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Biomedical subjects

Patrick Garnero

Publications and source records attributed to Patrick Garnero.

At least 19 recordsLinked to original sources

Effect of chondroitin sulphate in symptomatic knee osteoarthritis: a multicentre, randomised, double-blind, placebo-controlled study.

OBJECTIVE: To evaluate the efficacy and tolerability of chondroitin sulphate (chondroitin sulphate) in knee osteoarthritis. PATIENTS AND METHODS: A 24-week, randomised placebo-controlled trial of chondroitin sulphate (1 g/day) in patients with symptomatic knee osteoarthritis as measured on a visual analogue scale. Pain on daily activities and Lequesne's Index were the primary efficacy criteria. Secondary outcomes included the rate of responders according to the outcome measures in rheumatoid arthritis clinical trials of the Osteoarthritis Research Society International (OMERACT-OARSI) criteria, quality of life, patient's/physician's global assessments and carry-over effect after treatment. Biochemical markers of bone (CTX-I), cartilage (CTX-II) and synovium (hyaluronic acid) metabolism were also measured. Safety was assessed by recording adverse events (AEs). Statistical analysis was performed on the inter-group differences in the intention-to-treat population. RESULTS: 307 patients were included in the study. 28 (9%) patients discontinued the study because of lack of efficacy or AEs. At the end of treatment, the decrease in pain was -26.2 (24.9) and -19.9 (23.5) mm and improved function was -2.4 (3.4) (-25%) and -1.7 (3.3) (-17%) in the chondroitin sulphate and placebo groups, respectively (p = 0.029 and 0.109). The OMERACT-OARSI responder rate was 68% in the chondroitin sulphate and 56% in the placebo group (p = 0.03). The investigator's assessments and short form 12 (SF-12) physical component reported improvement more frequently in the chondroitin sulphate than in the placebo group (p = 0.044 and 0.021, respectively). No significant difference was observed between treatment groups for changes in biomarkers over 24 weeks. However, there was a significant difference between non-responders and responders according to the OARSI criteria for 24-week changes of CTX-I (p = 0.018) and CTX-II (p = 0.014). Tolerance was considered to be satisfactory. CONCLUSION: This study failed to show an efficacy of chondroitin sulphate on the two primary criteria considered together, although chondroitin sulphate was slightly more effective than placebo on pain, OMERACT-OARSI response rate, investigator's assessment and quality of life.

Administration, Oral↗

Non-enzymatic glycation of bone collagen modifies osteoclastic activity and differentiation.

Type I collagen, the major organic component of bone matrix, undergoes a series of post-translational modifications that occur with aging, such as the non-enzymatic glycation. This spontaneous reaction leads to the formation of advanced glycation end products (AGEs), which accumulate in bone tissue and affect its structural and mechanical properties. We have investigated the role of matrix AGEs on bone resorption mediated by mature osteoclasts and the effects of exogenous AGEs on osteoclastogenesis. Using in vitro resorption assays performed on control- and AGE-modified bone and ivory slices, we showed that the resorption process was markedly inhibited when mature osteoclasts were seeded on slices containing matrix pentosidine, a well characterized AGE. More specifically, the total area resorbed per slice, and the area degraded per resorption lacuna created by osteoclasts, were significantly decreased in AGE-containing slices. This inhibition of bone resorption was confirmed by a marked reduction of the release of type I collagen fragments generated by the collagenolytic enzymes secreted by osteoclasts in the culture medium of AGE-modified mineralized matrices. This effect is likely to result from decreased solubility of collagen molecules in the presence of AGEs, as documented by the reduction of pepsin-mediated digestion of AGE-containing collagen. We found that AGE-modified BSA totally inhibited osteoclastogenesis in vitro, most likely by impairing the commitment of osteoclast progenitors into pre-osteoclastic cells. Although the mechanisms remain unknown, AGEs might interfere with osteoclastic differentiation and activity through their interaction with specific cell-surface receptors, because we showed that both osteoclast progenitors and mature osteoclasts expressed different AGEs receptors, including receptor for AGEs (RAGEs). These results suggest that AGEs decreased osteoclast-induced bone resorption, by altering not only the structural integrity of bone matrix proteins but also the osteoclastic differentiation process. We suggest that AGEs may play a role in the alterations of bone remodeling associated with aging and diabetes.

