Plasma osteoprotegerin levels are associated with the presence and burden of cerebral small vessel disease in patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: Osteoprotegerin (OPG) is a component of the tumor necrosis factor receptor superfamily. Several studies have shown a relationship between OPG and cardiovascular diseases. We hypothesized that there is a relationship between plasma OPG levels and cerebral small vessel disease (SVD). METHODS: Patients diagnosed with their first cerebral ischemic infarction between April 2014 and March 2017 were enrolled. All the enrolled patients were evaluated through the hospital stroke protocol, including routine blood tests, brain imaging, and measuring the plasma OPG levels. The presence and burden of cerebral SVD [cerebral microbleeds (CMBs), asymptomatic lacunar infarction (ALI), high-grade perivascular space (HPVS), high-grade white matter hyperintensity (HWMH)], and total SVD score were assessed through brain magnetic resonance imaging. RESULTS: Of the 270 patients included in our study, 158 (58.5%) were men. The mean age of the patients was 63.8 ± 11.6 years. In multivariable analysis, plasma OPG levels were positively associated with the presence and burden of each cerebral SVD. The odds ratios (OR) of CMBs, ALI, HPVS, and HWMH for the association of OPG per standard deviation (SD) increase were 1.58 [95% confidence interval (CI), 1.09-2.27], 1.40 (95% CI, 1.04-1.88), 1.88 (95% CI, 1.27-2.78), and 1.47 (95% CI, 1.04-2.08), respectively. Plasma OPG levels were positively correlated with total SVD score (beta = 0.211, standard error = 0.061, p-value = 0.009, R2 = 0.275). CONCLUSIONS: Plasma OPG levels correlate with the presence and burden of cerebral SVD in patients with acute ischemic stroke.

Assessment of Serum sRANKL, sRANKL/OPG Ratio, and Other Bone Turnover Markers with the Estimated 10-Year Risk of Major and Hip Osteoporotic Fractures in Rheumatoid Arthritis: A Cross-Sectional Study.

BACKGROUND: Fracture risk assessment tool (FRAX) index was developed for estimating of the 10-year risk of major or hip osteoporotic fracture. To date, there is insufficient information regarding the correlation between FRAX and serum bone turnover markers (BTMs), such as soluble ligand of receptor activator of nuclear factor-κB (sRANKL), osteoprotegerin (OPG), and other molecules related with secondary osteoporosis in rheumatoid arthritis (RA). Therefore, this study is aimed at assessing the correlation between the FRAX and serum levels of sRANKL, OPG, sRANKL/OPG ratio, Dickkopf-1 (DKK-1), and sclerostin (SOST) in RA. METHODS: Cross-sectional study included 156 postmenopausal women with RA. Bone mineral density (BMD) was measured at lumbar spine (L1-L4) and total hip using dual-energy X-ray absorptiometry (DXA). RA patients were divided into (A) RA + osteoporosis and (B) RA without osteoporosis. FRAX scores were calculated including the total hip BMD. Serum sRANKL, OPG, DKK-1, and SOST levels were measured by ELISA. Pearson tests were used for assessing the correlation between serum levels of these molecules and FRAX scores in RA. RESULTS: The RA + osteoporosis group had elevated sRANKL levels (p = 0.005), higher sRANKL/OPG ratio (p = 0.017), decreased DKK-1 (p = 0.028), and lower SOST levels (p < 0.001). Low total hip BMD correlated with high sRANKL (p = 0.001) and sRANKL/OPG ratio (p = 0.005). Total hip and lumbar spine BMD correlated with DKK-1 (p = 0.009 and p = 0.05, respectively) and SOST levels (p < 0.001 and p < 0.001, respectively). Higher sRANKL levels and sRANKL/OPG ratio correlated with estimated 10-year risk of a major osteoporotic fractures (p = 0.003 and p = 0.003, respectively) and hip fracture (p = 0.002 and p = 0.006, respectively). High serum SOST levels were associated with a low estimated 10-year risk of a major osteoporotic fracture (p = 0.003) and hip fracture (p = 0.009). CONCLUSION: High sRANKL levels and sRANKL/OPG ratio can be useful to detect a subgroup of RA patients who has an increased 10-year risk of major and hip osteoporotic fractures.

Comprehensive assessment of tissue and serum parameters of bone metabolism in a series of orthopaedic patients.

