gene therapy works in animal models of rheumatoid arthritis...so what! 2006 Oct Rheumatoid arthritis (RA) is a systemic disease with polyarticular manifestation of chronic inflammation in the knees and small joints of hand and feet. The current systemic anti-tumor necrosis factor (TNF)-alpha therapies with biologics ameliorate disease in 60% to 70% of RA patients. However, biologics must be given systemically in relatively high dosages to achieve constant therapeutic levels in the joints, and side effects have been reported. To this end, local gene delivery can provide an alternative approach to achieve high, long-term expression of biologics, optimizing the therapeutic efficacy and minimizing systemic exposure. Evidence from animal models convincingly supports the application of local gene therapy in rheumatoid arthritis, but preclinical studies remain necessary to evaluate the merge of cell-specific targeting, viral vector development, and disease-regulated transgene expression to optimize efficacy and safety.
18930988 Clinical and radiological efficacy of initial vs delayed treatment with infliximab plus me 2009 Jul OBJECTIVES: To compare the clinical and radiological efficacy of initial vs delayed treatment with methotrexate (MTX) and infliximab (IFX) in patients with recent onset rheumatoid arthritis (RA). METHODS: In a post hoc analysis of the BeSt study (for Behandel Stratagieen, Dutch for treatment strategies), 117 patients who started initial MTX+IFX were compared with 67 patients who started MTX+IFX treatment after failing (disease activity score (DAS)>2.4; median delay to IFX: 13 months) on > or =3 traditional DMARDs. If the DAS remained >2.4, the protocol dictated IFX dose increases to 6, 7.5 and 10 mg/kg. In case of a DAS < or =2.4 for > or =6 months, IFX was tapered and finally stopped. We aimed to correct for allocation bias using propensity scores. Functional ability was measured by the Health Assessment Questionnaire (HAQ), radiological progression by Sharp/van der Heijde scoring (SHS). RESULTS: Baseline differences between the initial and delayed groups were no longer significant after propensity score adjustment. At 3 years after baseline, patients treated with initial MTX+IFX experienced more improvement in HAQ over time and were less likely to have SHS progression than patients treated with delayed MTX+IFX (p = 0.034). At 2 years after IFX initiation, more patients in the initial group compared with the delayed group could discontinue IFX after a good response (56% vs 29%, p = 0.008). CONCLUSIONS: The results of this post hoc analysis suggest that using MTX+IFX as initial treatment for patients with recent onset RA is more effective than reserving MTX+IFX for patients who failed on traditional DMARDs, with more HAQ improvement over time, more IFX discontinuation and less progression of joint damage.
17464617 Failure mechanisms in uncemented Kudo type 5 elbow prosthesis in patients with rheumatoid 2007 Apr BACKGROUND: Both components of the Kudo type 5 elbow prosthesis can be inserted with or without the use of cement. There have been no reports on the use of this prosthesis with all components uncemented in patients with rheumatoid arthritis. PATIENTS AND METHODS: We reviewed 49 primary uncemented Kudo type 5 elbow prostheses, inserted in 36 patients with rheumatoid arthritis, after mean 6 (2-10) years. Patients were assessed clinically both pre- and postoperatively (pain, instability, motion, ulnar neuropathy) and radiographically. Furthermore, at the time of follow-up clinical outcome was assessed using the Elbow Function Assessment Scale. RESULTS: At review, 7 of 49 elbows had undergone revision because of symptomatic loosening of the ulnar component. In 42 unrevised elbows, clinical outcome was excellent in 29, good in 7, fair in 5, and poor in one. 31 of 42 elbows had no pain; 11 were painful at rest (VAS 1-2) and/or as a result of activity (VAS 1-8). With revision as endpoint, survival was 86% at 6 years. Intraoperative malpositioning of the ulnar component with a valgus or varus alignment of < 5 degrees was associated with worse survival. INTERPRETATION: We found an unexpectedly high rate of loosening of the ulnar component, which was associated with intraoperative malpositioning of the prosthesis. The ulnar component of this prosthesis should not be inserted without cement in patients with rheumatoid arthritis.
