Bisphosphonates in bone diseases other than osteoporosis

Incident acute pseudogout and prior bisphosphonate use: Matched case-control study in the UK-Clinical Practice Research Datalink

Oral bisphosphonates are the most commonly used drugs to treat postmenopausal osteoporosis. Acute pseudogout is anecdotally reported to occur following bisphosphonate initiation but empirical data are lacking. We investigated whether treatment with oral bisphosphonates is a risk factor for incident acute pseudogout.A matched case-control study was undertaken using data from the UK-Clinical Practice Research Datalink. Adults who consulted for incident acute pseudogout between 1987 and 2012 were each matched for gender, age at pseudogout diagnosis, and general practice to up to 4 control subjects without pseudogout. The exposure of interest was a prescription for an oral bisphosphonate issued within the 60-day period prior to the date of incident acute pseudogout. Associations between incident acute pseudogout and prior bisphosphonate prescription were examined using conditional logistic regression, adjusting for hyperparathyroidism, osteoarthritis, rheumatoid arthritis, hemochromatosis, hypophosphatasia, and prescriptions for diuretics and oral corticosteroids.Two thousand eleven acute pseudogout cases were compared with 8013 matched controls without acute pseudogout (mean age [standard deviation] 72 years [14]; 52% male). One hundred twenty-three cases (6.1%) had received an oral bisphosphonate prescription in the 60-day exposure period compared with 305 controls (3.8%) (adjusted incidence rate ratio [IRR] 1.33; 95% confidence interval [CI] 1.05-1.69). This association was stronger in females (adjusted IRR 1.49; 95% CI 1.15-1.94) and was nonsignificant in males (0.83; 0.48-1.44).Incident acute pseudogout was associated with prescription of an oral bisphosphonate in the preceding 60 days. Prescribers should be aware of acute pseudogout as a possible side effect of bisphosphonate treatment. Further research is needed to explore the risks conferred by different bisphosphonates and the mechanism underlying this association.

Are there any differences in mandibular morphology of patients with bisphosphonate-related osteonecrosis of jaws?: a case-control study

OBJECTIVES:

The aim of this study was to compare the morphological differences in the mandible between patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) and healthy individuals and to detect the correlation between these parameters on panoramic radiography and CBCT.

METHODS:

The CBCT and panoramic images of patients with BRONJ (n = 32) and control groups (n = 32) were included in the study. All the comparisons were analyzed between the osteonecrosed and healthy sides of patients with BRONJ and control group. The panoramic radiographs were used to measure the values of the condyle angle, gonial angle, antegonial angle, antegonial depth, condylar height and ramal height. The mandibular cortical index (MCI) and bone quality index (BQI) were also examined on cross-sectional scans of CBCT images.

RESULTS:

There were significant differences in the MCI (p = 0.014) and BQI (p = 0.021) between the left and right side of the BRONJ group and also between the osteonecrosed side of the BRONJ and control group (p < 0.0001). No significant difference was found in other comparisons.

CONCLUSIONS:

The outcomes of the present study indicate that bisphosphonates influenced some internal morphological changes in the mandible. These changes may be a reason of BRONJ. But, these changes are not reflective of the measured values obtained using panoramic radiographs on the external morphology of the mandible.

Concentration-dependent effects of alendronate and pamidronate functionalized gold nanoparticles on osteoclast and osteoblast viability

Severe osteoporotic diseases, such as Paget's disease, Osteogenesis Imperfecta, and Legg Calve Perthes disease, lack treatments that address the pathobiology of the diseases, as well as, long-term and prospective studies. Bisphosphonates, which are known to dramatically hinder the viability of osteoclast cells, along with gold nanoparticles (GNP) are a potential theranostic for osteoporotic diseases. We evaluated GNP functionalized with two different bisphosphonates, namely, alendronate and pamidronate. RANKL differentiated murine pre-osteoclasts (Raw 264.7) and murine osteoblasts (7F2) were treated with varying concentrations ranging from 0.1-5 µM of free and GNP bound bisphosphonates. GNPs with an average size of ∼15 nm were functionalized with alendronate and pamidronate through surface modification by self-assembly. MTT viability assay results show no changes in viability of the osteoclasts when treated with free bisphosphonates in the range of 1-5 µM, but significant decrease on treatment with functionalized GNP at concentrations above the range of 0.1-1 µM depending on the bisphosphonate. Osteoblast cell viability is maintained at all but the highest concentrations used. Qualitative and quantitative characterization by Western Blot for RANKL expression in the osteoblast cell line shows that expression is largely maintained. These results provide a basis for methods that use bisphosphonate functionalized GNP in the treatment of osteoporotic bone diseases. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 21-29, 2017.

