Urinary CTX-II Research Articles

Urinary CTX-II predicts the risk of total joint replacement in postmenopausal women: a 18-year longitudinal study

Purpose: Identifying objective risk-factors for total joint replacement (TJR) is useful to enrich population at high risk in osteoarthritis (OA) clinical trials. In this study, we investigated the value of urinary CTX-II, a biochemical marker of cartilage breakdown, to predict TJR in postmenopausal women.

Clinical and biochemical factors associated with risk of total joint replacement and radiographic progression in osteoarthritis: Data from two phase III clinical trials

ObjectivesClinical trials of new disease-modifying treatments for osteoarthritis should demonstrate a positive effect on a functional outcome or reduction in joint failure in order to be considered successful. Total joint replacement (TJR) surgery may be considered as joint failure, but great variation in the incidence of TJR complicates its use as a study endpoint. Factors predicting elevated risk of TJR could potentially be used to enrich such outcome-trials. MethodsUsing cumulative data from two phase three clinical trials with urine samples from 1255 knee OA patients followed for two years, we assessed the value of a series of baseline clinical variables including the uCTX-II biomarker, as predictors of joint-space narrowing, Kellgren-Lawrence-grade progression, and total joint replacement. ResultsA prediction-model incorporating age, sex, BMI, CTX-II and KL-grade predicted TJR within the two-year period with an AUC of 0.75 (95% CI: 0.72–0.77). The participants with a cumulative KL-grade between knees of 5, 6, or 7 had a more than 3 times higher risk of TJR in the study period compared to lower (HR: 3.03, 95% CI: 1.54 to 5.96, p = 0.001). Age was associated with increased TJR risk (per 5 years of age: HR: 1.28, 95% CI: 1.03–3.79, p = 0.05). Baseline u-CTX-II was associated with elevated risk of radiographic progression in terms of both JSN and KL-grade. ConclusionsA composite model combining baseline age, sex, BMI, u-CTX-II and KL-grade was able to acceptably predict TJR during a two-year period. In the absence of baseline radiographic OA severity, u-CTX-II independently contributed to prediction of TJR. Baseline urine CTX-II was associated with risk of radiographic progression.

The association of plasma IL-1Ra and related cytokines with radiographic severity of early knee osteoarthritis

ObjectiveWe aimed to evaluate the association between inflammatory biomarkers in peripheral blood and severity of knee osteoarthritis (OA). MethodsWe performed a cross-sectional study in participants with frequent knee pain, evaluated radiographic and clinical severity. We measured inflammatory biomarkers: plasma (p) IL-1Ra, IL-1β, IL-18, serum (s) CD14, hsCRP and bone and cartilage biomarkers: urine (u) CTX-II, (s) HA, COMP, CTX-I, PIIANP. We assessed radiographic severity by Kellgren-Lawrence (KL) grading and Osteoarthritis Research Society International (OARSI) standardized scoring atlas; and clinical severity by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results139 participants (82% women, mean ± SD age: 55.5 ± 7.8 years) were included. (p) IL-1Ra was negatively associated with radiographic severity by KL grading (Spearman rho = −0.197, P = 0.021), osteophytes (Spearman rho = −0.217, P = 0.011), and joint space narrowing of index knee (Spearman rho = −0.172, P = 0.045); and KL sum score of both knees (Spearman rho = −0.180, P = 0.035), after adjustment for age, gender and body mass index (BMI). Other inflammatory markers were not associated with radiographic severity. Cartilage degradation markers (u) CTXII and (s) COMP were modestly associated with radiographic severity after adjustment. In multivariate models, (s) hsCRP and the bone and cartilage biomarkers, but not the inflammatory biomarkers, were associated with radiographic severity. ConclusionAmong the inflammatory biomarkers in peripheral blood, IL-1Ra was negatively associated with radiographic severity in this early knee OA cohort.

Can urinary CTX-II be a biomarker for knee osteoarthritis?

