Levels of circulating collagenase,stromelysin-1, and tissue inhibitor of matrix metalloproteinases 1 in patients with rheumatoid arthritis: relationship to serum levels of antigenic keratan sulfate and systemic parameters of inflammation

Objective. To measure serum levels of matrix metalloproteinase–1 (MMP-1), matrix metalloproteinase–3 (MMP-3), and tissue inhibitor of MMP–1 (TIMP-1) in patients with rheumatoid arthritis (RA) and in agematched control subjects, and to determine how these correlate with serum levels of antigenic keratan sulfate (KS) and other biochemical and clinical indicators of disease activity. Methods. Immunoassays were used to measure levels of MMP-1, MMP-3, TIMP-1, and antigenic KS. Radiologic and functional joint scores were based upon Steinbrocker's criteria. Erythrocyte sedimentation rates (ESR) and levels of C-reactive proteins (CRP) were measured. Results. In RA patients, levels of MMP-3 and TIMP-1 were significantly increased, and strongly correlated with the ESR and CRP levels but not with radiologic or functional joint scores. Levels of antigenic KS were significantly lower in RA patients and correlated negatively with systemic parameters of inflammation and serum levels of TIMP-1. Conclusions. The increase in serum levels of MMP-3 and TIMP-1 appears to reflect systemic inflammation in RA. The inverse correlation between serum levels of TIMP-1 and antigenic KS suggests that an upregulation of TIMP-1 synthesis might be responsible for the apparent suppression of cartilage aggrecan catabolism in patients with severe inflammatory changes.     

活动期类风湿关节炎患者血清基质金属蛋白酶一3及其组织抑制剂一1水平的检测和意义

目的研究活动期类风湿关节炎(rheumatoid arthritis,RA)患者血清基质金属蛋白酶一3(matrix metalloproteinase 3,MMP-3)、金属蛋白酶组织抑制剂一1(tissue inhibitors of metalloproteinase 1,TIMP-1)的水平及其相关影响因素,探讨MMP-3及TIMP-1在RA的作用机制.方法选择41例初诊活动期RA患者和30名正常健康志愿者,以酶联免疫吸附试验(ELISA)分别检测血清MMP-3及TIMP-1水平,计算MMP-3/TIMP-1,同时测定关节功能、X线、关节肿胀数(SJC)、血沉(ESR)、类风湿因子(RF)、C反应蛋白(CRP)等相关实验室指标.结果活动期RA患者血清MMP-3、TIMP-1明显增高(P＜0.01),且以MMP-3增高更为显著,MMP-3/TIMP-1较正常组亦增高(P＜0.05).不同关节功能分级时,上述指标差异无统计学意义(P＞0.05),而不同X线分期时,各指标差异有统计学意义(P＜0.01或P＜0.05).MMP-3、MMP-3/TIMP-1与SJC(P＜0.01)、CRP(P＜0.01)、ESR(P＜0.05)呈正相关,二者与年龄、病程、晨僵时间、RF无明显相关性(P＞0.05).结论 MMP-3、TIMP-1在RA血清中高水平存在,二者比例失衡导致RA发生.MMP-3、MMP-3/TIMP-1的高低可作为反映病情活动及预后的指标,阻断MMP-3高水平有可能成为治疗RA的新途径一.     

Reduction of serum matrix metalloproteinase 1 and matrix metalloproteinase 3 in rheumatoid arthritis patients following anti- tumour necrosis factor-alpha (cA2) therapy

Matrix metalloproteinase (MMP)-1 and MMP-3 levels were measured in serum samples from rheumatoid arthritis (RA) patients undergoing a double-blinded placebo-controlled trial with the chimaeric anti-tumour necrosis factor (TNF)-alpha antibody cA2. Both MMP-1 (P < 0.015), but to a larger extent MMP-3 (P < 0.001) levels were elevated in all RA patients prior to the commencement of the trial compared with normal control sera. Following cA2 therapy, MMP-1 and MMP-3 levels were assessed in the placebo, and 1 and 10 mg/kg cA2-treated groups at 7, 14, 21 and 28 days. In both the 1 and the 10 mg/kg cA2-treated groups, a significant decrease in serum MMP-3 levels at all time points was observed, reducing maximally to 41% of pre-infusion values at day 7. MMP-1 levels were also reduced, but less dramatically than MMP-3, to 85% of pre-infusion values after 14 days in the 10 mg/kg cA2 treated group. In a separate non-placebo-controlled study, we also evaluated the tissue inhibitor of metalloproteinase (TIMP)-1 levels in plasma following cA2 infusion. Pre-infusion TIMP-1 levels were above the normal control range, but were significantly reduced (P < 0.035) 14 days after infusion to 72% of pre-infusion values. This study confirms previous reports that MMP-3 levels are elevated and correlate with measures of inflammation in RA, and furthermore demonstrate that serum MMP-3 and MMP-1 levels are downmodulated following anti-TNF-alpha antibody therapy. Whilst serum MMP-3 levels correlated with C-reactive protein (CRP) both prior to and following anti-TNF-alpha antibody therapy, it remains to be demonstrated that serum MMP-3 and/or MMP-1 levels reflect the cartilage and bone resorptive processes which are evident in this disease.      