Bone diseases represent an increasing health burden worldwide, and basic research remains necessary to better understand the complexity of these pathologies and to improve and expand existing prevention and treatment approaches. In the present study, 216 bone samples from the caput femoris and collum femoris of 108 patients with degenerative or dysplastic coxarthrosis, hip fracture, or osteonecrosis were evaluated for the proportion of trabecular bone (TB) and expression of parathyroid hormone (PTH) type 1 receptor (PTH1R), osteoprotegerin (OPG), and receptor activator of nuclear factor kappa-B ligand (RANKL). Serum levels of PTH, OPG, soluble RANKL (sRANKL), alkaline phosphatase (AP), osteocalcin, total procollagen type-1 intact N-terminal propeptide (TP1NP), tartrate-resistant acid phosphatase type 5b (TRAP5b), sclerostin, and C-telopeptide of type-1 collagen (ICTP) were also determined. Age was positively correlated with serum levels of PTH, OPG, and sclerostin but negatively associated with TB and sRANKL. Women exhibited less TB, lower sclerostin and ICTP, and higher TRAP5b. Impaired kidney function was associated with shorter bone decalcification time, less TB, lower sRANKL, and higher serum PTH, OPG, and sclerostin. Furthermore, correlations were observed between bone PTH1R and OPG expression and between serum PTH, OPG, and AP. There were also positive correlations between serum OPG and TP1NP; serum OPG and sclerostin; serum AP, osteocalcin, and TRAP5b; and serum sclerostin and ICTP. Serum OPG was negatively associated with sRANKL. In summary, clear relationships between specific bone metabolism markers were observed, and distinct influences of age, sex, and kidney function, thus underscoring their suitability as diagnostic or prognostic markers.

Inflammation-Related Patterns in the Clinical Staging and Severity Assessment of Chronic Kidney Disease.

Chronic kidney disease (CKD) is an irreversible loss of kidney function, and it represents a major global public health burden due to both its prevalence and its continuously increasing incidence. Mineral bone disorders (MBDs) constitute a hallmark of CKD, and alongside cardiovascular complications, they underlie a poor prognosis for these patients. Thus, our study focused on novel CKD biomarker patterns and their impact on the clinical staging of the disease. As a first testing approach, the relative expression levels of 105 proteins were assessed by the Proteome Profiler Cytokine Array Kit for pooled CKD stage 2-4 serum samples to establish an overall view regarding the proteins involved in CKD pathogenesis. Among the molecules that displayed significant dysregulation in the CKD stages, we further explored the involvement of Dickkopf-related protein 1 (Dkk-1), a recognised inhibitor of the Wnt signalling pathway, and its crosstalk with 1,25OH2D3 (calcitriol) as new players in renal bone and vascular disease. The serum levels of these two molecules were quantified by an ELISA (76 samples), and the results reveal decreasing circulating levels of Dkk-1 and calcitriol in advanced CKD stages, with their circulating expression showing a downward trend as the CKD develops. In the next step, we analysed the inflammation and MBD biomarkers' expression in CKD (by xMAP array). Our results show that the molecules involved in orchestrating the inflammatory response, interleukin-6 (IL-6) and tumour necrosis factor alpha (TNFα), as well as the mineral biomarkers osteoprotegerin (OPG), osteocalcin (OC), osteopontin (OPN), and fibroblast growth factor 23 (FGF-23), correlate with Dkk-1 and calcitriol, raising the possibility of them being potential useful CKD biomarkers. These results reveal the impact of different biomarker patterns in CKD staging and severity, thus opening up novel approaches to be explored in CKD clinical management.

Assessment of the Levels of Level of Biomarkers of Bone Matrix Glycoproteins and Inflammatory Cytokines from Saudi Parkinson Patients.

Background. Parkinson's disease (PD) is the second most commonly neurodegenerative disease after Alzheimer's disease which occurs to nearly 1% of the population > 50 years old. Inflammatory and bone biomarkers have both become valuable tools for PD diagnosis and prognosis. However, no studies have examined these markers in Saudi patients diagnosed with PD. Objectives. To assess the biomarkers and proinflammatory cytokines from blood with PD in serum. Methods. In our study, we included 26 patients with PD and 24 controls. Blood samples were withdrawn from subjects with PD and their matched controls. Biomarkers multiplex assay from Milliplex was used to assess the levels of IL-1B, IL-6, TNF-α, osteoprotegerin (OPG), osteopontin (OPN), and PTH (parathyroid hormone). Data was analyzed using the Statistical Package, GraphPad Prism. Results. We found that IL-1ß cytokine is significantly higher in patients with PD (p value = 0.0014). However, there are no statistically significant variances found among the two studied groups with regard to the IL-6 and TNF-α cytokines levels. We also found that levels of PTH are decreased in the PD subjects than the age-matched controls (p value= 0.003). Also, the bone matrix glycoproteins, including osteoprotegerin (OPG) and osteopontin (OPN), are significantly upregulated (p value= 0.04 for OPG and p value= 0.003 for OPN), as compared to the controls. Conclusions. Our findings are reliable with the possibility that inflammatory and bone markers can be used as biomarkers in PD prognosis. However, to clarify the natural role and consequence of these markers in PD pathology, further larger cohort studies are needed.