BackgroundEarly diagnosis of knee osteoarthritis (OA) remains a diagnostic challenge. Urinary C-terminal cross-linked telopeptide of type II collagen (urinary CTX-II) is one of the potential OA biomarkers. However, conclusive evidence regarding the use of this biomarker as a tool for early diagnosis is still lacking. The purposes of this study were to compare urinary CTX-II levels in patients with knee OA and in healthy controls, to evaluate the correlation between urinary CTX-II levels, radiographic severity of OA, and patient-reported outcomes and to evaluate the effect of age and gender on urinary CTX-II levels in the Asian populations.MethodsTwo groups were studied. The OA group included 78 patients with knee OA aged > 40 years who met the diagnostic criteria for knee OA described by the American College of Rheumatology (ACR). The control group consisted of 51 healthy participants age > 40 years without clinical or radiographic evidence of knee OA. Bilateral knee radiographs were taken and classified according to the Kellgren and Lawrence (KL) grading system. Urinary CTX-II was measured using a competitive ELISA test and Western Ontario and Mcmaster Universities Arthritis Index (WOMAC) was also recorded in all participants.ResultsUrinary CTX-II was significantly higher in the OA group than in the control group (p < 0.001). The severe knee OA group (KL grade 3 and 4) had higher urinary CTX-II levels than mild knee OA group (KL grade 2) but the difference did not reach statistical significance (p = 0.2). There was a moderate correlation between urinary CTX-II levels and KL grades (r = 0.405, p < 0.001) and a weak correlation between urinary CTX-II levels and WOMAC index scores (r = 0.367, p < 0.001). Multiple regression analysis showed that urinary CTX-II was independently associated with KL grades. Whereas age, gender, and WOMAC index had no statistically significant influence on the urinary CTX-II levels.ConclusionsPatients with knee OA had higher urinary CTX-II levels than healthy controls. Moreover, levels of urinary CTX-II were independently correlated with radiographic severity of knee OA. Age, gender, and patient-reported outcomes exerted no effect on the urinary CTX-II levels.Level of evidenceDiagnostic Level III.

The cartilage degradation marker, urinary CTX-II, is associated with the risk of incident total joint replacement in postmenopausal women. A 18 year evaluation of the OFELY prospective cohort

Identifying objective risk-indicators for total joint replacement (TJR) is useful to enrich population at high risk in OA clinical trials. We investigate the association of urinary CTX-II, a biochemical marker of cartilage breakdown, with the risk of TJR. 478 postmenopausal women (mean age 65.5±7.5yr) from the OFELY cohort were studied. CTX-II, serum CTX-I (bone resorption) and PINP (bone formation), were measured at baseline. Association between CTX-II and incidence of TJR was assessed by Cox Hazard Regression. During a median (95%CI) 17.8 (15.0-18.1) years follow-up, 38 women sustained a TJR, including hip (n=29) or knee (n=9) replacement. CTX-II -but not CTX-I or PINP- was higher in patients with TJR (+34%, P=0.001 vs women with no TJR). Increased baseline CTX-II levels were associated with a higher risk of TJR with a Hazard Ratio (HR) (95 CI) of 1.45 (1.13-1.85) per 1 SD increase after adjustment for age, BMI and total hip BMD. CTX-II remained significantly associated with the risk of TJR after further adjustment for total WOMAC, prevalent knee OA (KL≥2) and self-reported hip OA [HR (95 CI): 1.31 (1.01-1.71), P=0,04]. When women were categorized as low and high CTX-II (lower and above the 95 percentile of healthy premenopausal women, respectively), subjects with high levels had an age-BMI-hip BMD adjusted HR (95 CI) of 3.00 (1.54-5.85) compared to women with low levels which remained significant after further adjustment for WOMAC, knee and/or hip OA [HR (95 CI): 2.45 (1.25-4.89), P=0.01]. CTX-II is an independent risk indicator of TJR in postmenopausal women suggesting that it may be useful to identify subjects at high risk of TJR.

Smartphone-integrated urinary CTX-II immunosensor based on wavelength filtering from chromogenic reaction

The integration of smart IT devices and biochemical assays with optical biosensing technology facilitates the development of efficacious optical biosensors for many practical diagnostic fields, owing to their minimized use of high-technical electronic components and simple operation. Herein, we introduced a simple optical biosensing system based on the specific wavelength filtering principle and count-based analysis method. The developed system uses a smartphone with a paper-based signal guide and a biosensing channel. The paper-based signal guide was prepared by printing red patterns of various brightness on a black background. Given that a blue product is generated as a result of horseradish peroxidase (HRP)-based enzymatic reaction in the biosensing channel, the channel could be used as a blue filter that absorbs red light. When red light reflected from the red pattern is absorbed by the channel, the pattern appears black. As such, the color of the patterns is assimilated with the black background, so it seems to disappear. Consequently, the amount of blue product relative to the concentration of the target analyte can be measured by counting the number of observed patterns on the paper-based signal guide. In this study, the concentration of urinary C-telopeptide fragment of type II collagen (uCTX-II, 0–10 ng/mL) was measured using the developed system without complicated equipment. In addition, the quantitative analysis of uCTX-II in the real urine sample was successfully performed. Therefore, we expect that the developed optical transducing system could be practically used for point-of-care testing (POCT) diagnosis under resource-limited environmental conditions.

