Clinical application of biochemical markers of bone turnover

A Comparative Analysis of Alkaline Phosphatase Levels in Gingival Crevicular Fluid of Patients Undergoing Growth Modulation Therapy With Twin Block, Forsus Fatigue Resistant, and Clear Block Appliances Compared to Normal Individuals: An In Vivo Study

Background In the contemporary era, where science and technology know no boundaries, this in vivo study explores the impact of growth modulation therapy using Twin Block, Forsus Fatigue Resistant, and Clear Block appliances on alkaline phosphatase (ALP) levels in gingival crevicular fluid (GCF). Bone physiology involves modeling and remodeling, with orthodontics applying forces to teeth, influencing tissue reactivity and bone modeling. ALP, a marker of osteoblast function, plays a crucial role in bone growth. GCF reflects immunological and inflammatory responses during orthodontic force application, making it a valuable medium for studying ongoing metabolic processes related to bone turnover. Aim The study aims to comparatively analyze ALP levels in GCF during growth modulation therapy, assessing the efficacy of Twin Block, Forsus Fatigue Resistant, and Clear Block appliances. The research involves 30 experimental samples divided into three study groups and a control group. The samples are collected at various time intervals, and ALP levels are analyzed using a spectrophotometer. Statistical analysis includes paired and unpaired t-tests, one-way analysis of variance (ANOVA), and multiple comparisons. Results Results demonstrate a significant increase in ALP levels during the growth modulation therapy, indicating a positive correlation with bone remodeling. Twin Block appears to be the most effective appliance, exhibiting higher ALP activity compared to Clear Block and Forsus groups. Conclusion In conclusion, this study provides valuable insights into the biochemical responses during growth modulation therapy, emphasizing the potential of GCF analysis in understanding orthodontic treatment effects.

A systematic review on the potential value of synovial fluid biomarkers to predict clinical outcomes in cartilage repair treatments

OBJECTIVE

Multiple biochemical biomarkers have been previously investigated for the diagnosis, prognosis and response to treatment of articular cartilage damage, including osteoarthritis (OA). Synovial fluid (SF) biomarker measurement is a potential method to predict treatment response and effectiveness. However, the significance of different biomarkers and their correlation to clinical outcomes remains unclear. This systematic review evaluated current SF biomarkers used in investigation of cartilage degeneration or regeneration in the knee joint and correlated these biomarkers with clinical outcomes following cartilage repair or regeneration interventions.

METHOD

PubMed, Institute of Science Index, Scopus, Cochrane Central Register of Controlled Trials, and Embase databases were searched. Studies evaluating SF biomarkers and clinical outcomes following cartilage repair intervention were included. Two researchers independently performed data extraction and Quality Assessment of Diagnostic Accuracy Score 2 (QUADAS-2) analysis. Biomarker inclusion, change following intervention and correlation with clinical outcome was compared.

RESULTS

9 studies were included. Study heterogeneity precluded meta-analysis. There was significant variation in sampling and analysis. 33 biomarkers were evaluated in addition to microRNA and catabolic/anabolic ratios. Five studies reported on correlation of biomarkers with six biomarkers significantly correlated with clinical outcomes following intervention. However, correlation was only demonstrated in isolated studies.

CONCLUSION

This review demonstrates significant difficulties in drawing conclusions regarding the importance of SF biomarkers based on the available literature. Improved standardisation for collection and analysis of SF samples is required. Future publications should also focus on clinical outcome scores and seek to correlate biomarkers with progression to further understand the significance of identified markers in a clinical context.

REGISTRATION NUMBER

PROSPERO CRD42022304298. Study protocol available on PROSPERO website.

Influence of short-term ovarian stimulation on bone metabolism in women undergoing fertility treatment

Objectives

Hormonal disturbances during menopause are an established influencing factor on bone health, but the role of controlled ovarian hyperstimulation for fertility treatment remains unclear. To evaluate the influence of ovarian stimulation on bone metabolism with particular regard to serum follicle-stimulating hormone (FSH) levels this prospective observational study was conducted.

Methods

A total of 71 women underwent controlled ovarian hyperstimulation with recombinant FSH (rFSH) or human menopausal gonadotropin (HMG) (FSH + LH) administered in individual doses, with gonadotropin-releasing hormone (GnRH) agonist down-regulation initiated in the luteal phase of the previous cycle. At four time points (start of down-regulation [T1], start of ovarian stimulation [T2], oocyte retrieval [T3] and luteal phase of the stimulation cycle [T4]), luteinizing hormone (LH), FSH, estradiol (E2), osteocalcin (OC), bone-specific alkaline phosphatase (BAP), as well as the bone resorption markers β-isomerized C-terminal telopeptide of type I collagen (β-CTX) and tartrate-resistant acid phosphatase (TRACP) were measured.

