Value of serum cartilage oligomeric matrix protein as a prognostic marker of large-joint damage in rheumatoid arthritis--data from the RAPIT study

Predictors of radiographic erosion and joint space narrowing progression in patients with early rheumatoid arthritis: a cohort study

Background

Radiographic damage in rheumatoid arthritis (RA) includes erosions and joint space narrowing (JSN). Different mechanisms may underlie their development. The objective of this study was to evaluate predictors of these entities separately.

Methods

Consecutive early RA patients (symptom duration ≤12 months) from a defined area (Malmö, Sweden) recruited during 1995–2005 were investigated. Radiographs of hands and feet were scored by a trained reader according to the modified Sharp-van der Heijde score. Fat mass and lean mass distribution were measured at baseline using dual energy x-ray absorptiometry. Potential predictors of erosion and JSN progression from inclusion to the 5-year follow-up were evaluated.

Results

Two hundred and thirty-three patients were included. Radiographs at baseline and 5 years were available for 162 patients. The median (interquartile) progression of erosion and JSN scores were 4 (0–8) and 8 (1–16), respectively. Rheumatoid factor (RF) was a robust significant predictor of both erosion and JSN score progression. In adjusted analyses, anti-CCP antibodies predicted erosions while the erythrocyte sedimentation rate was predictive of both outcomes. Smoking and high baseline disease activity (DAS28 > 5.1) predicted progression of erosions. Baseline erosion score was associated with progression of both erosion and JSN progression, while baseline JSN score was predictive only of the progression of JSN. Overweight/obesity (BMI ≥ 25 kg/m²) was a significant negative predictor of JSN score progression (β = − 0.14, p = 0.018, adjusted for RF, age, baseline JSN score) also when additionally adjusting for ever smoking (p = 0.041). Among female patients, this effect was observed in those of estimated post-menopausal age (> 51 years), but not in younger women. The truncal to peripheral fat ratio was associated with less JSN score progression in women, but not in men.

Conclusions

Overweight RA patients had less JSN progression, independent of smoking status. This effect was seen in particular among older women (mainly post-menopausal), but not younger. Truncal fat was associated with less JSN progression in female patients. Smoking predicted erosion progression, and erosions may precede JSN. BMI and fat distribution may influence cartilage damage in early RA and might be related to hormonal factors.

Joint remodeling outcome of serum levels of Dickkopf-1 (DKK1), cartilage oligomeric matrix protein (COMP), and C-telopeptide of type II collagen (CTXII) in rheumatoid arthritis

Introduction

Rheumatoid arthritis (RA) is the most widespread chronic inflammatory rheumatic disease over the world. It is characterized by chronic proliferation of synovium, cartilage destruction, and periarticular erosion/bone loss. We investigated the serum levels of the C-telopeptide of type II collagen (CTX-II), Dickkopf-1 (DKK1), and cartilage oligomeric matrix protein (COMP) in relationship to the disease activity.

Material and methods

Serum COMP, CTX-II, and DKK1 levels were measured in 63 RA patients and 50 person age and gender matched as a healthy controls by ELISA test. Disease activity score (DAS) were calculated.

Results

The mean level of and COMP and CTX-II were significantly higher in patients with RA than in healthy controls (5.71 ±7.04 vs. 2.70 ±1.31 ng/ml, and 0.45 ±0.27 vs. 0.23 ±0.16 ng/ml, respectively; p < 0.001). Also, DKK1 serum levels were significantly higher in patients with RA than in healthy controls (6970.68 ±7566.68 vs. 3276.96 ±1306.77 pg/m; p < 0.001). There was a positive significant correlation between DKK1 and swollen joint (r = 0.42, p < 0.001). There were no significant differences in the number of patients, gender, the duration of RA disease, DAS, and RF. Sensitivity was 58.7% and specificity was 85.7% at a cut-off point (> 3.6 ng/ml) for serum COMP in RA patients, while, sensitivity was 100% and specificity was 52.4% at a cut-off point (> 0.15 ng/ml) for serum CTX-II and sensitivity was 68.3% and specificity was 95.2 % at a cut-off point (> 4876 pg/ml) for serum DKK1.

Conclusions

Measurement of some serological biomarkers such as CTX-II, COMP, and DKK1 that reflect bone and cartilage destruction in RA patients could be used to indicate disease activity and early joint affection.