Adult↗

Prognostic value of PINP, bone alkaline phosphatase, CTX-I, and YKL-40 in patients with metastatic prostate carcinoma.

BACKGROUND: To examine the prognostic value of markers of bone metabolism (serum PINP, BAP, and CTX-I) and serum YKL-40 in metastatic prostate carcinoma (PC). METHODS: The biomarkers were determined by ELISAs in 153 metastatic PC patients before treatment with parenteral estrogen or total androgen ablation. The median follow-up was 4.9 years. One hundred fifteen patients died. RESULTS: The biomarkers were increased in the patients compared to controls (P < 0.001), and related to performance status and Soloway score (except YKL-40), but not to T-category and WHO tumor grade. PINP was elevated in 87%, BAP (55%), CTX-I (33%), and YKL-40 (43%). Univariate analysis showed an association to survival: PINP (HR = 1.6, P < 0.0001), BAP (HR = 1.4, P < 0.0001), CTX-I (HR = 1.7, P < 0.0001), and YKL-40 (HR = 1.4, P = 0.004). In multivariate Cox analysis performance status, WHO grade, Soloway score, PINP, and YKL-40 were independently predictive factors. CONCLUSIONS: High serum PINP, BAP, CTX-I, and YKL-40 are associated with poor outcome of metastatic PC patients.

Adipokines↗

Correlates of knee pain in younger subjects.

The aim of this study was to describe clinical, structural and biochemical factors associated with knee pain in younger subjects. A cross-sectional convenience sample of 371 male and female subjects (mean age, 45 years, range 26-61) was studied. Knee pain was assessed by questionnaire. Chondral defects, cartilage volume, and bone area of the right knee were determined using T1-weighted fat saturation magnetic resonance imaging (MRI). X-ray was performed on the same knee for the assessment of radiographic features of osteoarthritis. The urinary C-terminal cross-linking telopeptide of type II collagen (CTX-II) was measured by enzyme-linked immunosorbent assay (ELISA). Height and weight were measured by standard protocols and body mass index (BMI) was calculated. The prevalence of knee pain was 35% in this sample. Chondral defect scores (particularly femoral and patellar but not tibial) were significantly associated with knee pain in a dose-response fashion (all p<0.01). Cartilage volume and bone area were not associated with knee pain in multivariate analysis in this sample. Urinary CTX-II was higher in subjects with knee pain (p=0.04), but this became nonsignificant after adjustment for BMI and osteophytes (both of which were significant) suggesting potential mechanisms of effect. In conclusion, knee pain is significantly associated with non-full thickness chondral defects (particularly femoral and patellar), osteophytes, CTX-II, and obesity but not other factors. MRI and biochemical measures can add to radiographs in defining unexplained knee pain in younger subjects.

Adult↗

Risedronate decreases biochemical markers of cartilage degradation but does not decrease symptoms or slow radiographic progression in patients with medial compartment osteoarthritis of the knee: results of the two-year multinational knee osteoarthritis structural arthritis study.

OBJECTIVE: Bisphosphonates have slowed the progression of osteoarthritis (OA) in animal models and have decreased pain in states of high bone turnover. The Knee OA Structural Arthritis (KOSTAR) study, which is the largest study to date investigating a potential structure-modifying OA drug, tested the efficacy of risedronate in providing symptom relief and slowing disease progression in patients with knee OA. METHODS: The study group comprised 2,483 patients with medial compartment knee OA and 2-4 mm of joint space width (JSW), as determined using fluoroscopically positioned, semiflexed-view radiography. Patients were enrolled in 2 parallel 2-year studies in North America and the European Union. These studies evaluated the efficacy of risedronate at dosages of 5 mg/day, 15 mg/day, 35 mg/week (in Europe), and 50 mg/week (in North America) compared with placebo in reducing signs and symptoms, as measured by the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and patient global assessment (PGA) scores, and in slowing radiographic progression. RESULTS: A reduction of approximately 20% in signs and symptoms, as measured by WOMAC subscales and PGA scores, was observed in all groups, with no treatment effect of risedronate demonstrated. Risedronate did not significantly reduce radiographic progression as measured by decreased JSW or using a dichotomous definition of progression (joint space loss of >or=0.6 mm). Thirteen percent of patients receiving placebo demonstrated significant disease progression over 2 years. A dose-dependent reduction in the level of C-terminal crosslinking telopeptide of type II collagen, a cartilage degradation marker associated with progressive OA, was seen in patients who received risedronate. No increase in the number of adverse events was demonstrated for risedronate compared with placebo. CONCLUSION: Although risedronate (compared with placebo) did not improve signs or symptoms of OA, nor did it alter progression of OA, a reduction in the level of a marker of cartilage degradation was observed. A sustained clinically relevant improvement in signs and symptoms was observed in all treatment and placebo groups.