Associations between biomarkers of bone and cartilage turnover, gender, pain categories and radiographic severity in knee osteoarthritis

BackgroundExcessive cartilage degradation is a known characteristic of osteoarthritis (OA). Biochemical markers, such as uCTX-II, have been shown to be associated with disease severity, yet the tissue origin of CTX-II has been disputed. This analysis investigates the association between OA knee joints at different radiographic stages and pain categories with levels of uCTX-II and biomarkers of bone resorption and formation.MethodsBaseline data of two randomised clinical trials (NCT00486434 and NCT00704847) in patients with radiographic OA and presence of pain were analysed post hoc. A subgroup with available urine samples and evaluable radiographs for both knees (N = 1241) was analysed. Urine CTX-I, urine CTX-II and serum osteocalcin were analysed for associations with combined Kellgren-Lawrence (KL) scores, gender and pain for both knees to assess the contribution of joints at different stages.ResultsPain, BMI, age, gender and KL grade were all significantly associated with uCTX-II. The association between pain and CTX-II appeared to be driven by weight-bearing pain. The level of uCTX-II incrementally increased with higher radiographic severity of each knee. Levels of bone markers CTX-I and osteocalcin were both significantly associated with BMI and gender, but neither were associated with radiographic severity. Biomarker levels between male or female groups of identical KL scores were found to be higher in females compared to males in some but not all KL score groups.ConclusionsThese results indicate that levels of uCTX-II are independently associated with radiographic severity of OA and pain intensity. CTX-II was associated with weight-bearing pain, but not non-weight-bearing pain, independent of co-variates. Bilateral OA knee joints appear to contribute to uCTX-II levels in an incremental manner according to radiographic severity of single joints. The data suggest that biomarker differences between genders should be taken into account when evaluating these markers in the context of structural features of OA.

No association between local levels of molecular biomarkers and knee cartilage volumes early after anterior cruciate ligament injury

Purpose: Trauma induced cytokine response in knee injuries may play a role in the development of osteoarthritis. We hypothesize that the cartilage volume affects the release of cartilage proteins and/or the presence of cytokines in the acute stage after knee injuries. Primary aim of our study was to compare knee cartilage volumes, derived from magnetic resonance images (MRI), with concentrations of biomarkers in biofluids at baseline (early after injury) in patients with anterior cruciate ligament (ACL) injuries. Secondary aim was to examine the correlation of confounders on biomarker levels or cartilage volumes. Methods: The KANON cohort consists of patients with an acute ACL tear to a previously uninjured knee (n = 121; age 26 years at injury, 74% males). In biofluids, collected at a median of 17 days (range 1-44 days) after the ACL injury, biomarkers were assessed using immunoassays: cartilage biomarkers aggrecan ARGS neoepitope (ARGS; in-house assay), cartilage oligomeric matrix protein (COMP; BioVendor) and cross-linked C-telopeptide of type II collagen (CTX-II; IDS); bone biomarker cross-linked N-telopeptide of type I collagen (NTX-I; Osteomark); cytokines (multiplex assay, MSD) interleukin (IL) 6, 8, 10, tumor necrosis factor α (TNF) and interferon gamma (INF-γ). Cartilage volumes were obtained from sagittal 3D SPGR MRI (1.5 T Philips Gyroscan; resolution: 0.29x0.29x3.0mm) based on quality-controlled, manual segmentations in three different cartilage compartments: tibiofemoral joint (TFJ), patellofemoral joint (PFJ) and total knee joint (TFJ + PFJ). MR images were acquired at the same day as the serum and urine sampling, but on average 11 days (range 1-24 days) after collection of synovial fluid. In linear regression models, we estimated cartilage volume as explanatory for molecular biomarker concentrations adjusted for age and time between injury and sampling. Models including both men and women were additionally adjusted for sex. Since both sex and BMI were associated with cartilage volume (see below) and BMI associated with sex (data not shown), we decided to adjust only for sex. 46 synovial fluid, 117 serum and 115 urine samples from individuals with corresponding MRI assessed cartilage volumes were used in linear regression analyses. Biomarkers with values below lower limit of quantification (LLOQ) were imputed with LLOQ divided by 2, (N% with levels above LLOQ): i.e. synovial fluid INF-γ (87%), serum IL-10 (46%) and urine CTX-II (99%). Unadjusted correlation (Pearson), Mann-Whitney U-test and student’s t-test were used for estimation of confounders. P values less than 0.05 were considered significant. Results: None of the synovial fluid biomarkers associated with cartilage volumes: Total knee joint (Table 1), TFJ or PFJ (data not shown); additional adjustment for differences in time between MRI assessment and synovial fluid sampling gave similar results (data not shown). In analyses stratified by sex, serum ARGS and urine CTX-II associated positively with total knee joint and TFJ cartilage volume in men, while in women, serum TNF associated negatively with total knee joint cartilage volume; none of the other biomarkers showed any association to any of the cartilage compartment volumes. Effects of confounders (Table 2): age associated negatively with serum ARGS, urine CTX-II and urine NTX-I concentrations, and positively with serum COMP levels; BMI associated positively with cartilage volumes, serum COMP levels and negatively with urine CTX-II; time between injury and sampling associated negatively with synovial fluid cytokine concentrations and positively with serum ARGS; compared to women, men had 1.3-fold higher serum COMP levels (Mann-Whitney: p = 0.002; men n = 89, women n = 32) and 1.3- and 1.4-fold more cartilage volume (t-test: p < 0.001, men n = 89, women n = 32). No other associations were found between confounders and molecular biomarker levels or cartilage volumes (Table 2). Conclusions: We found no evidence in support of local cytokines or cartilage biomarkers in the synovial fluid to be cross-sectionally associated with cartilage volume in the early phase after ACL injury. An association between cartilage volume and serum ARGS-aggrecan or urine CTX-II concentrations was only found in men. Several confounders affect biomarker levels and the cartilage volume creating a complex pattern of causalities that must be considered in analysis models.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Correlation between urine CTX-II and synovial pathology in total knee arthroplasty patients