Serum matrix metalloproteinase 3 in early rheumatoid arthritis is correlated with disease activity and radiological progression

OBJECTIVE: To analyze the clinical significance of serial measurements of serum matrix metalloproteinase 3 (MMP-3) levels in relation to markers of disease activity and radiological progression in early rheumatoid arthritis (RA). METHODS: In a 3 year prospective study of 33 patients with early RA (symptoms < 1 year at entry) monthly measurements of serum MMP-3 were transformed into time integrated values for 6 month periods for comparison with other markers of disease activity like swollen joint count (SJC), tender joint count (TJC), Ritchie articular index (RAI), the disease activity score (DAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and radiological progression, scored according to Sharp's method, in which erosions and joint space narrowing are scored separately and combined to a total Sharp score. RESULTS: Significant correlations were found between serum MMP-3 and SJC, ESR, and CRP during all periods and between 6 and 30 months with the DAS. There were no correlations between serum MMP-3 and TJC or the RAI. During the first 12 months serum MMP-3 was correlated only with the item joint space narrowing of the Sharp score. After 12 months of followup it was also correlated with the total Sharp score and after 18 months it was correlated with all 3 items of the Sharp score. There was a wide interindividual variation in the relation between serum MMP-3 and radiological progression but intraindividually this relation seemed to be rather constant. CONCLUSION: Time integrated values of serum MMP-3 are correlated with time integrated values of other markers of disease activity such as joint swelling, ESR, CRP, and the DAS. Of the radiological scores, as outcome measures, especially joint space narrowing correlated closely with cumulative serum MMP-3.     

Serum matrix metalloproteinase 3 levels in comparison to C-reactive protein in periods with and without progression of radiological damage in patients with early rheumatoid arthritis

OBJECTIVE: To evaluate serum matrix metalloproteinase 3 (MMP-3) levels in comparison to C-reactive protein (CRP) in periods with and without progression of radiological damage in patients with early rheumatoid arthritis (RA). METHODS: Thirty-two patients with RA and radiological progression (> or = 5 points according to the Sharp/van der Heijde method) during 6 months followed by a 6-month period without radiological progression (< or = 1 point) were selected from a prospective follow-up study of early RA patients. Serum MMP-3 levels, CRP, the erythrocyte sedimentation rate (ESR), disease activity index (DAS), swollen joint count (SJC), tender joint count (TJC), and Ritchie articular index (RAI) were measured monthly and results were transformed into mean values for the 6-month periods. RESULTS: During the period with radiological progression the mean serum MMP-3 correlated significantly with the mean CRP (r = 0.68, p < 0.001), ESR (r = 0.54, p = 0.001) and swollen joint count (r = 0.48, p = 0.006). In the period without radiological progression the mean serum MMP-3 only correlated with the mean CRP (r = 0.44, p = 0.012). Individual changes--expressed in percentages (%)--between the two periods showed a decrease in both the mean serum MMP-3 and CRP in 19 and an increase in 3 patients, in parallel with other markers of disease activity in these patients (69% of cases). The individual change (%) in mean serum MMP-3 or CRP did not correlate with the difference in radiological progression between the two periods. CONCLUSIONS: Serum MMP-3 and CRP are closely related and there seems to be no difference between serum MMP-3 and CRP with regard to the monitoring of the progression of radiological damage.     

