Osteoclast signaling-targeting miR-146a-3p and miR-155-5p are downregulated in Paget's disease of bone.

MicroRNA (miRs) are small, non-coding RNA that post-transcriptionally regulate DNA expression. We hypothesized that specific miR profiles may be a feature of overactive osteoclasts in Paget's disease of bone (PDB), a disorder characterized by an increased and disorganized bone remodeling that typically begins with excessive bone resorption. We compared the expression profile of 13 miRs in human osteoclasts differentiated in vitro from peripheral blood mononuclear cells (PBMCs) of patients with PDB (n = 10) or age- and sex- matched healthy subjects (n = 10). We selected 13 miRs for testing, on the basis of their previously reported roles either in human osteoclast differentiation, in bone diseases, or in osteoclast important signaling pathways. From those expression results, 3 miRNAs were further selected for in-vitro studies aiming at modulating miR expression in human cord blood monocyte derived osteoclasts: 2 miRs (miR-146a-3p and miR-155-5p) whose expression was significantly reduced in pagetic osteoclasts, as well as miRNA-133a-3p, stable in PDB relative to controls, but with known regulatory importance within osteoclasts. We demonstrated a positive (miR-133a-3p) or negative (miR-155-5p, miR-146a-3p) impact of those miRs on the formation of osteoclasts and/or their bone resorption capacity in this human model. Signaling pathways were significantly affected, including p38 MAP-kinase (miR-133a-3p), RANKL-induced TRAF6/NFκB signaling (miR-146a-3p), and MITF expression (miR-155-5p). Osteoclast miRNA profiles might have an important value to yield significant new insights into the osteoclast phenotype in PDB and in other bone diseases with hyperactive osteoclasts.

Preventive Role of Vitamin D Supplementation for Acute Phase Reaction after Bisphosphonate Infusion in Paget's Disease.

CONTEXT: Intravenous aminobisphosphonates (N-BPs) can induce an acute phase reaction (APR) in up to 40% to 70% of first infusions, causing discomfort and often requiring intervention with analgesics or antipyretics. OBJECTIVE: Our aim was to explore the risk factors of APR in a large sample of patients with Paget's disease of bone (PDB) and to assess the possible preventive effects of vitamin D administration. METHODS: An observational analysis was performed in 330 patients with PDB at the time of N-BP infusion. Then, an interventional study was performed in 66 patients with active, untreated PDB to evaluate if vitamin D administration (oral cholecalciferol 50 000 IU/weekly for 8 weeks before infusion) may prevent APR. RESULTS: In a retrospective study, APR occurred in 47.6% and 18.3% of naive or previously treated patients, respectively. Its prevalence progressively increased in relation to the severity of vitamin D deficiency, reaching 80.0% in patients with 25-hydroxyvitamin D (25OHD) levels below 10 ng/mL (relative risk (RR) = 3.7; 95% confidence interval (CI) 2.8-4.7, P < .0001), even in cases previously treated with N-BPs. Moreover, APR occurred more frequently in patients who experienced a previous APR (RR = 2.8; 95% CI 1.5-5.2; P < .001) or in carriers of SQSTM1 mutation (RR = 2.3; 95% CI 1.3-4.2; P = .005). In the interventional study, vitamin D supplementation prevented APR in most cases, equivalent to a RR of 0.31 (95% CI 0.14-0.67; P < .005) with respect to prevalence rates of the observational cohort. A similar trend was observed concerning the occurrence of hypocalcemia. CONCLUSIONS: The achievement of adequate 25OHD levels is recommended before N-BP infusion in order to minimize the risk of APR or hypocalcemia in PDB.

Tartrate-resistant acid phosphatase 5b, but not periostin, is useful for assessing Paget's disease of bone.

