Radiographic changes in rheumatoid arthritis patients attaining different disease activity states with methotrexate monotherapy and infliximab plus methotrexate: the impacts of remission and tumour necrosis factor blockade.

OBJECTIVE: To examine the association of radiographic progression and disease activity states in patients with rheumatoid arthritis (RA) treated with methotrexate with or without infliximab. METHODS: Patients (n = 1049) with active RA for 3 years or less and no previous methotrexate treatment were randomly assigned (4 : 5 : 5) to receive methotrexate plus placebo or methotrexate plus infliximab 3 or 6 mg/kg at weeks 0, 2 and 6, and every 8 weeks thereafter to week 46. Disease activity was classified by the simplified disease activity index as remission (< or =3.3), low (>3.3 to < or =11), moderate (>11 to < or =26), high (>26). Radiographic progression was measured as a change from baseline to week 54 in total Sharp score. RESULTS: At weeks 14 and 54, more patients receiving methotrexate plus infliximab than methotrexate plus placebo were in remission (10.7% versus 2.8% week 14; 21.3% versus 12.3% week 54; p<0.001 for both). Methotrexate plus placebo halted radiographic progression only if patients achieved remission within 3 months, whereas methotrexate plus infliximab also halted or minimised progression in patients with low or moderate activity, respectively. Patients with persistently high disease activity levels had much less progression of joint damage if treated with methotrexate plus infliximab versus methotrexate monotherapy. Even with infliximab plus methotrexate there was a direct relationship between disease activity and radiographic changes, although the slope was deflected when compared with methotrexate monotherapy. CONCLUSION: With methotrexate, joint damage progresses even at low and moderate disease activity levels, whereas methotrexate plus infliximab inhibits radiographic progression across all disease activity states.

Ultrasonographic and radiographic results from a two-year controlled trial of immediate or one-year-delayed addition of infliximab to ongoing methotrexate therapy in patients with erosive early rheumatoid arthritis.

OBJECTIVE: To compare the impact of immediate and delayed introduction of anti-tumor necrosis factor therapy on inflammation and structural damage in methotrexate (MTX)-treated patients with early rheumatoid arthritis (RA). METHODS: Twenty-four patients with erosive early RA (duration < 3 years) who were receiving MTX were randomized to receive infliximab 5 mg/kg or placebo infusions at weeks 0, 2, and 6, and then every 8 weeks through week 46. Beginning at week 54 and thereafter, all patients received infliximab 5 mg/kg. Metacarpophalangeal joints were scanned using high-frequency ultrasonography and power Doppler imaging. Radiographs were evaluated using the modified Sharp/van der Heijde scoring system. RESULTS: From baseline to week 54, total synovial thickness was significantly improved in the infliximab + MTX group compared with the placebo + MTX group (median reduction 95.8% versus 37.5%; P = 0.005), as was the total color Doppler area (CDA; vascularity assessment) (median reduction 100% and 47.1%, respectively; P = 0.025). From week 0 to week 110, no significant between-group difference was observed in the change from baseline for total synovial thickening or the total CDA. At week 54, greater progression in the Sharp/van der Heijde score was apparent in patients receiving placebo + MTX compared with those receiving infliximab + MTX. Although radiographic progression in the placebo + MTX group was greatly reduced in the second year (after initiation of infliximab therapy), marked differences were observed between the infliximab + MTX group (median change in the Sharp/van der Heijde score 4.0) and the placebo + MTX group (median change 14.5) from baseline to week 110 (P = 0.076). CONCLUSION: The results indicate that the efficacy of 2 years of combination therapy with infliximab + MTX for inhibiting cumulative structural damage was superior to that of 1 year of treatment with MTX alone followed by the addition of infliximab.

Anti-TNF therapy: where have we got to in 2005?

The blockade of TNF has had significant impact on the therapy of a number of chronic autoimmune diseases. In this chapter we review the concepts leading up to this therapy in rheumatoid arthritis (RA), how it spreads into other autoimmune diseases, and how greater understanding of its use has led to augmented therapeutic benefit. There are still many limitations, but the prospects for the future are intriguing.

The 2005 International Symposium on Advances in Targeted Therapies: what have we learned in the 2000s and where are we going?