Osteoprotegerin Assessment Improves Prediction of Mortality in Stroke Patients.

BACKGROUND: Elevated circulating osteoprotegerin (OPG) level is associated with an increased risk of hospitalization for ischemic stroke and coronary artery disease. The aim of the present study was to analyze whether OPG assessment may improve the prediction of mortality in patients with stroke. PATIENTS AND METHODS: Serum OPG, fetuin A, 25-OH-D3, intact parathyroid hormone levels were assessed in serum samples which were left over after routine tests in a hospital laboratory. This assessment was conducted in 240 consecutive patients with acute ischemic stroke, admitted within 24hours after the onset of symptoms to the Stroke Unit. Mortality data were obtained from the local registry office. RESULTS: The mean OPG serum level was 14.6 ± 6.0pmol/L (range: 3.7-43.4). There were no significant differences in the OPG values between men and women (13.9 ± 5.0 versus 15.1 ± 6.7 pmol/L; P = .12). Therefore, tertiles were calculated for the whole group. During the follow-up, 85 (35.4%) patients died and 92 (38.3%) died or had recurrent stroke. OPG level appeared a significant predictors of death and composite end-point (death/recurrent stroke), in addition to the well-established once (age, atrial fibrillation, diabetes RANKIN at admission and discharge, severity of stroke). In multivariable stepwise backward analyses, the OPG level persisted as a significant and independent predictor of death (hazard ratio [HR] = 1.084 (95% confidence intervals: 1.036-1.134)] and composite and point (HR = 1.082 [1.037-1.129]). CONCLUSIONS: OPG level may be considered as a predictor of mortality in stroke patients.

[Methods of efficacy assessment of the knee joint radiosynoviorthesis- personal experience].

OBJECTIVE: Introduction: Radiosynoviorthesis (RS) is local method of treatment of remittent joint effusions among patients who obtained general improvement after disease modifying anti-rheumatic drugs therapy but one or a few joints stay resistant to this treatment and intraarticular corticosteroids injections. The aim: The attempt to identification methods of efficacy assessment of the 90yttrium knee joint RS. PATIENTS AND METHODS: Material and methods: The study group consisted of 43 patients with rheumatoid arthritis (RA) and 19 patients with inflammatory spondyloarthropaties (SPA) where 8 patients were treated for ankylosing spondylitis (AS), 4 for psoriatic arthritis (PsA) and 7 due to undifferentiated inflammatory spondyloarthropaties (USPA). The efficacy of RS was measured subjectively by the patient, physically by the physician and with the help of chosen scores (DAS28), questionnaires (HAQ), laboratory parameters [ESR, level of CRP, osteoprotegerin (OPG), serum amyloid A (SAA), hialuronic acid (HA)] and three-phase bone scintigraphy of affected knee joints. RESULTS: Results: In RA patients very good results - no knee effusion were obtained in 25 (58,1%) joints, good results - minimal effusion in 10 (23,3%) knees and lack of improvement in 8 (18,6%) patients. Cumulatively very good and good results were obtained in 35 (81,4%) treated knee joints. In SPA patients very good results were noted in 12 (63,2%), good in 5 (26,3%), lack of improvement in 2 (10,5%) patients. Cumulatively very good and good results were obtained in 17 (89,5%) treated knee joints. We observed favorable profile changes of chosen scores (DAS28), questionnaires (HAQ), laboratory parameters (ESR, CRP, OPG, SAA, HA) and results of three-phase bone scintigraphy of knee joints. CONCLUSION: Conclusions: 90Yttrium RS is effective treatment of recurrent knee joints effusion in patients with RA i SPA. RS despite being local treatment decreases unspecific inflammatory process and systemic disease activity among patients with RA i SPA. The anatomic period of affected knee joints has negative correlation with treatment efficacy. 90Yttrium RS is safe procedure, favourable profile changes of cartilage and bone turn-over markers after therapy indicates protective influence of RS on these structures. The treatment response based on physical examination, subjective patient's evaluation, acute phase laboratory parameter levels and appropriate scores, questionnaires and imaging exams is fast and long-lasting.

Cardiovascular risk assessment in osteoporotic patients using osteoprotegerin as a reliable predictive biochemical marker.

