Bisphosphonate treatment of bone disease

Clinical spectrum of rare bone fragility disorders and response to bisphosphonate treatment: a retrospective study

Osteogenesis Imperfecta (OI) is a clinically and genetically heterogeneous group of diseases characterized by brittle bones. Though genetic mutations in COL1A1 and COL1A2 account for approximately 85-90% of OI cases, there are now more than twenty genes described, responsible for rare forms of OI. Treatment is based on the use of bisphosphonates and though it is well established that they increase lumbar spine (LS) bone mineral density (BMD), the clinical impact on fracture reduction is still debated.In this study, we investigated the clinical characteristics of 38 patients with a bone fragility disorder that had variants in non-COL1A1/COL1A2 genes in order to study genotype-phenotype correlations, as the natural history of these rare forms is still not well known. We then studied the usefulness of bisphosphonate treatment by evaluating the effects on LS BMD, annual non-vertebral fracture rate, bone turnover markers and height. This study enabled us to better define the natural history of patients with non-COL1 pathogenic variants. Patients with CRTAP and TMEM38B variants consistently had a prenatal presentation with a short (<3rd p) and bowed femur. Importantly, this prenatal involvement does not predict the postnatal severity of the disease. Regarding treatment by bisphosphonates, all patients showed a significant increase in LS BMD while treated and this increase was dependent on the dose received. The increase in LS BMD also translated in a reduction of fracture rate during treatment. Finally, our study showed that the earlier bisphosphonates are initiated, the greater the fracture rate is reduced.

Influence of zoledronic acid and pamidronate on tooth eruption in children with osteogenesis imperfecta

INTRODUCTION

Osteogenesis imperfecta (OI) is a congenital disease comprising a heterogeneous group of inherited connective tissue disorders. The main treatment in children is bisphosphonate therapy. Previous animal studies have shown that bisphosphonates delay tooth eruption. The aim of this study is to determine whether patients with OI treated with pamidronate and/or zoledronic acid have a delayed eruption age compared to a control group of healthy children.

METHODS

An ambispective longitudinal cohort study evaluating the age of eruption of the first stage mixed dentition in a group of children with OI (n = 37) all treated with intravenous bisphosphonates compared with a group of healthy children (n = 89). Within the study group, the correlation (Pearson correlation test) between the type of medication administered (pamidronate and/or zoledronic acid) and the chronology of tooth eruption is established, as well as the relationship between the amount of cumulative dose received and tooth eruption.

RESULTS

The age of eruption of the study group was significantly delayed compared to the age of eruption of the control group for molars and lateral incisors (p < 0.05). Patients who received higher cumulative doses had a delayed eruption age compared to those with lower cumulative doses (p < 0.05). There is a high positive correlation between age of delayed tooth eruption and Zoledronic acid administration.

CONCLUSION

Patients with OI have a delayed eruption of the 1st stage mixed dentition compared to a control group of healthy children. This delayed eruption is directly related to the cumulative dose of bisphosphonates and the administration of zoledronic ac.

Navigating the Complex Landscape of Fibrodysplasia Ossificans Progressiva: From Current Paradigms to Therapeutic Frontiers

Fibrodysplasia ossificans progressiva (FOP) is an enigmatic, ultra-rare genetic disorder characterized by progressive heterotopic ossification, wherein soft connective tissues undergo pathological transformation into bone structures. This incapacitating process severely limits patient mobility and poses formidable challenges for therapeutic intervention. Predominantly caused by missense mutations in the ACVR1 gene, this disorder has hitherto defied comprehensive mechanistic understanding and effective treatment paradigms. This write-up offers a comprehensive overview of the contemporary understanding of FOP's complex pathobiology, underscored by advances in molecular genetics and proteomic studies. We delve into targeted therapy, spanning genetic therapeutics, enzymatic and transcriptional modulation, stem cell therapies, and innovative immunotherapies. We also highlight the intricate complexities surrounding clinical trial design for ultra-rare disorders like FOP, addressing fundamental statistical limitations, ethical conundrums, and methodological advancements essential for the success of interventional studies. We advocate for the adoption of a multi-disciplinary approach that converges bench-to-bedside research, clinical expertise, and ethical considerations to tackle the challenges of ultra-rare diseases like FOP and comparable ultra-rare diseases. In essence, this manuscript serves a dual purpose: as a definitive scientific resource for ongoing and future FOP research and a call to action for innovative solutions to address methodological and ethical challenges that impede progress in the broader field of medical research into ultra-rare conditions.

Bisphosphonates: From Pharmacology to Treatment

Bisphosphonates are among the most widely used drugs in the world for their many clinical indications. Their mechanism of action is based on the increase in the level of bone mineralization through the inhibition of osteoclastic activity and the induction of osteoblastic activity. Recent studies also attribute to bisphosphonates an antineoplastic activity, due to the ability of these drugs to inhibit neo angiogenesis, inhibiting the proliferation of endothelial cells. Bisphosphonates have several common properties, including poorly absorbed orally, high affinity for bone mineral, inhibitory effects on osteoclastic bone resorption, prolonged bone retention, and elimination in the urine. Bisphosphonates are generally well tolerated but their use can be, however, burdened by serious side effects such as hypocalcaemia, renal impairment, and aseptic osteonecrosis of the jaw.

Weight-Based Bisphosphonate Administration for Multiple Myeloma Patients and the Risks of Skeletal Complications

High-dose bisphosphonate for multiple myeloma patients might elevate risks of skeletal complications earlier than general expectations. This study aims to find incidences of atypical femoral fracture (AFF) and medication-related osteonecrosis of the jaw (MRONJ), elucidate their risk factors, and suggest cut-off values for the safer dosing of high-dose bisphosphonate treatment. By using the clinical data warehouse of a single institute, retrospective cohort data of multiple myeloma-diagnosed patients with high-dose bisphosphonate (pamidronate or zoledronate) treatment from 2009 to 2019 was extracted. Among 644 patients, the incidence of prominent AFF requiring surgery was 0.93% (6/644) and MRONJ was diagnosed in 11.8% (76/644) of the study population. For both AFF and MRONJ, the total potency-weighted sum of total dose per body weight (OR = 1.010, p = 0.005) were significant on logistic regression. Cutoffs of the potency-weighted total dose (mg) per body weight (kg) for AFF and MRONJ were 77.00 and 57.70 mg/kg, respectively. After roughly one year of treatment with high-dose zoledronate (about four years for pamidronate), an earlier thorough re-evaluation of skeletal complications should be taken. Body weight adjustments for accumulative dose calculation in terms of permissible dosing should be taken into consideration.