This essay summarises a personal perspective on where we have got to in the five years since the turn of the last century. The focus is on advances in knowledge of antitumour necrosis factor (anti-TNF) therapy of rheumatoid arthritis and other chronic immune-inflammatory rheumatic diseases. The accumulating knowledge is clarifying the scope and limitations of efficacy, safety, and durability of these agents. It is defining the unmet needs of patients and communities worldwide for the future. The call is for progress in providing more cost-effective advances in therapeutics that not only interrupt the disease process long term but also reverse the anatomical and functional consequences of disease and the impairment in quality of life.

Evidence of radiographic benefit of treatment with infliximab plus methotrexate in rheumatoid arthritis patients who had no clinical improvement: a detailed subanalysis of data from the anti-tumor necrosis factor trial in rheumatoid arthritis with concomitant therapy study.

OBJECTIVE: To assess the relationship between inflammation and joint destruction in rheumatoid arthritis (RA) patients who have not responded clinically to treatment. METHODS: Changes from baseline to week 54 in clinical variables and measures of radiographic progression were compared between patients who received infliximab (3 mg/kg or 10 mg/kg every 4 or 8 weeks) plus methotrexate (MTX) and those who received MTX plus placebo in the Anti-Tumor Necrosis Factor Trial in RA with Concomitant Therapy trial. RESULTS: At week 54, patients who did not show 20% improvement by American College of Rheumatology criteria (ACR20 nonresponders) while receiving infliximab plus MTX exhibited mild but statistically significant improvement in clinical variables, including the 28-joint Disease Activity Score (DAS28) (P < 0.001), tender joint count (P = 0.014), swollen joint count (P < 0.001), and C-reactive protein (CRP) level (P < 0.001). Whereas the clinical and CRP changes among ACR20 nonresponders to infliximab plus MTX were small and much lower than among ACR20 responders to this treatment, radiographic progression among ACR20 nonresponders to infliximab plus MTX was significantly inhibited (P < 0.001) compared with ACR20 nonresponders to MTX plus placebo. Radiographic progression was much greater in patients receiving MTX plus placebo than in patients receiving infliximab plus MTX, irrespective of ACR response status (mean change in modified Sharp/van der Heijde score 6.0 in ACR20 responders and 7.2 in ACR20 nonresponders in the MTX plus placebo-treated group, versus 0.1 in ACR20 responders and 1.2 in ACR20 nonresponders in the infliximab plus MTX-treated group). Furthermore, among patients who were ACR20 nonresponders through week 54, patients who were DAS nonresponders at weeks 30 and 54, and patients without any improvement in individual clinical variables, those receiving infliximab plus MTX still demonstrated inhibition of structural damage that was statistically significant compared with inhibition in patients who received MTX plus placebo (P < 0.05 to P < 0.001). CONCLUSION: Even in patients without clinical improvement, treatment with infliximab plus MTX provided significant benefit with regard to the destructive process, suggesting that in such patients these 2 measures of disease are dissociated.

Association between baseline radiographic damage and improvement in physical function after treatment of patients with rheumatoid arthritis.

OBJECTIVES: To identify factors associated with poor physical function in rheumatoid arthritis and to assess whether baseline joint damage has an impact on improvement in physical function during infliximab treatment. METHODS: 428 patients with active rheumatoid arthritis despite methotrexate treatment received methotrexate alone or with infliximab (3 mg/kg or 10 mg/kg every four or eight weeks) for 54 weeks (the ATTRACT trial). Data on clinical outcomes and physical function (assessed by the health assessment questionnaire (HAQ)) were collected. Structural damage was assessed using the van der Heijde modification of the Sharp score. Odds ratios (OR) for factors associated with severe functional disability (HAQ > or =2.0) at baseline were estimated using multiple logistic regression analyses, and baseline factors related to the change in physical function after treatment at week 54 were determined. RESULTS: Baseline radiographic scores were correlated with baseline HAQ scores. After adjustment for demographic characteristics in the logistic regression model, baseline disease activity scores, radiological joint damage, fatigue, and morning stiffness were found to be associated with severe functional disability (HAQ >2.0), with OR values of 2.00 (1.53 to 2.63), 1.82 (1.15 to 2.87), 1.19 (1.05 to 1.34), and 1.07 (1.01 to 1.13), respectively. In multiple linear regression analysis, physical disability, joint damage, and fatigue at baseline were correlated with less improvement in physical function after treatment. Infliximab treatment was associated with greater improvement in physical function. CONCLUSIONS: Greater joint damage at baseline was associated with poorer physical function at baseline and less improvement in physical function after treatment, underlining the importance of early intervention to slow the progression of joint destruction.