Results

The cyclic variations in FSH levels had a positive effect on the concentration profile of the bone resorption marker β-CTX (p=0.0001). Supraphysiologic estradiol levels showed a negative association with osteocalcin concentrations (p=0.017), and significantly lower OC and TRACP levels were observed at T4 compared to T1. By group comparison, women treated with rFSH presented with a higher bone turnover than the HMG group at the end of a stimulation cycle (T4).

Conclusions

Our results show that FSH is a significant influencing factor of bone metabolism. Overall, there was no evidence of enhanced bone resorption under short-term ovarian stimulation therapy. Further studies with bigger sample sizes are warranted to validate these results.

Consecutive changes in serum alkaline phosphatase isoenzyme 3 activities in Holstein heifers during the first 18 months of life

This study investigated consecutive fluctuations in serum activities of bone-specific alkaline phosphatase (ALP) isoenzyme 3 (ALP3) in 11 clinically healthy Holstein heifers during the first 18 months of life. ALP3 activities at the first sampling time point after weaning (3 months) were significantly lower than those at multiple time points during the pre-weaning period. Those activities increased from a minimum at 3 months to a peak at 6 months during the post-weaning period. In the anthropometric data, daily body weight and wither height gains appeared to be below the public data at 4 months and 4–5 months, respectively. The data suggested that serum ALP3 activity can be used to monitor skeletal growth of heifers at weaning.

Osteoblast-Based Therapy-A New Approach for Bone Repair in Osteoporosis: Pre-Clinical Setting

BACKGROUND

Osteoporosis is a metabolic bone disease characterized by low bone density resulting in increased fracture susceptibility. This research was constructed to uncover the potential therapeutic application of osteoblasts transplantation, generated upon culturing male rat bone marrow-derived mesenchymal stem cells (BM-MSCs) in osteogenic medium (OM), OM containing gold (Au-NPs) or gold/hydroxyapatite (Au/HA-NPs) nanoparticles, in ovariectomized rats to counteract osteoporosis.

METHODS

Forty rats were randomized into: (1) negative control, (2) osteoporotic rats, whereas groups (3), (4) and (5) constituted osteoporotic rats treated with osteoblasts yielded from culturing BM-MSCs in OM, OM plus Au-NPs or Au/HA-NPs, respectively. After 3 months, osterix (OSX), bone alkaline phosphatase (BALP), sclerostin (SOST) and bone sialoprotein (BSP) serum levels were assessed. In addition, gene expression levels of cathepsin K, receptor activator of nuclear factor-κb ligand (RANKL), osteoprotegerin (OPG) and RANKL/OPG ratio were evaluated using real-time PCR. Moreover, histological investigation of femur bone tissues in different groups was performed. The homing of implanted osteoblasts to the osteoporotic femur bone of rats was documented by Sex determining region Y gene detection in bone tissue.

RESULTS

Our results indicated that osteoblasts infusion significantly blunted serum BALP, BSP and SOST levels, while significantly elevated OSX level. Also, they brought about significant down-regulation in gene expression levels of cathepsin K, RANKL and RANKL/OPG ratio versus untreated osteoporotic rats. Additionally, osteoblasts nidation could restore bone histoarchitecture.

CONCLUSION

These findings offer scientific evidence that transplanting osteoblasts in osteoporotic rats regains the homeostasis of the bone remodeling cycle, thus providing a promising treatment strategy for primary osteoporosis.

Combining information from multiple bone turnover markers as diagnostic indices for osteoporosis using support vector machines

CONTEXT

Osteoporosis (OP) is a progressive systemic bone disease. Dual-energy X-ray absorptiometry (DXA) is routinely employed and is considered the gold standard method for the diagnosis of OP.

OBJECTIVE

We aimed to investigate the potential use of combined information from multiple bone turnover markers (BTMs) as a clinical diagnostic tool for OP.

MATERIALS AND METHODS

A total of 9053 Chinese postmenopausal women (2464 primary OP patients and 6589 healthy controls) were recruited. Serum levels of six common BTMs, including BAP, BSP, CTX, OPG, OST and sRANKL were assayed. Models based on support vector machine (SVM) were constructed to explore the efficiency of different combinations of multiple BTMs for OP diagnosis.

RESULTS

Increasing the number of BTMs used in generating the models increased the predictive power of the SVM models for determining the disease status of study subjects. The highest kappa coefficient for the model with one BTM (BAP) compared to DXA was 0.7783. The full model incorporating all six BTMs resulted in a high kappa coefficient of 0.9786.