The Role of Bisphosphonates in Childhood Diseases

Bisphosphonates have found in recent years an increasingly wide application in adult neoplastic diseases and osteoporosis. Their mechanism of action is based on the inhibition of bone turnover favouring, in particular, the mineralization and the reduction of the frequency of the remodelling cycles. The fields of application of bisphosphonates in paediatric age are constantly evolving although new trials are needed to define the schedule of administration and their long-term side effects.

Abnormalities in Tooth Formation after Early Bisphosphonate Treatment in Children with Osteogenesis Imperfecta

Treatment with intravenous bisphosphonate (BP) in children and adolescents with osteogenesis imperfecta (OI) started in Sweden in 1991. No human studies on the role of BP therapy in development of disturbances in tooth mineralization or tooth morphology have been published. The study cohort comprised 219 individuals who were divided into four groups: group 1, BP treatment onset before 2 years of age (n = 22); group 2, BP treatment onset between 2 and 6 years of age (n = 20); group 3, BP treatment onset between 6 and 10 years of age (n = 13); and a control group of patients with OI who had not received BP therapy (n = 164). The chi-square test was used in between-group comparisons of the prevalence of tooth agenesis. The prevalence of tooth agenesis was significantly higher in children who began BP treatment before the age of 2 years (group 1; 59%,) compared to the controls (10%; p < 0.001) and to children who had begun BP therapy between ages 2 and 6 years (group 2; 10%; p = 0.009) or between ages 6 and 10 years (group 3; 8%; p = 0.003). Different types of disturbances in the enamel formation were seen in 52 premolars, where 51 were seen in those who began BP treatment before the age of 2 years. To conclude, starting BP treatment before the age of 2 years increases the risk of abnormalities in tooth formation manifesting as morphological aberrations, tooth agenesis, and enamel defects.

Bone health in childhood cancer: review of the literature and recommendations for the management of bone health in childhood cancer survivors

In the past decades, new cancer treatment approaches for children and adolescents have led to a decrease in recurrence rates and an increase in long-term survival. Recent studies have focused on the evaluation of the late effects on bone of pediatric cancer-related treatments, such as chemotherapy, radiation and surgery. Treatment of childhood cancer can impair the attainment of peak bone mass, predisposing to premature onset of low bone mineral density, or causing other bone side-effects, such as bone quality impairment or avascular necrosis of bone. Lower bone mineral density and microarchitectural deterioration can persist during adulthood, thereby increasing fracture risk. Overall, long-term follow-up of childhood cancer survivors is essential to define specific groups at higher risk of long-term bone complications, identify unrecognized long-term adverse effects, and improve patient care. Children and adolescents with a cancer history should be carefully monitored, and patients should be informed of possible late complications of their previous medical treatment. The International Osteoporosis Foundation convened a working group to review the bone complications of pediatric cancer survivors, outlining recommendations for the management of bone health, in order to prevent and treat these complications.

Bone metabolism in Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disease of not well-defined etiology that involves immune cell activation and frequently affects the skeleton. Bone involvement in LCH usually presents in the form of osteolytic lesions along with low bone mineral density. Various molecules involved in bone metabolism are implicated in the pathogenesis of LCH or may be affected during the course of the disease, including interleukins (ILs), tumor necrosis factor α, receptor activator of NF-κB (RANK) and its soluble ligand RANKL, osteoprotegerin (OPG), periostin and sclerostin. Among them IL-17A, periostin and RANKL have been proposed as potential serum biomarkers for LCH, particularly as the interaction between RANK, RANKL and OPG not only regulates bone homeostasis through its effects on the osteoclasts but also affects the activation and survival of immune cells. Significant changes in circulating and lesional RANKL levels have been observed in LCH patients irrespective of bone involvement. Standard LCH management includes local or systematic administration of corticosteroids and chemotherapy. Given the implication of RANK, RANKL and OPG in the pathogenesis of the disease and the osteolytic nature of bone lesions, agents aiming at inhibiting the RANKL pathway and/or osteoclastic activation, such as bisphosphonates and denosumab, may have a role in the therapeutic approach of LCH although further clinical investigation is warranted.

Bisphosphonate Treatment and the Characteristics of Femoral Fractures in Children With Osteogenesis Imperfecta

CONTEXT

The short-term benefits of bisphosphonates (BPs) are evident in the treatment of children with osteogenesis imperfecta (OI), but some concerns related to long-term effects remain.

OBJECTIVE

To elucidate the effect of BPs on characteristics of femoral fractures in children with OI.

DESIGN AND SETTING

Retrospective cohort study at a university hospital.

PATIENTS AND MAIN OUTCOME MEASURE

The study included 93 patients with OI. We recorded fracture histories and analyzed all femoral fractures for location and fracture type using radiographs obtained at fracture diagnosis. Effects of BPs were evaluated by comparing fracture characteristics in three groups: patients (1) naive to BPs, (2) receiving ongoing BP treatment, and (3) whose treatment was discontinued.

RESULTS

In total, 127 femoral fractures occurred in 24 patients. Of the fractures, 63 (50%) occurred in patients naive to BPs, 44 (35%) during BP treatment, and 20 (16%) after treatment discontinuation. Mid or distal shaft fractures were most common (41%), followed by subtrochanteric (33%) and distal (20%) fractures. Almost all fractures were transverse (65%) or oblique (28%). The pattern of femoral fractures was similar in all three BP treatment groups (P = 0.78 for location; P = 0.35 for fracture type) and was not related to cumulative BP dose. Instead, OI type correlated with fracture characteristics, and distal location and transverse configuration were more common in the more severe types III and IV compared with type I OI.