Adult↗

Use of biochemical markers to study and follow patients with osteoarthritis.

Osteoarthritis is characterized by progressive destruction of articular cartilage and subchondral bone and synovial reaction. Radiologic findings that form the basis of the diagnosis of osteoarthritis are poorly sensitive to detect early disease and for monitoring progression of joint damage. Blood-based proteomic analyses suggest that biochemical alterations can be observed well before radiologic damage is evidenced. New cartilage-specific markers, including assays for type II collagen synthesis and degradation, have been developed. Recent prospective studies indicate that blood and urine levels of these new markers are associated with progression of joint damage. Biological markers respond rapidly to treatment and therefore will certainly play an important role in the development and the monitoring of disease-modifying therapies. Because osteoarthritis involves different tissues and complex biologic processes, a combination of different biochemical markers appears to be the most promising diagnostic strategy.

Biomarkers↗

Biochemical markers of bone turnover in the clinical development of drugs for osteoporosis and metastatic bone disease: potential uses and pitfalls.

Biochemical markers of bone turnover are used increasingly during the clinical development of drugs for the treatment of metabolic bone diseases such as Paget's disease, osteoporosis and cancer that has metastasised to the bone. However, assessing the optimal value of these markers is often complicated, and such an assessment is an obvious prerequisite for rational use of the markers and, consequently, potential improvement of clinical drug development. Biochemical markers of bone turnover are substances in the blood or urine that are produced or released during bone remodelling. They provide semiquantitative information on bone remodelling, and are often the most adequate tool to describe the pharmacodynamics of the drug. Their use has increased considerably because of dose-effect relationships that have been seen with certain drugs, but also because they have proven relationships with clinical outcomes in several metabolic bone diseases. However, there is a lack of information on the kinetics of these markers, and the immunoassays that are frequently used in their monitoring often measure a mixture of fragments rather than a single molecular entity. For drug development it should also be realised that different markers, but also different assays for the same marker, may provide different results, considerably limiting the ability to compare results. In postmenopausal osteoporosis, relationships have been shown between several biochemical markers of bone turnover, and either fracture risk and/or the antifracture efficacy of drugs. Such relationships can be used for the development of drugs with similar mechanisms of action, but also for the development of these drugs for closely related indications, such as corticosteroid-induced osteoporosis. In both of these instances, data on effects on biochemical markers of bone turnover are usually employed in combination with information about effects on bone mineral density. However, the relationships of these parameters with clinical outcomes may be remarkably different for drugs with alternative mechanisms of action, challenging the use of the markers for the development of new drugs for the treatment of patients with osteoporosis. At present, the pharmacological treatment of cancer that has metastasised to the bone is limited to several bisphosphonates. Recent studies have shown relationships between the normalisation of levels of biochemical markers of bone turnover and clinical outcomes, and prospective studies investigating the application of such relationships are ongoing. The markers may play an important role in the optimisation of registered bisphosphonate treatments. However, their role in the development of new drugs is still limited to dose selection, and potential relationships with clinical outcomes remain to be investigated in instances of new mechanisms of action. Biochemical markers of bone turnover are a valuable asset for drug development, but their rational use is determined by a number of variables. Correctly manipulating these may improve clinical development of drugs for the treatment of patients with metabolic bone diseases such as osteoporosis and cancer metastatic to the bone.

Adrenal Cortex Hormones↗

Extracellular post-translational modifications of collagen are major determinants of biomechanical properties of fetal bovine cortical bone.