Serum MMP-3 and MMP-1 and progression of joint damage in early rheumatoid arthritis

OBJECTIVE: Expression and activation of matrix metalloproteinases such as MMP-3 (stromelysin-1) and MMP-1 (collagenase-1) are increased in patients with rheumatoid arthritis (RA). Previous negative reports of their value as predictors of joint damage may be due to the lack of a large longitudinal study of early RA patients. This study evaluated their use in assessing early untreated patients with RA and predicting subsequent joint damage. METHODS: Ninety-eight patients with early untreated RA of less than 12 months duration and 20 normal controls had baseline serum samples tested with a double-antibody enzyme-linked immunosorbent assay for each of MMP-1 and MMP-3. The subsequent changes in Larsen score (DeltaLarsen) and Health Assessment Questionnaire (DeltaHAQ) over the first 12 months were recorded. RESULTS: Baseline serum levels of MMP-3 and MMP-1 correlated significantly with baseline C-reactive protein (CRP) (r=0.42 and 0.49, P<0.001), DeltaHAQ (r=0.32 and 0.30, P<0.01) and DeltaLarsen (r=0.23 and 0.32, P<0.05) respectively. Analysis of the group of patients with a normal CRP at presentation (n=21) showed correlation of the baseline MMP-3 and MMP-1 with the presence of erosive disease during the first 12 months (r=0.52 and 0.65 respectively, P<0.05). Logistic regression analysis, in the patients who were non-erosive at presentation, showed that the strongest correlation with progression in Larsen score was the baseline MMP-3 level (r=0.30, P=0.01). CONCLUSIONS: Baseline serum MMP-1 and MMP-3 levels correlate with disease activity and predict functional and radiographic outcome in early untreated RA. They may have a particular value in predicting the progression of erosive disease in patients who are not erosive at presentation.     

Serum matrix metalloproteinase 3 levels during treatment with sulfasalazine or combination of methotrexate and sulfasalazine in patients with early rheumatoid arthritis

OBJECTIVE: To determine the effects of treatment with sulfasalazine (SSZ) or the combination of methotrexate (MTX) and SSZ on serum matrix metalloproteinase 3 (MMP-3) levels in patients with early rheumatoid arthritis (RA). METHODS: Eighty-two patients with early RA (symptoms < 1 year and DMARD-naive at presentation) were selected who had been treated with SSZ (2000 mg/day) or with the combination of MTX (7.5-15 mg/week) and SSZ. Serum MMP-3 levels, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), swollen joint count (SJC), tender joint count (TJC), Ritchie articular index (RAI), and the Disease Activity Score (DAS) were determined at 4 week intervals during a followup of 28 weeks for each treatment group. Response was based on clinical grounds and CRP at 12, 20, and 28 weeks. RESULTS: SSZ responders (n = 52) had lower baseline values of serum MMP-3, CRP, and ESR, compared to partial/nonresponders (n = 30), but did not differ in joint scores and DAS. In the SSZ responder group all variables decreased. In the SSZ partial/nonresponders, CRP, ESR, and SJC decreased in contrast to serum MMP-3, TJC. RAI, and DAS-3. After addition of MTX all variables decreased in 24 of the 30 patients who had shown a partial or no response taking SSZ. In the SSZ responders there was a delayed decrease in serum MMP-3 compared to CRP. CONCLUSION: Serum MMP-3 levels decrease in patients with early RA who respond to SSZ or to the combination of MTX and SSZ. In patients who respond to SSZ the changes in serum MMP-3 levels indicate a delayed response compared to CRP.     

Anti-tumour necrosis factor (TNF)-alpha therapy (etanercept) down-regulates serum matrix metalloproteinase (MMP)-3 and MMP-1 in rheumatoid arthritis