CONCLUSION

Our findings showed that although single BTMs were not sufficient for OP diagnosis, appropriate combinations of multiple BTMs incorporated into the SVM models showed almost perfect agreement with the DXA.

Bone Turnover in Vertebral Fractures: Does it Effect the Decision of Surgery?

Background and Aim:

Instrumentation is commonly used in spinal surgery to stabilize the fracture. In the present study, we aimed to compare the early and late changes seen in bone production and degradation products in patients with traumatic spinal fracture who had been treated surgically or conservatively.

Materials and Methods:

Forty-three patients were admitted to the Neurosurgery Department with thoracolumbar or lumbar fracture in this prospective study. Patients were divided into two groups of surgically treated (n = 23) and nonsurgically/conservatively treated (n = 20) patients. The early and late changes seen in bone production and degradation products were compared in patients with traumatic spinal fracture who had been treated surgically or conservatively.

Results:

In conservatively treated patients, although osteocalcin level was slightly increased and deoxypiridinoline (DPD)/creatinine was slightly decreased after the treatment, the difference was not statistically significant (P = 0.08 and P = 0.539, respectively). There is no significant difference between admission time, posttreatment late period osteocalcin level, and DPD/creatinine ratio between the two group of patients (P = 0.215 and P = 0.236, respectively).

Conclusion:

We suggest that the healing and fusion processes in fractured vertebrae not only followed by the radiological examination but also by noninvasive biochemical changes seen in the serum levels of bone formation and resorption markers.

Evaluating the efficacy of functional electrical stimulation therapy assisted walking after chronic motor incomplete spinal cord injury: effects on bone biomarkers and bone strength

OBJECTIVES

To determine the efficacy of functional electrical stimulation therapy assisted walking (FES-T) compared to a conventional aerobic and resistance training (CONV) with respect to bone biomarkers and lower extremity bone strength outcomes among adults with chronic motor incomplete spinal cord injury (SCI).

DESIGN

Parallel group randomized controlled trial ( www.clinicaltrials.gov - NCT0020196819). Site: Tertiary academic rehabilitation centre in Canada.

METHODS

Adults with chronic (≥18 months) motor incomplete SCI (C2-T12 AIS C-D) were consented and randomized to FES-T or CONV training for 45 minutes thrice-weekly for 4 months. Osteocalcin (OC), β-cross laps (CTX) and sclerostin were assessed at baseline, and 4 months. Similarly, total hip, distal femur and proximal tibia region bone mineral density (BMD) via DXA (4500A, Hologic Inc. Waltham, MA, USA) and tibia bone quality via pQCT (Stratec XCT-2000, Mezintecknik, Pforzheim, Germany) were assessed at baseline, 4, and 12 months. Between group differences were analyzed using repeated measures general linear models.

RESULTS

Thirty-four participants (17 FES-T, 17 CONV) consented and were randomized, 27 participants completed the 4-month intervention and 12-month outcome assessments. Participants in the FES-T arm had a decrease in CTX and a significant increase in OC at intervention completion (P<0.05). Significant biomarker changes were not observed in the CONV group. No within or between group differences from baseline were observed in sclerostin or bone strength.

CONCLUSIONS

Four months of FES-T improved bone turnover (increase in OC and decrease in CTX) but not bone strength among individuals with chronic SCI. Future, long term FES-T may augment lower extremity bone strength.

Changes of Bone Turnover Markers in Long Bone Nonunions Treated with a Regenerative Approach

In this clinical trial, we investigated if biochemical bone turnover markers (BTM) changed according to the progression of bone healing induced by autologous expanded MSC combined with a biphasic calcium phosphate in patients with delayed union or nonunion of long bone fractures. Bone formation markers, bone resorption markers, and osteoclast regulatory proteins were measured by enzymatic immunoassay before surgery and after 6, 12, and 24 weeks. A satisfactory bone healing was obtained in 23 out of 24 patients. Nine subjects reached a good consolidation already at 12 weeks, and they were considered as the “early consolidation” group. We found that bone-specific alkaline phosphatase (BAP), C-terminal propeptide of type I procollagen (PICP), and beta crosslaps collagen (CTX) changed after the regenerative treatment, BAP and CTX correlated to the imaging results collected at 12 and 24 weeks, and BAP variation along the healing course differed in patients who had an “early consolidation.” A remarkable decrease in BAP and PICP was observed at all time points in a single patient who experienced a treatment failure, but the predictive value of BTM changes cannot be determined. Our findings suggest that BTM are promising tools for monitoring cell therapy efficacy in bone nonunions, but studies with larger patient numbers are required to confirm these preliminary results.