Correlation between urine CTX-II and synovial pathology in total knee arthroplasty patients

Protein biomarkers in serum and urine for determining presence or absence of hip dysplasia in a canine model.

This study compares serum and urine concentrations of relevant protein biomarkers among adult dogs with or without radiographic canine hip dysplasia (CHD). Adult (≥2 years of age), client-owned dogs (n = 74) radiographically categorized as having at least "good" hips (n = 49) or having "mild," "moderate," or "severe" hip dysplasia (n = 25) by the Orthopedic Foundation for Animals (OFA). Urine and serum samples were obtained from each dog at a single time-point and processed and analyzed for relevant protein biomarkers. Urinary concentrations of CTX-II (p < 0.001) and TIMP-1 (p = 0.002) were significantly lower in dogs with CHD compared to dogs with no CHD. ROC curve analyses were successful in establishing a panel of four biomarkers (urinary CTX-I and II, serum MMP-9, and serum PIICP) with high discriminatory capability for the presence or absence of hip dysplasia in adult dogs (AUC = 0.89). Urine and serum biomarkers can distinguish adult dogs with radiographic CHD from those with no CHD with a sensitivity of 0.95 and specificity of 0.77 using ROC analysis with AUC 0.89. Clinical Significance: This finding suggests that this simple, minimally invasive diagnostic technique has potential for discriminating dysplastic dogs from dogs with normal hips, with possible translational application to humans based on similar etiopathogenesis. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:1-5, 2019.

Bone Mineral Density and Bone Remodeling in Tunisian Patients with Inflammatory Bowel Disease

Background:A high prevalence of osteopenia and osteoporosis is observed in patients with Inflammatory Bowel Disease (IBD).Objective:The aim of our study was to investigate the prevalence of bone loss, bone remodeling and risk factors in Tunisian patient with IBD.Patients and Methods:The study included 40 patients with IBD and 32 age- and sex-matched healthy controls subjects. All participants underwent bone densitometry by dual energy X-ray absorptiometry at the femoral neck and lumbar spine. Serum levels of 25-hydroxy vitamin D (25(OH)D), parathyroid hormone (PTH), osteocalcin(OC), and urinary degradation products of C-terminal telopeptide of type I collagen (CTXI) were measured in all participants to assess the bone metabolism status.Results:Twelve (30%) patients were normal, 32.5% were osteopenic and 37.5% were osteoporotic. Osteoporosis was more frequent in IBD patients than controls (p=0.0001). Age and inflammation were associated with low bone mineral density (BMD). Mean calcium, phosphorus and alkaline phosphatase levels were similar in both groups. Median 25(OH) D levels were significantly lower in IBD patients compared with controls (p=0.0001). Median urinary CTXI levels were significantly higher in IBD patients compared with healthy controls (p=0.007). No significant differences between IBD patients and controls concerning the median serum OC and PTH levels were found.Conclusion:In our study, there is a high prevalence of low BMD in IBD patients and an increase in bone resorption without a change of bone formation. Low BMI and hypovitaminoses D were identified as risk factors for low BMD.