Mechanical behavior of bone depends on its mass and architecture, and on the material properties of the matrix, which is composed of a mineral phase and an organic component mainly constituted of type I collagen. Mineral accounts largely for the stiffness of bone, whereas type I collagen provides bone its ductility and toughness, i.e., its ability to undergo deformation and absorb energy after it begins to yield. The molecular mechanisms underlying the effect of alterations in type I collagen on bone mechanical properties are unclear. We used an in vitro model of fetal bovine cortical bone specimens (n = 44), where the extent of type I collagen cross-linking was modified by incubation at 37 degrees C for 0, 60, 90 and 120 days, keeping constant the architecture and the mineral content. At each incubation time, the following parameters were determined: (1) the bone concentration of enzymatic (pyridinoline; PYD and deoxypyridinoline, DPD) and non-enzymatic (pentosidine) crosslinks by HPLC, (2) the extent of aspartic acid isomerization of the type I collagen C-telopeptide (CTX) by ELISA of native (alpha CTX) and isomerized (beta CTX) forms, (3) the mineral density by DXA, (4) the porosity by micro-computed tomography and (5) the bending and compressive mechanical properties. Incubation of bone specimens at 37 degrees C for 60 days increased the level (per molecule of collagen) of PYD (+98%, P = 0.005), DPD (+42%, P = 0.013), pentosidine (+55-fold, P = 0.005), and the degree of type I collagen C-telopeptide isomerization (+4.9-fold, P = 0.005). These biochemical changes of collagen were associated with a 30% decrease in bending and compressive yield stress and a 2.5-fold increase in compressive post-yield energy absorption (P < 0.02 for all), with no significant change of bone stiffness. In multivariate analyses, the level of collagen cross-linking was associated with yield stress and post-yield energy absorption independently of bone mineral density, explaining up to 25% of their variance. We conclude that the extent and nature of collagen cross-linking contribute to the mechanical properties of fetal bovine cortical bone independently of bone mineral density.

Absorptiometry, Photon↗

Pretreatment levels of bone turnover and the antifracture efficacy of alendronate: the fracture intervention trial.

UNLABELLED: The influence of pretreatment bone turnover on alendronate efficacy is not known. In the FIT, we examined the effect of pretreatment bone turnover on the antifracture efficacy of daily alendronate given to postmenopausal women. The nonspine fracture efficacy of alendronate was significantly greater among both osteoporotic and nonosteoporotic women with higher baseline levels of the bone formation marker PINP. INTRODUCTION: Previous trials have shown that high bone turnover is associated with greater increases in BMD among bisphosphonate-treated women. The influence of pretreatment bone turnover levels on antifracture efficacy has not been well studied. MATERIALS AND METHODS: We randomized women 55-80 years of age with femoral neck BMD T scores < or = -1.6 to alendronate (ALN), 5-10 mg/day (n = 3105), or placebo (PBO; n = 3081). At baseline, 3495 women were osteoporotic (femoral neck BMD T score < or = -2.5 or prevalent vertebral fracture), and 2689 were not osteoporotic (BMD T score > -2.5 and no prevalent vertebral fracture). Pretreatment levels of bone-specific alkaline phosphatase (BSALP), N-terminal propeptide of type 1 collagen (PINP), and C-terminal cross-linked telopeptide of type 1 collagen (sCTx) were measured in all participants using archived serum (20% fasting). The risk of incident spine and nonspine fracture was compared in ALN- and PBO-treated subjects stratified into tertiles of baseline bone marker level. RESULTS AND CONCLUSIONS: During a mean follow-up of 3.2 years, 492 nonspine and 294 morphometric vertebral fractures were documented. Compared with placebo, the reduction in nonspine fractures with ALN treatment differed significantly among those with low, intermediate, and high pretreatment levels of PINP levels (p = 0.03 for trend). For example, among osteoporotic women in the lowest tertile of pretreatment PINP (<41.6 ng/ml), the ALN versus PBO relative hazard for nonspine fracture was 0.88 (95% CI: 0.65, 1.21) compared with a relative hazard of 0.54 (95% CI: 0.39, 0.74) among those in the highest tertile of PINP (>56.8 ng/ml). Results were similar among women without osteoporosis at baseline. Although they did not reach statistical significance, similar trends were observed with baseline levels of BSALP. Conversely, spine fracture treatment efficacy among osteoporotic women did not differ significantly according to pretreatment marker levels. Spine fracture treatment efficacy among nonosteoporotic women was related to baseline BSALP (p = 0.05 for trend). In summary, alendronate nonspine fracture efficacy is greater among both osteoporotic and nonosteoporotic women with high pretreatment PINP. If confirmed in other studies, these findings suggest that bisphosphonate treatment may be most effective in women with elevated bone turnover.