Osteoprotegerin (OPG), a member of the tumour necrosis factor receptor (TNFR) superfamily of proteins known to be involved in a large number of biological systems, plays a pivotal role in bone remodelling. In addition to the roles of OPG in bone metabolism, it has been reported to be associated with a high cardiovascular risk in patients with metabolic syndrome. In most cases, the exact functions of OPG remain to be established; however, the widespread expression of OPG suggests that this molecule may have multiple biological activities, mainly in the cardiometabolic environment. The aim of this study was to evaluate the value of OPG as a predictive marker for cardiovascular and metabolic risk in osteoporotic patients. The study group comprised patients with osteoporosis, in order to evaluate the association between OPG serum levels and cardiovascular pathology. Our results revealed significant correlations between classical biochemical bone and metabolic parameters, such as osteocalcin and parathyroid hormone with lipid and glucose biomarkers, sustaining the crosstalk between calcium and bone parameters and cardiovascular risk. The OPG serum level proved to have a significant and independent predictive value for metabolic syndrome (MetS) as a cardiovascular risk standard in osteoporotic patients. The OPG serum levels were increased in patients with MetS as a protective response against the atherosclerotic lesions. The serum levels of 25­hydroxy vitamin D had significant and independent predictive value for cardiovascular and metabolic risk in our subjects, sustaining the active role of vitamin D beyond the area of bone metabolism.

Assessment of OPG, RANKL, bone turnover markers serum levels and BMD after treatment with strontium ranelate and ibandronate in patients with postmenopausal osteoporosis.

INTRODUCTION: The aim of this study was to evaluate quantitative changes in OPG and RANKL proteins after treatment with strontium ranelate (SR) and ibandronate in patients with postmenopausal osteoporosis. MATERIAL AND METHODS: A total of 89 women with postmenopausal osteoporosis (PO), aged 51-85 years, patients of the Outpatient Clinic of Osteoporosis of the Military Teaching Hospital in Lodz, were enrolled in the study. The patients were randomly assigned to different therapies: ibandronate and (SR). Patients of the control group received only calcium and vitamin D3 supplements. The patients' visits were repeated after three and six months. Measurements of beta-CTX (C-terminal Telopeptide of type 1 collagen), osteocalcin, RANKL, osteoprotegerin (OPG), alkaline phosphatase concentrations in serum, as well as of total 24-hour calcium and phosphate levels in serum and urine, were carried out in material collected at baseline and after three and six months of therapy. Left hip and lumbar spine densitometry was done twice (at baseline visit and after six months). RESULTS: In all three groups there were no significant differences noted in the concentrations of OPG and RANKL serum protein levels during the study period. Both negative and positive correlations or tendencies of correlations were found between OPG serum concentrations and BMD changes in the SR group. CONCLUSIONS: Both ibandronate and SR do not seem to cause any significant changes in OPG and RANKL protein serum levels during the first six months of treatment. OPG may play a role in osteoclast activity suppression in the course of treatment with ibandronate in patients with PO. OPG may play an important role in the mechanism of SR therapy and may be viewed as a potentially valuable parameter for monitoring and predicting the course of treatment with SR in PO.

The Assessment of Selected Bone and Cartilage Biomarkers in Psoriatic Patients from Poland.

BACKGROUND: Psoriasis is an inflammatory disease in which joints involvement may be insidious and difficult to detect. Bone and cartilage biomarkers may be helpful in screening patients with psoriasis for psoriatic arthritis (PsA). OBJECTIVES: To assess bone and cartilage serum biomarkers in psoriasis. Methods. The study was conducted in 2014 and included 61 psoriatic patients and 30 healthy individuals. In both groups, the serum concentrations of soluble receptor activator of nuclear factor-κB ligand (sRANKL), cartilage oligomeric matrix protein (COMP), osteoprotegerin (OPG), and interleukin-20 (IL-20) were examined. Severity of skin lesions was assessed by Psoriasis Area and Severity Index (PASI), body surface area (BSA), and Physician Global Assessment (PGA) scores. RESULTS: The duration of psoriasis was from 1 year to 45 years. 22 patients suffered from concomitant PsA. The mean value of PASI was 23.1 ± 12.0 and BSA was 27.6 ± 20.6%. COMP, OPG, and IL-20 concentrations in psoriatic patients were significantly higher than in the control group. OPG/sRANKL ratio was significantly lower in PsA patients than in psoriatic patients without arthritis. CONCLUSIONS: Results of the conducted study suggest that COMP, OPG, IL-20, and OPG/sRANKL ratio may appear useful biomarkers of bone and cartilage involvement in psoriasis.

Assessment of bone turnover markers and bone mineral density in normal short boys.