The levels of urine CTX-II, C2C, and PYD in children patients with Kashin-Beck disease in Qinghai Province of China

BackgroundKashin-Beck disease (KBD) is an endemic and chronic osteoarthropathy. At present, the diagnosis of KBD mainly depends on the X-ray examination and which could not reflect early damage of cartilage sensitively. So, the aim of this study was to find effective and sensitive biomarkers for early diagnosis of pediatric KBD.MethodsA total of 122 children aged 7–15 years old from 3 villages of Qinghai Province were eligible for the study. Thirty-one, 41, and 50 children were assigned in case, internal, and external control groups, respectively. The levels of CTX-II, C2C, and PYD in urine were measured by using ELISA and compared statistically. In addition, the receiver operating characteristic curve (ROC) analysis was used to assess the performance of diagnostic biomarkers.ResultsThere were significant differences in levels of CTX-II, C2C, and PYD in urine of subjects among three groups. The levels of CTX-II and PYD in the case group were significantly higher than those in external and internal control groups. On the contrary, the level of C2C in the case group was lower than that in the external control group. Compared to the external control group, the area under the curve (AUC) of CTX-II, C2C, and PYD were 0.857, 0.837, and 0.79, and the AUC of CTX-II significantly higher than that of PYD. Compared to the internal control group, the AUC of CTX-II, C2C, and PYD were 0.911, 0.875, and 0.839, and there were no significant differences in the AUC among three indicators.ConclusionBoth CTX-II and PYD in urine could be used as biomarkers for early diagnosis of pediatric KBD, and the prediction accuracy of CTX-II was relatively superior.

Electroacupuncture Intervention Improves Cartilage Degeneration and Subchondral Bone Osteoporosis of Knee-joint Possibly by Adjusting OPG/RANK/RANKL Signaling in Ovariectomized Rats

To observe the effect of electroacupuncture (EA) on histopathological changes of cartilage and subchondral bone and osteoprotegerin (OPG)，receptor activator of nuclear factor-κB (RANK), and RANK ligand (RANKL) (OPG/RANK/RANKL) signaling and the expression of matrix metalloproteinase-13 (MMP-13) in ovariectomized(OVX)rats, so as to explore its mechanism underlying improvement of osteoporosis. Three-month female SD rats were randomly divided into sham operation, model and EA groups (n＝8 in each group). The ovoariectomy model was established by resection of bilateral ovaries. Rats of the sham group were treated by simple removal of a piece of adipose tissue around the bilateral ovaries. EA (3 Hz/15 Hz, 1 mA) was applied to bilateral "Sanyinjiao" (SP 6), "Yanglingquan" (GB 34), "Yinlingquan" (SP 9) and "Zusanli" (ST 36) for 30 min, once daily (except the weekends) for 12 weeks. The histopathological changes of the subchondral bone of the right knee-joint were observed after Saffron O dyeing and evaluated by Mankin's score, and its anatomical structure including the bone volume fraction (bone volume/tissue volume, BV/TV), trabecular bone number (Tb. N) and trabecular thickness (Tb.Th), trabecular separation (Tb.Sp) was observed by using Micro CT imaging. The urine C-terminal cross-linking telopeptide of type Ⅰ collagen (CTX-Ⅰ), CTX-Ⅱ (two bone resorption markers) and serum estrogen (E 2) contents were assayed by ELISA, and the expression levels of OPG, RANKL and MMP-13 mRNAs in the cartilage tissue of the left knee-joint were detected by quantitative RT-PCR. Following modeling, the BV/TV, Tb. N and Tb.Th levels were significantly decreased (P<0.01) and Tb.Sp and Mankin's score obviously increased in the model group compared with the sham group (P<0.01), suggesting a formation of osteoporosis and degeneration of the cartilage tissue. The serum E 2 content and OPG mRNA level in the cartilagetissue were significantly down-regulated (P<0.01), and urine CTX-Ⅰ and CTX-Ⅱ contents and RANKL mRNA and MMP-13 mRNA expression levels cartilagetissue were considerably up-regulated in the model group relevant to the sham group (P<0.01). After EA intervention, modeling-induced decrease of BV/TV, Tb.N, Tb.Th, E 2 and OPG mRNA levels and OVX-induced increase of Tb.Sp, Mankin's score, CTX-Ⅰ， CTX-Ⅱ， RANKL mRNA and MMP-13 mRNA levels were all completely reversed in the EA group relevant to the model group (P<0.01，P<0.05)．. EA intervention can inhibit subchondral bone osteoporosis and articular cartilage degeneration of knee-joint in OVX rats, which is closely associated with its effects in inhibiting the down-regulation of serum E 2 and OPG mRNA expression and up-regulation of CTX-Ⅰ， CTX-Ⅱ， RANKL mRNA and MMP-13 mRNA levels, including adjusting OPG/RANK/RANKL signaling.