OBJECTIVES: Matrix metalloproteinases (MMPs) are cytokine-modulated enzymes that play an important role in the pathogenesis of rheumatoid arthritis (RA) by inducing bone resorption and cartilage destruction. This study evaluated the modulation of serum and synovial MMPs and their inhibitor, tissue inhibitor of matrix metalloproteinases (TIMP)-1, by therapy with soluble tumour necrosis factor (TNF) alpha receptor (etanercept). METHODS: Serum samples were collected from 60 RA patients at baseline and after 8 or 12 weeks of treatment. Paired synovial biopsies were obtained from 11 patients at two time points, before and after 8 weeks of treatment. We measured serum levels of MMP-1, MMP-3 and TIMP-1 by ELISA. Immunohistological analysis of synovial tissue was performed using monoclonal antibodies specific for MMP-1, MMP-3 and TIMP-1. RESULTS: Etanercept therapy significantly down-regulated serum levels of MMP-3 and MMP-1 in parallel with the reduction in inflammatory parameters (C-reactive protein concentration and erythrocyte sedimentation rate) in RA patients. Baseline pretreatment serum levels of MMP-3 correlated with changes in clinical disease activity during therapy. No consistent changes in serum level of TIMP-1 were observed, while ratios of MMP-1 and MMP-3 to TIMP-1 were down-regulated following etanercept treatment. Immunohistochemical analyses revealed great interindividual variability, with generally a high level of expression of MMP and low expression of TIMP. No significant change in the pattern or number of positive cells occurred during therapy. CONCLUSIONS: In RA patients, etanercept therapy down-regulates serum levels of MMP-3 and MMP-1 and the ratio between MMPs and TIMP-1. This may be an important mechanism for the prevention of future development of joint damage.     

The effects of pulse methylprednisolone on matrix metalloproteinase and tissue inhibitor of metalloproteinase-1 expression in rheumatoid arthritis

OBJECTIVE: To investigate the effects of a 1000 mg i.v. pulse of methylprednisolone succinate (pulse therapy) on the expression of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in the synovial membrane of the knee in patients with rheumatoid arthritis (RA). METHODS: Sequential arthroscopic biopsies of the knee were taken before and 24 h after pulse therapy (11 patients), at disease relapse (three patients) and after retreatment with pulse therapy (one patient). Immunoperoxidase staining for MMP-1 (interstitial collagenase), MMP-3 (stromelysin-1) and TIMP-1 was performed and the immunoreactive staining quantified by colour video image analysis. RESULTS: In the synovial lining layer, MMP-1 and TIMP-1 immunostaining was reduced by a mean of 47% (P = 0.02) and 72% (P = 0.05), respectively, 24 h after pulse methylprednisolone therapy. In the synovial sublining layer, MMP-1 was reduced by a mean of 51% (P = 0.08) and TIMP-1 by a mean of 73% (P = 0.02) 24 h after pulse methylprednisolone therapy. There was no change in MMP-3 staining in the synovial lining or sublining layer. CONCLUSIONS: High-dose pulse methylprednisolone therapy is associated with a rapid (within 24 h) and substantial decrease in the expression of MMP-1 and TIMP-1 but not MMP-3 in the synovial membrane in RA.     

Synovial tissue protease gene expression and joint erosions in early rheumatoid arthritis

OBJECTIVE: To relate the expression of proteases in the lining and sublining layers of the synovial membrane to the rate of joint damage during 1 year in patients with early inflammatory arthritis. METHODS: Samples of synovial membrane were obtained by closed-needle biopsy or needle arthroscopy from inflamed knees of 20 patients with early inflammatory polyarthritis (mean disease duration 9.6 months, range 2 weeks to 18 months). Expression of matrix metalloproteinase 1 (MMP-1), cathepsin B (CB), and cathepsin L (CL) was examined using in situ hybridization. Immunohistochemistry was used to identify infiltrating mononuclear cell populations. Radiographs of the hands and feet, performed at presentation and after 1 year, were evaluated for the development of new erosions. RESULTS: Twelve patients had rheumatoid arthritis (RA), 6 had psoriatic arthritis (PsA), 1 had gout, and 1 had an undifferentiated arthritis. Six patients had erosions at presentation. Eleven patients (10 with RA, 1 with PsA) demonstrated at least 1 new erosion after 1 year of followup. MMP-1, CB, and CL messenger RNA (mRNA) were expressed in the synovial membrane of all patients and were present throughout the lining layer, as well as in perivascular cellular infiltrates and endothelial cells in the sublining layer. In the lining layer, the mean percentages of protease mRNA-positive cells per high-power field were higher in those patients who developed new joint erosions than in those without evidence of joint damage. A similar pattern was observed in the sublining layer, where mean numbers of protease mRNA-positive cells were also greater in patients with new joint erosions. There were significant differences between the two groups in MMP-1 mRNA expression in both the lining and sublining layers (P = 0.0007 and P = 0.0027, respectively), as well as in sublining layer CL mRNA expression (P = 0.017), but not in CB mRNA expression. Numbers of lining layer CD68+ cells correlated positively with lining layer MMP-1 mRNA expression (P = 0.043) and with the development of new joint erosions (P = 0.002). CONCLUSION: The detection of MMP-1, CB, and CL in the synovium soon after the onset of symptoms highlights the potential for early joint destruction in patients with RA. High levels of MMP-1 mRNA expression in the lining layer distinguished patients with more rapidly progressive erosive disease. This is the first study to demonstrate features of early synovial pathophysiology that may identify patients at increased risk of developing new joint erosions.     

