Anne C. Bay-Jensen

IL-6 Receptor Inhibition Positively Modulates Bone Balance in Rheumatoid Arthritis Patients with an Inadequate Response to Anti-Tumor Necrosis Factor Therapy: Biochemical Marker Analysis of Bone Metabolism in the Tocilizumab RADIATE Study (NCT00106522)

OBJECTIVE To evaluate changes in biochemical markers of bone metabolism in response to tocilizumab in patients with anti-tumor necrosis factor-refractory rheumatoid arthritis (RA). METHODS RADIATE was a randomized, double-blind, placebo-controlled, parallel-group phase 3 trial. C-reactive protein, osteocalcin (OC), C-terminal telopeptides of type-I collagen (C-terminal telopeptides of type-1 collagen (CTX-I) and type-I collagen degradation product), and matrix metalloproteinase-3 (MMP-3) serum levels were analyzed from 299 RA patients. Patients were randomly assigned to either tocilizumab (4 or 8 mg/kg) or placebo intravenously every 4 weeks, along with concomitant stable methotrexate (10 to 25 mg weekly) in all treatment arms. The change in biochemical markers CTX-I and OC in combination was evaluated as a measure of net bone balance, a reflection of the change in equilibrium between resorption and formation. RESULTS Both tocilizumab doses decreased C-reactive protein levels and significantly inhibited cathepsin K-mediated bone resorption in RADIATE subjects, as measured by a decrease in CTX-I. There was a significant overall improvement in net bone balance at week 16 as measured by a decrease in the CTX-I:OC ratio (-25%, P < 0.01). Furthermore, a significant reduction in MMP-3 (43%, P < 0.001) and type-I collagen degradation product levels (18%, P < 0.001) were observed following treatment, both consistent with decreased MMP-mediated type-I collagen catabolism in joint tissue. CONCLUSIONS In anti-tumor necrosis factor-refractory patients, tocilizumab significantly reduced the levels of biochemical markers of cathepsin K-mediated bone resorption and MMP-mediated tissue degradation and remodeling. These observations suggest that tocilizumab has a positive effect on bone balance, which could in part explain the retardation of progressive structural damage observed with tocilizumab. Clinical trial registry number: NCT00106522.

Association between experimental pain biomarkers and serologic markers in patients with different degrees of painful knee osteoarthritis.

To assess the association between pain mechanisms (sensitization) and biochemical markers for cartilage, bone, and inflammation in patients with knee pain.

Serological identification of fast progressors of structural damage with rheumatoid arthritis

IntroductionRheumatoid arthritis (RA) patients with structural progression are in most need of immediate treatment to maintain tissue integrity. The serum protein fingerprint, type I collagen degradation mediated by matrix metalloproteinases (MMP)-cleavage (C1M), is a biomarker of tissue destruction. We investigated whether baseline serum C1M levels could identify structural progressors and if the biomarker levels changed during anti-inflammatory treatment with tocilizumab (TCZ).MethodsThe LITHE-biomarker study (NCT00106535, n = 585) was a one-year phase III, double-blind, placebo (PBO)-controlled, parallel group study of TCZ 4 or 8 mg/kg every four weeks, in RA patients on stable doses of methotrexate (MTX). Spearmans ranked correlation was used to assess the correlation between baseline C1M levels and structural progression at baseline and at weeks 24 and 52. Multivariate regression was performed for delta structural progression. Change in C1M levels were studied as a function of time and treatment.ResultsAt baseline, C1M was significantly correlated to C-reactive protein (P <0.0001), visual analog scale pain (P <0.0001), disease activity score28-erythrocyte sedimentation rate (DAS28-ESR) (P <0.0001), joint space narrowing (JSN) (P = 0.0056) and modified total Sharp score (mTSS) (P = 0.0006). Baseline C1M was significantly correlated with delta-JSN at Week 24 (R2 = 0.09, P = 0.0001) and at Week 52 (R2 = 0.27, P <0.0001), and with delta-mTSS at 24 weeks (R2 = 0.006, P = 0.0015) and strongly at 52 weeks (R2 = 0.013, P <0.0001) in the PBO group. C1M levels were dose-dependently reduced in the TCZ + MTX group.ConclusionsBaseline C1M levels correlated with worsening joint structure over one year. Serum C1M levels may enable identification of those RA patients that are in most need of aggressive treatmentTrial registrationClinicalTrials.gov: NCT00106535

Circulating citrullinated vimentin fragments reflect disease burden in ankylosing spondylitis and have prognostic capacity for radiographic progression.