C-Terminal Cross-Linked Telopeptides of Type II Collagen as Biomarker for Radiological Knee Osteoarthritis: A Meta-Analysis.

C-terminal cross-linked telopeptides of type II collagen (CTX-II) are one of the most frequently assessed markers for osteoarthritis (OA) diagnosis. The aim of this meta-analysis was to confirm the diagnostic value of urinary CTX-II in knee OA. PubMed, ScienceDirect, and EMBASE were searched for studies measured urinary CTX-II in patients with knee OA and in healthy controls. Urinary CTX-II levels were compared between knee OA patients and controls. Differences between groups were expressed as standardized mean differences (SMD) when individual outcomes were measured with different scales. Otherwise, outcomes were presented as mean differences (MD). Subgroup analyses were also conducted to compare efficiency of urinary CTX-II between Kellgren-Lawrence (KL) classification, genders, ethnicities, and study size. Thirteen studies involved a total of 2856 participants were included. Pooled SMD showed that urinary CTX-II levels were significantly elevated in knee OA group compared to controls (SMD 0.82; 95% CI 0.41-1.24; P < 0.0001). For KL 3 to 4 versus KL 2, higher urinary CTX-II levels were found in severe knee OA patients. Subgroup analyses revealed that urinary CTX-II performed better in females as compared with males and in European subjects as compared with Asian population. Also, study size did not influence the statistic results. This is the largest scale meta-analysis assessing the diagnostic performance of urinary CTX-II levels as biomarker for knee OA. According to our findings, urinary CTX-II levels have a potential to distinguish knee OA patients from healthy controls which can serve as biomarker for knee OA.

Association between US and MRI scores and correlations with urinary C-terminal telopeptide Type II collagen levels for early detection of hemophilic arthropathy of the knee

Assessment of knee hemophilic arthropathy (HA) requires objective measures. There is no consensus on a preferable ultrasonography (US) scoring system, whereas a reliable scoring system for magnetic resonance imaging (MRI) was developed by the International Prophylaxis Study Group of the World Federation of Hemophilia (IPSG-WFH). In this crosssectional study, a new US scoring system for early detection of knee HA was developed based on 25 peer-reviewed articles published between 1999 and 2015; furthermore, its associations with the MRI scoring system and urinary C-terminal telopeptide type II collagen (CTX-II) levels were investigated. In total, 27 children with severe hemophilia A were recruited. Early HA was confirmed using radiography as Arnold-Hilgartner stages 0–II. Knee MRI and US were scored using the MRI IPSG-WFH and new US scoring systems; urinary CTX-II levels were measured using enzyme-linked immunosorbent assay. Correlations were identified using Spearman test. The US scoring system included joint effusion, synovial hypertrophy and hypervascularization on power Doppler US, hemosiderin deposition, and cartilage damage. The US and MRI scores showed a moderate correlation; the US score and urinary CTX-II levels showed no correlation. The new US score can be used as an alternative to MRI for assessing early-stage kne HA.