The time course and mechanisms of change in biomarkers of joint metabolism in response to acute exercise and chronic training in physiologic and pathological conditions

PURPOSE

The benefits of exercise across the lifespan and for a wide spectrum of health and diseases are well known. However, there remains less clarity as to the effects of both acute and chronic exercise on joint health. Serum biomarkers of joint metabolism are sensitive to change and have the potential to differentiate between normal and adverse adaptations to acute and chronic load. Therefore, the primary objective of this review is to evaluate how serum biomarkers can inform our understanding of how exercise affects joint metabolism.

METHODS

A comprehensive literature search was completed to identify joint biomarkers previously used to investigate acute and chronic exercise training.

RESULTS

Identified biomarkers included those related to joint cartilage, bone, synovium, synovial fluid, and inflammation. However, current research has largely focused on the response of serum cartilage oligomeric matrix protein (COMP) to acute loading in healthy young individuals. Studies demonstrate how acute loading transiently increases serum COMP (i.e., cartilage metabolism), which is mostly dependent on the duration of exercise. This response does not appear to be associated with any lasting deleterious changes, cartilage degradation, or osteoarthritis.

CONCLUSION

Several promising biomarkers for assessing joint metabolism exist and may in future enhance our understanding of the physiological response to acute and chronic exercise. Defining 'normal' and 'abnormal' biomarker responses to exercise and methodological standardisation would greatly improve the potential of research in this area to understand mechanisms and inform practice.

Predictive factors for radiographic progression of large joint damage in patients with rheumatoid arthritis treated with biological disease-modifying antirheumatic drugs (bDMARDs): Results of 3 to 4 years of follow-up

Objectives: Little information is available regarding long-term follow-up of radiographic progression of damage (RPD) to large joints during treatment of rheumatoid arthritis (RA) with biological disease-modifying antirheumatic drugs (bDMARDs). We evaluated 3- to 4-year follow-up results and the associations between RPD and patient background and Larsen grade (LG) of joints.Methods: Seventy-one RA patients receiving bDMARDs for 3 to 4 years or who achieved bDMARD-free status were included. The mean age and disease duration at the start of bDMARDs were 62.4 years and 10.8 years, respectively. A total of 314 joints, including shoulders, elbows, hips, knees, and ankles, were evaluated to determine whether RPD was present by comparing radiographs before and after treatment.Results: RPD was observed in 24 patients (33.8%) and 34 joints (10.8%). Joints with an LG of III or higher had significantly higher rates of RPD than those with LGs I and II. Multivariate logistic regression analysis revealed that stage and health assessment questionnaire (HAQ) score at 18-months were independent risk factors for RPD (cut-off value: 2.5, odds ratio: 7.222 for stage; cut-off value: 0.9375, odds ratio: 6.278 for HAQ at 18-months).Conclusion: Stage, HAQ at 18-months, and LG at the start of bDMARDs were predictive of RPD after 3 to 4 years. bDMARDs should be started before both stage and LG exceed III and the therapeutic strategy should be determined so that HAQ does not exceed 1.0 during treatment.

Role of Serum cartilage oligomeric matrix protein (COMP) in the diagnosis of rheumatoid arthritis (RA): A case-control study

Objective

To analyse the role of serum cartilage oligomeric matrix protein (COMP) levels in the differential diagnosis of rheumatoid arthritis (RA).

Methods

This case–control study analysed the clinical and laboratory characteristics of patients with RA and healthy control subjects. The diagnostic ability of COMP for RA was evaluated by comparing it with anti-cyclic citrullinated peptide antibody levels. The sensitivity, specificity, positive and negative predictive values were calculated.

Results

The study enrolled 82 patients with RA and 34 healthy control subjects. The serum COMP level was significantly higher in patients with RA compared with control subjects (mean ± SD 29.51 ± 9.21 ng/ml versus 17.85 ± 5.55 ng/ml, respectively). The serum COMP level was significantly higher in patients with active RA compared with patients with RA in remission (mean ± SD 33.08 ± 8.80 ng/ml versus 24.94 ± 7.65 ng/ml, respectively). The cut-off value for COMP to discriminate patients with RA from healthy individuals was 21.51 ng/ml (sensitivity 0.817, specificity 0.882, positive predictive value 0.944, negative predictive value 0.667, and accuracy 0.836).

Conclusion

The serum COMP level has the potential to be used as a biological marker for differentiating between patients with RA and healthy individuals.