BACKGROUND: Periostin is a matricellular protein with a preferential location in cortical bone and periosteal tissue, and tartrate-resistant acid phosphatase 5b (TRAP5b) is a marker of osteoclast numbers. In Paget's disease of bone (PDB), there is increased cortical thickening and probably increased periosteal apposition, along with increased osteoclast numbers. OBJECTIVES: To analyse if circulating periostin is a biomarker for PDB, and if it is associated with disease activity and involvement of long bones that represent major cortical contribution. Also, to analyse whether TRAP5b, a scarcely explored bone resorption marker, is useful in the assessment of PDB. PATIENTS AND METHODS: We recruited 42 patients with PDB (13F/29M; 71 ±â€¯11.6 yrs). 71.4% had active disease, 66.6% had polyostotic disease and 54.8% had long bone involvement. Blood and urine samples were taken between 8:00 and 10:00 A.M. after an overnight fast. Periostin and TRAP5b were measured in serum, using commercial ELISA assays (Biomedica and IDS, respectively). Serum total ALP, PINP, CTX, bone ALP and urinary NTX were measured. Reference values for periostin and TRAP5b were obtained from 45 healthy subjects. RESULTS: Serum periostin did not differ between patients and controls (989.4 ±â€¯173.2 vs. 966.9 ±â€¯195.4 pMol/L, p = 0.572). No significant differences were observed between patients with and without active disease (964.5 ±â€¯168.8 vs.1051.6 ±â€¯175.6 pMol/L, p = 0.143), involvement or not of long bones (1022.2 ±â€¯145.8 vs 949.7 ±â€¯198.2 pMol/L, p = 0.181) and monostotic or polyostotic disease (963.8 ±â€¯198.7 vs 1002.2 ±â€¯161.4 pMol/L, p = 0.505). There were significant correlations between serum periostin and all bone turnover markers (bone ALP, PINP, uNTX, sCTX and TRAP5b) in PDB patients with active disease, but not in the inactive PDB group. Serum TRAP5b was significantly higher in PDB patients than in controls (4.43 ±â€¯1.76 vs. 3.21 ±â€¯1.02 U/L, p < 0.001), in those with active disease (4.98 ±â€¯1.76 vs. 3.07 ±â€¯0.72 U/L, p < 0.001) and in patients with polyostotic disease than in those with monostotic disease (4.81 ±â€¯1.79 vs 3.68 ±â€¯1.5 U/L, p = 0.005). TRAP5b levels were not influenced by previous bisphosphonate treatment (4.14 ±â€¯1.42 vs. 4.84 ±â€¯2.02 U/L, p = 0.206). CONCLUSIONS: Periostin is not useful for assessing PDB, whilst TRAP5b, which has been a scarcely explored bone turnover marker until now, may be useful in the analysis of this disease, providing new information on the resorption process. In addition, periostin levels correlate with all classical BTMs in active PDB, suggesting that this marker may reflect periosteal and cortical metabolism in accelerated bone turnover states.

Diagnosis and Management of Paget's Disease of Bone in Adults: A Clinical Guideline.

An evidence-based clinical guideline for the diagnosis and management of Paget's disease of bone (PDB) was developed using GRADE methodology, by a Guideline Development Group (GDG) led by the Paget's Association (UK). A systematic review of diagnostic tests and pharmacological and nonpharmacological treatment options was conducted that sought to address several key questions of clinical relevance. Twelve recommendations and five conditional recommendations were made, but there was insufficient evidence to address eight of the questions posed. The following recommendations were identified as the most important: 1) Radionuclide bone scans, in addition to targeted radiographs, are recommended as a means of fully and accurately defining the extent of metabolically active disease in patients with PDB. 2) Serum total alkaline phosphatase (ALP) is recommended as a first-line biochemical screening test in combination with liver function tests in screening for the presence of metabolically active PDB. 3) Bisphosphonates are recommended for the treatment of bone pain associated with PDB. Zoledronic acid is recommended as the bisphosphonate most likely to give a favorable pain response. 4) Treatment aimed at improving symptoms is recommended over a treat-to-target strategy aimed at normalizing total ALP in PDB. 5) Total hip or knee replacements are recommended for patients with PDB who develop osteoarthritis in whom medical treatment is inadequate. There is insufficient information to recommend one type of surgical approach over another. The guideline was endorsed by the European Calcified Tissues Society, the International Osteoporosis Foundation, the American Society of Bone and Mineral Research, the Bone Research Society (UK), and the British Geriatric Society. The GDG noted that there had been a lack of research on patient-focused clinical outcomes in PDB and identified several areas where further research was needed. © 2019 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Distrofia ósea esclerosante mixta / Mixed-sclerosing-bone-dystrophy