Absorptiometry, Photon↗

Effects of oral alendronate on BMD in adult patients with osteogenesis imperfecta: a 3-year randomized placebo-controlled trial.

UNLABELLED: A 3-year, randomized, double-blind, placebo-controlled trial evaluated the effect of oral alendronate on the BMD of 64 adult patients with osteogenesis imperfecta. The mean increases in the lumbar spine BMD were 10.1 +/- 9.8% (p < 0.001) and 0.7 +/- 5.7% in the alendronate and placebo groups, respectively. Oral alendronate increases BMD in adult patients with osteogenesis imperfecta. INTRODUCTION: This study evaluated the effect of oral alendronate on the BMD of adult patients with osteogenesis imperfecta. MATERIALS AND METHODS: We carried out a 3-year, randomized, double-blind, placebo-controlled trial of oral alendronate in 64 adult patients with osteogenesis imperfecta. The primary endpoint was the difference between the groups in the mean percent change in lumbar spine BMD at 3 years. Secondary outcomes included changes in BMD of total hip, vertebral and peripheral fracture incidence, pain, hearing loss, and bone turnover biochemical markers. Patients were treated daily with either placebo or 10 mg alendronate. All received 1 g of calcium and 800 IU of vitamin D daily. RESULTS: The mean +/- SD increases in the lumbar spine BMD were 10.1 +/- 9.8% (p < 0.001) and 0.7 +/- 5.7% in the alendronate and placebo groups, respectively. Hip BMD increased in the alendronate group by 3.3 +/- 0.5% (p = 0.001) and decreased in the placebo group by 0.3 +/- 0.6%. The sample size was not sufficient to determine an effect of alendronate on fracture rate. A significant increase of the pain score was noted in the alendronate group (p = 0.04) in the intent-to-treat analysis but not in the per protocol analysis. There was no change in hearing in either group. Bone resorption and formation biochemical markers were significantly decreased in the alendronate group (p < 0.001). There were no differences in severe adverse effects between the groups, but there was an increase in nonsevere upper gastrointestinal effects in the alendronate group (p = 0.003). CONCLUSIONS: Oral alendronate increases BMD and increase nonsevere gastrointestinal adverse effects but does not modify the hearing loss in adult patients with osteogenesis imperfecta. More studies are needed to evaluate an effect on the fracture rate.

Absorptiometry, Photon↗

Identification of osteopenic women at high risk of fracture: the OFELY study.

UNLABELLED: About one-half of women with incident fractures have BMD above the WHO diagnostic threshold of osteoporosis. In the OFELY study, low BMD, increased markers of bone turnover, and prior fracture could be used to identify, within osteopenic women, those at high risk of fracture. INTRODUCTION: Recent data suggest that about one-half of women with incident fractures have BMD above the World Health Organization (WHO) diagnostic threshold of osteoporosis (T score<or=-2.5). We aimed to identify, within osteopenic women, those at high risk of fracture. MATERIALS AND METHODS: In the 671 postmenopausal women (mean age: 62 years) belonging to the Os des Femmes de Lyon (OFELY) population-based prospective cohort, we measured at baseline BMD by DXA at the spine and total hip, bone turnover markers (BTM) and clinical risk factors for osteoporosis. All fragility vertebral or nonvertebral fractures, confirmed by radiographs, were assessed during a median follow-up of 9.1 years (IQ: 2.3). RESULTS: 158 incident fractures were recorded in 116 women: 8% in normal, 48% in osteopenic, and 44% in osteoporotic women. Among osteopenic women, low BMD (-2.5<T score<or=-2.0) was associated with an increased fracture risk with an age-adjusted hazard ratio (HR) of 2.5 (1.3-4.6). In addition, age, prior fracture, and high BTM-but not other risk factors-were independently associated with an increased fracture risk with an age-adjusted HR of 2.2 (1.2-4.3) for prior fractures and 2.2 (1.4-3.8) for bone alkaline phosphatase (BALP) in the highest quartile. In the whole group of osteopenic women, a large majority of incident fractures occurred in those with a low BMD, prior fractures, or BALP in the highest quartile, with an age-adjusted HR of 5.3 (2.3-11.8). The 10-year probability of fracture in osteopenic women was 26% if at least one predictor was present, contrasting with 6% in those without any of the three risk factors. CONCLUSIONS: In postmenopausal women with osteopenia, low BMD, increased BTM, and prior fracture are associated with an increased risk of fracture in the subsequent 10 years. Their assessment may play an important role in identifying women at high risk of fracture who could not be adequately detected by BMD measurement alone and who may benefit from a therapeutic intervention.