AIM: To investigate whether there is a change in bone turnover-related biochemical markers and bone mineral density of children with constitutional delay of growth and puberty (CDGP) in the prepubertal period. METHODS: We measured serum calcium, phosphorus, alkaline phosphatase, parathormone, 25-OH vitamin D, osteocalcin, osteoprotogerin and urinary deoxypyridinoline levels (D-pyd), and bone mineral density (BMD) in 31 prepubertal boys with CDGP. These children were compared with 22 prepubertal boys with familial short stature (FSS) and 27 normal prepubertal boys. RESULTS: Urinary D-pyd was significantly high in CDGP group as compared to control group (p=0.010). Volumetric BMD did not significantly differ between CDGP, FSS, and control groups (p=0.450). Volumetric BMD and urinary D-pyd levels of FSS and control groups were similar. Mean or median levels of calcium, phosphorus, alkaline phosphatase, parathormone, and osteoprotegerin did not significantly differ between CDGP, FSS, and control groups. CONCLUSIONS: Our data suggest that prepubertal boys with CDPG have normal bone turnover. However, their significantly higher urinary D-pyd levels relative to those of FSS and control groups might be an indicator of later development of osteoporosis. Therefore, long-term follow-up studies monitoring bone mineral status of prepubertal boys with CDPG from prepuberty to adulthood are needed to better understand bone metabolism of these patients.

Assessment of the Effect of Methotrexate Therapy on Bone Metabolism in Patients with Rheumatoid Arthritis.

Proinflammatory cytokines and growth factors, which regulate mutual interactions between immune system cells and bone tissue cells, play a major role in the formation of bone changes in rheumatoid arthritis (RA). The aim of the work was to assess serum concentration of osteoprotegerin (OPG), RANKL, Dkk-1 and sclerostin in RA patients compared to a control group and to analyze changes of these concentrations during methotrexate (MTX) therapy. Patients enrolled in the study were 30 women of Caucasian origin aged 30-74 years with RA. Patients with active form of the disease were administered recommended doses of MTX for at least 6 months. The study group was divided into subgroup I-patients with improvement; and subgroup II-patients with no improvement. The control group consisted of 12 healthy women in the age of 41-73. Before MTX therapy, RA patients had higher levels of RANKL (644.97 ± 477.13 vs. 255.19 ± 130.26 pmol/l), lower values of OPG/RANKL (0.01 ± 0.0101 vs. 0.02 ± 0.0078) and higher levels of Dkk-1 protein (1821.32 ± 1060.28 vs. 548.52 ± 36.35 pg/ml) compared to the control group. In the analyzed group of patients (all patients receiving MTX regardless of responder non responder status) after 6 months of therapy, a statistically significant increase in the ratio of OPG/RANKL was found (0.0118 ± 0.0102 vs. 0.0141 ± 0.0118; p = 0.02). The index value of OPG/RANKL differed significantly depending on the resultant effect of treatment (0.01702 ± 0.01274 in the subgroup of improvement vs. 0.00675 ± 0.00289 in the subgroup without improvement). The difference in the mean concentrations of Dkk-1 before and after treatment with MTX between subgroups I and II was statistically significant (p = 0.002). In subgroup I, mean concentration of Dkk-1 decreased after 6 months of treatment with MTX (2054.72 ± 1004.74 vs. 1831.70 ± 851.70 pg/ml); while in subgroup II, the mean concentration of Dkk-1 increased (1214.48 ± 738.32 vs. 2275.01 ± 1385.23 pg/ml). There were no statistically significant changes in the mean concentrations of sclerostin before and after treatment with MTX (in whole group treatment with MTX, in subgroup I, and in subgroup II). The results confirm the presence of disorders of bone metabolism in patients with RA. Treatment with MTX affects the value of the ratio of OPG/RANKL and concentration of Dkk-1.

[Assessment of osteopontin and osteoprotegerin levels in abdominal aortic aneurysm patients]. / Ocena stezenia osteopontyny i osteoprotegryny u chorych z tetniakiem aorty brzusznej.

Abdominal Aortic Aneurysm (AAA) is multifactorial disease with unknown ethiology. Among the theories on the pathogenesis of AAA are some ge. netic factors, infections, disorders in connective tissue (collagenosis), arteriosclerosis, inflammation, incorrect immune response (autoimmunity). It was discovered that crucial for AAA development is intense inflammatory reaction combined with high proteolytic activity. Recent evidence confirmed the association between osteopontin (OPN) and osteoprotegerin (OPG) levels and cardiovascular diseases and arterio. sclerosis. The aim of this work was assessment of plasma levels of OPN and OPG in the group of the patients with AAA and correlation of results with clinical parameters, "classical" risk factors for development of AAA, arteriosclerosis and morbidity. The reference group consist of the patients with Leriche Syndrome (LS). The OPG level was assessed in plasma and OPN levels were assessed in plasma and urine. Plasma OPG levels were higher in AAA group than in LS group (difference not statistically significant, p = 0.0549). It was statistically significant positive correlation between plasma OPN levels and CRP levels in the groups of AAA and LS patients. It was not any association between plasma OPG and OPN levels and abdominal aortic diameter. Plasma OPG levels correlated positively with the existence of coronary artery disease in AAA patients. Insignificant, but higher levels of this protein were found also in a group of AAA patient with myocardial infarction. In LS group we found statistically significant positive association between plasma OPG levels and patient with stroke. However, in AAA patients with incidence of stroke, we found higher plasma levels of OPN. Interestingly, there was not any association between OPN levels in the urine and clinical parameters, risk factors and morbidity, including kidney diseases. inflammatory role of OPN and depicts better reflection of inflammatory reaction of OPN than OPG in both group of patients. Plasma OPG levels in AAA patients are more associated with coronary artery disease than with peripheral artery disease, what is characteristic for LS patients. Lack of association of urine OPN levels with above mentioned parameters suggest minor importance of this urine protein in clinical condition evaluation of patients with AAA and advanced arteriosclerosis.