Changes in the concentration of plasma matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases-1 (TIMP-1) after total joint replacement in patients with arthritis

Matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) have been reported to be associated with arthritis. Total joint replacement results in total resection of cartilage and synovium at the joint. We investigated longitudinal changes in plasma MMP and TIMP after total joint replacement. Eight patients with osteoarthritis (OA) and 15 patients with rheumatoid arthritis (RA) had total knee or total hip replacements. Plasma was collected from all patients before surgery and at 1 week and 6 weeks after surgery. In RA patients the plasma MMP-3 and the MMP-3/TIMP-1 ratio decreased after total joint replacement, whereas CRP and ESR did not change. Therefore, CRP and ESR reflect systemic inflammation; however, plasma MMP-3 and the MMP-3/TIMP-1 ratio may reflect inflammation and/or degeneration of the affected joint. Received: 1 October 2001 / Accepted: 26 May 2002 Correspondence and offprint requests to: Dr Masaaki Takahashi, Department of Orthopedic Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, 431-3192, Japan. Tel: +81-53-435-2299; Fax: +81-53-435-2296; E-mail: taka1m@hama-med.ac.jp     

Elevated matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1 in obese children and adolescents

Matrix metalloproteinases (MMPs) have been implicated in the atherosclerotic process and risk factors for the disease such as hypertension, hyperlipidemia, or diabetes mellitus in adults. So far, circulating levels of MMPs and their tissue inhibitors (TIMPs) have not been assessed in children and adolescents with obesity, a known risk factor for cardiovascular disease. Plasma levels of MMP-9 and TIMP-1 were measured immunoenzymatically in 45 obese children and adolescents, aged 15 +/- 1.8 years. The control group consisted of 28 healthy children, aged 14.5 +/- 2.5 years. MMP-9 and TIMP-1 concentrations were higher in obese children than in the control group (MMP-9: 553.5 +/- 311 vs 400.4 +/- 204 ng/mL, respectively; P = .02; TIMP-1: 161.2 +/- 32 vs 143.1 +/- 20.1 ng/mL, respectively; P = .03). We found significantly higher levels of MMP-9 in obese children with coexisting hypertension than in obese normotensive patients (635 +/- 308 vs 450 +/- 289 ng/mL, respectively; P = .04). MMP-9 correlated with body mass index (BMI) (r = 0.33, P = .005) and fasting insulin (r = 0.3, P = .013); TIMP-1 correlated with BMI (r = 0.35, P = .006). In the group of obese hypertensive children (n = 25), MMP-9 correlated with BMI (r = 0.41, P = .001), systolic blood pressure (r = 0.41, P = .002), fasting insulin (r = 0.37, P = .006), and homeostasis model assessment index of insulin resistance (r = 0.27, P = .03). TIMP-1 correlated with BMI (r = 0.33, P = .025) and systolic (r = 0.38, P = .008) and diastolic (r = 0.47, P = .001) blood pressure. In the regression models, MMP-9 was found to be dependent on fasting insulin (R(2) = 0.16, P = .04), and TIMP-1 on BMI (R(2) = 0.14, P = .04). In the obese hypertensive group, TIMP-1 was dependent on diastolic blood pressure (R(2) = 0.18, P = .04). Obese children and adolescents have elevated plasma concentrations of MMP-9 and TIMP-1. Coexistence of hypertension may exacerbate alterations of extracellular matrix turnover in these patients. It might be hypothesized that elevated MMP and TIMP concentrations may be related to increased cardiovascular risk in obese and particularly in obese hypertensive children and adolescents.     

Serum levels of hyaluronan, antigenic keratan sulfate, matrix metalloproteinase 3, and tissue inhibitor of metalloproteinases 1 change predictably in rheumatoid arthritis patients who have begun activity after a night of bed rest.