Adult↗

Effect of risedronate on joint structure and symptoms of knee osteoarthritis: results of the BRISK randomized, controlled trial [ISRCTN01928173].

To determine the efficacy and safety of risedronate in patients with knee osteoarthritis (OA), the British study of risedronate in structure and symptoms of knee OA (BRISK), a 1-year prospective, double-blind, placebo-controlled study, enrolled patients (40-80 years of age) with mild to moderate OA of the medial compartment of the knee. The primary aims were to detect differences in symptoms and function. Patients were randomized to once-daily risedronate (5 mg or 15 mg) or placebo. Radiographs were taken at baseline and 1 year for assessment of joint-space width using a standardized radiographic method with fluoroscopic positioning of the joint. Pain, function, and stiffness were assessed using the Western Ontario and McMaster Universities (WOMAC) OA index. The patient global assessment and use of walking aids were measured and bone and cartilage markers were assessed. The intention-to-treat population consisted of 284 patients. Those receiving risedronate at 15 mg showed improvement of the WOMAC index, particularly of physical function, significant improvement of the patient global assessment (P < 0.001), and decreased use of walking aids relative to patients receiving the placebo (P = 0.009). A trend towards attenuation of joint-space narrowing was observed in the group receiving 15 mg risedronate. Eight percent (n = 7) of patients receiving placebo and 4% (n = 4) of patients receiving 5 mg risedronate exhibited detectable progression of disease (joint-space width >or= 25% or >or= 0.75 mm) versus 1% (n = 1) of patients receiving 15 mg risedronate (P = 0.067). Risedronate (15 mg) significantly reduced markers of cartilage degradation and bone resorption. Both doses of risedronate were well tolerated. In this study, clear trends towards improvement were observed in both joint structure and symptoms in patients with primary knee OA treated with risedronate.

Adult↗

Consumption of a high calcium mineral water lowers biochemical indices of bone remodeling in postmenopausal women with low calcium intake.

Many postmenopausal women have a calcium intake far below the recommended amount and, in addition to attempting to improve their diet, need a calcium supplement. The aim of the study was to assess the effects of the consumption of a high calcium mineral water (HCaMW) on biochemical indices of bone remodeling in postmenopausal women with low Ca intake. A 6-month randomized double-blind placebo-controlled trial was designed to assess the effects of a daily consumption of 1 liter of a HCaMW (596 mg Ca/l) on serum parathyroid hormone (PTH) and biochemical markers of bone remodeling in postmenopausal women with a dietary Ca intake lower than 700 mg/day. The placebo group drank 1 liter of a mineral water with a low calcium content (10 mg/l). One hundred eighty healthy women were recruited (mean age: 70.1+/-4.0 years); 152 completed the 6-month trial. The changes from baseline of biochemical indices after 6 months consisted of a significant 14.1% decrease of serum PTH, osteocalcin (-8.6%), bone alkaline phosphatase (-11.5%), serum (-16.3%) and urine (-13.0%) type-1 collagen C-telopeptide in the HCaMW group compared to the placebo group, where all biochemical indices increased after 6 months. The additive effect of a small vitamin D supplement (400 iu/day) was also evaluated. In women receiving vitamin D in addition to HCaMW, the decrease in bone indices was not found to be greater than in women drinking only the HCaMW. A daily supplement of 596 mg of Ca through the consumption of 1 l of HCaMW was able to lower serum PTH and the indices of bone turnover in postmenopausal women with a low Ca intake. This could contribute to the repair of calcium deficiency and to the reduction of age-related bone loss in this population.