Inflammation is preceded by tumor necrosis factor-dependent infiltration of mesenchymal cells in experimental arthritis.

OBJECTIVE: To determine the involvement of mesenchymal progenitor cells in the induction of collagen-induced arthritis (CIA). METHODS: DBA/1 mice were immunized with type II collagen in adjuvant or adjuvant alone, and the presence of mesenchymal cells in the joints of prearthritic mice was studied by immunohistochemistry. RESULTS: An analysis of the joints on day 10 postimmunization (at least 10 days before the onset of arthritis) revealed synovial hyperplasia without leukocytic infiltration. Large, round cells expressing bone morphogenetic protein receptors (BMPRs), which serve as markers for primitive mesenchymal cells, were present in increased numbers in the bone marrow adjacent to the joint, in the synovium itself, and within enlarged bone canals that connect the bone marrow to the synovium. Similar changes were observed in mice given adjuvant without collagen. Adjuvant-induced infiltration of BMPR(+) cells and enlargement of bone canals were abrogated by anti-tumor necrosis factor (anti-TNF) treatment and were absent in TNFR p55/p75(-/-) mice. Increased numbers of bone marrow cells and enlarged bone canals were observed in nonimmunized TNF transgenic mice (which spontaneously develop arthritis). CONCLUSION: These findings suggest that in CIA, there is an antigen-independent (innate) prearthritic phase that prepares the joint for the subsequent immune-mediated arthritis. The induction phase involves marrow-derived mesenchymal cells and requires the presence of TNF.

Raised serum vascular endothelial growth factor levels are associated with destructive change in inflammatory arthritis.

OBJECTIVE: To determine whether elevated levels of the angiogenic cytokine vascular endothelial growth factor (VEGF), detected on presentation to an early arthritis clinic, are associated with the development of chronic and erosive arthritis. METHODS: Concentrations of VEGF and its soluble receptor, soluble fms-like tyrosine kinase 1 (sFlt-1), were measured by enzyme-linked immunosorbent assay in serum samples from patients with early (<2 years from onset) arthritic symptoms in the peripheral joints, namely early rheumatoid arthritis (RA), self-limiting arthritis (viral, reactive, and idiopathic inflammatory arthritis), or psoriatic arthritis. In addition, measurements were made in random samples from patients with longstanding (>3 years from symptom onset) RA treated with disease-modifying antirheumatic drugs, from patients with osteoarthritis (OA), and from patients with polyarthralgia without arthritis, as well as from nonarthritic controls. RESULTS: Serum VEGF levels at presentation were elevated in patients with inflammatory arthritis (RA, psoriatic, and self-limiting arthritis) as well as in patients with OA, in comparison with nonarthritic controls. Moreover, serum VEGF concentrations were significantly higher in patients with early RA than in patients with self-limiting arthritis. Serum VEGF levels at presentation in patients with early RA correlated significantly with the development of radiographic damage after 1 year. Improvement in the clinical symptoms of RA was associated with a reduction in serum VEGF levels. Serum sFlt-1 levels were raised in patients with early and longstanding RA and in those with self-limiting arthritis, and correlated positively with the serum VEGF concentrations in patients with inflammatory arthritis. CONCLUSION: These findings implicate the proangiogenic cytokine VEGF in the persistence of inflammatory arthritis, and support the hypothesis that expansion of the synovial vasculature is important for the development of joint destruction in RA.

Cytokine blockade in rheumatoid arthritis.

As we enter the 2000's it is clear that cytokine blockade is an effective therapeutic strategy for rheumatoid arthritis. In this brief review, we will review the rationale for anti TNFalpha therapy, the current status of therapy and focus on the regulation of TNFalpha production in rheumatoid synovium. New approaches to studying TNF regulation in RA and of elucidating the controversial role of T cells in this complex disease will be described.