El término "distrofia ósea esclerosante mixta" describe la combinación de las características radiológicas correspondientes a melorreostosis, osteopoiquilosis y osteopatía estriada, como entidades individuales, que ocurren en un mismo paciente. El objetivo de esta comunicación es presentar el caso clínico de una paciente con diagnóstico de distrofia ósea esclerosante mixta y, a partir de este caso, realizar una revisión sobre el tema. (AU)

The term "mixed-sclerosing-bone-dystrophy" describes the combination of the radiological characteristics corresponding to melorheostosis, osteopoikilosis and osteopathia striata, as individual conditions, ocurring in the same patient. The aim of this communication is to present the clinical case of a patient diagnosed with mixed-sclerosing-bone-dystrophy and, based on this case, to undertake a review of this condition. (AU)

Clinical utility of bone markers in various diseases.

Measurements of bone markers (BMs) in peripheral blood or urine are a pivotal part of bone research within modern clinical medicine. In recent years the use of BMs increased substantially as they can be useful either to diagnose bone (related) disease and to follow its natural history, but also to monitor the effects of interventions. However, the use of BMs is still complicated mainly due to (pre)analytical variability of these substances, limited accessibility of assays, variable cut-off values in different countries and laboratories and heterogeneous results with regard to clinical implications of measuring BMs in several studies. This review will provide the clinician with a practical guide, based on current evidence, in which circumstances to test which bone markers for optimal diagnostic purposes, in order to improve patient care in different areas of bone diseases including Paget's disease, primary osteoporosis, tumor induced osteomalacia, hypophosphatemic rickets, van Buchem disease, chronic kidney disease, rheumatoid arthritis, neoplasma/multiple myeloma, type 2 diabetes mellitus and primary hyperparathyroidism. The clinician should consider fasting state, recent fractures, aging, menopausal status, concomitant liver and kidney disease when ordering and interpreting BM measurements as these factors might result in misleading BM concentrations. We found that BMs are clearly useful in the current diagnosis of tumor induced osteomalacia, van Buchem disease, Paget's disease and hypophosphatemic rickets. In addition, BMs are useful to monitor disease activity in chronic kidney disease, Paget's disease and are useful to monitor treatment adherence in osteoporosis.

Interleukin-6 trans-signaling and pathological low back pain in patients with Paget disease of bone.

The interleukin (IL)-6 biological system plays a key role in the pathogenesis of Paget disease (PD) of bone and pathological bone pain. Bone pain, particularly in the lower back region, is the most frequent symptom in patients with PD. This case-control study aimed to evaluate the relationship between the IL-6 system and low back pain (LBP) in patients with PD. We evaluated 85 patients with PD, with the disease localized in the lumbar spine, pelvis, and/or sacrum, and classified them based on the presence or absence of LBP, before and after aminobisphosphonate treatment. We also examined 32 healthy controls without LBP. Before treatment, IL-6 levels in patients with PD were higher than those in the controls, without difference between patients with or without LBP. Patients with PD with LBP (35/85) showed higher IL-6-soluble receptor (sIL-6R) and lower soluble glycoprotein (sgp) 130 levels compared with both patients with PD without LBP and controls (sIL-6R: 46.9 ± 7.4 vs 35.4 ± 8.6 vs 29.9 ± 4.2 ng/mL; sgp130: 307.2 ± 35.4 vs 341.4 ± 41.4 vs 417.1 ± 58.5 ng/mL, respectively). Paget disease remission, 6 months after treatment, is associated with LBP improvement. This phenomenon is associated with reduced sIL-6R levels and increased sgp130 levels in patients with PD with LBP at the baseline. Considering the biological properties of IL-6, sIL-6R, and sgp130, the results of the study suggest that the perception of LBP in patients with PD could be linked to an enhanced transmission of IL-6 signal in the specialized neural system activated by nociceptors.