CONCLUSION

Characteristics of femoral fractures in children with OI are affected by OI type but not by BP exposure.

Interventions to prevent and treat corticosteroid-induced osteoporosis and prevent osteoporotic fractures in Duchenne muscular dystrophy

BACKGROUND

Corticosteroid treatment is considered the 'gold standard' for Duchenne muscular dystrophy (DMD); however, it is also known to induce osteoporosis and thus increase the risk of vertebral fragility fractures. Good practice in the care of those with DMD requires prevention of these adverse effects. Treatments to increase bone mineral density include bisphosphonates and vitamin D and calcium supplements, and in adolescents with pubertal delay, testosterone. Bone health management is an important part of lifelong care for patients with DMD.

OBJECTIVES

To assess the effects of interventions to prevent or treat osteoporosis in children and adults with DMD taking long-term corticosteroids; to assess the effects of these interventions on the frequency of vertebral fragility fractures and long-bone fractures, and on quality of life; and to assess adverse events.

SEARCH METHODS

On 12 September 2016, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL Plus to identify potentially eligible trials. We also searched the Web of Science ISI Proceedings (2001 to September 2016) and three clinical trials registries to identify unpublished studies and ongoing trials. We contacted correspondence authors of the included studies in the review to obtain information on unpublished studies or work in progress.

SELECTION CRITERIA

We considered for inclusion in the review randomised controlled trials (RCTs) and quasi-RCTs involving any bone health intervention for corticosteroid-induced osteoporosis and fragility fractures in children, adolescents, and adults with a confirmed diagnosis of DMD. The interventions might have included oral and intravenous bisphosphonates, vitamin D supplements, calcium supplements, dietary calcium, testosterone, and weight-bearing activity.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed reports and selected potential studies for inclusion, following standard Cochrane methodology. We contacted study authors to obtain further information for clarification on published work, unpublished studies, and work in progress.

MAIN RESULTS

We identified 18 potential studies, of which two, currently reported only as abstracts, met the inclusion criteria for this review. Too little information was available for us to present full results or adequately assess risk of bias. The participants were children aged five to 15 years with DMD, ambulant and non-ambulant. The interventions were risedronate versus no treatment in one trial (13 participants) and whole-body vibration versus a placebo device in the second (21 participants). Both studies reported improved bone mineral density with the active treatments, with no improvement in the control groups, but the abstracts did not compare treatment and control conditions. All children tolerated whole-body vibration treatment. No study provided information on adverse events. Two studies are ongoing: one investigating whole-body vibration, the other investigating zoledronic acid.

AUTHORS' CONCLUSIONS

We know of no high-quality evidence from RCTs to guide use of treatments to prevent or treat corticosteroid-induced osteoporosis and reduce the risk of fragility fractures in children and adults with DMD; only limited results from two trials reported in abstracts were available. We await formal trial reports. Findings from two ongoing relevant studies and two trials, for which only abstracts are available, will be important in future updates of this review.

Timing of dental development in osteogenesis imperfecta patients with and without bisphosphonate treatment

Bisphosphonates have established their role as medical therapy for pediatric osteogenesis imperfecta (OI) patients. Since bisphosphonates have also been shown to delay tooth development in animal models, we aimed to assess whether the medication has a similar effect on children with OI. In this cross-sectional study, bisphosphonate-treated OI patients of whom dental panoramic tomograph was taken between 3 and 16years of age formed the study group. The patients, 22 in total, had been treated with pamidronate, zoledronic acid or risedronate for at least one year before the radiography. Developmental stage of the permanent teeth, resorption of the deciduous teeth, and number of the erupted permanent teeth were radiographically assessed in the left mandibular quadrant. Dental panoramic tomographs of 50 OI patients, naïve to bisphosphonates, and of 50 healthy individuals of the same age were used as controls. The dental development was statistically significantly accelerated in the OI group naïve to bisphosphonates showing median advancement of dental age by 0.63years from chronological age and median increase in the number of erupted teeth by 0.31 as compared to Finnish norms. Bisphosphonate-treated OI patients displayed, however, age-appropriate dental development. The OI patients not treated with bisphosphonates also showed statistically significantly faster resorption of the deciduous teeth than the treated ones, and displayed an altered interrelationship between the resorption stage of an individual primary tooth and the developmental stage of the succedaneous permanent tooth, unlike the OI patients treated with bisphosphonate. No correlation between either cumulative bisphosphonate dose or between treatment length and any measured component of the dental development was found. To conclude, OI itself was found to lead to advanced dental development. Bisphosphonate treatment had a delaying effect in all the three aspects studied, resulting in a rate of dental development indistinguishable from normal.

Bisphosphonates in Langerhans Cell Histiocytosis: An International Retrospective Case Series

Background

Bone is the most common organ of involvement in patients with Langerhans cell histiocytosis (LCH), which is often painful and associated with significant morbidity from pathological fractures. Current first-line treatments include chemotherapy and steroids that are effective but often associated with adverse effects, whereas the disease may reactivate despite an initial response to first-line agents. Bisphosphonates are osteoclast inhibitors that have shown to be helpful in treating bone lesions of LCH. To date, there are no large international studies to describe their role in treating bone lesions of LCH.

Method

We conducted a multicenter retrospective review of 13 patients with histologically proven LCH, who had received bisphosphonates either at diagnosis or at disease reactivation.

Results

Ten patients (77%) had a single system bone disease, and 3 (23%) had bone lesions as part of multisystem disease. Median follow-up time post-bisphosphonate therapy was 4.6 years (range, 0.8 to 8.2 years). Treatment with bisphosphonates was associated with significant pain relief in almost all patients. Twelve (92%) achieved resolution of active bone lesions, and 10 out of them had no active disease for a median of 3.5 years (range, 0.8 to 5 years). One patient did not respond. No major adverse effects were reported in this series.