Aged↗

Urinary type II collagen helical peptide (HELIX-II) as a new biochemical marker of cartilage degradation in patients with osteoarthritis and rheumatoid arthritis.

OBJECTIVE: Type II collagen, which consists of a large helical domain and telopeptides at each end, is the most abundant protein of cartilage matrix. The aim of this study was to develop a biochemical marker reflecting the degradation of the helical region of type II collagen and to evaluate its clinical performance in patients with osteoarthritis (OA) and rheumatoid arthritis (RA). METHODS: We developed a competitive polyclonal antibody-based enzyme-linked immunosorbent assay (ELISA) using the 622-632 peptide derived from the sequence of the alpha1 chain of human type II collagen (HELIX-II) as immunogen and standard. We measured urinary levels of HELIX-II peptide and C-terminal crosslinking telopeptide of type II collagen (CTX-II) in 90 patients with knee OA (73% women; mean +/- SD age 63.0 +/- 8.0 years, mean +/- SD disease duration 6.1 +/- 6.8 years), 89 patients with early RA (disease duration </=3 years) (79% women; mean +/- SD age 48.7 +/- 11.6 years), 25 patients with Paget's disease of bone (HELIX-II only), and 162 healthy controls. In RA patients, we investigated the relationships between baseline urinary HELIX-II and CTX-II levels and the progression of joint destruction as measured by the changes in the total Sharp score (average from 2 independent readers) over 1 year. RESULTS: The intraassay and interassay variations of the HELIX-II ELISA were lower than 13% and 15%, respectively. The HELIX-II ELISA showed no significant cross-reactivity with human intact or denatured type II collagen, with the homologous peptides from human type I or type III collagens, or with HELIX-II peptides elongated (by 1 amino acid) or shortened (by 1 or 2 amino acids) at the C-terminal end, indicating that the HELIX-II ELISA recognized a neoepitope from the alpha1 chain of type II collagen. Median urinary HELIX-II levels were increased in patients with knee OA (by 56%; P < 0.0001) or early RA (by 123%; P < 0.0001) compared with those in age- and sex-matched healthy controls. Baseline urinary HELIX-II levels in the highest tertile were associated with an increased risk of radiographic progression in RA (increase in the total Sharp score >/=0.5 units/year), with an odds ratio (OR) of 5.9 (95% confidence interval [95% CI] 2.0-17.2) after adjustment for serum C-reactive protein (CRP) levels and baseline joint damage. Patients with increased levels of both urinary HELIX-II and CTX-II had the highest risk of progression (OR 17.5 [95% CI 3.1-99]). CONCLUSION: The HELIX-II ELISA is specific for type II collagen degradation, has adequate technical performance, and can distinguish patients with knee OA or RA from healthy controls. Elevated HELIX-II levels are associated with increased risk of radiographic progression in RA independently of CRP levels, baseline joint damage, and urinary CTX-II levels. The HELIX-II ELISA should be useful for the clinical investigation of patients with arthritis and for identifying RA patients at higher risk of progression.

Aged↗

Recommendations for monitoring antiresorptive therapies in postmenopausal osteoporosis.

Antiresorptive agents are effective in preventing and treating postmenopausal osteoporosis, provided they are taken as directed. Regular physical examinations including height measurements may fail to ensure optimal compliance. Bone mineral density (BMD) measurement is indispensable for determining whether treatment is warranted. The measurement can be repeated after 2 years at least, provided quality-control procedures are adequate. BMD changes over time should be compared to the least significant change calculated from the in vivo BMD reproducibility at the measurement center. However, BMD changes are not correlated with the fracture risk reduction induced by antiresorptive treatment. Biochemical markers for bone turnover can be monitored after only 3-6 months provided steps are taken to control for intraindividual variability. They are useful when patient compliance is poor or the treatment response inadequate.