The Effects of Aerobic and Resistance Exercise on Markers of Large Joint Health in Stable Rheumatoid Arthritis Patients: A Pilot Study

OBJECTIVE

Exercise is beneficial for people with rheumatoid arthritis (RA). However, patients and health professionals have expressed concern about the possible detrimental effects of exercise on joint health. The present study investigated the acute and chronic effects of high-intensity, low-impact aerobic and resistance exercise on markers of large joint health in RA.

METHODS

Eight RA patients and eight healthy, matched control (CTL) participants performed 30 minutes' high-intensity, low-impact aerobic and lower-body resistance exercise, one week apart. Primary outcome measures assessing joint health were serum cartilage oligomeric matrix protein (sCOMP) and knee joint synovial inflammation (Doppler ultrasound colour fraction; CF). These measures were taken at baseline, immediately after and 0.5, one, two, six and 24 hours post-exercise. In a separate study, nine RA patients completed eight weeks of progressive exercise training. The same outcome measures were reassessed at baseline, and at one hour post-exercise of training weeks 0, 1, 4 and 8.

RESULTS

RA patients showed higher overall sCOMP [RA: 1,347 ± 421, CTL: 1,189 ± 562 ng/mL; p < 0.05; effect size (ES) = 0.32] and CF when scanned longitudinally (RA: 0.489 ± 0.30 × 10(-3) , CTL: 0.101 ± 0.13 × 10(-3) ; p < 0.01; ES = 1.73) and transversely (RA: 0.938 ± 0.69 × 10(-3) , CTL: 0.199 ± 0.36 × 10(-3) ; p < 0.01; ES = 1.33) than CTL. However, no acute effects on joint health were observed post-exercise. Similarly, no chronic effects were observed over eight weeks of combined aerobic and resistance training in RA, with positive effects on physical fitness and function.

CONCLUSIONS

RA patients on stable treatment with low disease activity were able to perform an individually prescribed high-intensity, low-impact aerobic and resistance exercise without changes in markers of large joint health. Copyright © 2015 John Wiley & Sons, Ltd.

Early increase in serum-COMP is associated with joint damage progression over the first five years in patients with rheumatoid arthritis

BACKGROUND

Currently available biomarkers for the early tissue process leading to joint damage in rheumatoid arthritis are insufficient and lack prognostic accuracy, possibly a result of variable activity of the disease over time. This study represents a novel approach to detect an altered activity of the disease process detected as increasing serum-COMP levels over a short time and whether this would correlate with joint damage progression over the first 5 years of disease.

METHODS

In all, 349 patients from the Swedish BARFOT early RA study were examined. Serum-COMP was analysed by ELISA at diagnosis and after 3 months. Based on changes in serum-COMP levels, three subgroups of patients were defined: those with unchanged levels (change ≤ 20%) (N=142), decreasing levels (> 20%) (N=173) and increasing levels (> 20%) (N=34). Radiographs of hands and feet were obtained at inclusion, after 1, 2 and 5 years and scored according to Sharp van der Heijde (SHS). Radiographic progression was defined as increase in SHS by ≥5.8.

RESULTS

The group of patients with increasing COMP levels showed higher median change in total SHS and erosion scores at 1, 2 and 5 year follow-up compared with the groups with stable or decreasing COMP levels. Furthermore, the odds ratio of radiographic progression was 2.8 (95% CI 1.26-6.38) for patients with increasing COMP levels vs. patients with unchanged levels.The group of patients with increasing COMP levels had higher ESR at inclusion but there were no baseline differences between the groups for age, gender, disease duration, disease activity (DAS28), function (HAQ), CRP, nor presence of rheumatoid factor or anti-CCP. Importantly, neither did changes over the 3-month period in DAS28, HAQ, ESR nor CRP differ between the groups and these variables did not correlate to joint damage progression.

CONCLUSION

Increasing serum-COMP levels between diagnosis and the subsequent 3 months in patients with early RA represents a novel indicator of an activated destructive process in the joint and is a promising tool to identify patients with significant joint damage progression during a 5-year period.

Relations of serum COMP to cardiovascular risk factors and endothelial function in patients with rheumatoid arthritis treated with methotrexate and TNF-α inhibitors

OBJECTIVE

To examine whether serum level of cartilage oligomeric matrix protein (S-COMP) is related to methotrexate (MTX) or to MTX and tumor necrosis factor-α (TNF-α) combination treatment for rheumatoid arthritis (RA); and to investigate whether S-COMP is related to cardiovascular risk factors including endothelial dysfunction and level of anticitrullinated protein antibodies (ACPA) in patients with RA.