Adult Paget's disease of bone: a review.

Adult PD of bone is the second commonest metabolic bone condition after osteoporosis. The condition is characterized by increased bone cell activity, with bone-resorbing osteoclasts often larger and containing more nuclei than normal, and osteoblasts producing increased amounts of disorganized bone. This leads to expanded bone of poor quality possessing both sclerotic and lytic areas. PD of bone has a strong genetic element, with a family history being noted in 10-20% of cases. A number of genetic defects have been found to be associated with the condition. The most common disease-associated variants identified affect the SQSTM1 gene, providing insights into disease aetiology, with the clinical value of knowledge of SQSTM1 mutation status currently under active investigation. The diagnosis may be suggested by an isolated raised total ALP without other identifiable causes. This can be confirmed on plain X-rays and the extent determined by isotope bone scan. The mainstays of treatment are the bisphosphonates, especially i.v. zoledronate, which results in long-term suppression of bone turnover. ALP is the usual means of monitoring the condition, although more specific bone turnover markers can be helpful, especially in coincident liver disease. Patients should be followed up to monitor for biochemical relapse or development of complications, which may require medical or surgical intervention.

Long-Term Randomized Trial of Intensive Versus Symptomatic Management in Paget's Disease of Bone: The PRISM-EZ Study.

It has been suggested that normalization of bone turnover may improve clinical outcome in Paget's disease of bone (PDB) by preventing complications such as fractures and the development of osteoarthritis. Here we investigated the long-term effects of a treatment strategy that aimed to normalize bone turnover in PDB with that of symptomatic treatment. The study group comprised 502 subjects who were enrolled into a 3-year extension of the Paget's Disease: Randomized Trial of Intensive versus Symptomatic Management (PRISM) study. Intensive bisphosphonate therapy was continued in 270 of these subjects with the aim of normalizing bone turnover using zoledronic acid as the treatment of first choice. Symptomatic treatment continued in 232 subjects in whom bisphosphonates were only given for the treatment of bone pain. The primary outcome was fracture and secondary outcomes were orthopedic procedures, quality of life, and bone pain, adjusted for baseline characteristics. Serum total alkaline phosphatase (ALP) concentrations were significantly lower in the intensive group on entry to the study and the differences between groups increased as the study progressed. There were no clinically important differences in quality of life measures or bone pain between the treatment groups. Intensive treatment was associated with a nonsignificant increase in fracture risk (hazard ratio = 1.90; 95% CI, 0.91 to 3.98; p = 0.087), orthopedic procedures (1.81; 95% CI, 0.71 to 4.61; p = 0.214), and serious adverse events (relative risk 1.28; 95% CI, 0.96 to 1.42). We conclude that long-term intensive bisphosphonate therapy confers no clinical benefit over symptomatic therapy and is associated with a nonsignificant increase in the risk of fractures, orthopedic events, and serious adverse events. The results of this study suggest that in patients with established PDB, bisphosphonate therapy should focus on control of symptoms rather than suppression of bone turnover. © 2016 American Society for Bone and Mineral Research.

Circulating Dickkopf-1 and sclerostin in patients with Paget's disease of bone.

