Urinary markers of type I collagen degradation in the dog

A Preliminary Study of the Effect of Hyperadrenocorticism on Calcium and Phosphate Concentrations, Parathyroid Hormone and Markers of Bone Turnover in Dogs

Reports on the effects of hyperadrenocorticism (HAC) on bone turnover in dogs are largely confined to radiographic studies. The aim of this study was to more accurately assess bone turnover in dogs with HAC by measuring circulating total and ionized calcium and phosphate concentrations, both intact and whole parathyroid hormone (PTH) concentrations and markers of both osteoblastic (osteocalcin) and osteoclastic [carboxyterminal cross-linked telopeptide of type 1 collagen (ICTP) and urine aminoterminal telopeptide of type 1 collagen (NTX) activity]. Dogs with HAC and a control group were prospectively enrolled for comparison. Results from 49 dogs with HAC were compared with 39 dogs from a hospital control population. Plasma intact and whole PTH concentrations were determined using a human immunoradiometric assay. Serum osteocalcin and NTX concentrations were measured using human enzyme linked immunosorbent assays. Serum ICTP concentration was measured using a human radioimmunoassay. Total calcium concentrations in dogs with HAC (2.67 ± 0.25 mmol/L) were not significantly different than in the control group (2.67 ± 0.14 mmol/L). By contrast, phosphate concentrations were significantly (P = 0.0143) higher in dogs with HAC (1.46 ± 0.30 mmol/L) compared to the control group (1.28 ± 0.33 mmol/L). The median intact PTH concentration in HAC dogs was 9.25 (range, 1.34–95.45) pmol/L, which was significantly (P < 0.0001) higher than in the control group [median, 3.88 (range, 2.01–10.31) pmol/L]. Whole PTH concentrations were also significantly (P < 0.0001) higher in the HAC group [median, 4.61 (range, 0.56–125.16) pmol/L] compared to the control group [median, 1.83 (range, 0.88–6.81) pmol/L]. Serum osteocalcin and urine NTX concentrations were not significantly different between the two groups of dogs. The median ICTP concentration in dogs with HAC was 2.98 (range, 1.15–6.62) ng/mL which was significantly (P < 0.0001) lower than in the control dogs [median, 7.30 (range, 3.68–21.25) ng/mL]. Both whole and intact PTH concentrations are increased in dogs with HAC compared to a hospital control population. This does not however appear to be associated with a decrease in bone formation (as assessed by osteocalcin) or an increase in bone resorption (as assessed by ICTP and urine NTX).

Bone biochemical markers for assessment of bone responses to differentiated phosphorus supply in growing-finishing pigs

Phosphorus (P) is essential for building and maintaining a healthy and strong skeleton. Moreover, dietary P supply may play a role for bone turnover, and the excretion of bone turnover metabolites may be useful as markers for sufficient dietary P supply. The objective was to study the long-term effects of low, medium, and high dietary P supply on bone metabolism in terms of serum concentration and urinary excretion of bone turnover components and metabolites in healthy growing-finishing pigs compared with bone mineral content (BMC) and bone mineral density (BMD) of humerus and femur. Pigs were fed diets containing low [LP; 4.1 g/kg dry matter (DM)], medium (MP; 6.2 g/kg DM), or high dietary P (HP; 8.9 g/kg DM) from 39.7 kg body weight (BW) until slaughter at 110 kg BW. Urine and blood were collected at 40, 70, and 110 kg BW while bones were collected at slaughter. Serum was analyzed for osteocalcin (OC), bone alkaline phosphatase (BAP), and C-terminal telopeptides of type I collagen (CTX-I), whereas urine was analyzed for pyridinoline (PYD), deoxypyridinoline (DPD), CTX-I, hydroxylysine (HYL), galactosyl-hydroxylysine (GAL-HYL), glycosyl-galactosyl-hydroxylysine (GLC-GAL-HYL), and hydroxyproline (HYP). Humerus and femur were analyzed for BMC and BMD. The LP diet caused reduced OC and increased BAP and CTX-I concentrations in serum. Furthermore, BAP was increased in response to the HP diet. Urine metabolites of bone resorption were all increased in pigs fed the LP diet, but only a few responses were obtained in response to the HP diet. Furthermore, age-related decreases were identified for BAP, HYL, GAL-HYL, and GLC-GAL-HYL. Bone mineral content and BMD were markedly lowered in pigs fed the LP diet but were not affected in pigs fed the HP diet. In conclusion, OC, BAP, and CTX-I in serum have proved useful for P adequacy in growing-finishing pigs. In addition, urine bone resorption metabolites have also proved useful for P adequacy and analysis of PYD, DPD, and CTX-I was considered to be the most relevant markers due to their specificity for bone and their negative correlation with BMD, BMC, ash, calcium (Ca), and P contents. Finally, DPD may be the preferred marker in long-term P feeding assessments.