METHODS

Clinical and laboratory measures, including S-COMP and reactive hyperemic index (RHI), were examined in 55 consecutive patients with RA starting with either MTX (n = 34) or MTX and anti-TNF-α treatment (n = 21) at baseline, and after 6 weeks and 6 months.

RESULTS

S-COMP was similar in the 2 treatment regimens during followup. We found a positive relationship between S-COMP at baseline and the use of disease-modifying antirheumatic drugs the last year preceding the study (p = 0.001), and a negative relation to current use of systemic glucocorticosteroids (p = 0.044). The nonsignificant change in S-COMP between baseline and the 6-month followup was positively and independently related to change in ACPA level (p = 0.009). There was no significant association between RHI and level of S-COMP at baseline.

CONCLUSION

The cartilage turnover marker S-COMP did not change significantly after 6 months' treatment with MTX with or without a TNF-α inhibitor in patients with RA. The positive association between S-COMP and ACPA suggests that these factors might interact, and could both be contributors to an unknown link between inflammation and cartilage destruction in patients with RA. S-COMP was not related to endothelial function in patients with RA, or to other cardiovascular risk factors studied. Clinical Trials registration number NCT00902005.

Cartilage Oligomeric Matrix Protein Associates Differentially with Erosions and Synovitis and Has a Different Temporal Course in Cyclic Citrullinated Peptide Antibody (Anti-CCP)-positive versus Anti-CCP-negative Early Rheumatoid Arthritis

Objective.

Cyclic citrullinated peptide antibody (anti-CCP)-positive and anti-CCP-negative rheumatoid arthritis (RA) have been suggested as 2 distinctive disease subsets with respect to disease activity and prognosis. Previously, we proposed that anti-CCP antibodies might have a chondrocyte-suppressive effect. We aimed to compare circulating cartilage oligomeric matrix protein (COMP), a marker of cartilage turnover, in untreated anti-CCP-positive and anti-CCP-negative RA, and to study the temporal pattern of COMP through 4 years of treatment, including the relationship to imaging and clinical findings.

Methods.

A total of 160 patients with newly diagnosed RA who were naive to disease-modifying antirheumatic drugs were included in the CIMESTRA trial. Ninety healthy blood donors served as controls. Demographic and disease measures including Disease Activity Score in 28 joints, IgM rheumatoid factor, anti-CCP, Health Assessment Questionnaire, visual analog scale scores for pain and global and physician assessment, and magnetic resonance imaging (MRI) of the nondominant hand were recorded at baseline. COMP in serum was measured by ELISA at inclusion and serially through 4 years.

Results.

Median baseline COMP was higher in patients with RA [9.8 U/l (interquartile range 8.96, 10.5)] compared with controls [8.3 U/l (IQR 7.84, 8.9); p < 0.001] and remained elevated at 4 years [10.8 U/l (IQR 10.2, 11.7); p < 0.001]. At baseline, anti-CCP-positive patients had lower COMP than anti-CCP-negative patients (p = 0.048). In anti-CCP-positive patients, COMP exhibited a parabolic course over 4 years, while COMP in anti-CCP-negative patients had an almost linear course. In anti-CCP-positive patients, COMP was associated with MRI edema and erosion score, while COMP was correlated with synovitis score in anti-CCP-negative individuals.

Conclusion.

Our study provides additional evidence for the existence of different disease pathways in anti-CCP-positive and anti-CCP-negative subsets of RA, and evidence that anti-CCP antibodies may be implicated in the disease process by modifying cartilage metabolism.

Biochemical markers of ongoing joint damage in rheumatoid arthritis--current and future applications, limitations and opportunities

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease associated with potentially debilitating joint inflammation, as well as altered skeletal bone metabolism and co-morbid conditions. Early diagnosis and aggressive treatment to control disease activity offers the highest likelihood of preserving function and preventing disability. Joint inflammation is characterized by synovitis, osteitis, and/or peri-articular osteopenia, often accompanied by development of subchondral bone erosions, as well as progressive joint space narrowing. Biochemical markers of joint cartilage and bone degradation may enable timely detection and assessment of ongoing joint damage, and their use in facilitating treatment strategies is under investigation. Early detection of joint damage may be assisted by the characterization of biochemical markers that identify patients whose joint damage is progressing rapidly and who are thus most in need of aggressive treatment, and that, alone or in combination, identify those individuals who are likely to respond best to a potential treatment, both in terms of limiting joint damage and relieving symptoms. The aims of this review are to describe currently available biochemical markers of joint metabolism in relation to the pathobiology of joint damage and systemic bone loss in RA; to assess the limitations of, and need for additional, novel biochemical markers in RA and other rheumatic diseases, and the strategies used for assay development; and to examine the feasibility of advancement of personalized health care using biochemical markers to select therapeutic agents to which a patient is most likely to respond.