Cone beam computed tomography for diagnosis of bisphosphonate-related osteonecrosis of the jaw: evaluation of quantitative and qualitative image parameters

OBJECTIVE

To assess the diagnostic performance of quantitative and qualitative image parameters in cone-beam computed tomography (CBCT) for diagnosis of bisphosphonate-related osteonecrosis of the jaw (BRONJ).

MATERIALS AND METHODS

A BRONJ (22 patients, mean age 70.0 years) group was age and gender matched to a healthy control group (22 patients, mean age 68.0 years). On CBCT images two independent readers performed quantitative bone density value (BDV) measurements with region and volume-of-interest (ROI and VOI) based approaches and qualitative scoring of BRONJ-associated necrosis, sclerosis and periosteal thickening (1 = not present to 5 = definitely present). Intraoperative and clinical findings served as standard of reference. Interreader agreements and diagnostic performance were assessed by intraclass correlation coefficients (ICC), kappa-statistics and receiver-operating characteristic (ROC) analysis.

RESULTS

Twenty-three regions in 22 patients were affected by BRONJ. ICC values for mean BDV VOI and mean BDV ROI were 0.864 and 0.968, respectively (p < 0.001). The area under the curve (AUC) for mean BDV VOI and mean BDV ROI was 0.58/0.83 with a sensitivity of 57/83% and specificity of 61/77% for diagnosis of BRONJ, respectively. Kappa values for presence of necrosis, sclerosis and periosteal thickening were 0.575, 0.617 and 0.885, respectively. AUC values for qualitative parameters ranged between 0.90-0.96 with sensitivity of 96% and specificities between 79-96% at respective cutoff scores.

CONCLUSIONS

BRONJ can be effectively diagnosed with CBCT. Qualitative image parameters yield a higher diagnostic performance than quantitative parameters, and ROI-based attenuation measurements were more accurate than VOI-based measurements.

Enhanced anti-tumor activity and safety profile of targeted nano-scaled HPMA copolymer-alendronate-TNP-470 conjugate in the treatment of bone malignances

Bone neoplasms, such as osteosarcoma, exhibit a propensity for systemic metastases resulting in adverse clinical outcome. Traditional treatment consisting of aggressive chemotherapy combined with surgical resection, has been the mainstay of these malignances. Therefore, bone-targeted non-toxic therapies are required. We previously conjugated the aminobisphosphonate alendronate (ALN), and the potent anti-angiogenic agent TNP-470 with N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer. HPMA copolymer-ALN-TNP-470 conjugate exhibited improved anti-angiogenic and anti-tumor activity compared with the combination of free ALN and TNP-470 when evaluated in a xenogeneic model of human osteosarcoma. The immune system has major effect on toxicology studies and on tumor progression. Therefore, in this manuscript we examined the safety and efficacy profiles of the conjugate using murine osteosarcoma syngeneic model. Toxicity and efficacy evaluation revealed superior anti-tumor activity and decreased organ-related toxicities of the conjugate compared with the combination of free ALN plus TNP-470. Finally, comparative anti-angiogenic activity and specificity studies, using surrogate biomarkers of circulating endothelial cells (CEC), highlighted the advantage of the conjugate over the free agents. The therapeutic platform described here may have clinical translational relevance for the treatment of bone-related angiogenesis-dependent malignances.

Effect of alendronate therapy in children with osteogenesis imperfecta

OBJECTIVE

To evaluate the effect of orally administered alendronate in children with osteogenesis imperfecta.