OBJECTIVE Ankylosing spondylitis (AS) has been considered a seronegative rheumatic disease based on absent or low levels of antibodies against citrullinated proteins. The present study was undertaken to evaluate whether a citrullinated and matrix metalloproteinase-degraded fragment of vimentin (VICM) could be a prognostic biomarker in AS. METHODS VICM was measured in serum samples from healthy controls (n=35), control patients with rheumatoid arthritis (RA) (n=47), and patients with AS (n=201). The optimal cutoff for diagnostic sensitivity and specificity was determined by receiver operating characteristic curve analysis. Baseline and 2-year spine radiographs were available from 118 AS patients, and were scored using the modified Stoke AS Spine Score (mSASSS). We assessed correlations with patient demographic characteristics (age, disease duration), disease activity (Bath AS Disease Activity Index [BASDAI], C-reactive protein level), and disease severity (mSASSS) using Spearmans rho. The independent association of VICM with 2-year radiographic progression, defined as a change of >0 in the mSASSS or the development of a new syndesmophyte, was analyzed by multivariate regression. RESULTS Levels of degraded VICM were significantly higher in both RA patients and AS patients than in healthy controls (both P<0.001). AS patients with the highest levels of VICM had the largest burden of disease (P<0.01), i.e., highest mSASSS score and BASDAI. VICM levels were significantly and independently associated with radiographic progression after 2 years (β=0.69, P=0.0005). Patients with both a high VICM level and a high baseline mSASSS had the highest risk of radiographic progression (odds ratio 13 for mSASSS change, 32 for new syndesmophytes), with progression occurring in 67% of these patients. CONCLUSION The present findings show that serum VICM may be of prognostic value in AS. The data also suggest that citrullination may be relevant in AS pathogenesis.

Circulating protein fragments of cartilage and connective tissue degradation are diagnostic and prognostic markers of rheumatoid arthritis and ankylosing spondylitis.

Inflammation driven connective tissue turnover is key in rheumatic diseases, such as ankylosing spondylitis (AS). Few biomarkers are available for measuring disease prognosis or the efficacy of interventions applied in these tissue-related conditions. Type II collagen is the primary structural protein of cartilage and type III collagen of connective tissues, and obvious targets for the collagenalytic, which increase during tissue inflammation. The objective of the study was to investigate the diagnostic and prognostic utility of cartilage, C2M, and synovial, C3M, turnover biomarkers in AS. Serum samples were retrieved from patients suffering from AS (n = 103), RA (n = 47) and healthy controls (n = 56). AS progressors were defined as having new vertebral syndesmophytes or more that 3 unit change in mSASSS over a two-year period. Type II collagen degradation markers in serum were measured by the C2M ELISA, and type III collagen degradation by the C3M ELISA. Logistic regression and dichotomized decision tree were used to analyze the prognostic value of the markers individually or in combination. Both C2M and C3M levels were significantly higher in RA patients than in healthy controls (p<0.0001). Diagnostic utility was analyzed by ROC and areas under the curve (AUCs) were 72% and 89% for C2M and C3M, respectively. Both C2M and C3M, were significantly higher in serum samples from AS patient than from healthy controls (p<0.0001). The AUCs of C2M and C3M, respectively, were 70% and 81% for AS. A combination of C2M and C3M, dichotomized according to best cut-offs for individual markers, could correctly identify 80% of the progressors and 61% of the non-progressors. The present study is the first to show that specific biomarkers of cartilage and connective tissue degradation facilitate both diagnosis and prediction of progression of RA and AS.

Identifying specific profiles in patients with different degrees of painful knee osteoarthritis based on serological biochemical and mechanistic pain biomarkers: a diagnostic approach based on cluster analysis

Abstract Biochemical and pain biomarkers can be applied to patients with painful osteoarthritis profiles and may provide more details compared with conventional clinical tools. The aim of this study was to identify an optimal combination of biochemical and pain biomarkers for classification of patients with different degrees of knee pain and joint damage. Such profiling may provide new diagnostic and therapeutic options. A total of 216 patients with different degrees of knee pain (maximal pain during the last 24 hours rated on a visual analog scale [VAS]) (VAS 0-100) and 64 controls (VAS 0-9) were recruited. Patients were separated into 3 groups: VAS 10 to 39 (N = 81), VAS 40 to 69 (N = 70), and VAS 70 to 100 (N = 65). Pressure pain thresholds, temporal summation to pressure stimuli, and conditioning pain modulation were measured from the peripatellar and extrasegmental sites. Biochemical markers indicative for autoinflammation and immunity (VICM, CRP, and CRPM), synovial inflammation (CIIIM), cartilage loss (CIIM), and bone degradation (CIM) were analyzed. WOMAC, Lequesne, and pain catastrophizing scores were collected. Principal component analysis was applied to select the optimal variable subset, and cluster analysis was applied to this subset to create distinctly different knee pain profiles. Four distinct knee pain profiles were identified: profile A (N = 27), profile B (N = 59), profile C (N = 85), and profile D (N = 41). Each knee pain profile had a unique combination of biochemical markers, pain biomarkers, physical impairments, and psychological factors that may provide the basis for mechanism-based diagnosis, individualized treatment, and selection of patients for clinical trials evaluating analgesic compounds. These results introduce a new profiling for knee OA and should be regarded as preliminary.