Conclusion

Bisphosphonates are well-tolerated drugs that can significantly improve bone pain and induce remission in active bone LCH. Future prospective studies evaluating the role of bisphosphonates in LCH are warranted.

The Effect of Osteoporosis Treatments on Fatigue Properties of Cortical Bone Tissue

Bisphosphonates are commonly prescribed for treatment of osteoporosis. Long-term use of bisphosphonates has been correlated to atypical femoral fractures (AFF). AFFs arise from fatigue damage to bone tissue that cannot be repaired due to pharmacologic treatments. Despite fatigue being the primary damage mechanism of AFFs, the effects of osteoporosis treatments on fatigue properties of cortical bone are unknown. To examine if fatigue-life differences occur in bone tissue after different pharmacologic treatments for osteoporosis, we tested bone tissue from the femurs of sheep given a metabolic acidosis diet to induce osteoporosis, followed by treatment with a selective estrogen reception modulator (raloxifene), a bisphosphonate (alendronate or zoledronate), or parathyroid hormone (teriparatide, PTH). Beams of cortical bone tissue were created and tested in four-point bending fatigue to failure. Tissues treated with alendronate had reduced fatigue life and less modulus loss at failure compared to other treatments, while tissue treated with PTH had a prolonged fatigue life. No loss of fatigue life occurred with zoledronate treatment despite its greater binding affinity and potency compared to alendronate. Tissue mineralization measured by microCT did not explain the differences seen in fatigue behavior. Increased fatigue life with PTH suggests that current treatment methods for AFF could have beneficial effects for restoring fatigue life. These results indicate that fatigue life differs with each type of osteoporosis treatment.

Crystal structure of bis-[(1-ammonio-1-phosphono-eth-yl)phospho-nato]tetra-aqua-cadmium dihydrate: a powder X-ray diffraction study

In the compound [CdL₂(H₂O)₄]·2H₂O [L = (1-ammonio-1-phosphono­eth­yl)phospho­nate, C₂H₈NO₆P₂⁻], the Cd^II ion is situated on an inversion centre being coordinated by four aqua mol­ecules in the equatorial plane and two deprotonated phospho­nate O atoms from two L ligands in the axial positions in a distorted octa­hedral geometry. Each ligand L exists in a zwitterionic form, and with an intra­molecular O—H⋯O inter­action forming an S(6) ring motif and two intra­molecular N—H⋯O inter­actions each generating an S(5) ring motif. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link complex mol­ecules into a three-dimensional network with voids of 38 ų filled with ordered lattice water mol­ecules, which are also involved in O—H⋯O hydrogen bonding.

In the title compound, [CdL₂(H₂O)₄]·2H₂O [L = (1-ammonio-1-phosphono­eth­yl)phospho­nate, C₂H₈NO₆P₂⁻], the Cd^II ion is situated on an inversion centre being coordinated by four aqua mol­ecules in the equatorial plane and two phosphonate O atoms from two deprotonated L ligands in the axial positions in a distorted octa­hedral geometry. The asymmetric unit contains one-half of the complex mol­ecule and one lattice water mol­ecule. The ligand L exists in a zwitterionic form, with a positive charge on the NH₃ group and a negative charge on the O atom of the non-coordinating phospho­nate group, and with an intra­molecular O—H⋯O inter­action forming an S(6) ring motif and two intra­molecular N—H⋯O inter­actions each generating an S(5) ring motif. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link the complex mol­ecules into a three-dimensional network in which the voids of 38 ų are filled with ordered lattice water mol­ecules, which are also involved in O—H⋯O hydrogen bonding.

Cranial base pathology in pediatric osteogenesis imperfecta patients treated with bisphosphonates

OBJECT

Cranial base pathology is a serious complication of osteogenesis imperfecta (OI). Our aim was to analyze whether bisphosphonate treatment, used to improve bone strength, could also prevent the development of craniocervical junction pathology (basilar impression, basilar invagination, or platybasia) in children with OI.

METHODS

In this single-center retrospective study the authors analyzed the skull base morphology from lateral skull radiographs and midsagittal MR images (total of 94 images), obtained between the ages of 0 and 25 years in 39 bisphosphonate-treated OI patients. The results were compared with age-matched normative values and with findings in 70 OI patients who were not treated with bisphosphonates. In addition to cross-sectional data, longitudinal data were available from 22 patients with an average follow-up period of 7.6 years. The patients, who had OI types I, III, IV, VI, and VII, had been treated with zoledronic acid, pamidronate, or risedronate for 3.2 years on average.

RESULTS

Altogether 33% of the 39 bisphosphonate-treated patients had at least 1 cranial base anomaly, platybasia being the most prevalent diagnosis (28%). Logistic regression analysis suggested a higher risk of basilar impression or invagination in patients with severe OI (OR 22.04) and/or older age at initiation of bisphosphonate treatment (OR 1.45), whereas a decreased risk was associated with longer duration of treatment (OR 0.28). No significant associations between age, height, or cumulative bisphosphonate dose and the risk for cranial base anomaly were detected. In longitudinal evaluation, Kaplan-Meier curves suggested delayed development of cranial base pathology in patients treated with bisphosphonates but the differences from the untreated group were not statistically significant.

CONCLUSIONS

These findings indicate that cranial base pathology may develop despite bisphosphonate treatment. Early initiation of bisphosphonate treatment may delay development of craniocervical junction pathology. Careful followup of cranial base morphology is warranted, particularly in patients with severe OI.

The use of bisphosphonates in children: review of the literature and guidelines for dental management

Bisphosphonates are inhibitors of osteoclastic bone resorption with therapeutic benefit in a variety of bone disorders in both adults and children. While these agents have been routinely used in adults for the past three decades, their more recent introduction into paediatric medicine means there is a paucity of data on long-term safety and effects on dental development. There is uncertainty regarding the dental management of children treated with bisphosphonates, particularly when invasive dental procedures, such as extractions and oral surgical procedures, are required. There are limited data with which to make recommendations about the dental management of patients treated with bisphosphonates, and there are no published recommendations that specifically address paediatric patients. This paper aims to outline paediatric uses and adverse effects of bisphosphonates and present recommendations on the dental management of children receiving bisphosphonates.