METHODS

Thirty children (16 girls and 14 boys; mean age at baseline 10.7 +/- 6.0 years; range 4-16 years) with osteogenesis imperfecta type I (n = 22), III (n = 2), or IV (n = 6) were treated with alendronate (5 mg/day in patients aged 4-10 years and 10 mg/day in children >10 years of age) for 3 years.

RESULTS

After 1 year of alendronate therapy we observed a significant increase in areal and volumetric bone mineral density Z-scores (from -2.03 +/- 1.51 to -1.04 +/- 1.20, and from -1.91 +/- 1.38 to -1.33 +/- 1.30, respectively, P < 0.001), together with a significant drop in fracture rate (from 3.77 +/- 1.57 to 0.13 +/- 0.57, P < 0.000001), relief of chronic pain (from 3.83 +/- 1.44 days of pain/week to 0.73 +/- 0.77, P < 0.000001) and improvement in ambulation/mobility (P < 0.00002). After additional 2 years of therapy there were no further significant changes in these parameters, however the improvement was still remarkable in comparison to the pretreatment values (P < 0.003, P < 0.004, P < 0.000001, P < 0.000001 and P < 0.00001, respectively). A significant drop in markers of bone turnover (urinary deoxypyridinoline and serum osteocalcin) occurred after 3 years of therapy (P < 0.003 and 0.004, respectively). No adverse reactions were observed throughout the treatment.

CONCLUSIONS

Alendronate has positively influenced quality of life in paediatric patients with osteogenesis imperfecta. Bisphosphonate therapy should be used only in the context of a well-defined protocol.

Controlled trial of pamidronate in children with types III and IV osteogenesis imperfecta confirms vertebral gains but not short-term functional improvement

Bisphosphonates have been widely administered to children with OI based on observational trials. A randomized controlled trial of q3m intravenous pamidronate in children with types III and IV OI yielded positive vertebral changes in DXA and geometry after 1 year of treatment, but no further significant improvement during extended treatment. The treated group did not experience significantly decreased pain or long bone fractures or have increased motor function or muscle strength.

INTRODUCTION

Bisphosphonates, antiresorptive drugs for osteoporosis, are widely administered to children with osteogenesis imperfecta (OI). Uncontrolled pamidronate trials in OI reported increased BMD, vertebral coronal area, and mobility, and decreased pain. We conducted a randomized controlled trial of pamidronate in children with types III and IV OI.

MATERIALS AND METHODS

This randomized trial included 18 children (4-13 years of age) with types III and IV OI. The first study year was controlled; 9 children received pamidronate (10 mg/m2/day IV for 3 days every 3 months). Four children in each group also received recombinant growth hormone (rGH) injections (0.06 mg/kg/day for 6 days/week). Seven children in the treatment group received pamidronate for an additional 6-21 months. All patients had L1-L4 DXA, spine QCT, spine radiographs, and musculoskeletal and functional testing.

RESULTS

In the controlled phase, treated patients experienced a significant increase in L1-L4 DXA z score (p < 0.001) and increased L1-L4 mid-vertebral height (p = 0.014) and total vertebral area (p = 0.003) compared with controls. During extended treatment, DXA z scores and vertebral heights and areas did not increase significantly beyond the 12-month values. Fracture rate decreased significantly in the upper extremities (p = 0.04) but not the lower extremities (p = 0.09) during the first year of treatment. Gross motor function, muscle strength, and pain did not change significantly during the controlled or extended treatment phases.

CONCLUSIONS

A controlled trial confirmed the spine benefits of short-term pamidronate treatment in children with types III and IV OI. Pamidronate increased L1-L4 vertebral DXA and decreased vertebral compressions and upper extremity fractures. Vertebral measures did not improve during the extended treatment phase. The treatment group did not experience decreased lower extremity long bone fractures, significant improvement in growth, ambulation, muscle strength, or pain. There was substantial variability in individual response to treatment.