Serum CTX-II does not measure the same as urinary CTX-II

Serum CTX-II does not measure the same as urinary CTX-II

A machine learning approach to knee OA phenotyping

Purpose: Knee osteoarthritis (KOA) is a heterogeneous condition characterized by changes in a variety of joint tissues and driven by a number of different potential mechanisms. To date, most clinical trials of disease modifying drugs have treated all KOA as the same disease, based primarily on radiographic features, and have failed to improve outcomes. The purpose of this study was to explore machine learning approaches to phenotyping in KOA in order to better define the progressor phenotype that may be more responsive to a disease modifying intervention. Methods: We focused on identifying differences between those knees that progressed by both radiographic (loss of medial joint space width) and pain (using the WOMAC pain scale) criteria (“progressors”) and those that did not progress by either of these (“non-progressors”), as defined by the publicly available FNIH OA Biomarkers Consortium dataset of 600 individuals with 76 demographic, imaging (quantitative and semi-quantitative MRI), and biochemical variables. First, problematic variables and observations were removed, leaving 597 observations and 73 variables. The data were transformed to reduce skewness and standardized to address differences in scale. Direction-projection-permutation (DiProPerm) hypothesis testing was used to test equality of distributions (by z-score) in the Distance-Weighted Discrimination (DWD) direction as quantified by the mean difference, using 100 permutations. Loadings on the DWD direction demonstrate the relative contribution of each variable to the class differences (e.g., progressors compared with non-progressors). In addition, we explored k-means clustering to partition the observations into 2 subgroups (additional subgroups were not supported by various statistical indices). Given multiple comparisons, a z-score of at least 3 (P value∼0.001) was considered statistically significant. Results: When considering all observations and all variables simultaneously, the progressors and non-progressors clearly separated with a z-score of 10.10 (Table 1).Table 1Z-scores derived from the DiProPerm test for the difference between progressors and non-progressors.All variablesDemographicQuantitative MRISemi-Quant MRIBiochemicalDiProPerm z-scoresAll observations10.101.4711.6210.282.432 clusters16.191.496.515.722.0124.771.394.735.780.97z-scores >3 are statistically significant at P<0.001, in bold. Open table in a new tab z-scores >3 are statistically significant at P<0.001, in bold. No statistical improvement was seen with partitioning the observations into 2 clusters, although some of these clusters did have significant z-scores. We were also able to study the 4 groups of variable data separately, finding higher z-scores for the MRI variables (11.62 for quantitative and 10.28 for semi-quantitative), with lower scores for demographic and biochemical markers. Again, lesser z-scores were seen for the 2 clusters compared with using all observations. Finally, we were interested in the relative contributions of each variable to the overall difference between progressors and non-progressors (Fig. 1), where the DWD loadings were represented in a bar plot for the 40 variables with the greatest contribution. The greatest positive contribution was seen for WOMAC pain (which is part of the progression construct), lateral meniscal extrusion, and serum PIIANP; the largest negative contributions were from the number of subregions with bone marrow lesions, the number of locations with any osteophyte, and urine CTX-II. Conclusions: These innovative methods provide a way to assess numerous variables of different types and scalings simultaneously in relation to KOA progression as shown here, or for assessing any other outcome of interest. Such methodology could identify both known and novel KOA phenotypes, potentially improving patient selection for specific interventions and providing insight into pathophysiology in this heterogeneous condition.

INVOSSA, a first-in-class of cell and gene therapy for osteoarthritis treatment: the phase III trial

Purpose: INVOSSA is a cell-and gene therapy for osteoarthritis consisting of allogeneic non-transformed (HC cells) and retrovirally transduced chondrocytes to overexpress TGF-β1 (TC cells) by the ratio of 3:1. Methods: We randomly assigned 163 patients with knee osteoarthritis to receive intra-articular INVOSSA or placebo. Primary efficacy measures were changes in subjective assessment by International Knee Documentation Committee (IKDC) and pain severity by Visual Analog Scale (VAS) at week 52. Secondary efficacy measures included IKDC and VAS at week 26 and 39; pain, stiffness, physical function by Western Ontario and McMaster Universities Arthritis Index (WOMAC); pain, symptoms, daily activities, function in sport and recreation, quality of life by Knee Injury and Osteoarthritis Outcome Score (KOOS), X-ray, MRI, and soluble biomarkers in urine and blood. The observation period was one year post a single injection. Results: INVOSSA was associated with statistically significant improvement versus placebo in IKDC total score and individual categories, and in VAS score at week 26, 39, and 52. The WOMAC and KOOS scores were also improved in INVOSSA group compared with placebo. Serum CTX-I was significantly lower in the INVOSSA treatment group at week 39 and 52. Urine CTX-II showed a trend toward improvement in the INVOSSA treatment group, although the differences were not meeting statistically significant. MRI assessment showed that patients treated with INVOSSA showed improved cartilage thickness and subchondral bone area in all knee regions, although not meeting statistical significance. Most frequent adverse events in the INVOSSA group were peripheral edema (9%), arthralgia (8%), joint swelling (6%), and injection-site pain (5%). Conclusions: INVOSSA was associated with statistically significant improvement in function and pain in patients with knee osteoarthritis with mild to severe adverse events. The INVOSSA treatment also showed structural improvements from the MRI and liquid biomarker evaluations, where INVOSSA hold potential as a DMOAD.

