Assessment of urinary hydroxypyridinium cross-links measurement in osteoarthritis

The urinary levels of CTX-II, C2C, PYD, and Helix-II increased among adults with KBD: a cross-sectional study

Background

Kashin-Beck disease (KBD) is an endemic osteoarthropathy, and its pathogenesis is still not entirely clear. Pathologically, many KBD changes are similar to those of osteoarthritis (OA). Therefore, this study aimed to identify changes in the levels of potential urinary biomarkers for OA, including C-telopeptide of type II collagen (uCTX-II), type II collagen cleavage neoepitope (uC2C), pyridinoline (uPYD), and uHelix-II, among adults with KBD.

Methods

Urinary samples of 83 external control (EC) subjects, 91 KBD patients, and 86 internal control (IC) subjects were tested by ELISA after the subjects completed a questionnaire and X-ray examination.

Results

The medians of the four markers in the KBD group were higher than those in the EC group and those in the IC group. The medians in the grade II KBD group were higher than those in the grade I group but were not statistically significant (P = 0.301, P = 0.408, P = 0.204, and P = 0.898 for uCTX-II, uC2C, uPYD, and uHelix-II, respectively). The area under the curve (AUC) of uCTX-II (0.775) was higher than that of the others (0.672, 0.639, and 0.628 for uC2C, uPYD, and uHelix-II, respectively).

Conclusion

The levels of uCTX-II, uC2C, uPYD, and uHelix-II were elevated in adults with KBD and showed an increasing trend as the severity of KBD increased. The prediction accuracy of uCTX-II was more useful than that of the others for assisting in the diagnosis of KBD.

Review of Prospects of Biological Fluid Biomarkers in Osteoarthritis

Osteoarthritis (OA) is a degenerative disease of the joints and is one of the leading causes of disability in adults. However, there are no key therapeutics for OA and medical treatment is based on managing the symptoms and slowing down progression of the disease. Diagnostics based on clinical examination and radiography have provided little information about metabolic changes in joint tissues, disease onset and progression. Due to lack of effective methods for early detection and evaluation of treatment outcome, the measurement of biochemical markers (biomarkers) shows promise as a prospective method aiding in disease monitoring. OA biomarkers that are present in biological fluids such as blood, urine and synovial fluid, sources that are easily isolated from body, are of particular interest. Moreover, there are increasingly more studies identifying and developing new biomarkers for OA. In this review, efforts have been made to summarize the biomarkers that have been reported in recent studies on patients. We also tried to classify biomarkers according to tissue metabolism (bone, cartilage and synovial metabolism markers), pathological pathways (inflammatory and genetic markers) and biological function (chemokines, growth factors, acute phase proteins, etc.).

Biomarkers in the development of novel disease-modifying therapies for osteoarthritis

Identification and utilization of biomarkers is vitally important for the successful development of disease-modifying osteoarthritis drugs. Biochemical and imaging platforms hold great promise to deliver such biomarkers. Studies indicate a marked increase in biochemical products arising from the breakdown and biosynthesis of collagen, extracellular matrix and bone in osteoarthritis. These molecules have been associated with disease severity and may also have prognostic value as indicators of disease progression. However, issues including biological variability and lack of tissue specificity currently hinder the utility of these molecular markers in drug development. Imaging technologies hold great potential for sensitive and accurate measurement of disease-related structural damage. Drawbacks, including expense, need for validation and limited accessibility also limit the utility of these technologies. In this article, the potential value and challenges in developing and utilizing biomarkers in disease-modifying osteoarthritis drug development will be discussed.

Evaluation of Pentosan Polysulfate Sodium in the Postoperative Recovery from Cranial Cruciate Injury in Dogs: A Randomized, Placebo-Controlled Clinical Trial

OBJECTIVE

To evaluate the efficacy of pentosan polysulfate (PPS) for improving the recovery period and mitigate the progression of osteoarthritis (OA) of the canine stifle after extracapsular stabilization of cranial cruciate ligament (CCL) injuries.

STUDY DESIGN

Randomized, blinded, placebo-controlled clinical trial.

ANIMALS

Dogs (n=40) with unilateral CCL instability.

METHODS

Each dog had an extracapsular stabilization of the stifle with or without partial meniscectomy. Dogs were divided into 4 groups based on preoperative radiographic assessment and whether a partial meniscectomy was performed. Dogs were randomly assigned to either (3 mg/kg) PPS or placebo treatment in each group, and then injected subcutaneously weekly for 4 weeks. Lameness, radiographic changes, biological marker concentration in blood and urine, and ground reaction forces (GRFs) were collected preoperatively, and at 6, 12, 24, and 48 weeks. Data were analyzed within and between groups using repeated measures ANOVA; P<.05 was considered significant.