18846007 CTLA4Ig and the therapeutic potential of T cell co-stimulation blockade. 2008 Jul It is now generally accepted that CD4 T cells are critical players in the initiation of adaptive immune responses by contributing to the terminal differentiation of effector B cells or CD8+ T cells. It is therefore not surprising that CD4+ T cell activation is tightly controlled through the concerted action of a large number of molecular interactions. Activation requires not only the recognition of the appropriate antigen within a MHC molecule by the T cell receptor TCR but also the delivery of co-stimulatory signals by the antigen presenting cell APC . As a consequence therapeutic modulation of co-stimulatory molecules for instance with CTLA4Ig can lead to interference with T cell activation and consequently abrogation of pro-inflammatory manifestations mediated by cell types influenced by CD4+ T cells such as B cells CD8+ T cells or macrophages. This type of observations provided the rationale for the use of co-stimulatory blockade in autoimmunity and other immunopathology characterized by inappropriate immune activation such as rheumatoid arthritis RA . Several studies have also suggested that besides the non-specific anti-inflammatory effects co-stimulation blockade may in certain conditions promote the induction of long term immune tolerance.
16273310 Evaluating the Korean version of the Multidimensional Health Assessment Questionnaire in p 2006 May Although the Health Assessment Questionnaire (HAQ) and the Modified Health Assessment Questionnaire are useful tools for assessing and monitoring patients with rheumatic diseases, they have a "floor effect" and do not fully reflect the psychological status of patients. Recently, the Multidimensional Health Assessment Questionnaire (MDHAQ) was developed to overcome these shortcomings. We translated the MDHAQ into the Korean language and evaluated its reliability and validity for use with Korean-speaking patients with rheumatoid arthritis (RA). The questionnaire was translated into the Korean language by three translators, who were aware of its objectives, and it was translated back into the English language by three different translators. One question was modified to reflect Korean culture, and imperial measures were changed to metric measures because most Koreans use the metric system. The Korean MDHAQ was administered to 136 patients with RA who were attending the outpatient rheumatology clinic at the Chonnam National University Hospital (Gwangju, South Korea). Test-retest reliability was assessed in 101 patients after 1 week. To assess criterion validity, we compared MDHAQ scores with HAQ scores and the American College of Rheumatology (ACR) functional class. To test construct validity, the MDHAQ was compared to ACR core criteria (tender and swollen joint count, pain, patient's global assessment, physician's global assessment, erythrocyte sedimentation rate, and C-reactive protein), the Beck Depression Inventory (BDI), and the State-Trait Anxiety Inventory (STAI). The test-retest reliability was analyzed by computing kappa statistics, which ranged from 0.60 to 0.76. Cronbach's alpha coefficient ranged from 0.892 to 0.938. The MDHAQ was significantly correlated with the HAQ and ACR functional class (all p<0.001). The correlations between the MDHAQ scores and the ACR core set, BDI, and STAI were all high and statistically significant. The Korean version of the MDHAQ is a reliable, valid tool for assessing Korean patients with RA.
18975350 Prevalence and course of forefoot impairments and walking disability in the first eight ye 2008 Nov 15 OBJECTIVE: To evaluate the prevalence and 8-year course of forefoot impairments and walking disability in patients with rheumatoid arthritis (RA). METHODS: A total of 848 patients with recent-onset RA from 1995 through the present were included. The patients were assessed annually. Pain and swelling of the metatarsophalangeal (MTP) joints, erosions and joint space narrowing of the MTP joints and first interphalangeal joints, and the Health Assessment Questionnaire walking subscale were analyzed using descriptive and correlational techniques. RESULTS: Pain and swelling of > or = 1 MTP joint was present in 70% of patients at baseline, decreasing to approximately 40-50% after 2 years. The forefoot erosion score was > or = 1 in 19% of the patients at baseline, and the prevalence of forefoot erosion increased to approximately 60% after 8 years, during which the mean forefoot erosion score increased from 1.3 to 7.9. At least mild walking disability was present in 57% of patients at baseline, stabilizing at approximately 40% after 1 year. CONCLUSION: The prevalence rates for pain and swelling of the MTP joints and walking disability are initially high and then stabilize, but the prevalence and severity of forefoot joint damage increase during an 8-year course of RA. The findings of this study quantitatively emphasize the importance of forefoot involvement in patients with RA.