Chronic relapsing homologous collagen-induced arthritis in DBA/1 mice as a model for testing disease-modifying and remission-inducing therapies.

OBJECTIVE: To test whether the chronic relapsing arthritis induced by immunizing DBA/1 mice with homologous type II collagen is a valuable model for testing disease-modifying antiarthritic drugs. METHODS: Six-week-old male DBA/1 mice were immunized with murine type II collagen in Freund's complete adjuvant, resulting in a chronic relapsing polyarthritis in >80% of the mice 4 weeks after immunization. At the onset of clinical arthritis, mice were treated for 4 weeks with different treatments, including anti-tumor necrosis factor (anti-TNF) and antiinterleukin-12 (anti-IL-12) antibodies, salbutamol, or indomethacin. Alternatively, treatment was administered as a pulse at the beginning of clinical arthritis. Pulse treatments tested included anti-CD3 in combination with anti-TNF, anti-TNF alone, and anti-CD4, either alone or in combination with anti-TNF. After 4 weeks of arthritis, mice were killed and hind paws were assessed histologically for joint damage. RESULTS: Anti-TNF and salbutamol both suppressed clinical arthritis more effectively than indomethacin and, moreover, protected the joints from damage, whereas indomethacin did not. Anti-IL-12 treatment initiated after the onset of clinical symptoms accelerated disease. Pulse therapy with anti-CD3 plus anti-TNF was found to induce remission, clinically as well as histologically, whereas a pulse with either anti-CD4, anti-TNF, or the combination of anti-CD4 plus anti-TNF was less effective. CONCLUSION: Chronic relapsing homologous collagen-induced arthritis is a valuable model for identifying remission-inducing antiarthritic drugs and has predictive value with respect to their joint-protective potency.

Tumour necrosis factor as a therapeutic target in rheumatoid arthritis and other chronic inflammatory diseases: the clinical experience with infliximab (REMICADE).

Therapeutic strategies that aim to neutralise the important pro-inflammatory cytokine tumour necrosis factor alpha (TNF alpha) have gained considerable prominence in the therapy of chronic inflammatory diseases, notably rheumatoid arthritis and Crohn's disease. This drug focus review will concentrate on the antitumour necrosis factor antibody infliximab (Remicade), which has been approved for the treatment of rheumatoid arthritis and Crohn's disease in both the US and Europe. In addition, infliximab is under investigation for several other indications, mainly inflammatory rheumatic diseases. Clinical trials have been persuasive that infliximab is both safe and effective, and it has been proven to be far superior to the conventional drug therapy in both rheumatoid arthritis and Crohn's disease. Remarkably, infliximab in combination with methotrexate controls both the inflammatory joint symptoms and the progression of joint damage, which renders it a very attractive therapeutic option in moderate to severe, therapy-resistant rheumatoid arthritis.

Anti-TNF alpha therapy of rheumatoid arthritis: what have we learned?

Rheumatoid arthritis (RA), a systemic disease, is characterized by a chronic inflammatory reaction in the synovium of joints and is associated with degeneration of cartilage and erosion of juxta-articular bone. Many pro-inflammatory cytokines including TNF alpha, chemokines, and growth factors are expressed in diseased joints. The rationale that TNF alpha played a central role in regulating these molecules, and their pathophysiological potential, was initially provided by the demonstration that anti-TNF alpha antibodies added to in vitro cultures of a representative population of cells derived from diseased joints inhibited the spontaneous production of IL-1 and other pro-inflammatory cytokines. Systemic administration of anti-TNF alpha antibody or sTNFR fusion protein to mouse models of RA was shown to be anti-inflammatory and joint protective. Clinical investigations in which the activity of TNF alpha in RA patients was blocked with intravenously administered infliximab, a chimeric anti-TNF alpha monoclonal antibody (mAB), has provided evidence that TNF regulates IL-6, IL-8, MCP-1, and VEGF production, recruitment of immune and inflammatory cells into joints, angiogenesis, and reduction of blood levels of matrix metalloproteinases-1 and -3. Randomized, placebo-controlled, multi-center clinical trials of human TNF alpha inhibitors have demonstrated their consistent and remarkable efficacy in controlling signs and symptoms, with a favorable safety profile, in approximately two thirds of patients for up to 2 years, and their ability to retard joint damage. Infliximab (a mAB), and etanercept (a sTNF-R-Fc fusion protein) have been approved by regulatory authorities in the United States and Europe for treating RA, and they represent a significant new addition to available therapeutic options.