RESULTS

No adverse reactions to PPS were reported. Thirty-nine dogs completed a minimum of 24-weeks follow-up and 33 dogs completed 48 weeks. All dogs clinically improved after surgery without differences in lameness score, vertical GRFs, or radiographic progression. Grouped and evaluated only by initial radiographic score, PPS-treated dogs improved significantly faster in braking GRFs than placebo-treated dogs. In dogs with partial meniscectomies, urine deoxypyridinoline, and serum carboxy-propeptide of type II collagen were significantly increased at 6 weeks in placebo-treated dogs compared with PPS-treated dogs.

CONCLUSIONS

PPS administered after stabilization of the cruciate deficient stifle may prove to be a useful adjunctive treatment option, although further studies are necessary to substantiate this claim.

Long-term administration of 4G-beta-D-galactosylsucrose (lactosucrose) enhances intestinal calcium absorption in young women: a randomized, placebo-controlled 96-wk study

This study determined the effect of long-term administration of 4(G)-beta-D-galactosylsucrose (lactosucrose; LS) on intestinal calcium absorption. In a randomized, single-blind, parallel-group study, LS (n=9, 6.0 g twice daily) or a placebo (maltose; n=8, 6.0 g twice daily) was administered to healthy young women for 92 wk: the study also included a 4-wk post-administration period. All participants completed the study. Dietary nutrient intake; fecal weight, pH, and moisture content; fecal concentrations of short-chain fatty acids (SCFA), putrefactive products, ammonia, and minerals (calcium, magnesium, phosphorus, and iron); and serum calcium and osteocalcin concentrations were measured every 24 wk. Urinary pyridinoline (PYR) and deoxypyridinoline (DPD), and urinary calcium excretion were measured every 12 wk. Significant effects of oligosaccharide treatment, time, and the interaction between oligosaccharide treatment and time were observed for fecal pH, SCFA, ammonia, and putrefactive product values (p<0.05). Fecal pH, ammonia, and putrefactive product values decreased in the LS group, and the fecal SCFA concentration significantly increased during the administration period; these changes were not observed 4 wk post-administration. To examine the mineral balance of calcium, magnesium, and phosphorus in detail, all the participants completed a 6-d mineral balance study, sometime between week 56 and 60 of the longer study. During the mineral balance study, the daily calcium intake was set at 400 mg; all feces and urine were collected each day for 6 d after an 8-d acclimation period. In the balance study, fecal calcium excretion was significantly lower in the LS group than in the placebo group (p<0.05), and apparent calcium absorption and retention, apparent magnesium and phosphorus absorption, and magnesium retention were significantly higher in the LS group than in the placebo group (p<0.05). Our results suggest that the administration of LS produces a long-term enhancement of intestinal calcium absorption in healthy young women with lower than recommended calcium intakes.

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

OBJECTIVE

To evaluate the performance of biochemical and traditional markers in predicting radiographic progression in rheumatoid arthritis (RA).

METHODS

One hundred thirty-two patients with early RA were treated with nonbiologic therapies for 2 years and studied longitudinally. Genomic DNA was analyzed for presence of the shared epitope. Levels of matrix metalloproteinases (matrix metalloproteinase 1 [MMP-1], MMP-13, and MMP-3), tissue inhibitor of metalloproteinases 1 (TIMP-1), and cartilage oligomeric matrix protein (COMP) were assessed in serially obtained serum samples. The presence of pyridinoline (Pyr), deoxypyridinoline, glycosylated Pyr (Glc-Gal-Pyr), and C-telopeptide of type II collagen (CTX-II) was assessed in urine samples. Radiographs obtained at entry and at 2 years were evaluated using the modified Larsen score.

RESULTS

Baseline and 2-year radiographs were available from 118 patients. Larsen scores worsened during the 2 years in 50 patients, while 68 patients had no radiographic progression. Levels of a variety of biochemical markers, i.e., MMP-3, CTX-II, COMP, TIMP-1, Pyr, and Glc-Gal-Pyr, correlated significantly with radiographic progression at entry and longitudinally as assessed by area under the curve (AUC). By multivariate analysis, a model including MMP-3 and CTX-II was identified as providing the best prediction of radiographic progression at entry (predictive accuracy by receiver operating characteristic [ROC] AUC = 0.76 [95% confidence interval 0.66-0.85]), while a combination of MMP-3, CTX-II, and swollen joint count formed the best longitudinal AUC model (predictive accuracy by ROC AUC = 0.81 [95% confidence interval 0.73-0.89]). Patient-reported measures (Health Assessment Questionnaire, pain scores) were of limited use. In a subset of 50 patients who were treated with methotrexate (MTX) during the followup period, median serum MMP-3 levels decreased after the initiation of MTX therapy (P = 0.0003).