Assessment of the relationship between melatonin, hormones of the pituitary-ovarian, -thyroid and -adrenocortical axes, and osteoprotegerin and its ligand sRANKL in girls with anorexia nervosa.

BACKGROUND: It has been suggested that disturbances in melatonin (MEL) secretion might play a role in osteoporosis development in females with anorexia nervosa (AN). It might be hypothesized that changes in the levels of hormones of the pituitary-ovarian, -thyroid and -adrenocortical axes might mediate the potential relationship between MEL and bone tissue. AIM: We investigated whether a relationship existed between MEL and LH, FSH-E2, TSH-FT3, FT4 and ACTH-cortisol axes in girls with AN. We also aimed to establish whether such a relationship might adversely affect the balance of the OPG/sRANKL system. MATERIAL/METHODS: Eighty-six girls with AN and 21 healthy subjects aged 12.6 to 18.2 years participated in the study. The serum levels of hormones as well as OPG and sRANKL were determined by radioimmunoassay (RIA), immunoradiometric assay (IRMA) or enzyme-linked immunosorbent assay (ELISA) methods. DISCUSSION: Our study participants with AN showed a significant reduction in body mass and body mass index (BMI), a decrease in LH, E2 and FT3 concentrations, increased MEL concentration at 02.00 hours and increased amplitude between its nocturnal and morning levels (Δ MEL2.00/9.00) as well as an increase in cortisol concentration. These changes were associated with a significant increase of OPG and sRANKL levels and a decrease in the OPG/sRANKL ratio. BMI values correlated positively with LH, FSH, E2, FT3 and the OPG/sRANKL ratio while the correlation between BMI and cortisol was negative. Δ MEL2.00/9.00 correlated positively with cortisol and negatively with LH, FSH, E2, FT3 concentrations and the OPG/sRANKL ratio. A positive correlation was observed between LH, E2 and the OPG/sRANKL ratio as well as between cortisol and sRANKL while the correlation between LH and OPG as well as between cortisol and the OPG/sRANKL ratio was negative. E2 and LH were shown to be significant and independent predictors of Δ MEL2.00/9.00. LH turned out to be a significant and independent predictor of OPG, cortisol and FT3 were significant and independent predictors of sRANKL, while LH, E2, Δ MEL2.00/9.00 and FT3 were significant predictors of the OPG/sRANKL ratio. CONCLUSIONS: Alterations in OPG and sRANKL levels observed in girls with AN are associated with changes in nocturnal MEL secretion, the circadian rhythm of MEL, and LH, E2, FT3 and cortisol levels. Dysregulation of the relationships between MEL and LH, E2, FT3 and cortisol found in girls with AN might affect the balance of the OPG/sRANKL system. Low values of the OPG/sRANKL ratio associated with high OPG and sRANKL levels suggest some defect in the mechanism compensating for bone remodeling disturbances.

Assessment of OPG/RANK/RANKL gene expression levels in peripheral blood mononuclear cells (PBMC) after treatment with strontium ranelate and ibandronate in patients with postmenopausal osteoporosis.

CONTEXT: Recent research results have confirmed the high significance of the OPG/RANK/RANKL system in the development of bone diseases. AIM: The aim of the reported study was to assess gene expression levels of the OPG/RANK/RANKL system in peripheral blood mononuclear cells (PBMCs) after strontium ranelate (SR) and ibandronate administered to patients with postmenopausal osteoporosis. PATIENTS AND METHODS: A total of 89 postmenopausal women, aged 51 to 85 years, patients of the Outpatient Clinic of Osteoporosis of the Military Teaching Hospital in Lodz, were enrolled into the study. The patients were randomly assigned to different medical therapies: ibandronate and SR. Patients of the control group received only calcium and vitamin D3 supplements. Patient visits were repeated after 3 and 6 months. Measurements of serum alkaline phosphatase concentrations and of RNA expression in PBMCs as well as of total serum calcium and phosphate levels and of their 24-hour urine excretion rates were carried out in material, collected at baseline and after 3 and 6 months of the therapy. Densitometry of the left hip and of the lumbar spine was done at the baseline visit and after 6 months. RESULTS: The differences in gene expressions of RANKL and RANK were not significant during the study period and did not differ between the groups in a statistically significant manner. No OPG gene expression was observed in PBMCs of patients in any of the studied groups and at any time point. The tendency of correlation (P = .07) was observed between decreasing RANK gene expression and increasing bone mineral density in the patients treated with SR. CONCLUSIONS: Both ibandronate and SR do not seem to cause any significant changes in gene expression levels of OPG/RANK/RANKL in PBMCs during the first 6 months of treatment.