Langerhans cell histiocytosis case with dense metaphyseal band sign

Eosinophilic granuloma, a type of Langerhans cell histiocytosis, exhibits a classic vertebral collapse, which is called vertebra plana (Calve's disease) and it manifests as a solitary bony lesion. Vertebra plana can cause severe pain in patients. Bisphosphonates (clodronate, pamidronate and zoledronic acid) have been recently used to treat osteolytic bone lesions of LCH. Zoledronic acid has 100 times relative potency that of pamidronate. We report a case of a 10-year-old girl who had zoledronic acid treatment for severe back pain due to vertebra plana. X-ray photographs of the patient's body showed dense metaphyseal band sign, which can be found in lead poisoning, treated leukemia, healing rickets, recovery from scurvy, vitamin D hypervitaminosis, congenital hypothyroidism and hypoparathyroidism. Increased biological potent zoledronic acid deprived her of severe back pain due to vertebra plana and might cause dense metaphyseal band sign of her skeleton. Conclusion; We have cured the severe back pain of a 10-year-old girl case of eosinophilic granuloma with zoledronic acid. After that treatment, X-ray photographs of the patient's body showed dense metaphyseal band sign. There have been few such cases reported until now.

Can bisphosphonates play a role in the treatment of children with chronic kidney disease?

In patients with chronic kidney disease (CKD) renal osteodystrophy, in the form of either low- or high-turnover bone disease, is quite common. While renal transplantation is expected to reverse renal osteodystrophy, long-term treatment with glucocorticoids before and/or after transplantation may lead to osteoporosis instead. Osteoporosis is defined as a skeletal disease with low bone mineral density, microarchitectural deterioration, and concomitant fragility. In adults, bisphosphonates are widely used to treat osteoporosis and other diseases associated with excessive bone resorption. In pediatric CKD patients the efficacy and safety of these drugs have not yet been addressed adequately and thus no evidence-based recommendations regarding the optimal type of bisphosphonate, dosage, or duration of therapy are available. Furthermore, while in adults the determination of areal bone mineral density is sufficient to diagnose osteoporosis, this is not the case in children. Instead, in pediatric patients, careful morphological assessment of bone structure and formation is required. Indeed, data from studies with uremic rats indicated that bisphosphonates, via a deceleration of bone turnover, have the potential not only to aggravate pre-existing adynamic bone disease, but also to impair longitudinal growth. Thus, the widespread use of bisphosphonates in children with CKD should be discouraged until the risks and benefits have been carefully elucidated in clinical trials.

Administration of sodium ibandronate in the treatment of complicated giant cell tumor of the spine

STUDY DESIGN

Case study.

OBJECTIVE

To present three complicated cases of giant cell tumor of the spine treated with sodium ibandronate.

SUMMARY OF BACKGROUND DATA

Spinal giant cell tumors are a rare clinical entity with a high recurrence rate after operation. Furthermore, complete resection of such lesions remains a challenging surgical problem. Up to this point, no effective adjuvant therapy has been reported for primary or recurrent spinal giant cell tumors.

METHODS

One patient with a recurrent giant cell tumor of the seventh thoracic vertebra, one patient with a fifth lumbar vertebral giant cell tumor, and one patient with recurrent giant cell tumor of the sacrum were treated with sodium ibandronate either postoperatively or upon recurrence of the tumor.

RESULTS

The first patient with recurrent thoracic giant cell tumor recovered both clinically and radiologically after treatment with sodium ibandronate without reoperation at 6-years follow-up. The second patient also recovered with no recurrence of the tumor at 4-years follow-up. In the third case, although not fully recovered, the recurrent sacral tumor was under control after treatment with sodium ibandronate at 2-years follow-up.

CONCLUSION

These case studies demonstrate the potential promise of using sodium ibandronate in the treatment of primary and recurrent giant cell tumors of the spine. Furthermore, clinical evaluation should be performed in future studies.

Skeletal imaging effects of pamidronate therapy in osteosarcoma patients

BACKGROUND

After observing metaphyseal changes in pediatric and young adult patients with osteosarcoma who were treated with pamidronate, we initiated a retrospective study to identify bone findings on computed radiography of the chest and extremities, chest CT, extremity MRI, and radionuclide bone scans in this population.

OBJECTIVE

To review the generalized skeletal imaging findings on computed radiography, CT, and MR examinations in patients with osteosarcoma (OS) receiving pamidronate.

MATERIALS AND METHODS

A retrospective review of 40 patients with newly diagnosed OS (mean age, 16.5 years) receiving pamidronate with chemotherapy were identified at one institution. Computed radiography, CT, MR, and bone scans on 36 patients were reviewed for osseous changes.

RESULTS

Dense metaphyseal bands at the growth plates in long bones, epiphyseal ossification centers, anterior rib ends, sternum and spine were observed. Osseous changes occurred on CT in 69% of patients, and on computed chest radiography in 53%. Bone-within-bone appearance in the spine and ossification centers was identified on computed radiography in 36%.

CONCLUSION

OS patients treated with pamidronate can develop metaphyseal sclerotic bands as well as epiphyseal and vertebral endplate sclerosis progressing to a bone-within-bone appearance. Findings occur more frequently in younger patients with open epiphyses.