Paget disease of bone is a chronic metabolic bone disorder characterized by increased bone resorption and new bone formation. The aim of this study is defining the role of inhibitors of canonical Wnt/b-catenin signaling pathway in patients with Paget disease of bone. Scarce and contrasting results have been reported in literature. We studied 40 patients (15 females and 25 males) with radiological and scintigraphic evidence of Paget disease of bone and 40 healthy subjects matched by age and sex. N-propeptide of type I collagen, C-terminal telopeptide of type I collagen, sclerostin, and Dickkopf-related protein 1 (DKK1) were evaluated by blood samples in our laboratory. As expected, mean serum levels of bone turnover markers (N-propeptide of type I collagen and C-terminal telopeptide of type I collagen) were significantly higher in the Paget disease of bone group compared with the control group. No difference was observed between groups in Dickkopf-1 and sclerostin. Dickkopf-1 and sclerostin were never correlated with each other or with bone turnover markers. Sclerostin was positively correlated with age. In conclusion, our results suggest that the regulators of the Wnt-ß catenin pathway are not altered in patients with Paget disease of bone. The positive correlation we found between sclerostin and age in Paget disease of bone patients indicates that in comparative studies, sclerostin serum levels must be adjusted for age.

Diagnosis and treatment of Paget's disease of bone : A clinical practice guideline.

Paget's disease of bone (osteitis deformans) is a benign focal disorder of accelerated skeletal remodeling. Either a single bone (monostotic) or multiple bones (polyostotic) can be affected. In patients with suspected Paget's disease plain radiographs of the suspicious regions of the skeleton are recommended. The initial biochemical evaluation of a patient should be done using serum total ALP (alkaline phosphatase) or with the use of a more specific marker of bone formation: PINP (intact N-terminal type 1 procollagen propeptide) or CTX (cross-linked C­telopeptide). Treatment with a bisphosphonate is recommended for most patients with active Paget's disease who are at risk for further skeletal and extraskeletal complications. A single dose of 5 mg i.v. zoledronate as the treatment of choice in patients without contraindications is suggested. Oral bisphosphonates are less potent when compared to zoledronate. Treatment with an antiresorptive agent induces a more rapid decrease in resorption markers compared to formation marker. Measurement of total ALP or other baseline disease activity markers (e. g. CTX) at 6 to 12 weeks, when bone turnover will have shown a substantial decline, is an acceptable and cost-effective option. Maximum suppression of high bone turnover may require measurement at 6 months after administration. In patients with increased bone turnover, biochemical follow-up is recommended to be used as a more objective indicator of relapse rather than symptoms. The prolonged response after zoledronate treatment should be assessed every 1-2 years after normal bone turnover. With less potent drugs, every 6 to 12 months is appropriate.

Durability of Response to Zoledronate Treatment and Competing Mortality in Paget's Disease of Bone.

There has been a marked secular trend in recent decades toward patients with Paget's disease presenting at a greater age and having less extensive skeletal involvement. Over a similar time frame more potent bisphosphonates with a long duration of effect have been developed, raising the prospect of many patients needing only once in a lifetime treatment. We studied a cohort of 107 patients who had been treated with intravenous zoledronate for the first time at a mean age of 76 years. Sequential measurements of the bone turnover marker procollagen-1 NT-peptide (P1NP) were made for up to 10 years. By 9 years, 64% showed some loss of zoledronate effect (defined as a doubling of P1NP from the nadir value after treatment), but only 14% had a biochemical relapse (defined as a P1NP value >80 µg/L). The mortality rate was substantially greater than the relapse rate-by 10 years more than half the cohort had died (p < 0.0001). We conclude that for the majority of older people with Paget's disease a single intravenous infusion of zoledronate will provide disease suppression for the remainder of their lives. © 2016 American Society for Bone and Mineral Research.

Paget's disease with craniofacial and skeletal bone involvement.

Paget's disease is a metabolic disorder of bone caused due to defect in the remodelling process and is very common in western countries but is very rare in Asians and Africans. It was first described by a British scientist Sir James Paget in 1877. It can be monostotic or polyostotic depending on the number of bones involved. It most commonly affects older people of more than 50 years. Disease involvement can be symptomatic or asymptomatic depending on the extent of the disease process. Diagnosis of Paget's disease can be made by raised serum alkaline phosphatase levels, radiological examination and by radioisotope bone scans.

Paget's disease of bone: an osteoimmunological disorder?