Preliminary investigation of urine N-telopeptide concentration as a biomarker of bone resorption in dogs receiving glucocorticoids

OBJECTIVES

The influence of glucocorticoid therapy on bone resorption in dogs using a urine N-telopeptide assay was investigated.

MATERIALS AND METHODS

Thirty-one dogs receiving oral glucocorticoids and 31 age-matched healthy control dogs were enrolled. Urine N-telopeptide concentration was measured using a commercially available immunoassay and results were expressed as a ratio against urinary creatinine concentration. Dogs receiving glucocorticoids were divided into three subgroups based on daily glucocorticoid dose and three subgroups based on treatment duration. Urine N-telopeptide concentration was then compared between groups.

RESULTS

Urine N-telopeptide concentration was significantly higher in dogs receiving glucocorticoids compared to the control group.

CLINICAL SIGNIFICANCE

This preliminary study demonstrates significant increase in urine N-telopeptide concentration in dogs receiving glucocorticoid therapy compared to control dogs. Further studies are needed to assess whether this increase in urine N-telopeptide concentration correlates with decreases in bone mineral density as has been identified in humans.

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.

Osteoporotic risk and physeal closure in prepubertal ovariohysterectomized cats

We aimed to examine the early effects of prepubertal ovariohysterectomy (P-OHE) on bone loss and proximal physeal closure in cats. Fourteen kittens randomly underwent P-OHE or sham operations (S-OP) at three months (mo) of age and were allocated to group I and group II. Each mo between four and nine mo of age, dual-energy X-ray absorptiometry (DEXA) scans were performed to determine the total body bone mineral density (BMD) and bone mineral content (BMC). Proximal radial physeal closure and radial length were determined by radiography. Bone-specific alkaline phosphatase (BAP), carboxy-terminal collagen teleopeptide (CTX), 17-β estradiol, progesterone, calcium (Ca) and phosphorus (P) were measured in the serum samples. No significant differences were observed between the groups in terms of BMD, BMC, BAP, BAP/CTX, P, progesterone and body weight (BW) (between 4 and 9mo) and for Ca (between 5 and 9mo) and for CTX levels (between 4 and 8mo). The 17-β estradiol was significantly higher at 6, 8 and 9mo of age in the S-OP group due to puberty (P=0.02, P=0.03 and P=0.02 respectively). Although there was a significant difference (P=0.0002) between the P-OHE and S-OP groups in terms of the proximal radial physeal closure times (7.43±0.20mo and 6.14±0.14mo, respectively), no significant difference was observed for the mean radius length (10.59±0.10cm and 10.06±0.27cm, respectively) at the last evaluation time. In conclusion, prepubertal ovariohysterectomized cats do not have any osteoporotic risks until nine mo of age and exhibit a delayed physeal closure time without a change in radius length.

Influence of racing on the serum concentrations of acute-phase proteins and bone metabolism biomarkers in racing greyhounds

This study was designed to evaluate the influence of racing on the serum concentrations of the acute-phase proteins (APPs) C-reactive protein (CRP), haptoglobin (Hp) and serum amyloid A (SAA) in 32 endurance-racing greyhounds. The study also aimed to investigate the effect of a 7 km race on the bone biomarkers osteocalcin (OC), bone-specific alkaline phosphatase (b-ALP) and pyridinoline cross-links (PYD). Total white blood cell (WBC) count, and the serum concentrations of cortisol, tumour necrosis factor-α (TNF-α), vitamin D and testosterone were also determined. Blood samples were collected 24 h prior to (T0) and within 2 h of completion of the race (T1). Compared to baseline values, WBC count did not change significantly (P = 0.2300), serum cortisol, Hp and SAA increased, while TNF-α and CRP decreased (P <0.0001 for each). There were no significant differences between the pre- and post-race serum concentrations of OC and PYD (P = 0.9500 and P = 0.2600, respectively), but serum b-ALP increased significantly (P = 0.0004). Serum concentrations of vitamin D and testosterone increased after racing (P = 0.0100 and P <0.0001, respectively). In this study, a 7 km race stimulated an acute-phase response, demonstrated by significant increases in the serum concentrations Hp and SAA in racing greyhounds. Increased serum b-ALP post-race probably indicates a change in bone metabolism and deserves further study.