Bone turnover markers in sheep and goat: A review of the scientific literature

Bone turnover markers (BTMs) are product of bone cell activity and are generally divided in bone formation and bone resorption markers. The purpose of this review was to structure the available information on the use of BTMs in studies on small ruminants, especially for monitoring their variations related to diet, exercise, gestation and metabolic lactation state, circadian and seasonal variations, and also during skeletal growth. Pre-clinical and translational studies using BTMs with sheep and goats as animal models in orthopaedic research studies to help in the evaluation of the fracture healing process and osteoporosis research are also described in this review. The available information from the reviewed studies was systematically organized in order to highlight the most promising BTMs in small ruminant research, as well as provide a wide view of the use of sheep and goat as animal models in orthopaedic research, type of markers and commercial assay kits with cross-reactivity in sheep and goat, method of sample and storage of serum and urine for bone turnover markers determination and the usefulness and limitations of bone turnover markers in the different studies, therefore an effective tool for researchers that seek answers to different questions while using BTMs in small ruminants.

The Effects of Hormonal Therapy and Exercise on Bone Turnover in Postmenopausal Women: A Randomised Double-Blind Pilot Study

INTRODUCTION

Hormone replacement therapy (HRT) and walking were investigated independently and in combination, to determine which treatment provided most effect on bone turnover in postmenopausal women.

METHODS

Using a randomised double-blind pilot study, 10 subjects received HRT (transdermal estradiol, 50 μg/day and oral MPA 5 mg/day) and 12 received placebo for 20 weeks. Following a baseline period of treatment, both groups undertook a graduated walking regimen, which increased in intensity, duration and frequency parameters from weeks 8-20. Measurements of aerobic capacity, female sex hormones, bone formation markers [osteocalcin (OC) and bone alkaline phosphatase (BAP)] and bone resorption markers [deoxypyridinoline (DPD) and pyridinoline (PYR)] were measured at baseline (T1), week 8 (T2) and week 20 (T3).

RESULTS

Age, time of postmenopause, weight or body mass index were no different between each groups. The HRT group had significantly higher estradiol levels compared with the placebo group at T2 and T3. FSH and LH levels were significantly reduced following HRT. DPD and PYR were significantly reduced from baseline levels at T2 and T3 with HRT. No significant changes occurred in OC or BAP levels with either HRT or walking. Walking did not change bone turnover markers in either the HRT or placebo group.

CONCLUSION

HRT reduces bone resorption, however, walking alone at the intensity and duration prescribed, or the combination of HRT and walking, provided no additional benefit after menopause. Therefore, HRT, but not walking is an effective treatment in reducing bone turnover in postmenopause women.

Bone turnover biomarkers and risk of osteoporotic hip fracture in an Asian population

While epidemiologic studies suggest that bone turnover biomarkers may predict hip fracture risk, findings are inconsistent and Asian data are lacking. We conducted a matched case-control (1:1) study nested in the Singapore Chinese Health Study, a population-based prospective cohort of Chinese men and women (45-74years) recruited from 1993 to 1998 in Singapore. One hundred cases with incident hip fracture and 100 individually matched controls were randomly selected from 63,257 participants. Serum bone turnover biomarkers, namely bone alkaline phosphatase (bone ALP), osteocalcin (OC), procollagen type I N propeptide (PINP), N-terminal and C-terminal crosslinking telopeptide of type I collagen (NTX-I and CTX-I) were measured using immunoassays. Hip fracture cases had significantly higher serum levels of OC, PINP, CTX-I and NTX-I than controls (p<0.05). There was a dose-dependent positive relationship between OC, PINP, CTX-I and NTX-I and risk of hip fracture (all Ps for trend≤0.006), where the risk was significantly increased by 4.32-8.23 folds for the respective BTM [Quartile (Q) 4 vs. Q1]. The odds ratio [OR (95% CI)] at the highest quartile (Q4) was 6.63 (2.02-21.18) for PINP and 4.92 (1.67-14.51) for CTX-I. The joint effect of PINP and CTX-I showed a 7-fold increase in risk (OR: 7.36; 95% CI: 2.53-21.41) comparing participants with higher levels of PINP (Q4) and CTX-I (Q3-Q4) to those with low levels of PINP (Q1-Q3) and CTX-I (Q1-Q2). Our data demonstrated that higher serum levels of bone turnover biomarkers were associated with increased risk of hip fracture in an Asian population.