Biomarkers↗

Knee cartilage defects: association with early radiographic osteoarthritis, decreased cartilage volume, increased joint surface area and type II collagen breakdown.

OBJECTIVE: To generate hypotheses regarding the associations between knee cartilage defects and knee radiographic osteoarthritis (ROA), cartilage volume, bone size and type II collagen breakdown in adults. METHODS: A cross-sectional convenience sample of 372 male and female subjects (mean age 45 years, range 26-61) was studied. Knee cartilage defect score (0-4) and prevalence (a defect score of > or =2), cartilage volume, and bone surface area were determined using T1-weighted fat saturation MRI. Urinary levels of C-terminal crosslinking telopeptide of type II collagen (U-CTX-II) were measured by enzyme-linked immunosorbent assay. Height, weight and ROA were measured by standard protocols. RESULTS: In multivariate analysis, the severity and prevalence of knee cartilage defects were significantly and independently associated with tibiofemoral osteophytes (regression coefficient (beta): +0.86 to +1.31/unit, odds ratio (OR): 2.97-3.68/unit, all P<0.05 with the exception of OR in lateral tibiofemoral compartment) and tibial bone area (beta: +0.11 to +0.25/cm2; OR: 1.33-1.58/cm2, all P<0.01). Knee cartilage defects were inconsistently associated with joint space narrowing after adjustment for osteophytes but consistently with knee cartilage volume (beta: -0.27 to -0.70/ml; OR: 0.16-0.56/ml, all P<0.01 except for OR at lateral tibial cartilage site P=0.06). Lastly, knee cartilage defect severity was significantly associated with U-CTX-II (Partial r=+0.18, P<0.001 for total cartilage defect score). CONCLUSION: Osteophytes and increasing knee bone size may be causally related to knee cartilage defects. Furthermore, knee cartilage defects may result in increased cartilage breakdown leading to decreased cartilage volume and joint space narrowing suggesting an important role for knee cartilage defects in early knee OA.

Adult↗

Cross-sectional association of 10 molecular markers of bone, cartilage, and synovium with disease activity and radiological joint damage in patients with hip osteoarthritis: the ECHODIAH cohort.

OBJECTIVE: To investigate the associations of molecular markers of joint tissue turnover with clinical and radiological variables in patients with hip osteoarthritis (OA). METHODS: Patients of the ECHODIAH trial cohort (60% female; mean age 63 yrs, disease duration 5 yrs) fulfilling the American College of Rheumatology criteria for hip OA were studied. Pain was assessed using a 100 mm visual analog scale, and the presence of night pain and morning stiffness was observed as the index of joint inflammation. Joint space width (JSW) and subchondral bone sclerosis were assessed on hip radiographs. Ten markers were measured, 8 in serum: N-propeptides of collagen type I (PINP) and type III (PIIINP), cartilage oligomeric matrix protein (COMP), YKL-40, hyaluronan (HA), matrix metalloproteases (MMP1 and MMP3), and ultrasensitive C-reactive protein (CRP); and 2 in urine: C-terminal crosslinking telopeptides of collagen type I (CTX-I) and type II (CTX-II). Analyses of 376 patients with measurements of all the markers included principal component analyses to identify independent clusters of markers; followed by stepwise multivariate regressions to determine associations between markers, clinical variables, and radiographic signs of joint damage. RESULTS: Markers could be segregated into independent clusters: CTX-II, PINP, and CTX-I for cartilage degradation and bone turnover; COMP, PIIINP, and HA as potential markers of synovitis; and CRP and YKL-40, which are likely to indicate systemic inflammation; plus MMP1 and MMP3. After adjustment for age, sex, and body mass index, pain was significantly associated with CTX-II (p = 0.0095) and CRP (p = 0.046) and joint inflammation with COMP (p = 0.013). Radiographic signs of joint damage were associated with CTX-II (p = 0.001 for JSW; p = 0.007 for bone sclerosis). CONCLUSION: This cross-sectional study of OA molecular markers in a large cohort may provide biological evidence of different pathophysiological processes involved in hip OA. Among the markers measured, CTX-II showed the most consistent association with the symptoms and joint damage of OA.

Biomarkers↗