OBJECTIVE: To evaluate whether and how moderate physical activity following a night of rest influences serum levels of matrix metalloproteinase 3 (MMP-3), tissue inhibitor of metalloproteinases 1 (TIMP-1), antigenic keratan sulfate (Ag KS), and hyaluronan (HA) in 10 normal subjects and 38 patients with rheumatoid arthritis (RA). METHODS: Blood was obtained from 20 RA patients before they arose from a night's sleep, and again 1 and 4 hours after they had begun to perform moderate physical activity. Another 18 RA patients remained in bed and blood was sampled at the same time periods. Serum levels of MMP-3, TIMP-1, Ag KS, and HA were measured by enzyme-linked immunosorbent assay. Clinical activity was evaluated by the Lansbury index. RESULTS: Both in normal subjects and in RA patients who did not remain in bed throughout the period of blood sampling, levels of HA, Ag KS, and MMP-3 increased significantly during the first hour after the subjects arose: the increase in HA and Ag KS correlated with the Lansbury index in the RA group. Three hours later, levels of Ag KS had dropped to baseline values in both groups of subjects. Levels of HA remained significantly and moderately elevated in the RA group but not in the control group, while levels of MMP-3 did not drop significantly in either group. In contrast, levels of HA, Ag KS, and MMP-3 did not change significantly in RA patients who had remained in bed. Unlike the other markers, the levels of TIMP-1 remained unchanged at the different time periods in all 3 groups studied. CONCLUSION: Significant changes in serum levels of some metabolic markers occur during the first hour after one arises from a night of sleep, especially in patients with RA. Measurement of the magnitude of these changes at different times in individual patients provides very different information about metabolic changes occurring in joint tissue than does measurement of the level of the markers at a single time point, as is usually currently reported.     

Production of cytokines, vascular endothelial growth factor, matrix metalloproteinases, and tissue inhibitor of metalloproteinases 1 by tenosynovium demonstrates its potential for tendon destruction in rheumatoid arthritis

OBJECTIVE: To investigate the role of proinflammatory cytokines, vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs), and tissue inhibitor of metalloproteinases 1 (TIMP-1) in the destruction of tendons by tenosynovium in rheumatoid arthritis (RA). METHODS: Synovial specimens were obtained from encapsulating tenosynovium (n = 17), invasive tenosynovium (n = 13), and wrist joints (n = 17) in 18 RA patients undergoing wrist extensor tenosynovectomy. Synovial membrane cells were dissociated from connective tissue by enzyme digestion and cultured in vitro for 48 hours, and harvested supernatants were assayed for the cytokines tumor necrosis factor alpha (TNFalpha) and interleukin-6 (IL-6), VEGF, MMPs 1, 2, 3, and 13, and TIMP-1 by enzyme-linked immunosorbent assay. Gelatin zymography was performed to demonstrate enzyme activity. Statistical analysis was performed using Student's paired 2-tailed t-tests for parametric data and the Wilcoxon signed rank test for nonparametric data. RESULTS: MMP-1 and MMP-13 levels were approximately 2.5-fold higher in invasive tenosynovium compared with encapsulating tenosynovium. Levels of MMP-2 were approximately 1.5-fold higher in invasive tenosynovium compared with both encapsulating tenosynovium and wrist joint synovium. MMP-13 (P = 0.009) and IL-6 (P = 0.03) levels were significantly lower in encapsulating tenosynovium compared with wrist joint synovium. Levels of VEGF, TIMP-1, TNFalpha, and MMP-3 were similar in all synovial sample groups. Zymography demonstrated enzyme activity in all synovium samples from all 9 patients assessed. CONCLUSION: Tenosynovium produces proinflammatory cytokines and proteolytic enzymes that are important in the tissue degradation seen in RA. Increased production of the enzymes MMP-1, MMP-2, and MMP-13 by invasive tenosynovium suggests a possible explanation for the worse prognosis and increased rupture rate associated with invasive tenosynovitis in RA. Production of VEGF by tenosynovium suggests that angiogenesis may have a role in tenosynovial proliferation and invasion of tendons.     