Benefits of exercise in rheumatoid arthritis

This paper aims to highlight the importance of exercise in patients with rheumatoid arthritis (RA) and to demonstrate the multitude of beneficial effects that properly designed exercise training has in this population. RA is a chronic, systemic, autoimmune disease characterised by decrements to joint health including joint pain and inflammation, fatigue, increased incidence and progression of cardiovascular disease, and accelerated loss of muscle mass, that is, “rheumatoid cachexia”. These factors contribute to functional limitation, disability, comorbidities, and reduced quality of life. Exercise training for RA patients has been shown to be efficacious in reversing cachexia and substantially improving function without exacerbating disease activity and is likely to reduce cardiovascular risk. Thus, all RA patients should be encouraged to include aerobic and resistance exercise training as part of routine care. Understanding the perceptions of RA patients and health professionals to exercise is key to patients initiating and adhering to effective exercise training.

Value of entheseal ultrasonography and serum cartilage oligomeric matrix protein in the preclinical diagnosis of psoriatic arthritis

Objective:

To evaluate the utility of entheseal ultrasonography and serum COMP in the preclinical diagnosis of psoriatic arthritis.

Methods:

60 psoriatic patients were divided into: 30 patients with psoriasis (group I) and 30 patients with psoriatic arthritis as control (group II). They underwent independent clinical and ultrasonographic examination of both lower limbs at the calcaneal insertions of Achilles tendons. Psoriatic arthritis disease activity and severity was assessed by modified DAS28 and Steinbrockers scores. Serum levels of COMP were measured for all patients by ELISA.

Results:

On clinical examination, no entheseal abnormalities were detected in group I while they were present in 23.3% of group II with statistically significant difference between them (P < 0.001). Ultrasonographic entheseal abnormalities were detected in 33.3% of group I and in 46.7% of group II with no significant difference between them (P > 0.05). Serum COMP were significantly elevated in group I and II with no statistically significant difference between them (mean ± SD 5.9 ± 3 and 6.8 ± 12 respectively, P > 0.05). Entheseal ultrasound was more specific (67%) while serum COMP was more sensitive (87%) in the preclinical diagnosis of psoriatic arthritis. Serum COMP levels were significantly correlated with CRP in both groups and with DAS28 and Steinbrockers scores in group II (P < 0.01).

Conclusion:

Entheseal ultrasonography and serum COMP levels may be used complementary to each other for preclinical diagnosis of psoriatic arthritis. Serum COMP seems to be promising prognostic marker for psoriatic arthritis patients.

The role of ADAMTS-7 and ADAMTS-12 in the pathogenesis of arthritis

Loss of articular cartilage caused by extracellular matrix breakdown is the hallmark of arthritis. Degradative fragments of cartilage oligomeric matrix protein (COMP) have been observed in arthritic patients. ADAMTS-7 and ADAMTS-12, two members of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family, have been associated with COMP degradation in vitro, and are significantly overexpressed in the cartilage and synovium of patients with rheumatoid arthritis. Recent studies have demonstrated the importance of COMP degradation by ADAMTS-7 and ADAMTS-12. Specifically, the size of COMP fragments generated by ADAMTS-7 or ADAMTS-12 is similar to that of COMP-degradative fragments seen in arthritic patients. In addition, antibodies against ADAMTS-7 or ADAMTS-12 dramatically inhibit tumor necrosis factor-induced and interleukin-1beta-induced COMP degradation in cartilage explants. Furthermore, suppression of ADAMTS-7 or ADAMTS-12 expression using the small interfering RNA silencing approach in human chondrocytes markedly prevents COMP degradation. COMP degradation mediated by ADAMTS-7 and ADAMTS-12 is inhibited by alpha(2)-macroglobulin. More significantly, granulin-epithelin precursor, a newly characterized chondrogenic growth factor, disturbs the interaction between COMP and ADAMTS-7 and ADAMTS-12, preventing COMP degradation by these enzymes. This Review summarizes the evidence demonstrating that ADAMTS-7 and ADAMTS-12 are newly identified enzymes responsible for COMP degradation in arthritis, and that alpha(2)-macroglobulin and granulin-epithelin precursor represent their endogenous inhibitors.