CONCLUSION

These results indicate that biochemical markers are useful predictors of radiographic progression in RA and that serum MMP-3 levels decrease significantly with MTX therapy. Multivariate models that include MMP-3 and CTX-II perform better than existing traditional markers in predicting radiographic outcome in RA.

Effects of zoledronate on markers of bone metabolism and subchondral bone mineral density in dogs with experimentally induced cruciate-deficient osteoarthritis

OBJECTIVE

To evaluate effects of zoledronate on markers of bone metabolism in dogs after transection of the cranial cruciate ligament (CrCL).

ANIMALS

21 adult dogs.

PROCEDURE

Unilateral CrCL transection was performed arthroscopically. Dogs were allocated to 3 groups (control group, low-dose zoledronate [10 microg/kg, SC, q 90 d for 12 months], and high-dose zoledronate [25 microg/kg, SC, q 90 d for 12 months]). Serum osteocalcin (OC), serum bone-specific alkaline phosphatase (BAP), and urine pyridinoline and deoxypyridinoline concentrations were measured at 0, 1, 3, 6, 9, and 12 months after surgery. Bone mineral density (BMD) was determined in the distal portion of the femur and proximal portion of the tibia via computed tomography at each time point. Data were analyzed by a repeated-measures ANOVA.

RESULTS

oledronate inhibited OC in the high-dose group at 9 and 12 months and at 12 months in the low-dose group, compared with the control group. High-dose zoledronate decreased BAP concentrations 3 and 9 months after surgery. In the control group, BMD was decreased in the femoral condyle and caudal tibial plateau. Zoledronate prevented significant BMD decreases starting 1 month after transection, compared with control dogs. In the caudomedial aspect of the tibial plateau, both zoledronate groups had significant increases in BMD after 3 months, compared with control dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Zoledronate may reduce subchondral bone loss and effect markers of bone metabolism in dogs with experimentally induced instability of the stifle joint and subsequent development of osteoarthritis.

Telopeptides as markers of bone turnover in rheumatoid arthritis and osteoarthritis

AIMS

The aim of the present study was to determine if urinary excretion of type I collagen N-terminal telopeptides (UrNTx) and deoxypyridinoline (UrDPD) and serum levels of type I collagen C-terminal telopeptides (SeCTx) differed in patients with rheumatoid arthritis (RA) compared with populations matched for age and gender with and without osteoarthritis (OA). The correlation of markers of bone turnover with disease activity in patients with RA or radiographic severity in patients with OA was also examined.

METHODS

Patients with RA aged >50 years (men) and >60 years (women) were identified from computer databases at two tertiary referral centres for rheumatology. Strict exclusion criteria were applied to avoid the effects of factors known to influence markers of bone turnover. Patients with RA and OA were matched for age and sex with a control population free of known arthritic disease and a population with OA. Bone markers were assayed in serum and urine. Urine markers were measured on three consecutive days and mean values used to minimize day-to-day variability of these analytes.

RESULTS

The level of UrNTx was elevated in patients with RA compared with normal controls and patients with OA. UrNTx and UrDPD correlated with markers of disease activity in patients with RA (erythrocyte -sedimentation rate and C-reactive protein), but not with -clinical signs of inflammation (swollen and tender joint counts). Patients with OA failed to show any correlation between markers of bone turnover and radiographic severity.

CONCLUSIONS

These data support a role for the use of UrNTx and UrDPD in further studies of the patho-physiology of RA and in longitudinal studies designed to modify the course of clinical disease.

Urinary type II collagen C-telopeptide levels are increased in patients with rapidly destructive hip osteoarthritis

OBJECTIVE

To compare type II collagen degradation using a new urinary specific marker in patients with rapidly destructive and those with slowly progressive hip OA.

METHODS

Twelve patients with rapidly destructive and 28 patients with slowly progressive hip OA were included in a prospective, cross sectional case-control study. Urinary levels of C-terminal crosslinking telopeptide of collagen type II (CTX-II) as a marker of cartilage degradation were measured by an ELISA, and urinary free deoxypyridinoline (free DPD), a marker of bone resorption, was measured by high performance liquid chromatography. One x ray evaluation of the hips and urine samples was made in all patients when the diagnosis of OA was established.