Updated recommendations for the diagnosis and management of osteoporosis: a local perspective

Postmenopausal osteoporosis and osteoporosis in elderly men are major health problems, with a significant medical and economic burden. Although osteopenia and osteoporosis are more common locally than in the West, fracture rates are generally less than in Western countries. Vitamin D deficiency is common in the region and contributes adversely to bone health. Vitamin D deficiency should be suspected and treated in all subjects with ostopenia or osteoporosis. The use of risk factors to determine fracture risk has been adopted by the World Health Organization and many international societies. Absolute fracture risk methodology improves the use of resources by targeting subjects at higher risk of fractures for screening and management. The King Faisal Specialist Hospital Osteoporosis Working Group recommends screening for women 65 years and older and for men 70 years and older. Younger subjects with clinical risk factors and persons with clinical evidence of osteoporosis or diseases leading to osteoporosis should also be screened. These guidelines provide recommendations for treatment for postmenopausal women and men older than 50 years presenting with osteoporotic fractures for persons having osteoporosis-after excluding secondary causes-or for persons having low bone mass and a high risk for fracture. The Working Group has suggested an algorithm to use at King Faisal Specialist Hospital that is based on the availability, cost, and level of evidence of various therapeutic modalities. Adequate calcium and vitamin D supplement are recommended for all. Weekly alendronate (in the absence of contraindications) is recommended as first-line therapy. Alternatives to alendronate are raloxifene or strontium ranelate. Second-line therapies are zoledronic acid intravenously once yearly, when oral therapy is not feasible or complicated by side effects, or teriparatide in established osteoporosis with fractures.

Low bone density and bone metabolism alterations in Duchenne muscular dystrophy: response to calcium and vitamin D treatment

Boys with Duchenne muscular dystrophy often have reduced bone mass and increased fracture risk. In this prospective study on 33 patients, calcifediol (25-OH vitamin D(3)) plus adjustment of dietary calcium to the recommended dose reduced bone resorption, corrected vitamin D deficiency, and increased bone mass in about two-thirds of cases.

INTRODUCTION

Low BMC and BMD and bone metabolism alterations are frequent in boys with Duchenne muscular dystrophy (DMD), especially now that long-term glucocorticosteroid (GC) treatment is the standard of care. This prospective study was designed to evaluate the effects of a first-line treatment (25-OH vitamin D(3) [calcifediol] plus adjustment of dietary calcium to the recommended daily dose) on bone.

METHODS

Thirty-three children with DMD on GC treatment were followed for 3 years: one of observation and two of treatment.

MAIN OUTCOME

spine and total body BMC and BMD increase; secondary outcome: changes in bone turnover markers (C-terminal [CTx] and N-terminal [NTx] telopeptides of procollagen type I; osteocalcin [OC]).

RESULTS

During the observation year, BMC and BMD decreased in all patients. At baseline and after 12 months, serum CTx and urinary NTx were higher than normal; OC and parathyroid hormone at the upper limit of normal; 25-OH vitamin D(3) significantly lower than normal. After 2 years of calcifediol and calcium-rich diet, BMC and BMD significantly increased in over 65% of patients, and bone metabolism parameters and turnover markers normalized in most patients (78.8%). During the observation year, there were four fractures in four patients, while during the 2 years of treatment there were two fractures in two patients.

CONCLUSIONS

Calcifediol plus adequate dietary calcium intake seems to be an effective first-line approach that controls bone turnover, corrects vitamin D deficiency, and increases BMC and BMD in most patients with DMD. Lack of response seems related to persistently high bone turnover.

Nationwide survey of bisphosphonate therapy for children with reactivated Langerhans cell histiocytosis in Japan

BACKGROUND

Several studies have suggested that Langerhans cell histiocytosis (LCH) is responsive to treatment with bisphosphonates (BPs). However the efficacy and safety of BPs therapy for childhood LCH is unknown.

PROCEDURE

Data on children with LCH who had received BPs therapy were collected retrospectively from hospitals participating in the Japanese Pediatric Leukemia/Lymphoma Study Group.

RESULTS

Twenty-one children with histologically proven LCH were identified. Of these, the case histories of 16 children who had been treated with pamidronate (PAM) for disease reactivation were analyzed in detail. The median post-PAM therapy follow-up period was 2.8 years (range: 0.9-9.3 years). The median age at commencement of PAM therapy was 9.4 years (range: 2.3-15.0 years). All children had one or more bone lesions but none had risk organ (RO) involvement. In the majority of the children, six courses of PAM were administered at a dose of 1.0 mg/kg/course at 4-week intervals. In 12 of the 16 children, all active lesions including lesions of the skin (n = 3) and soft tissues (n = 3) resolved. Of these children, eight children had no active disease for a median of 3.3 years post-PAM therapy (range: 1.8-9.3 years). Progression-free survival (PFS) was 56.3 ± 12.4% at 3 years. PFS was significantly higher in children with a first reactivation compared with children experiencing a second or subsequent reactivation.

CONCLUSIONS

PAM may be an effective treatment for reactivated LCH with bone lesions. A prospective trial of the efficacy of PAM in recurrent pediatric LCH is warranted.

Oral Alendronate Treatment for Severe Polyostotic Fibrous Dysplasia due to McCune-Albright Syndrome in a Child: A Case Report

Polyostotic fibrous dysplasia (FD) associated to McCune-Albright Syndrome (MAS) often leads to fractures, deformities, and bone pain resulting in bad quality of life. Parenteral bisphosphonates have been used in children and adolescents to improve these symptoms with few adverse effects. We evaluated the response to oral Alendronate in a girl with severe MAS FD and observed improved quality of life with reduction of bone pain.

Low bone mass in Pompe disease: muscular strength as a predictor of bone mineral density

Pompe disease is an inherited metabolic myopathy caused by deficiency of acid alpha-glucosidase. The introduction of enzyme replacement therapy as treatment for the disease may change prospects for patients and may require that more attention be paid to co-morbidities such as osteoporosis.

METHODS

Bone mineral status was assessed in children and adults with Pompe disease and compared with reference values by means of dual energy X-ray absorptiometry (DXA) technology (GE Lunar DPX, GE Health Care). Bone mineral density (BMD) of the total body and the lumbar spine (L2-L4) was measured in adults and children; BMD of the femoral neck was measured in adults only. Exclusion criteria were: age<4 years, severe contractures, and inability to transfer the patient.