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.

Association between absolute tumor burden and serum bone-specific alkaline phosphatase in canine appendicular osteosarcoma

BACKGROUND

In dogs with appendicular osteosarcoma (OSA), increased pretreatment serum bone-specific alkaline phosphatase (BALP) activity is a negative prognostic factor, associated with shorter disease-free intervals and survival times, but a biologic basis for observed differential serum BALP activities in canine OSA patients remains incompletely defined.

OBJECTIVE

Serum BALP activity will correlate with absolute tumor burden in dogs with OSA.

ANIMALS

This study included 96 client-owned dogs with appendicular OSA.

METHODS

In canine OSA cell lines, the expression and membranous release of BALP was evaluated in vitro. The correlation between serum BALP activity and radiographic primary tumor size was evaluated in OSA-bearing dogs. In dogs developing visceral OSA metastases, serial changes in serum BALP activities were evaluated in relation to progression of macroscopic metastases, and visceral metastatic OSA cells were evaluated for BALP expression.

RESULTS

In vitro, BALP expression was not associated with either tumorigenic or metastatic phenotype, rather the quantity of membranous BALP released was proportional with cell density. In dogs devoid of macroscopic metastases, there was a positive correlation between serum BALP activity and absolute primary tumor size. In dogs with progressive OSA metastases, serum BALP activity increased and coincided with the development of macroscopic metastases. OSA cells derived from visceral metastatic lesions retained BALP expression.

CONCLUSIONS AND CLINICAL IMPORTANCE

Tumor burden is a determinant of serum BALP activity in dogs with appendicular OSA. The association between increased pretreatment BALP activity and negative clinical prognosis may simply be attributed to greater initial tumor burden, and consequently more advanced tumor stage.

Double-blind placebo-controlled trial of adjuvant pamidronate with palliative radiotherapy and intravenous doxorubicin for canine appendicular osteosarcoma bone pain

BACKGROUND

Canine osteosarcoma (OSA) causes focal malignant osteolysis leading to severe pain. Despite the documented efficacy of radiotherapy or IV aminobisphosphonates for managing cancer bone pain, their potential combined therapeutic value has not been reported in OSA-bearing dogs.

HYPOTHESIS

Pamidronate combined with standardized palliative therapy will improve pain control and bone biologic effects in OSA-bearing dogs.

ANIMALS

Fifty dogs with appendicular OSA treated with standardized palliative therapy and either pamidronate or sterile saline.

METHODS

Randomized, prospective, double-blinded, placebo-controlled study. Treatment responses for dogs receiving standardized palliative therapy with (n = 26) or without (n = 24) adjuvant pamidronate were serially evaluated for changes in subjective pain scores, urine N-telopeptide (NTx) excretion, primary tumor relative bone mineral density (rBMD), and computerized pressure platform gait analysis.

RESULTS

Median duration of subjective pain relief for dogs treated with adjuvant pamidronate or placebo was 76 and 75 days, respectively (P= .39). Forty percent (20/50; pamidronate [11/26] and placebo [9/24]) of dogs experienced durable analgesia, defined by pain alleviation > or =112 days. For patients achieving durable pain control, dogs treated with pamidronate achieved greater reductions in NTx excretion and larger increases in rBMD compared with placebo controls. Changes in peak vertical force assessed by computerized pressure platform gait analysis correlated with pain alleviation in OSA-bearing dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Combining pamidronate with standardized palliative therapy is safe, but does not clearly improve pain alleviation. However, in dogs achieving durable pain control, adjuvant pamidronate appears to decrease focal bone resorption in the local tumor microenvironment.

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.

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.

The efficacy of the bone markers osteocalcin and the carboxyterminal cross-linked telopeptide of type-I collagen in evaluating osteogenesis in a canine crural lengthening model

The aim of the present study was to determine the efficacy of the bone markers osteocalcin (OC) and carboxyterminal cross-linked telopeptide of type-I collagen (ICTP) in evaluating new bone formation in the dog, using commercially available immunoassay kits. Dogs were randomly divided into three groups and a circular external skeletal fixation system (CESF) was mounted on the tibia. In the first group a distraction osteogenesis procedure of the crus was performed. The second group received an osteotomy without crural lengthening, whereas the third group served as a sham-operated control. Bone formation was assessed using densitometric image analysis of crural radiographs. Despite significant differences in the amount of newly formed bone, this finding was not reflected in the plasma levels of OC and ICTP. In conclusion, OC and ICTP were not efficacious as markers of bone formation and resorption during osteogenesis in this canine model.