16534538 [Productivity costs of rheumatoid arthritis in Germany. Cost composition and prediction of 2006 Oct OBJECTIVE: Identification of predictors for the productivity cost components: (1) sick leave, and (2) work disability in gainfully employed and (3) impaired household productivity in unemployed patients with rheumatoid arthritis (RA) from the societal perspective. METHODS: Investigation of productivity costs was linked to a multicenter, randomized, controlled trial evaluating the effectiveness of clinical quality management in 338 patients with RA. The productivity losses were assessed according to the German Guidelines on Health Economic Evaluation. By means of multivariate logistic regression analyses, predictors of sick leave, work disability (employed patients, n=96), and for days confined to bed in unemployed patient (n=242) were determined. RESULTS: Mean annual costs of 970 EUR arose per person taking into consideration all patients (453 EUR sick leave, 63 EUR work disability, 454 EUR impaired productivity of unemployed patients). Disease activity, disease severity, and impaired physical function were global predictors for all of the cost components investigated. Sick leave costs were predicted by prior sick leave periods and the vocational status blue collar worker, work disability costs by sociodemographic variables (marital status, schooling), and the productivity costs of unemployed patients by impaired mental health and impaired physical functions. CONCLUSIONS: Interventions such as reduction in disease progression and control of disease activity, early vocational rehabilitation measures and vocational retraining in patients at risk of quitting working life, and self-management programs to learn coping strategies might decrease future RA-related productivity costs.
17922664 Understanding the mechanisms of action of methotrexate: implications for the treatment of 2007 Methotrexate has been widely used for the treatment of rheumatoid arthritis (RA). The mechanisms of action of methotrexate are complex. Developed as a folic acid analogue, methotrexate inhibits purine and pyrimidine synthesis, which accounts for its efficacy in the therapy of cancer as well as for some of its toxicities. Recently, many studies have focused on the adenosine-mediated antiinflammatory effects of methotrexate. Certain aspects of methotrexate toxicities are also attributed to adenosine release. A better understanding of the mechanisms of action and toxicities of methotrexate will direct clinicians in their treatment approach and toxicity monitoring. Toward that objective, the latest developments in the pharmacokinetics, mechanism of action, pharmacogenetics, and toxicity of methotrexate are herein discussed.
16765715 Bronchiectasis in rheumatoid arthritis: report of four cases and a review of the literatur 2006 Jun OBJECTIVE: To describe patients with rheumatoid arthritis (RA) who subsequently developed bronchiectasis (BR) and to review the literature on biologic response modifiers (BRM) in relation to infectious complications in the management of these patients. METHODS: We describe 4 patients with RA who were diagnosed with BR out of a cohort of 170 patients. We then performed a comprehensive review of the English language literature on the major clinical trials for RA that involved the BRMs etanercept, infliximab, anakinra, and adalimumab. We focused on inclusion/exclusion criteria involving pulmonary disease and infectious complications in these trials. RESULTS: Of the 4 patients we describe, all developed BR after the diagnosis of RA was established, had positive cyclic citrullinated peptide antibodies, had extra-articular manifestations, and had clinical courses complicated by pneumonia. Management strategies were influenced by these factors in all of the patients described. Of the 16 clinical trials on BRMs reviewed, few studies mentioned BR as an exclusion criteria or reported pneumonia as a specific infectious complication. CONCLUSIONS: BR may be considered as an extra-articular pulmonary manifestation of RA. The infectious complications associated with BR in these patients underscore the management challenge, especially in choosing whether or not to treat with BRMs. Further studies are needed to analyze the infectious complications in RA trials with BRMs, specifically, to assess the risk of patients with BR. Risk stratification in these patients may require screening them for the presence of underlying BR.