Influence of hypoxia on the expression of matrix metalloproteinase-1, -3 and tissue inhibitor of metalloproteinase-1 in rheumatoid synovial fibroblasts

OBJECTIVE: The rheumatoid synovium is a hypoxic environment, and hypoxia has been implicated as a factor in the pathogenesis of rheumatoid arthritis (RA). The purpose of this study was to investigate the effect of hypoxia on the expression of matrix metalloproteinase (MMP)-1, -3 and tissue inhibitor of metalloproteinase (TIMP)-1 in rheumatoid synovial fibroblasts. METHODS: Synovial fibroblasts obtained from RA patients were cultured for 48 h under normoxic or hypoxic conditions. Assays included western blot analysis and enzyme-linked immunosorbent assay (ELISA) for MMP-1, -3 and TIMP-1, and northern blot analysis to measure TIMP-1 mRNA levels. RESULTS: Compared with normoxic culture, hypoxia increased MMP-1 and MMP-3 expression in rheumatoid synovial fibroblasts. Hypoxia decreased TIMP-1 expression in rheumatoid synovial fibroblasts, as measured by both protein and mRNA levels. CONCLUSION: These results suggest that microenvironmental conditions, such as hypoxia, may directly contribute to joint destruction in RA by increasing the ratio of MMP-1, -3 to TIMP-1 production in synovial fibroblasts.     

Serum interleukin 6 (il-6A) concentration correlates with matrix metalloproteinases and their tissue inhibitors in rheumatoid arthritis

We explored whether the serum concentration of interleukin 6 (IL-6) is associated with matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in rheumatoid arthritis (RA) patients. Serum levels of IL-6, interstitial collagenase (MMP-1), stromelysin-1 (MMP-3), gelatinase B (MMP-9), TIMP-1 and TIMP-2 were assessed with an ELISA technique in 30 RA patients. We observed the association between IL-6 and MMP-1 (p < 0.001), MMP-3 (p < 0.05), MMP-9 (p < 0.001), TIMP-1 (p < 0.01) and TIMP-2 (p < 0.05). Additionally, serum IL-6, measured MMPs and TIMP-1 correlated with the erythrocyte sedimentation rate, C reactive protein plasma level and the number of swollen joints. We suggest that assessing the serum IL-6, MMP-1, MMP-3, MMP-9 and TIMP-1 levels may be helpful in the prediction of the RA activity.     

Quantitation of metalloproteinase gene expression in rheumatoid and psoriatic arthritis synovial tissue distal and proximal to the cartilage-pannus junction

OBJECTIVE: The distinct and different patterns of radiological damage in psoriatic arthritis (PsA) and rheumatoid arthritis (RA) may be a product of the relative balance of proteolytic enzyme and inhibitor gene expression in synovial tissue. This study compared metalloproteinase gene expression in synovium located proximal to the cartilage-pannus junction (CPJ) and distal to the CPJ (non-CPJ) in patients with PsA and RA. METHODS: Synovial biopsies were obtained from CPJ and non-CPJ sites under direct vision at arthroscopy of an inflamed knee in patients with PsA (n = 12) and RA (n = 12) who were not under disease modifying antirheumatic drug treatment. A competitive, quantitative RT-PCR technique was established for synovial RNA using a polycompetitor construct containing mRNA-specific primer sites for collagenase (MMP-1), stromelysin (MMP-3), tissue inhibitor of metalloproteinase-1 (TIMP-1), and GAPDH. cDNA products were separated and quantified by ethidium bromide stained gel electrophoresis and mRNA values were normalized relative to GAPDH expression. RESULTS: MMP-1, MMP-3, and TIMP-1 mRNA were upregulated in RA and PsA synovium with a prodestructive (MMP-1 + MMP-3)/TIMP-1 balance in both diseases. Similar levels of MMP mRNA expression were observed in PsA and RA despite the presence of less radiological erosion in the PsA group. No difference was observed in the degree of upregulation of MMP-1, MMP-3, or TIMP-1 mRNA in paired biopsies from CPJ and non-CPJ sites in either PsA (n = 8) or RA (n = 10). The ratio of TIMP-1 expression in CPJ compared to non-CPJ biopsies was higher in patients with nonerosive disease (10.1 +/- 27.8) than in erosive patients (0.75 +/- 0.27; p = 0.07). CONCLUSION: PsA and RA have similar levels of MMP-1, MMP-3, and TIMP-1 mRNA expression in synovium. There is no evidence of increased metalloproteinase mRNA expression at the CPJ in RA or PsA. The different patterns of radiological progression seen in RA and PsA were not explained by differences in synovial mRNA expression of MMP-1, MMP-3, or TIMP-1.     