Quantification of “end products” of tissue destruction in inflammation may reflect convergence of cytokine and signaling pathways – implications for modern clinical chemistry

Abstract The degree of inflammation in auto-immune diseases such as rheumatoid arthritis is often assessed in serum and used for diagnostic and prognostic purposes. The serum levels of acute inflammatory signaling molecules (C-reactive protein and serum amyloid A) in conjunction with the important pro-inflammatory cytokines themselves may have limited utility due to several limitations. (1) These traditional biomarkers are associated with substantial variation due to biological not technical issues. (2) The combined burden of cytokines rather than one single player may be responsible for the progression of disease. (3) The cellular and tissue origins of cytokines that are detected systemically are difficult to determine as the cytokines lack tissue specificity. (4) There is substantial redundancy in the signaling potential of cytokines. Despite these major limitations, the total burden of inflammatory signaling molecules and pro-inflammatory cytokines are important in assessing the degree of inflammation in conjunction with a diagnosis of disease. The total burden of signaling ultimately results in protease expression, tissue destruction and disease progression. One of the pivotal events in the downstream inflammatory signaling is the generation of pathological enzymes, which results in the release of small but tissue-specific protein fragments into the serum that may be used as molecular biochemical markers. We discuss the potential of this new class of biochemical markers, which may be viewed as “end products of tissue destruction”. These so-called protein fingerprints may also be considered end-products of the convergence cytokine signaling pathways, as they are the final end-result of tissue destruction.

Alpha C-telopeptide of type I collagen is associated with subchondral bone turnover and predicts progression of joint space narrowing and osteophytes in osteoarthritis.

To evaluate joint tissue remodeling using the urinary collagen biomarkers urinary α‐C‐telopeptide of type I collagen (α‐CTX) and urinary C‐telopeptide of type II collagen (CTX‐II) and to determine the association of these biomarkers with osteoarthritis (OA) severity, progression, and localized knee bone turnover.

The collagen turnover profile is altered in patients with inguinal and incisional hernia

BACKGROUND Disturbed metabolism in the extracellular matrix (ECM) contributes to formation of abdominal wall hernias. The aim of this study was to gain deeper insight into the ECM turnover in hernia patients by analyzing serum biomarkers specifically reflecting collagen synthesis and breakdown in the interstitial matrix (types I, III, and V collagens) and in the basement membrane (type IV collagen). MATERIAL AND METHODS Patients with 3 different types of hernias were included: Primary unilateral inguinal hernia (n = 17), multiple hernias defined as ≥3 hernias (n = 21), and incisional hernia (n = 25). Patients without hernias scheduled to undergo elective operation for gallstones (n = 18) served as controls. Whole venous blood was collected preoperatively. Biomarkers for synthesis of interstitial matrix (PINP, Pro-C3, P5CP) and basement membrane (P4NP) as well as corresponding degradation (C1M, C3M, C5M, and C4M) were measured in serum by validated, solid-phase competitive assays. RESULTS In inguinal hernia patients, the turnover of the interstitial matrix collagens type III (P < .042) and V (P < .001) was decreased compared with controls, whereas the turnover of the basement membrane collagen type IV was increased (P < .001). In incisional hernia patients, the turnover of type V collagen was decreased (P = .048) and the turnover of type IV collagen was increased compared with the hernia-free controls (P < .001). CONCLUSION Hernia patients demonstrated systemically altered collagen metabolism. The serologic turnover profile of type IV collagens may predict the presence of inguinal and incisional hernia. Regulation of type IV collagen turnover may be crucial for hernia development.

Estrogen inhibits Dlk1/FA1 production: A potential mechanism for estrogen effects on bone turnover

We have recently identified delta‐like 1/fetal antigen 1 (Dlk1/FA1) as a novel regulator of bone mass that functions to mediate bone loss under estrogen deficiency in mice. In this report, we investigated the effects of estrogen (E) deficiency and E replacement on serum (s) levels of Dlk1/FA1 (s‐Dlk1FA1) and its correlation with bone turnover markers. s‐Dlk1/FA1 and bone turnover markers (serum cross‐linked C‐telopeptide [s‐CTX] and serum osteocalcin) were measured in two cohorts: a group of pre‐ and postmenopausal women (n = 100) and a group of postmenopausal women, where half had received estrogen‐replacement therapy (ERT, n = 166). s‐Dlk1/FA1 and s‐CTX were elevated in postmenopausal E‐deficient women compared with premenopausal E‐replete women (both p < 0.001). s‐Dlk1/FA1 was correlated with s‐CTX (r = 0.30, p < 0.01). ERT in postmenopausal women decreased s‐Dlk1/FA1, as well as s‐CTX and s‐osteoclacin (all p < .0001). Changes in s‐Dlk1 were significantly correlated with those observed in s‐CTX (r = 0.18, p < 0.05) and s‐osteocalcin (r = 0.28, p < 0.001). In conclusion, s‐Dlk1/FA1 is influenced by E‐deficiency and is correlated with bone turnover. Increased levels of s‐Dlk1/FA1 in postmenopausal women may be a mechanism mediating the effects of estrogen deficiency on bone turnover.