Evaluation of TNF-alpha and IL-1 blockade in collagen-induced arthritis and comparison with combined anti-TNF-alpha/anti-CD4 therapy.

We have evaluated the effects of anti-TNF-alpha, anti-IL-1, and combined anti-TNF-alpha/anti-CD4 therapy in collagen-induced arthritis. Blockade of TNF-alpha or IL-1 before disease onset delayed, but did not prevent, the induction of arthritis. When treatment was initiated after onset of arthritis, anti-TNF-alpha, anti-IL-1beta, and anti-IL-1R (which blocks IL-1alpha and IL-1beta) were all found to be effective in reducing the severity of arthritis, with anti-IL-1R and anti-IL-1beta showing greater efficacy than anti-TNF-alpha. Anti-IL-1beta was equally as effective as anti-IL-1R, indicating that IL-1beta plays a more prominent role than IL-1alpha in collagen-induced arthritis. An additive effect was observed between anti-TNF-alpha and anti-IL-1R in the prevention of joint erosion and in normalization of the levels of serum amyloid P. Combined anti-TNF-alpha/anti-CD4 therapy also caused normalization of serum amyloid P levels. The therapeutic effect of anti-TNF-alpha plus anti-CD4 was comparable to that of anti-TNF-alpha plus anti-IL-1R, suggesting that combined anti-TNF-alpha/anti-CD4 therapy prevents both TNF-alpha- and IL-1-mediated pathology. Anti-TNF-alpha treatment reduced IL-1beta expression in the joint and, conversely, anti-IL-1beta treatment reduced TNF-alpha expression. Combined anti-TNF-alpha/anti-CD4 treatment almost completely blocked the expression of IL-1beta, thereby confirming the ability of this form of combination therapy to prevent IL-1ss-mediated pathology.

Mesenchymal precursor cells in the blood of normal individuals.

STATEMENT OF FINDINGS: Mesenchymal precursor cells found in the blood (BMPCs) of normal persons adhere to plastic and glass and proliferate logarithmically in DMEM-20% fetal calf serum (FCS) without growth factors. They form cells with fibroblast-like and stromal morphology, which is not affected by eliminating CD34, CD3, or CD14 cells. Osteogenic supplements (dexamethasone, ascorbic acid, and beta-glycerophosphate) added to the culture inhibited fibroblast formation, and BMPCs assumed the cuboidal shape of osteoblasts. After 5 days in supplemented medium, the elutriated cells displayed alkaline phosphatase (AP), and the addition of bone morphogenetic protein (BMP)2 (1 ng) doubled AP production (P < 0.04). Two weeks later, 30% of the cells were very large and reacted with anti-osteocalcin antibody. The same cultures also contained sudanophlic adipocytes and multinucleated giant cells that stained for tartrate-resistant acid phosphatase (TRAP) and vitronectin receptors. Cultured BMPCs immunostain with antibodies to vimentin, type I collagen, and BMP receptors, heterodimeric structures expressed on mesenchymal lineage cells. In addition, BMPCs stain with anti-CD105 (endoglin), a putative marker for bone-marrow mesenchymal stem cells (MSCs).

Assessment of antibodies to double-stranded DNA induced in rheumatoid arthritis patients following treatment with infliximab, a monoclonal antibody to tumor necrosis factor alpha: findings in open-label and randomized placebo-controlled trials.