Effect of age and sex on bone markers in Chlorocebus aethiops raised in captivity

BACKGROUND

The objective was to evaluate the procollagen type I N-propeptide (PINP), osteocalcin (OC), β-crosslaps (β-CTX), and parathyroid hormone (PTH) in relation to age and sex of Chlorocebus aethiops in captivity.

METHODS

Seventy-three monkeys were divided into four age groups: AG1 (juvenile); AG2 (young adult); AG3 (adult); and AG4 (senile). An electrochemiluminescence immunoassay with an Elecsys 2010 analyzer was used to determine the serum markers of bone.

RESULTS AND CONCLUSIONS

Sex did not influence the results of the markers. However, the variables PINP, OC, and β-CTX were negatively correlated with age (r = -0.643; r = -0.711; r = -0.488; P < 0.001, respectively), and PTH was correlated positively with age (r = 0.418, P < 0.001). The data obtained can be used as biomarkers of bone metabolism reference intervals in healthy C. aethiops in captivity.

Use of a Gonadotropin-releasing Hormone Analog to Treat Idiopathic Central Precocious Puberty Is Not Associated with Changes in Bone Structure in Postmenarchal Adolescents

STUDY OBJECTIVES

To evaluate bone quantity and quality in postmenarchal adolescents treated for idiopathic central precocious puberty (CPP) in childhood with a gonadotropin-releasing hormone analog (GnRHa) and to determine the serum concentrations of bone remodeling markers.

DESIGN AND PARTICIPANTS

This cross-sectional study included 53 postmenarchal adolescent girls who were divided into 2 groups: 27 adolescents who were treated with GnRHa in childhood for idiopathic CPP (the CPP group) and 26 women who presented with physiological development of secondary sex traits (the control group).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Weight, height, body mass index, age at menarche, time since menarche, body composition, bone mineral density (BMD), bone quality, and serum insulin, glucose, osteocalcin, and carboxyl-terminal telopeptide of type I collagen concentrations were compared in the 2 groups. BMD data were analyzed by using both dual-energy x-ray absorptiometry (DXA) and osteosonography, and body composition was measure with the use of DXA and electrical bioimpedance.

RESULTS

BMD and bone quality did not differ significantly between the CPP and control groups when analyzed by using DXA or osteosonography. Serum osteocalcin concentration was significantly lower (P = .02) in the CPP than in the control group. Insulin was higher in the CPP group, and hyperinsulinemia was an independent predictor of bone quantity and quality assessed by using osteosonography. Body mass index and percent fat were determined by using DXA, and the duration of use of GnRHa treatment and the time since GnRHa discontinuation were not independent predictors of bone quantity and quality.

CONCLUSION

Postmenarchal adolescents treated with GnRHa for CPP in childhood did not show a reduction in bone quantity or quality.

Bone turnover markers for early detection of fracture healing disturbances: A review of the scientific literature

Imaging techniques are the standard method for assessment of fracture healing processes. However, these methods are perhaps not entirely reliable for early detection of complications, the most frequent of these being delayed union and non-union. A prompt diagnosis of such disorders could prevent prolonged patient distress and disability. Efforts should be directed towards the development of new technologies for improving accuracy in diagnosing complications following bone fractures. The variation in the levels of bone turnover markers (BTMs) have been assessed with regard to there ability to predict impaired fracture healing at an early stage, nevertheless the conclusions of some studies are not consensual. In this article the authors have revised the potential of BTMs as early predictors of prognosis in adult patients presenting traumatic bone fractures but who did not suffer from osteopenia or postmenopausal osteoporosis. The available information from the different studies performed in this field was systematized in order to highlight the most promising BTMs for the assessment of fracture healing outcome.

Serum total and bone alkaline phosphatase levels and their correlation with serum minerals over the lifespan of sheep

This study aimed to assess serum total alkaline phosphatase (ALP) and its bone isoform (BALP) levels during the ageing and in different physiologic states of sheep, in order to expand the knowledge about the variation of these biomarkers over the sheep lifespan. Ninety female sheep were divided into nine groups of various ages and physiological states (dry, lactation and pregnancy). Serum ALP, BALP and mineral levels were determined by commercial immunoassay, molecular absorbance spectrophotometry and chemical luminescence for BALP determination. Serum ALP and BALP decreased as sheep aged, and no statistically significant differences were obtained between ewes in different physiologic states. The continuous decline of serum BALP concentration along the sheep lifespan, namely in mature and old sheep, is a sign of decreasing bone turnover associated with ageing. Serum calcium concentrations increased slightly until 2 years of age and then showed a tenuous but statistically significant decrease in mature sheep, while serum phosphorus maintained an uninterrupted decrease as sheep matured. The knowledge of serum values of bone biomarkers throughout the sheep lifespan may be useful in preclinical orthopaedic research studies and for animal science studies using sheep.