Increased matrix metalloproteinase-3 serum levels in rheumatic diseases: relationship with synovitis and steroid treatment

OBJECTIVE: To determine matrix metalloproteinase-3 (MMP-3) serum levels in patients with rheumatic diseases and to study the relation between MMP-3 and C reactive protein (CRP) levels. METHODS: MMP-3 serum levels were determined by enzyme linked immunosorbent assay (ELISA) in (a) patients with active inflammatory rheumatic diseases: rheumatoid arthritis (RA), psoriatic arthritis, polymyalgia rheumatica, acute crystal arthritis, and ankylosing spondylitis; (b) patients with active inflammatory systemic diseases: cutaneo-articular or renal systemic lupus erythematosus (SLE), systemic sclerosis, and vasculitides; (c) patients with non-inflammatory rheumatic diseases: osteoarthritis and fibromyalgia; (d) critically ill patients without rheumatic diseases, representing an acute inflammatory control group; (e) healthy controls. RESULTS: MMP-3 serum levels were significantly increased in patients with active RA, psoriatic arthritis, and polymyalgia rheumatica, whether treated or not by corticosteroids, and in female patients with acute crystal arthritis. MMP-3 serum levels were normal in steroid-free patients with active cutaneo-articular or renal SLE, systemic sclerosis, and vasculitides but were significantly increased in steroid treated patients. MMP-3 levels were normal in fibromyalgia, osteoarthritis, ankylosing spondylitis, and acute inflammatory controls. MMP-3 was significantly correlated with CRP in RA (r=0.5, p=0.0004) but not in any of the other disease groups. CONCLUSIONS: MMP-3 serum levels are increased in inflammatory rheumatic diseases characterised by joint synovitis, such as RA, polymyalgia rheumatica, psoriatic arthritis, and acute crystal arthritis-that is, whether the diseases are acute or chronic, erosive or not. They are normal in SLE, systemic sclerosis, and vasculitides as well as in non-rheumatic inflammatory controls, but are significantly increased by steroids. These data strongly suggest that serum MMP-3 reflects synovial inflammation.     

Biomarkers predict radiographic progression in early rheumatoid arthritis and perform well compared with traditional markers

OBJECTIVE: To evaluate the performance of biochemical and traditional markers in predicting radiographic progression in rheumatoid arthritis (RA). METHODS: One hundred thirty-two patients with early RA were treated with nonbiologic therapies for 2 years and studied longitudinally. Genomic DNA was analyzed for presence of the shared epitope. Levels of matrix metalloproteinases (matrix metalloproteinase 1 [MMP-1], MMP-13, and MMP-3), tissue inhibitor of metalloproteinases 1 (TIMP-1), and cartilage oligomeric matrix protein (COMP) were assessed in serially obtained serum samples. The presence of pyridinoline (Pyr), deoxypyridinoline, glycosylated Pyr (Glc-Gal-Pyr), and C-telopeptide of type II collagen (CTX-II) was assessed in urine samples. Radiographs obtained at entry and at 2 years were evaluated using the modified Larsen score. RESULTS: Baseline and 2-year radiographs were available from 118 patients. Larsen scores worsened during the 2 years in 50 patients, while 68 patients had no radiographic progression. Levels of a variety of biochemical markers, i.e., MMP-3, CTX-II, COMP, TIMP-1, Pyr, and Glc-Gal-Pyr, correlated significantly with radiographic progression at entry and longitudinally as assessed by area under the curve (AUC). By multivariate analysis, a model including MMP-3 and CTX-II was identified as providing the best prediction of radiographic progression at entry (predictive accuracy by receiver operating characteristic [ROC] AUC = 0.76 [95% confidence interval 0.66-0.85]), while a combination of MMP-3, CTX-II, and swollen joint count formed the best longitudinal AUC model (predictive accuracy by ROC AUC = 0.81 [95% confidence interval 0.73-0.89]). Patient-reported measures (Health Assessment Questionnaire, pain scores) were of limited use. In a subset of 50 patients who were treated with methotrexate (MTX) during the followup period, median serum MMP-3 levels decreased after the initiation of MTX therapy (P = 0.0003). CONCLUSION: These results indicate that biochemical markers are useful predictors of radiographic progression in RA and that serum MMP-3 levels decrease significantly with MTX therapy. Multivariate models that include MMP-3 and CTX-II perform better than existing traditional markers in predicting radiographic outcome in RA.