Fibulin-3 and other cartilage metabolism biomarkers in relationship to calprotectin (MRP8/14) and disease activity in rheumatoid arthritis patients treated with anti-TNF therapy.

Fibulin-3 (Fib-3) is a new potential biomarker of articular cartilage metabolism. The aim of the study was to evaluate the effect of anti-TNF therapy on serum fibulin-3, cartilage oligomeric matrix protein (COMP), procollagen II C-propeptide (PIICP), and urinary C-terminal telopeptide of type II collagen (CTX-II) levels in relation to calprotectin (MRP8/14) and disease activity in rheumatoid arthritis patients. In the study, 35 female patients with rheumatoid arthritis (RA) were investigated. The concentration of fibulin-3, COMP, PIICP, MRP8/14, and urinary CTX-II in serum was measured before and after anti-TNF therapy. Ten healthy women were investigated as the controls. The concentration of fibulin-3 in RA patients before treatment did not differ significantly from the concentration of fibulin-3 in the control group. A significantly higher concentration of fibulin-3 was noted prior to treatment in the group of women with a worse response to the therapy (non-responders) compared to the concentration of fibulin-3 in the healthy women. During the anti-TNF therapy, the serum fibulin-3 level decreased in patients. The fibulin-3 level correlated with CRP and ESR after anti-TNF treatment. Significant lowering of MRP8/14 was noted in the patients after anti-TNF therapy. No correlation between fibulin-3 and MRP8/14 was observed in the study group or in the control group. During the anti-TNF therapy, the serum fibulin-3 level decreased in RA patients. Serum MRP8/14 concentration also decreased. No correlation between fibulin-3 and MRP8/14 was observed in the study group before and after the treatment. We found a poor correlation between serum fibulin-3 and other cartilage metabolism biomarkers after anti-TNF therapy.

Association Between Biochemical Markers of Bone Turnover and Bone Changes on Imaging: Data From the Osteoarthritis Initiative

To determine the relationship between biochemical markers involved in bone turnover and bone features on imaging in knees with osteoarthritis (OA). We analyzed data from the Foundation for the National Institutes of Health OA Biomarkers Consortium within the Osteoarthritis Initiative (n = 600). Bone marrow lesions (BMLs), osteophytes, and subchondral bone area (mm2 ) and shape (position on 3-D vector) were assessed on magnetic resonance images, and bone trabecular integrity (BTI) was assessed on radiographs. Serum and urinary markers (serum C-terminal crosslinked telopeptide of type I collagen [CTX-I], serum crosslinked N-telopeptide of type I collagen [NTX-I], urinary NTX-I, urinary C-terminal crosslinked telopeptide of type II collagen [CTX-II], and urinary CTX-Iα and CTX-Iβ) were measured. The associations between biochemical and imaging markers at baseline and over 24 months were assessed using regression models adjusted for covariates. At baseline, most biochemical markers were associated with BMLs, with C statistics for the presence/absence of any BML ranging from 0.675 to 0.688. At baseline, urinary CTX-II was the marker most consistently associated with BMLs (with odds of having ≥5 subregions affected compared to no BML increasing by 1.92-fold [95% confidence interval (95% CI) 1.25, 2.96] per 1 SD of urinary CTX-II), large osteophytes (odds ratio 1.39 [95% CI 1.10, 1.77]), bone area and shape (highest partial R2 = 0.032), and changes in bone shape over 24 months (partial R2 range 0.008 to 0.024). Overall, biochemical markers were not predictive of changes in BMLs or osteophytes. Serum NTX-I was inversely associated with BTI of the vertical trabeculae (quadratic slope) in all analyses (highest partial R2 = 0.028). We found multiple significant associations, albeit mostly weak ones. The role of systemic biochemical markers as predictors of individual bone anatomic features of single knees is limited based on our findings.