Relationship between bone turnover biomarkers, mandibular bone mineral density, and systemic skeletal bone mineral density in premenopausal and postmenopausal Indian women

OBJECTIVE

Postmenopausal osteoporosis is one of the most common metabolic bone disorders. Osteoporosis is reported to cause bone loss in the alveolar processes of maxilla and mandible, which provide bony framework for tooth anchorage. However, the association between systemic osteoporosis and oral health remains controversial. Available evidence suggests that Indian women have lower peak bone mass than their Western/other Asian counterparts. The present study evaluated the relationship between mandibular bone mineral density (mBMD), systemic skeletal BMD, and bone metabolism in premenopausal and postmenopausal Indian women.

METHODS

One hundred twenty-four premenopausal and 247 postmenopausal healthy women were included in the study. The BMD of the body of mandible, radius ultradistal, total hip, femur neck, and lateral spine were measured using dual-energy x-ray absorptiometry. Serum and urine biomarkers were determined using commercial kits.

RESULTS

Univariate regression analysis followed by stepwise multivariate regression analysis to obtain the best fit model demonstrated the BMD of radius ultradistal, serum inorganic phosphorus, estradiol, and sex hormone-binding globulin as significant predictors of mBMD in premenopausal women. The BMD of femur neck, serum ionized calcium, bone-specific alkaline phosphatase, osteocalcin, and urine total pyridinoline were significantly associated with mBMD in postmenopausal women. The significant association between mBMD and number of teeth present was observed in the whole group of premenopausal and postmenopausal women.

CONCLUSIONS

Varied predictors of mBMD were observed in premenopausal and postmenopausal women. The results suggest that the screening for these biomarkers and serum ionized calcium should be useful (1) to assess the status of mBMD particularly in women requiring surgical dental intervention that include bone manipulation and (2) for early detection and management of women with the risk of developing osteoporosis.

Critical analysis of biomarkers in the current periodontal practice

Periodontal disease is a chronic microbial infection that triggers inflammation-mediated loss of the periodontal ligament and alveolar bone that supports the teeth. Because of the increasing prevalence and associated comorbidities, there is a need for the development of new diagnostic tests that can detect the presence of active disease, predict future disease progression, and evaluate the response to periodontal therapy, thereby improving the clinical management of periodontal patients. The diagnosis of active phases of periodontal disease and the identification of patients at risk for active disease represent challenges for clinical investigators and practitioners. Advances in diagnostic research are moving toward methods whereby the periodontal risk can be identified and quantified by objective measures using biomarkers. Patients with periodontitis may have elevated circulating levels of specific inflammatory markers that can be correlated to the severity of the disease. Advances in the use of oral fluids as possible biological samples for objective measures of the current disease state, treatment monitoring, and prognostic indicators have boosted saliva- and other oral-based fluids to the forefront of technology. Gingival crevicular fluid (GCF) is an inflammatory exudate that can be collected at the gingival margin or within the gingival crevice. This article highlights recent advances in the use of biomarker-based disease diagnostics that focus on the identification of active periodontal disease from plaque biofilms, GCF, and saliva.

Quantification of human serum procollagen C-proteinase enhancer (hsPCPE) glycopattern

BACKGROUND

Procollagen C-proteinase enhancer 1 (PCPE1), a glycoprotein secreted from differentiating osteoblast, enhances the rate-limiting step of collagen type I fibrillar formation. It is expressed and secreted by cells that produce collagen type I and has the potential to be a marker for bone pathologies.

METHODS

We developed an assay to quantify PCPE glycopattern based on isoelectric focusing (IEF) and detection with a bio-imaging camera (coefficient of variation within and between assays, 15% and 20%, respectively).

RESULTS

PCPE was quantified in 39 serum samples from healthy subjects (17 females and 22 males). The concentration in the serum was 305(274) ng/ml, median(IQR). The level of the PCPE isoforms and their relative distribution were altered in patients with bone disorders.

CONCLUSIONS

The data generated by our system, support our hypothesis that combined data on PCPE concentration and isoforms may be useful for the diagnosis and follow-up of bone diseases. Further research, on larger cohorts of both normal subjects and patients, must be done.