A comparison of methods for measuring serum and urinary markers of bone metabolism in cats

Biochemical markers of bone cell activity have recently been shown to be useful for monitoring skeletal health in domestic animals, including dogs and horses. The aim of this study was to evaluate a number of biochemical assays, originally developed for use in humans, for their ability to measure indicators of bone cell activity in serum and urine of normal cats over a range of ages. Bone alkaline phosphatase (BAP), a marker of bone formation, was measured in serum using wheatgerm lectin precipitation (WGL) and by ELISA. The curve derived from serial dilution of feline serum was parallel with the ELISA standard curve, indicating species cross-reactivity, and there was a significant relationship between assays (rs = 0.97, P < 0.001). Deoxypyridinoline (DPD), a marker of bone resorption, was measured in its total form in urine by HPLC and ELISA, and in its free form in serum and urine by ELISA. The dilution curve for free DPD in urine showed parallelism with the assay standard curve; however, the curves for total DPD in urine and serum did not. A significant relationship was established between total urinary DPD (HPLC) with total serum DPD (rs = 0.69, P < 0.001), and with free urinary DPD (rs = 0.95, P < 0.001) concentrations. Carboxy-terminal telopeptide of type I collagen (CTX) concentration, another marker of bone resorption, was measured in serum and urine by ELISA, and there was a significant relationship between assays (rs = 0.82, P < 0.001). CTX could not be measured reliably using an auto-analysis method. A significant relationship was established between total urinary DPD (HPLC) with serum CTX (rs = 0.59, P < 0.05), and urinary CTX (rs = 0.65, P < 0.001) concentrations. BAP (ELISA and WGL), total urinary DPD (HPLC), urinary CTX (ELISA), and serum CTX (ELISA) concentrations were significantly inversely correlated with age (rs = -0.66, -0.88, -0.61, -0.70, and -0.51, P < 0.05 respectively). Cats under two years of age had significantly higher BAP, total urinary DPD (HPLC), and urinary CTX concentrations compared to older cats. In conclusion, this study has shown that a number of commercially available assays provide reliable methods for non-invasively monitoring bone cell activity in cats and has shown that bone turnover decreases within the first two years of life, until complete skeletal maturity is attained. Future studies can now be directed at evaluating the potential clinical application of these methods.

Markers of bone metabolism in dog breeds of different size

Serum and urinary markers of bone turnover may be of value in animals as noninvasive tools for determining the response of the skeleton to disease and injury. Although normal values for bone markers have been reported for the Beagle, concerns remain that breed to breed differences will complicate the interpretation of bone marker data in dogs. To explore this, we examined serum bone markers in two breeds of vastly different size, Pomeranians and Irish Wolfhounds. Our hypothesis was that serum concentrations of bone markers are similar in toy and giant dog breeds and fall within the same range as those reported for Beagles. Bone alkaline phosphatase (BALP) and carboxy-terminal telopeptide of type I collagen (ICTP), respectively markers of bone formation and bone resorption, were measured in age matched Pomeranians (n=14) and Irish Wolfhounds (n=14). No statistically significant differences between the mean BALP and mean ICTP serum concentrations from Pomeranians and Irish Wolfhounds were found. All BALP and ICTP concentrations were within the reference range reported for Beagles. The results of this study suggest that serum BALP and ICTP concentrations in giant and toy breeds are the same as in Beagles and that these assays may be used for dogs of all sizes.

Biochemical markers of bone metabolism in animals: uses and limitations

Routine assessment of the skeleton's response to disease and injury traditionally has consisted of plain-film radiography supplemented with advanced imaging techniques, such as computed tomography, magnetic resonance imaging, nuclear scintigraphy, and bone densitometry. Although these techniques provide increased sensitivity as compared with radiography, they still are limited by the fact that they can only document the net results of past skeletal activity. In contrast, serum and urinary biomarkers of bone formation and resorption provide near real-time information about bone cell activity. In this review, I describe the scientific rationale behind the use of these markers in humans and detail the efforts that have been made to adapt this technology to veterinary medicine and animal research. Commercial assay kits that are applicable to different animal species are described, and the potential limitations of the technology are discussed. The goal of this review is to provide clinical pathologists and researchers with the information needed to decide whether the use of bone markers is likely to be helpful and to select the most appropriate marker (or panel of markers) to answer a particular question.