Assessment and clinical implications of RANK/RANKL/OPG pathway as markers of bone tumor progression in patients with NET harboring bone metastases.

INTRODUCTION: The impact on the survival of bone metastases (BM) in patients with neuroendocrine tumor (NET) is a matter of debate. BM have a key role in causing symptoms and in decreasing patients' quality of life. Although the mechanisms of the development of BM are not completely clear, it is now well understood that the Receptor Activator of Nuclear factor Kappa-B-/Ligand (RANK/RANKL)/osteoprotegerin (OPG) pathway plays a relevant role. AIM: To characterize the RANK/RANKL/OPG pathway in patients affected with NET. PATIENTS AND METHODS: Two cohorts of 15 patients each were enrolled in the study; one cohort was affected with NET without BM and the second cohort was affected with NET with BM. The serum RANK/RANKL/OPG pathway was assessed in both the groups. RESULTS: Serum OPG levels and RANKL/OPG ratio were lower and higher, respectively, in NET patients harboring BM than in those without BM. During the ROC analysis, a cut-off value of 1071 pg/ml for OPG and 0.62 for RANKL/OPG ratio were able to significantly distinguish between the two groups. CONCLUSIONS: This study indicates that RANK/RANKL/OPG pathway is imbalanced in patients with NET harboring BM. Specific alterations of this pathway could predict an early development of BM.

Changes in serum levels of TNF-alpha, IL-6, OPG, RANKL and their correlation with radiographic and clinical assessment in fragility fractures and high energy fractures.

Stages of bone turnover during fracture repair can be assessed employing serum markers of osteoblastic and osteoclastic activity, inflammatory cytokines, clinical evaluation and imaging instruments. Our study compare the fracture healing process in fragility fractures and high energy fractures by evaluating serum changes of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), osteoprotegerin (OPG) and receptor activator of the nuclear factor-kB ligand (RANKL) in combination with radiographic (Radiographic Union Scale for Tibial fractures, RUST) and clinical (Lower extremity measure, LEM) assessments. We enrolled 56 patients divided into four corresponding groups: group A with high energy trauma fracture (tibial/femoral shaft); group B with low energy trauma fracture (femoral fractures); healthy (control A) and osteoporotic subjects (control B). Blood samples were collected before surgery (T0) and after 10 weeks (T10). Serum concentrations of IL-6, TNF-alpha, RANKL and OPG were quantified using commercial enzyme-linked immunosorbent assay (ELISA) kits. Our results show that RANKL values are significantly higher at T10 than at T0 in low energy trauma fractures (group B). OPG is significantly lower in each control group than that of the respective fractured group and its concentration at T0 and at T10 is significantly lower in high than in low energy fractures. RANKL/OPG ratio is significantly higher in both controls than in fractured groups, and significantly increases after 10 weeks. IL-6 and TNF-alpha concentrations significantly decrease during fracture healing and are higher in high (group A) than in low energy fractures (group B). Significant differences were also found in both RUST score and LEM between groups A and B. Changes in TNF-alpha and IL-6 levels correlate with RUST and LEM in fragility and high energy fractures, while RANKL/OPG ratio is associated with these clinical parameters only in fragility fractures. These findings suggest that serum levels of IL-6, TNF-alpha, RANKL and OPG might be used to monitor the stages of fracture repair. Further studies will be needed to confirm the role of these cytokines in fracture repair.

Multimarker risk assessment including osteoprotegerin and CXCL16 in acute coronary syndromes.