[Diagnostic value of bone metabolic markers ICTP and BAP in lung cancer patients with bone metastases]

背景与目的

骨代谢标志物是一类源于骨基质或骨细胞的代谢指标，可反映骨代谢情况。本研究旨在探讨血清骨代谢生化指标Ⅰ型胶原交联羧基端肽（cross-linked telopeptide of type Ⅰ collage, ICTP）和骨特异性碱性磷酸酶（bone-specific alkaline phosphatase, BAP）在肺癌骨转移诊断中的意义及其临床应用价值。

方法

采用前瞻性对照方法，共入组110例，分为3组。初治肺癌患者共90例，临床分期为Ⅳ期，分为骨转移组50例和非骨转移组40例，健康对照组20例，采用酶联免疫法和电化学发光免疫测定法检测所有入组者治疗前的血清骨代谢生化指标ICTP和BAP水平，对骨转移的各因素与血清ICTP和BAP的相关性进行统计学分析。

结果

骨转移组的血清ICTP和BAP水平显著高于非骨转移组和健康对照组（P < 0.05）。多发性骨转移组（骨转移数≥3）的血清BAP水平显著高于少发性骨转移组（骨转移数 < 3）（P < 0.05）。混合性骨转移组的血清BAP水平显著高于溶骨性骨转移组（P < 0.05）。ICTP和BAP在肺癌骨转移诊断中的敏感性分别为18%和40%，特异性分别为98.3%和95%，准确度分别为61.8%和70%。联合检测血清ICTP和BAP可提高其敏感性和准确度（分别为52%和74.5%）。

结论

由于检测方便、无创性、成本较低，血清骨代谢生化指标ICTP和BAP在肺癌骨转移的临床诊断中有一定的实用价值。

Influence of long-term thromboprophylaxis with low-molecular-weight heparin (enoxaparin) on changes of bone metabolism markers in pregnant women

This is a first descriptive, retrospective, observational study aiming to evaluate the changes in bone turnover markers in pregnant women and to assess the effect of a long-term treatment with low-molecular-weight heparin (LMWH), specifically, enoxaparin. Study involved 50 pregnant Caucasian women with thrombophilia. The patients either received prophylactic enoxaparin once daily subcutaneously (N = 35) or were observed without treatment (N = 15). Concentrations of total serum alkaline phosphatase (total AP), bone alkaline phosphatase (bone AP), osteoprotegerin (OPG), and the receptor activator of nuclear factor κB ligand (RANKL) were measured at 15, 25, and 35 weeks of gestation. Total serum AP increased with gestational age. In the group treated with enoxaparin, the percentage of bone AP concentration was lower (P < .05) than in the control group. Serum OPG also increased with gestational age, but no significant difference was found between the groups with- and without treatment. Despite the OPG increased, RANKL did not change.

Treatment with tyrosine kinase inhibitors in patients with metastatic renal cell carcinoma is associated with drug-induced hyperparathyroidism: a single center experience in 59 patients

PURPOSE

Multi-targeted tyrosine kinase inhibitors (MTKIs) are the standard in the treatment of metastatic renal cell carcinoma (mRCC). In spite their clinical activity, interaction with physiological functions has been shown. Here, we report on alterations of the bone mineral metabolism in patients with mRCC treated with MTKIs.

METHODS

Fifty-nine patients with mRCC treated during April 2005 and September 2009 at our center were evaluated. Demographics, chemistry, parathyroid and renal function, bone metastasis and clinics were assessed, retrospectively. Parathyroid hormone (PTH), calcium and phosphate were either determined prior to, during or after cessation of MTKI therapy.

RESULTS

From evaluable patients, 90% (N = 53) received at least one MTKI treatment, 10% (N = 8) had evaluations without MTKI exposure. The mean PTH value prior to MTKI treatment was 49.4 (range (r):2.5-115), increased during the therapy to 121.2 (r:5-302) (P = 0.003) and returned to its basic values after MTKI cessation. In parallel, mean phosphate significantly decreased during the treatment from 1.10 (r = 0.66-1.59) to 0.87 (r = 0.48-1.45) (P < 0.001) and calcium showed a slight decrease (P = 0.039). PTH alterations were associated with clinical signs in some patients but not with bone metastasis or renal function. Univariate logistic regression analysis of pathologically elevated PTH levels revealed an association with MTKI treatment duration.

CONCLUSION

Even though the mechanism of bone mineral alteration remains elusive, the MTKI treatment is associated with a dysregulated parathyroid axis, which may have clinical implications in a number of patients. Furthermore, prospective trials are mandatory, and PTH monitoring should be considered in selected patients during MTKI treatment.

Correlation between bone markers and bone mineral density in postmenopausal women with osteoporosis

OBJECTIVE

To study the relationship between bone markers and bone mineral density (BMD) in an effort to identify their utility in postmenopausal women with osteoporosis.