Osteoimmunology represents a large area of research resulting from the cross talk between bone and immune systems. Many cytokines and signaling cascades are involved in the field of osteoimmunology, originating from various cell types. The RANK/receptor activator of nuclear factor Kappa-B ligand (RANKL)/osteoprotegerin (OPG) signaling has a pivotal role in osteoimmunology, in addition to proinflammatory cytokines such as tumor necrosis factor-α, interleukin (IL)-1, IL-6, and IL-17. Clinically, osteoimmunological disorders, such as rheumatoid arthritis, osteoporosis, and periodontitis, should be classified according to their pattern of osteoimmunological serum biomarkers. Paget's disease of bone is a common metabolic bone disorder, resulting from an excessively increased bone resorption coupled with aberrant bone formation. With the exception of the cellular responses to measles virus nucleocapsid protein and the interferon-gamma signature, the exact role of the immune system in Paget's disease of bone is not well understood. The cytokine profiles, such as the increased levels of IL-6 and the interferon-gamma signature observed in this disease, are also very similar to those observed in other osteoimmunological disorders. As a potential osteoimmunological disorder, the treatment of Paget's disease of bone may also benefit from progress made in targeted therapies, in particular for receptor activator of nuclear factor Kappa-B ligand and IL-6 signaling inhibition.

Clinical efficacy of oral risedronate therapy in Japanese patients with Paget's disease of bone.

Paget's disease of bone (PDB) is a chronic disorder characterized by localized bone regions with excessive bone turnover. Although oral risedronate (17.5 mg daily for 8 weeks) was recently approved in Japan, its efficacy is not well understood. We retrospectively examined the efficacy of oral risedronate in PDB patients in a clinical setting. Eleven patients whose serum alkaline phosphatase (ALP) level exceeded the upper limit of the normal range were treated. Patients whose ALP levels normalized and remained so for 12 months after therapy initiation were defined as responders. Treatment was repeated if bone pain recurred or if serum ALP levels increased at least 25% above the nadir. Six patients (55%) were responsive to the therapy. A higher prevalence of skull lesions, higher serum calcium levels at treatment initiation and antecedent treatments of bisphosphonates were predictors of resistance against the therapy. Fresh frozen serum samples obtained from some treatment sessions were evaluated for metabolic bone markers such as bone-specific ALP (BAP), type I procollagen N-terminal pro-peptide (PINP), N-treminal crosslinking telopeptide of type I collagen and C-treminal crosslinking telopeptide of type I collagen (CTX). A significant reduction of P1NP preceded that of serum ALP levels in the responders, which was followed by a similar occurrence for BAP and osteocalcin (BGP) levels. A temporary decrease in CTX levels was noted. No significant changes in markers (including ALP level) were observed in non-responder and repeat-treatment groups. P1NP levels may be more useful than ALP levels in assessing treatment efficacy. Repeat treatment effectiveness for the repeat-treatment group was limited.

Bone-specific alkaline phosphatase by immunoassay or electrophoresis: their use in clinical practice.

BACKGROUND: Measurement of bone-specific alkaline phosphatase (BALP) may be useful in diagnosing and monitoring metabolic bone disease. This study aimed to evaluate the BALP immunoassay and compare it with electrophoresis (densitometry) for the quantitation of BALP. METHODS: Metra BALP immunoassay kits were used for the method comparison. BALP was also quantitated by electrophoresis (densitometry) in seven patients with active Paget's disease. RESULTS: Immunoassay results did not correlate well with densitometrically quantitated BALP, as there was a statistically significant (p<0.01), negative bias (22%) for results obtained by immunoassay compared with those derived by densitometry. Possible interference in the immunoassay with other isoforms of alkaline phosphatase (ALP) such as liver, placental and intestinal was also observed. The Metra BALP immunoassay is quoted as having an upper dynamic limit of 140 U/L and recommends that samples only require dilution above this level; we observed inconsistent results upon dilution of samples below this level. CONCLUSIONS: Immunoassay and electrophoresis did not correlate well for BALP quantitation. Possible interference with other isoforms of ALP was observed with the BALP immunoassay. The accuracy of the BALP immunoassay is questionable at higher concentrations.