RESULTS

46 patients were enrolled in the study; 36 adults and 10 children. The BMD was significantly lower in Pompe patients than in healthy individuals. Sixty-seven percent of patients had a BMD Z-score below -1, 26% were classified as osteoporosis/low bone mass for chronological age (T-score<-2.5 in adults or Z-score<-2 in children), 66% had a BMD Z-score below -1 of the femoral neck, and 34% had a BMD Z-score below -1 for the lumbar spine. Osteoporosis/low bone mass for chronological age was more frequent in patients who were wheelchair-bound, but was also observed in ambulant patients. We found a significant correlation between proximal muscle strength and total body BMD. Of the 10 children, 8 (all four patients with the classic infantile form) had a low BMD.

CONCLUSION

Low BMD is a frequent finding in patients with Pompe disease and may be causally related to decreased proximal muscle strength. BMD should be monitored at regular intervals. Children deserve specific attention.

Fractures in myelomeningocele

Background

In patients with myelomeningocele (MMC), a high number of fractures occur in the paralyzed extremities, affecting mobility and independence. The aims of this retrospective cross-sectional study are to determine the frequency of fractures in our patient cohort and to identify trends and risk factors relevant for such fractures.

Materials and methods

Between March 1988 and June 2005, 862 patients with MMC were treated at our hospital. The medical records, surgery reports, and X-rays from these patients were evaluated.

Results

During the study period, 11% of the patients (n = 92) suffered one or more fractures. Risk analysis showed that patients with MMC and thoracic-level paralysis had a sixfold higher risk of fracture compared with those with sacral-level paralysis. Femoral-neck z-scores measured by dual-energy X-ray absorptiometry (DEXA) differed significantly according to the level of neurological impairment, with lower z-scores in children with a higher level of lesion. Furthermore, the rate of epiphyseal separation increased noticeably after cast immobilization. Mainly patients who could walk relatively well were affected.

Conclusions

Patients with thoracic-level paralysis represent a group with high fracture risk. According to these results, fracture and epiphyseal injury in patients with MMC should be treated by plaster immobilization. The duration of immobilization should be kept to a minimum (<4 weeks) because of increased risk of secondary fractures. Alternatively, patients with refractures can be treated by surgery, when nonoperative treatment has failed.

Driven to death: Inhibition of farnesylation increases Ras activity and promotes growth arrest and cell death [corrected]

To improve cancer outcomes, investigators are turning increasingly to small molecule medicines that disrupt vital signaling cascades, inhibit malignant growth, or induce apoptosis. One vital signaling molecule is Ras, and a key step in Ras activation is membrane anchoring of Ras through prenylation, the C-terminal addition of a lipid anchor. Small molecule inhibitors of farnesyltransferase (FTI), the enzyme most often responsible for prenylating Ras, showed clinical promise, but development of FTIs such as tipifarnib has been stalled by uncertainty about their mechanism of action, because Ras seemed unimpeded in tipifarnib-treated samples. Interpretation was further complicated by the numerous proteins that may be farnesylated, as well as availability of an alternate prenylation pathway, geranylgeranylation. Our initial observations of varied response by cancer cell lines to tipifarnib led us to evaluate the role of FTI in Ras signal alteration using various tumor models. We describe our novel counterintuitive finding that endogenous Ras activity increases in cancer cell lines with low endogenous Ras activity when farnesyltransferase is inhibited by either tipifarnib or short hairpin RNA. In response to tipifarnib, variable growth arrest and/or cell death correlated with levels of activated extracellular signal–regulated kinase (ERK) and p38 mitogenactivated protein kinase (MAPK). Sensitivity to tipifarnib treatment was shown by growth inhibition and by an increase in subdiploid cell numbers; cells with such sensitivity had increased activation of ERK and p38 MAPK. Because Ras must be prenylated to be active, our findings suggest that geranylgeranylated N-Ras or K-Ras B interacts differently with downstream effector proteins in sensitive cancer cells responding to tipifarnib, switching the balance from cell proliferation to growth inhibition [corrected].

Bisphosphonate treatment modifies canine bone mineral and matrix properties and their heterogeneity

Bone loss and alterations in bone quality are major causes leading to bone fragility in postmenopausal women. Although bisphosphonates are well known to reduce bone turnover and prevent bone loss in postmenopausal osteoporosis, their effects on other bone properties are not fully characterized. Changes in bone mineral and matrix properties may contribute to the anti-fracture efficacy observed with bisphosphonate treatments. The aim of this work was to analyze the effect of a 1-year treatment with either alendronate or risedronate, at low and high doses, on spatially resolved bone material and compositional properties that could contribute to the fracture efficacy of these agents. Distal tibias from 30 normal beagles that had been treated daily for 1 year with oral doses of vehicle (Veh), alendronate (Aln) at 0.2 or 1 mg/kg, and risedronate (Ris) at 0.1 or 0.5 mg/kg were analyzed by Fourier Transform Infrared imaging (FTIRI) to assess the changes in both mineral and matrix properties in discrete bone areas. The widths at half maximum of the pixel histograms for each FTIRI parameter were used to assess the heterogeneity of the bone tissue. Aln and Ris increased the mineral content and the collagen maturity mainly in cancellous bone and at the endocortical surface. Significant differences were observed in the mineral content and in the hydroxyapatite crystallinity distribution in bone tissue, which can contribute to reduced ductility and micro-crack accumulation. No significant differences were observed between low and high dose nor between Aln and Ris treatments. These results show that pharmacologic suppression of bone turnover increases the mineral and matrix bone tissue maturity in normal cancellous and endocortical bone areas where bone turnover is higher. These positive effects for decreased fracture risk are also associated with a loss of bone heterogeneity that could be one factor contributing to increased bone tissue brittleness and micro-crack accumulation.