16736164 Leflunomide increases the risk of early healing complications in patients with rheumatoid 2006 Oct The aim of this object is to study whether treatment with biological or leflunomide increases the risk of wound-healing complications after elective orthopedic surgery. Between March 2002 and September 2003, 201 patients participated in this study with the following inclusion criteria: (a) Rheumatoid arthritis (RA) or psoriatic arthritis (psA), (b) therapy with: MTX, leflunomide, etanercept, infliximab, adalimumab, anakinra, (c) undergoing elective orthopedic surgery. The incidence of early postoperative wound-healing complications was compared among the different groups. In comparison with patients who received MTX therapy (n = 59), the risk of postoperative wound-healing complications in patients undergoing leflunomide therapy (n = 32) was significantly higher: 13.6% in the MTX group, 40.6% in the leflunomide group (P = 0.01). It is recommended that leflunomide medication for patients with RA undergoing elective orthopedic surgical procedure is interrupted preoperatively to reduce the risk of early wound-healing complications or infections.
17952482 Sulfasalazine-induced hypersensitivity syndrome and hemophagocytic syndrome associated wit 2008 Mar A 58-year-old woman with rheumatoid arthritis (RA) developed fever, skin eruptions, leukocytopenia, and thrombocytopenia, 3 weeks after treatment with sulfasalazine. A skin biopsy showed hydropic degeneration of keratinocytes and lymphocytic infiltrate. A bone marrow aspiration demonstrated an increased number of macrophages with hemophagocytosis. Although serologic tests for Epstein-Barr virus (EBV) indicated a previous infection, EBV deoxyribonucleic acid was detected in her serum by polymerase chain reaction. Cessation of sulfasalazine and administration of steroids led to dramatic improvement. This case illustrates that the hemophagocytic syndrome associated with reactivation of EBV can occur as part of drug hypersensitivity reactions in RA patients taking sulfasalazine.
16397736 Peripheral bone status in rheumatoid arthritis evaluated by digital X-ray radiogrammetry a 2006 Jan The development of secondary osteoporosis in rheumatoid arthritis (RA) has recently become well recognized, characterized by demineralization at axial and in particular periarticular peripheral bone sites. Our aim was to evaluate multisite quantitative ultrasound (QUS) compared to digital X-ray radiogrammetry (DXR) by the quantification of cortical bone loss dependent on the severity of RA. Fifty-three patients with verified RA underwent QUS measurements (Sunlight Omnisense 7000) with estimation of the speed of sound (QUS-SOS) at the distal radius and at the phalanx of the third digit. Also, bone mineral density (DXR-BMD) and metacarpal index (DXR-MCI) were estimated on metacarpals II-IV using DXR technology. Additionally, Larsen score and Steinbroker stage were assessed. Disease activity of RA was estimated by disease activity score 28 (DAS 28). For the group with minor disease activity (3.2 5.1), QUS-SOS of the radius revealed a significant correlation to DXR-BMD (R = 0.71) and DXR-MCI (R = 0.84), whereas for QUS-SOS (phalanx) no significant association to the DXR parameters was shown. The DXR parameters and, to a lesser extent, the QUS data also demonstrated pronounced declines in the case of accentuated disease activity (DAS > 5.1). Both DXR-BMD (-25.9 %, P < 0.01) and DXR-MCI (-38.6 %, P < 0.01) revealed a notable reduction dependent on the severity of RA. Otherwise, QUS-SOS marginally decreased, with -2.6% (radius) and -3.9% (phalanx). DXR revealed a significant reduction of DXR-BMD as well as DXR-MCI dependent on the severity of RA and surpassed multisite QUS as a promising diagnostic tool.