OBJECTIVE: CXCL16 and osteoprotegerin (OPG) both predict mortality in acute coronary syndromes. We hypothesized that a combination of CXCL16 and OPG concentrations would add prognostic information to the Global Registry of Acute Coronary Events (GRACE) score in patients hospitalized for acute coronary syndromes. METHODS AND RESULTS: We assessed the associations between circulating OPG and soluble CXCL16 levels, obtained within 24 hours of admission (day 1) and after 3 months, and mortality, heart failure and reinfarction in 1322 patients admitted with acute coronary syndromes. After adjustment for the GRACE score, medication, diabetes mellitus and sex, the combination of high values (fourth quartile) for OPG and CXCL16 at baseline was associated with increased short-term (3 months) cardiovascular mortality (hazard ratio, 3.28; 95% CI, 1.84-5.82; P<0.0001). The combined high values were also significantly associated with the long-term (median 91 months) prognosis after adjustment, with hazard ratios 2.18 for cardiovascular mortality (95% CI, 1.62-2.92; P<0.0001), and 2.22 for heart failure (95% CI, 1.67-2.96; P<0.0001). These long-term associations remained significant after further adjustment for left ventricular ejection fraction, C-reactive protein, and pro B-type natriuretic peptide. For 635 patients with blood samples within 24 hours and at 3 months, the combination of high CXCL16 and OPG values (fourth quartile) in the early or stable phase was of a similar order associated with mortality and morbidity beyond 3 months. CONCLUSIONS: Circulating CXCL16 and OPG are independent predictors of long-term mortality and heart failure development in acute coronary syndromes patients, even after extensive adjustments. Their combination gives more information than either marker alone.

[Assessment of selected bone metabolism marker concentrations in children with cystic fibrosis]. / Analiza stezen wybranych parametrów metabolizmu kostnego u dxieci chorych na mukowiscydoze.

AIM: The aim of this study was to assess bone formation and resorption processes and bone metabolism regulators, such as osteoprotegerin and fetuin-A in children with cystic fibrosis. MATERIAL AND METHODS: We examined 45 children with cystic fibrosis aged 5-13 years treated at the Institute of Mother and Child in Warsaw. The control group consisted of 35 healthy children in the same synage range without any diseases which may influence bone metabolism. We determined serum calcium and phosphate levels by colorimetric methods, vitamin D3 by the chemiluminiscence method and bone metabolism markers (osteocalcin, 5b isoenzyme of tartrate-resistant acid phosphatase, osteoprotegerin, fetuin-A) by immunoenzymatic methods. RESULTS: Mean serum concentrations of calcium and phosphate in the studied children were within the reference ranges. However, the level of 25-hydroxyvitamin D3 was significantly lower in patients with cystic fibrosis compared to the controls (19.3±7.6 vs 25.2±8.9 ng/ml, p<0.01). In cystic fibrosis children we observed a statistically significant lower concentration of osteocalcin (81.9±28.9 vs 97.9±28.6 ng/ ml, p<0.01) and similar activity of 5b isoenzyme of tartrate-resistant acid phosphatase (12.5±2.9 vs 13.4±3.5 U/L) as compared to healthy peers. Mean serum concentration of osteoprotegerin in patients with CF was significantly lower than in the control children (4.1±0.98 vs 4.59±0.86 pmol/l, p<0.05). Serum concentration of fetuin-A was comparable in both groups of children. CONCLUSIONS: In children with cystic fibrosis changes in the profile of bone metabolism markers were observed. Even patients with CF who are clinically stable and supplemented with vitamins are at risk of osteopenia and osteoporosis in their later life. Therefore, they should be under a comprehensive medical and nutritional care in order to achieve their optimal peak bone mass.

Assessment of the genetic effects of polymorphisms in the osteoprotegerin gene, TNFRSF11B, on serum osteoprotegerin levels and carotid plaque vulnerability.

BACKGROUND AND PURPOSE: Osteoprotegerin (OPG) is a secretory glycoprotein which belongs to the tumor necrosis factor receptor family. Various mechanisms have been suggested by which calcification might alter atherosclerotic plaque stability, but the significance of this intimal calcification is controversial. High concentrations of OPG have been associated with the presence of vascular and cardiovascular diseases. This study was designed to assess the association between gene polymorphisms of the OPG gene (TNFRSF11B), the serum OPG level, and plaque stability in patients with carotid atherosclerosis. METHODS: We studied 177 patients with internal carotid artery stenosis who underwent carotid endarterectomy and also 303 controls. Carotid endarterectomy samples removed from patients were assessed by immunohistochemistry. Concentrations of OPG were measured and gene polymorphisms were examined by polymerase chain reaction and restriction enzyme analysis and were compared, initially between patients with carotid atherosclerosis and controls, and subsequently between stable and unstable carotid plaques. RESULTS: We found that the GG genotype of the T245G polymorphism, the CC genotype of the T950C polymorphism, and the CC genotype of the G1181C polymorphism were significantly higher in patients with carotid plaque than in controls (21.5% versus 10.9% , P<0.01; 15.8% versus 7.6%, P<0.01; and 20.3% versus 10.9%, P<0.01, respectively) and that these polymorphisms were associated with high serum OPG levels (4.02 [3.07] versus 2.94 [1.81] pmol/L; P<0.01), which were significantly higher in patients with unstable atherosclerotic plaques (5.86 [4.02] versus 3.53 [1.87] pmol/L; P<0.01). CONCLUSIONS: The TNFRSF11B gene polymorphisms studied are associated with high serum OPG levels and might be potential markers for plaque instability.