RESULTS

Patients with hip OA had higher mean (SD) urinary CTX-II levels than 65 healthy age matched controls (492 (232) v 342 (141), p<0.001), but no significant difference was seen for urinary free DPD (p=0.30). Increased urinary CTX-II, but not urinary free DPD, correlated significantly with decreased minimum joint space width assessed by radiograph of the hip. Mean urinary CTX-II levels were significantly higher in patients with rapidly progressive OA than in the slowly progressive group (612 (218) v 441 (221), p=0.015), whereas no significant difference of urinary free DPD was seen between the two groups (p=0.55).

CONCLUSION

Patients with hip OA have increased CTX-II degradation as assessed by a new urinary marker. Increased urinary CTX-II levels are associated with rapidly destructive disease, suggesting that this marker might be useful in identifying patients with hip OA at high risk for rapid progression of joint damage.

Cross sectional evaluation of biochemical markers of bone, cartilage, and synovial tissue metabolism in patients with knee osteoarthritis: relations with disease activity and joint damage

OBJECTIVE

To analyse the relations between the urinary levels of type II collagen C-telopeptide (CTX-II) and glucosyl-galactosyl pyridinoline (Glc-Gal-PYD)-two newly developed biochemical markers of type II collagen and synovial tissue destruction respectively-disease activity and the severity of joint destruction in patients with knee osteoarthritis (OA). The clinical performance of these two new markers was compared with that of a panel of other established biochemical markers of connective tissue metabolism.

METHODS

The following biochemical markers were measured in a group of 67 patients with knee OA (mean age 64 years, median disease duration eight years ) and in 67 healthy controls: for bone, serum osteocalcin, serum and urinary C-telopeptide of type I collagen (CTX-I); for cartilage, urinary CTX-II, serum cartilage oligomeric matrix protein (COMP), and serum human cartilage glycoprotein 39 (YKL-40); for synovium, urinary Glc-Gal-PYD, serum type III collagen N-propeptide (PIIINP), serum hyaluronic acid (HA); and for inflammation, serum C reactive protein. Biochemical markers were correlated with pain and physical function (WOMAC index) and with quantitative radiographic evaluation of the joint space using the posteroanterior view of the knees flexed at 30 degrees.

RESULTS

All bone turnover markers were decreased in patients with knee OA compared with controls (-36%, -38%, and -52%, p<0.0001 for serum osteocalcin, serum CTX-I and urinary CTX-I, respectively). Serum COMP (+16%, p=0.0004), urinary CTX-II (+25%, p=0.0009), urinary Glc-Gal-PYD (+18%, p=0.028), serum PIIINP (+33%, p<0.0001), and serum HA (+ 233%, p<0.0001) were increased. By univariate analyses, increased urinary Glc-Gal-PYD (r=0.41, p=0.002) and decreased serum osteocalcin (r=-0.30, p=0.025) were associated with a higher total WOMAC index. Increased urinary CTX-II (r=-0.40, p=0.0002) and Glc-Gal-PYD (r=-0.30, p=0.0046) and serum PIIINP (r=-0.29, p=0.0034) were the only markers which correlated with joint surface area. By multivariate analyses, urinary Glc-Gal-PYD and CTX-II were the most important predictors of the WOMAC index and joint damage, respectively.

CONCLUSION

Knee OA appears to be characterised by a systemic decrease of bone turnover and increased cartilage and synovial tissue turnover. CTX-II, Glc-Gal-PYD, and PIIINP may be useful markers of disease severity in patients with knee OA.

Osteoporosis. Definition and clinical presentation

Osteoporosis is a skeletal condition characterized by decreased density (mass/volume) of normally mineralized bone. The reduced bone density leads to decreased mechanical strength, thus making the skeleton more likely to fracture. Postmenopausal osteoporosis (Type I) and age-related osteoporosis (Type II) are the most common primary forms of bone loss seen in clinical practice. Secondary causes of osteoporosis include hypercortisolism, hyperthyroidism, hyperparathyroidism, alcohol abuse, and immobilization. In the development of osteoporosis, there is often a long latent period before the appearance of the main clinical manifestation, pathologic fractures. The earliest symptom of osteoporosis is often an episode of acute back pain caused by a pathologic vertebral compression fracture, or an episode of groin or thigh pain caused by a pathologic hip fracture. In the diagnostic process, the extent and severity of bone loss are evaluated and secondary forms of bone loss are excluded. A careful diagnostic work-up that includes clinical history, physical examination, laboratory evaluation, bone densitometry, and radiographic imaging will allow the clinician to determine the cause of osteoporosis and to institute medical interventions that will stabilize and even reverse this frequently preventable condition.