Maladie de Paget, prise en charge thérapeutique

Bisphosphonates, potent anti-osteoclastic agents, are nowadays the first-line therapy for Paget's disease of bone. Solid evidence about efficacy and the risk/benefit ratio favor tiludronate and risedronate for oral administration and pamidronate for intravenous administration. Treatment is always intermittent, with the frequency of therapeutic sequences depending on the specific drug and the quality and duration of response. Treatment response is assessed by the extent of the reduction of biochemical markers of bone turnover, especially plasma total alkaline phosphatase. The goal of the treatment is to induce full remission, that is, normal levels of alkaline phosphatase. Bisphosphonates should be used in all patients with bone involvement that might create long-term articular (arthropathy) or neurologic (compression) complications. This aggressive strategy is the most likely to provide effective prevention of complications in the long term.

Paget's disease of bone

Paget's disease of bone is characterized by an anarchic bone remodelling, associated with morphological and functional abnormalities of osteoclasts. Its prevalence and incidence rates decreased gradually over the past two decades; the reason for this remains unclear. The aetiology of the disease is still obscure, the paramyxoviral theory being very controversial. Recent advances in understanding of the disease come from genetic studies, with the identification of specific mutations in the p62-sequestosome gene, which could be involved in pathogenetic mechanisms leading to increased osteoclast activity. The disease affects one or several bone pieces, leading to bone pain, deformities, characteristic imaging features, and increased markers of bone remodelling. The long-lasting disease activity leads to complications, including arthropathies, neurological compressions, fissures or fractures and, rarely, osteosarcomatous transformation of a pagetic lesion. Potent bisphosphonates have proven their efficacy in reducing symptoms and disease activity. They are currently used as the first-line treatment with the goal of normalizing bone remodelling and, hopefully, preventing late complications.

Beyond the gap: functions of unpaired connexon channels

Gap junctions consist of intercellular channels that connect the cytoplasm of adjacent cells directly and allow the exchange of small molecules. These channels are unique in that they span two plasma membranes--the more orthodox ion or ligand-gated channels span only one. Each cell contributes half of the intercellular channel, and each half is known as a connexon or hemichannel. Recent studies indicate that connexons are also active in single plasma membranes and that they might be essential in intercellular signalling beyond their incorporation into gap junctions.

Alendronate treatment for infants with osteogenesis imperfecta: demonstration of efficacy in a mouse model

Recent non-placebo-controlled studies of the bisphosphonate pamidronate have shown it to be effective in reducing fractures and improving bone density in infants and children with osteogenesis imperfecta (OI). To evaluate the effects of bisphosphonate treatment in a controlled study, the oim/oim mouse model of OI was studied. Nursing infant mouse pups (approximately 2 wk old) with moderate to severe OI (oim/oim mouse) and age- and background-matched control mice (+/+) were treated either with the third-generation bisphosphonate alendronate (ALN), or with saline. Fracture risk, bone quality, and growth were evaluated over a 12-wk treatment period. ALN at a dose of 0.03 mg/kg/d or saline was administered via s.c. injection to infant oim/oim and wild-type (+/+) mice from 2 to 14 wk of age (n = 20 per subgroup). The average number of fractures sustained by the ALN-treated oim/oim mice was reduced significantly compared with the untreated oim/oim mice (0.7 +/- 0.7 fractures/mouse versus 2.0 +/- 0.2 fractures/mouse). Bone density increased significantly in the femur and the spine with treatment (2.0 +/- 0.5 versus 1.2 +/- 0.5 in femur and 2.1 +/- 0.5 versus1.6 +/- 0.5 in spine). Histologic evaluation revealed the percentage of metaphyseal tibial bone increased significantly with treatment in both +/+ and oim/oim mice. Mechanical testing revealed an increase in structural stiffness for both treated +/+ and oim/oim mice compared with untreated animals. None of the material properties examined were significantly altered with treatment, nor was spinal curvature affected. Weight gain and long bone growth were comparable in the treated and untreated oim/oim mice. In wild-type mice, femur lengths were significantly shorter in the treated mice compared with untreated counterparts. This animal study demonstrates that treatment of OI in mice as early as 2 wk of age with ALN appears to be effective in reducing fractures and increasing bone properties. Based on the data from this study, ALN therapy in infants with OI should prove to be effective.