OBJECTIVE: To compare the incidence of anti-double-stranded DNA (anti-dsDNA) antibodies in rheumatoid arthritis (RA) patients receiving either single or multiple doses of a chimeric anti-tumor necrosis factor alpha (anti-TNFalpha) antibody or placebo infusions, with or without methotrexate, in open-label, randomized, placebo-controlled trials. METHODS: Multiple sera obtained from 156 patients before and after treatment with infliximab and from 37 patients treated with placebo infusions were tested for anti-dsDNA antibodies by 3 methods: Crithidia luciliae indirect immunofluorescence test (CLIFT), a commercial Farr assay (Ortho Diagnostics radioimmunoassay [RIA]) in which the antigen source is mammalian DNA, and a Farr assay employing 125I-labeled circular plasmid DNA (Central Laboratory of The Netherlands Red Cross Blood Transfusion Service [CLB] RIA). Patients with positive findings on the CLIFT were also tested for antibodies to histones (H1-H5) and chromatin and for IgM rheumatoid factors (IgM-RFs). RESULTS: None of the RA patients had a serum sample that was positive for anti-dsDNA antibodies by the CLIFT prior to infliximab therapy. Of the 22 patients who developed a positive CLIFT result, 11 (7% of 156 exposed to infliximab) also had positive findings on the Ortho RIA at a concentration of >10 units/ml and another 8 (5%) were positive at a concentration of >25 units/ml. In all but 1 patient, the anti-dsDNA antibodies were solely of the IgM isotype. Only 1 patient had detectable anti-dsDNA antibodies by the CLB RIA. All sera containing anti-dsDNA by the CLIFT contained antibodies to chromatin, and sera from 2 patients also contained antibodies to histones. IgM-RF titers showed a significant reduction following infliximab therapy in these 22 patients. One patient developed anti-dsDNA antibodies of IgG, IgA, and IgM isotype and had positive results on both Farr assays (peaking at 22 weeks and resolving by 54 weeks); this was associated with a reversible lupus syndrome. CONCLUSION: Anti-dsDNA antibodies of IgM class are induced by infliximab therapy; the frequency is dependent on the assay method used. Only 1 of the 156 patients who were treated with infliximab developed a self-limiting clinical lupus syndrome; that patient developed high titers of anti-dsDNA antibodies of IgG, IgM, and IgA class, as detected by the CLIFT and by 2 different Farr assays.

Systemic anti-tumor necrosis factor alpha therapy in rheumatoid arthritis down-regulates synovial tumor necrosis factor alpha synthesis.

OBJECTIVE: To investigate the hypothesis that tumor necrosis factor alpha (TNFalpha) blockade in rheumatoid arthritis (RA) diminishes synovial synthesis of TNFalpha, interleukin-1alpha (IL-1alpha), and IL-1beta. METHODS: Patients with active RA received a single 10 mg/kg infusion of infliximab. Multiple synovial biopsy specimens were obtained from a knee the day before infusion and 14 days later. A modified immunohistochemical method detecting cytokine-producing rather than cytokine-binding cells was applied to determine synthesis of TNFalpha, IL-1alpha, and IL-1beta in fixed, cryopreserved sections. Computerized image analysis using two different methodologies was performed by independent observers blinded to the identity of samples. RESULTS: All 8 patients met the American College of Rheumatology 20% improvement response criteria (ACR 20) at 2 weeks, and half of these patients met the ACR 50. With a few exceptions, there was concordance between both image analysis methodologies regarding the direction of change in immunopositive area fraction for all cytokines analyzed. TNFalpha synthesis was significantly reduced after treatment (P = 0.05 at the Karolinska Institute, Stockholm, Sweden; P = 0.008 at the Kennedy Institute, London, UK). Patients meeting the ACR 50 were those with the highest baseline levels of TNFalpha synthesis. There was a significant correlation between baseline levels of TNFalpha expression and change in TNFalpha levels in response to therapy. Both IL-1alpha and IL-1beta synthesis were reduced in 3 patients; IL-1alpha synthesis alone was reduced in 2 patients and IL-1beta synthesis alone was reduced in 2 patients. In 1 patient, neither IL-1alpha nor IL-1beta synthesis was reduced. CONCLUSION: Analysis of synovial tissue by means of immunomorphology and image analysis in a clinical trial setting may allow the drawing of biologically meaningful conclusions. Synovial TNFalpha synthesis was reduced 2 weeks after infliximab treatment. Reductions in IL-1alpha and IL-1beta synthesis were demonstrated in a subgroup of patients. High levels of synovial TNFalpha production prior to treatment may predict responsiveness to therapy.