METHODS

Eighty-two consecutive postmenopausal women with untreated osteoporosis were included in the study. Forearm, spinal, and femoral BMD by dual-energy x-ray absorptiometry and markers of bone formation (serum osteocalcin and bone-specific alkaline phosphatase) and bone resorption (urinary free deoxypyridinoline) were measured in all patients. Patients with low serum vitamin D levels, secondary osteoporosis, or clinically significant systemic disease were excluded from the study. The patients were classified on the basis of BMD of the lumbar spine into the following 3 groups: mild (n = 23) (T score -2.5 through -3), moderate (n = 42) (T score -3.1 through -4), or severe (n = 17) (T score <or=-4.1) osteoporosis. One-way analysis of variance and Pearson correlation were used for statistical analysis, with a P value <.05 being considered significant.

RESULTS

Serum osteocalcin was significantly different among the 3 study groups (4.1 +/- 2.7, 4.5 +/- 3.1, and 6.7 +/- 5.6 ng/mL, respectively; P = .0349) and had a significant negative correlation with BMD (r2 = -0.0779; P = .0168). Other bone markers such as bone-specific alkaline phosphatase and urinary free deoxypyridinoline did not correlate with the underlying BMD.

CONCLUSION

In our study, osteocalcin was significantly correlated with BMD in postmenopausal women with osteoporosis. Other bone markers did not correlate with BMD. Further large-scale population data and analyses are needed to confirm these findings.

Outcome measures for evaluation of treatments for osteonecrosis

With the advent of cell-based therapies, biologics, and pharmaceuticals for the potential treatment of osteonecrosis, it is important to conduct evaluations using scientifically accepted outcomes measures. For the treatment of osteonecrosis, most studies have focused on pain relief, surgery, or the need for surgery, disease progression (advancing stage), and change in lesion size. Quantification of imaging techniques continue to gain in sophistication but have not yet been validated for use in clinical trials. Despite recent interest in using biomarkers or genetic markers in the diagnosis and analysis of disease progression, more research is needed to determine the sensitivity and specificity of these techniques with respect to osteonecrosis.

Different patterns of human serum procollagen C-proteinase enhancer1 (PCPE1)

BACKGROUND

Procollagen C-proteinase (PCP) enhancer 1 (PCPE1) specifically stimulates the PCP activity of bone morphogenic protein 1 (BMP1), a multisubstrate enzyme essential to the formation of extracellular matrix, via direct interaction with its substrate procollagen. Thus, in this study we sought to determine if serum PCPE1 (sPCPE1), a regulator of collagen formation, can be used as a diagnostic marker of collagen metabolism/remodeling.

METHODS

We developed a method to track sPCPE1, and the findings were applied to evaluate the association of sPCPE1 glycopatterns with growth and presence of bone complication.

RESULTS

Isoelectric focusing revealed that sPCPE1 has a multi-band appearance and that sPCPE1 glycopatterns are due to an N-linked oligosaccharide decorated with sialic acid. Evaluation of PCPE1 glycopatterns in different groups of subjects revealed a significant difference among preterm babies, term babies, and adults. Furthermore, in adults with breast cancer, the glycopattern intensity correlated with the presence of bone metastasis.

CONCLUSIONS

The sPCPE1 glycopattern appears to be associated with the physiological and pathological states of bone. This study shows for the first time sPCPE1 glycopattern and suggest that changes in glycosylation of the protein may be in correlation with collagen metabolism. Studies are currently underway to determine its appearance in the serum of normal population on one hand and its appearance during growth and metabolic bone diseases on the other hand.

Advances in collagen cross-link analysis

The combined application of ion-trap mass spectrometry and peptide-specific antibodies for the isolation and structural analysis of collagen cross-linking domains is illustrated with examples of results from various types of collagen with the emphasis on bone and cartilage. We highlight the potential of such methods to advance knowledge on the importance of post-translational modifications (e.g., degrees of lysine hydroxylation and glycosylation) and preferred intermolecular binding partners for telopeptide and helical cross-linking domains in regulating cross-link type and placement.

Knochenstoffwechsel

In order to accommodate individual load, the skeletal system is in a continual state of change. Bone metabolism guarantees optimal bone structure. The osteoblasts are responsible for the synthesis and the osteoclasts for resorption of the bone. A finely adjusted interplay between molecular mechanisms leads, via cytokines, hormones and growth factors, to an homeostasis in bone metabolism. Disturbances of this process lead via increased bone resorption to osteoporosis, and via increased synthesis to osteopetrosis. This contribution describes the known molecular mechanisms in this remodelling process.