16395746 Evolution of antinuclear antibodies and clinical patterns in patients with active rheumato 2006 Jan OBJECTIVE: To investigate the effect of longterm infliximab therapy on serum levels of fluorescent antinuclear and anti-double and single-stranded DNA antibodies (FANA, anti-dsDNA, anti-ssDNA) in patients with rheumatoid arthritis (RA), and their possible association with clinical evolution. METHODS: Sera from 58 RA patients, treated for one to 3 years with infliximab, were retrospectively analyzed. Matched control groups were RA patients treated with corticosteroids or methotrexate. FANA were tested using HEp-2 cells, and anti-dsDNA and anti-ssDNA IgG by ELISA. After 28 months of infliximab therapy, clinical status was evaluated in 43/58 patients with uninterrupted therapy and associations with autoantibody levels were investigated. Data were documented for patients who discontinued infliximab. RESULTS: Over the 3 year period, significant increases in FANA and anti-ssDNA IgG levels were observed in infliximab treated patients (p < 0.001 and p < 0.01, respectively). In 43 patients with an uninterrupted infliximab regimen, association was found between high FANA (>or= 1/1280) and lower age (p = 0.048) and patient's assessment of infliximab's efficacy (p = 0.014). Three patients developed anti-dsDNA IgG, preceded by high anti-ssDNA IgG levels, and one of them developed a lupus-like syndrome. Neither the initial presence of high FANA levels nor their increase >or= 1/1280 was significantly associated with discontinuation of infliximab. In contrast, at baseline (p = 0.0012) and at the time of infliximab discontinuation (p = 0.0078), anti-ssDNA IgG (>or= 500 arbitrary units) were more frequent in 7 patients who stopped infliximab due to skin or systemic anaphylactoid reactions. CONCLUSION: Monitoring of serum FANA, anti-dsDNA, and anti-ssDNA IgG antibodies provided predictors of lupus-like symptoms and/or anaphylactoid reactions in patients with RA.
17304274 [Treatment of rheumatic patients in a warm climate abroad]. 2007 Feb 15 Adult rheumatic and psoriatic patients in Norway have been offered state-funded treatment in a warm climate since 1976. The offer has since then been extended to other patient groups with chronic diseases. We here present a program, which mainly consists of intensive physical treatment in a warm, sunny and dry climate, for adults with chronic rheumatic disease. The article is based on available statistics and literature found by searching Medline, PubMed and Cochrane. Patients are selected for the program according to diagnosis, physical function and disease severity and activity. The majority of the patients have rheumatoid arthritis, ankylosing spondylitis or psoriatic arthritis. The treatment is demanding and is not suitable for all. There are two closing dates for applications, 1. October and 1. February.
17763413 Development of an ex vivo cellular model of rheumatoid arthritis: critical role of CD14-po 2007 Sep OBJECTIVE: To establish an ex vivo cellular model of pannus, the aberrant overgrowth of human synovial tissue (ST). METHODS: Inflammatory cells that infiltrated pannus tissue from patients with rheumatoid arthritis (RA) were collected without enzyme digestion, and designated as ST-derived inflammatory cells. Single-cell suspensions of ST-derived inflammatory cells were cultured in medium alone. Levels of cytokines produced in culture supernatants were measured using enzyme-linked immunosorbent assay kits. ST-derived inflammatory cells were transferred into the joints of immunodeficient mice to explore whether these cells could develop pannus. CD14 and CD2 cells were depleted by negative selection. RESULTS: Culture of ST-derived inflammatory cells from 92 of 111 patients with RA resulted in spontaneous reconstruction of inflammatory tissue in vitro within 4 weeks. Ex vivo tissue contained fibroblasts, macrophages, T cells, and tartrate-resistant acid phosphatase-positive multinucleated cells. On calcium phosphate-coated slides, ST-derived inflammatory cell cultures showed numerous resorption pits. ST-derived inflammatory cell cultures continuously produced matrix metalloproteinase 9 and proinflammatory cytokines associated with osteoclastogenesis, such as tumor necrosis factor alpha, interleukin-8, and macrophage colony-stimulating factor. More importantly, transferring ST-derived inflammatory cells into the joints of immunodeficient mice resulted in the development of pannus tissue and erosive joint lesions. Both in vitro development and in vivo development of pannus tissue by ST-derived inflammatory cells were inhibited by depleting CD14-positive, but not CD2-positive, cells from ST-derived inflammatory cells. CONCLUSION: These findings suggest that overgrowth of inflammatory cells from human rheumatoid synovium simulates the development of pannus. This may prove informative in the screening of potential antirheumatic drugs.