Infliximab and methotrexate in the treatment of rheumatoid arthritis. Anti-Tumor Necrosis Factor Trial in Rheumatoid Arthritis with Concomitant Therapy Study Group.

BACKGROUND: Neutralization of tumor necrosis factor a (TNF-alpha) for three to six months reduces the symptoms and signs of rheumatoid arthritis. However, the capacity of this approach to effect a more sustained benefit and its effect on joint damage are not known. METHODS: We treated 428 patients who had active rheumatoid arthritis despite methotrexate therapy with placebo or infliximab, a chimeric monoclonal antibody against TNF-alpha, in intravenous doses of 3 or 10 mg per kilogram of body weight every 4 or 8 weeks in combination with oral methotrexate for 54 weeks. We assessed clinical responses with use of the criteria of the American College of Rheumatology, the quality of life with a health-status questionnaire, and the effect on joint damage radiographically. RESULTS: The combination of infliximab and methotrexate was well tolerated and resulted in a sustained reduction in the symptoms and signs of rheumatoid arthritis that was significantly greater than the reduction associated with methotrexate therapy alone (clinical response, 51.8 percent vs. 17.0 percent; P<0.001). The quality of life was also significantly better with infliximab plus methotrexate than with methotrexate alone. Radiographic evidence of joint damage increased in the group given methotrexate, but not in the groups given infliximab and methotrexate (mean change in radiographic score, 7.0 vs. 0.6, P<0.001). Radiographic evidence of progression of joint damage was absent in infliximab-treated patients whether or not they had a clinical response. CONCLUSIONS: In patients with persistently active rheumatoid arthritis despite methotrexate therapy, repeated doses of infliximab in combination with methotrexate provided clinical benefit and halted the progression of joint damage.

Mesenchymal cells expressing bone morphogenetic protein receptors are present in the rheumatoid arthritis joint.

OBJECTIVE: To evaluate the presence of cells of an early mesenchymal lineage, as judged by the expression of bone morphogenetic protein receptors (BMPRs), in the joints of normal individuals and patients with rheumatoid arthritis (RA). METHODS: Synovial fluids, single cell suspensions of cultured fibroblast-like synoviocytes (FLS), and synovial tissues were examined by immunohistology with antibodies to BMPR type IA (BMPRIA), BMPRIB, and BMPRII and then quantified using computerized image analysis. Other antibodies were evaluated by cytofluorography. RESULTS: In primary cultures of joint effusions from patients with RA and other forms of inflammatory arthritis, there were large adherent cells with the appearance of either fibroblasts or stromal cells that stained with antibodies to mesenchymal elements-CD44, type I collagen, alpha-actin, and vimentin-but not with antibodies to hematopoietic markers. These cells proliferated rapidly, expressed BMPRIA and BMPRII, and soon became the predominant cells in culture. They were retained through multiple passages and persistently displayed surface vascular cell adhesion molecule 1. Immunohistochemical analysis of cultured RA FLS (passages 3, 4, and 6; n = 6) revealed that 11.6% were BMPR-positive, while only 2.0% of osteoarthritis FLS (passage 4; n = 3) were BMPR-positive, and 1 normal synovial culture had no BMPR-positive cells. In all RA synovial membranes examined (n = 9), BMPRI- and BMPRII-expressing cells were identified in the intimal lining and were also scattered in the subintima. These cells constituted approximately 25% and approximately 7% of the cells in each area, respectively. Double immunostaining showed no coexpression of BMPR-positive cells with CD68, CD34, or CD3. Cells expressing BMPR were not seen in any normal synovial samples (n = 4). Strong staining for BMPR was identified on cells at the invasive front of the pannus and at sites of cartilage erosion. CONCLUSION: The inflamed RA joint contains BMPR-positive mesenchymal cells. Their origin is still speculative, but since their counterparts in the bone marrow are essential for osteoclastogenesis, support lymphocyte development and maturation, and protect T cells and B cells from programmed cell death, the BMPR-positive cells may be essential elements in the pathogenesis of RA and other inflammatory forms of chronic synovitis.