In vitro assessment of liposomal neridronate on MDA-MB-231 human breast cancer cells

Bisphosphonates have been used for decades in the standard therapy of bone-related diseases, including bone metastasis of various malignancies, and they might as well be toxic on early cancer cells themselves. In order to allow a better delivery of neridronate (a N-containing bisphosphonate with relatively poor activity), liposomes were evaluated in vitro on cancer cell lines (MDA-MB-231, U87-MG and Caco2). After chemical synthesis, this water-soluble molecule was encapsulated into liposomes containing DOPC:DOPG:Chol (72:27:1 molar ratio). The influence of neridronate (free or liposomal) on cell viability or proliferation after treatment was evaluated using the MTT method, as well as cell migration and invasion assays; these techniques showed a drastic improvement of the action of neridronate on MDA-MB-231 cells with an EC(50) 50 times lower when neridronate was encapsulated. Internalization of liposomes was followed by flow cytometry and fluorescence microscopy, demonstrating internalization via the endocytic pathway. Furthermore, since overexpression of matrix metalloproteinases (particularly MMP-2 and MMP-9) has been correlated to poor prognosis in many cancer types, detection of MMP expression is a satisfactory indication of the therapy efficiency and was then performed on treated cells. On MDA-MB-231 cells, MPPs expression was also significantly reduced by neridronate while entrapped in liposomes.

Safety and efficacy of intravenous zoledronic acid in paediatric osteoporosis

AIM

To study the safety and efficacy of zoledronic acid treatment in children with osteoporotic bone disorders.

STUDY DESIGN

Observational study in 22 patients with osteogenesis imperfecta and related conditions who were treated at our institution with zoledronic acid. These patients had initial treatment with pamidronate. Lumbar spine z-scores, annual change in areal bone mineral density, bone mineral adjusted density, fracture number and linear growth before and after zoledronic acid treatment was commenced were compared.

RESULTS

Patients were treated for a mean of 3.4 years with zoledronic acid after a mean of 3.75 years of pamidronate therapy. There was no difference in areal bone mineral density accrual in the first year of zoledronic acid treatment compared to the preceding year of pamidronate treatment. Lumbar spine z-scores and bone mineral adjusted density continued to increase with zoledronic acid. Number of fractures during treatment was significantly reduced compared to baseline with either bisphosphonate, with no difference between treatments. Linear growth was not affected.

CONCLUSIONS

Zoledronic acid is at least as effective as pamidronate as treatment for paediatric osteoporosis, and has a similar safety profile.

Management of osteoporosis in children

Osteoporosis is being increasingly recognised in paediatric practice as a consequence of several factors. These include the increasing complexity of chronic conditions and the associated treatments managed by paediatricians. In addition, the improved care provided to children with chronic illness has led to many of them living long enough to develop osteoporosis. The availability of methods to assess bone density in children as a surrogate marker of bone strength and the possibility of medical treatment to increase bone density have also resulted in an increased awareness of groups of children who may be at risk of osteoporosis. This article reviews the current definition of osteoporosis in children, aetiological factors and the evidence for effective treatment.

Determination of bisphosphonate active pharmaceutical ingredients in pharmaceuticals and biological material: a review of analytical methods

Bisphosphonates is a class of chemical compounds finding extensive medical applications against bone disorders including osteoporosis, Pagets' disease, etc. Non-N-containing members include etidronate, clodronate and tiludronate, while N-containing bisphosphonates include active pharmaceutical compounds such as pamidronate, neridronate, olpadronate, alendronate, ibandronate, risedronate and zoledronate. The present study covers 20 years of analytical research on this group of compounds, focusing on bioanalytical and pharmaceutical QC applications. A wide range of analytical techniques is presented and critically discussed including among others liquid and gas phase separations, electrophoretic, electroanalytical, automated and enzymatic approaches.

Osteogenesis imperfecta: diagnosis and treatment

Osteogenesis imperfecta is a heritable disorder characterized by extremely fragile bones, blue sclerae, dentinogenesis imperfecta, hearing loss, and scoliosis. In 1979, Sillence classified the condition into four types based on genetic and clinical criteria. Three more classifications have subsequently been added. Diagnosis of osteogenesis imperfecta may be done prenatally (in severe cases), clinically, radiographically, or via biochemical or genetic examination. Medical treatment consists of bisphosphonate use, even in patients younger than age 2 years. Surgical treatment consists of internal splinting of long bones. Research is currently being done on the use of smart intramedullary rods (ie, composed of nitinol shape-memory alloy) for correction of bone deformity and on the use of bone marrow transplantation to increase osteoblast density, thereby reducing fracture frequency.

Bisphosphonate-associated osteonecrosis of the jaw: does it occur in children?

BACKGROUND

Bisphosphonate use in adult patients has been linked to osteonecrosis of the jaw (ONJ). This complication has not been systematically assessed in a paediatric population receiving bisphosphonates.

OBJECTIVE

To assess our cohort of paediatric patients treated with intravenous bisphosphonate for occurrence of ONJ.

DESIGN

Observational study at a tertiary children's hospital.

PATIENTS

A total of 42 paediatric patients with osteoporosis who received bisphosphonate infusions for a mean of 6.5 years (SD 2.7 years) were assessed clinically and radiographically for possible ONJ. Among 42, 37 patients had received disodium pamidronate 1 mg/kg/dose at a mean cumulative dose of 19.8 mg/kg and zoledronic acid (ZA) 0.05 mg/kg/dose at a mean cumulative dose of 0.49 mg/kg; four had received ZA and one received pamidronate alone. Invasive dental treatment during bisphosphonate treatment, a known risk factor for osteonecrosis, was specifically assessed.

RESULTS

In all patients assessed, including 11 who had invasive dental treatment, there were no cases of osteonecrosis.

CONCLUSION

ONJ has so far not been demonstrated in this patient group.

No osteonecrosis in jaws of young patients with osteogenesis imperfecta treated with bisphosphonates

BACKGROUND

Recent reports of osteonecrosis of the jaw (ONJ) after dental surgery in patients treated with second- and third-generation nitrogen-containing bisphosphonates instigated this retrospective study. As treatment with bisphosphonates in patients with osteogenesis imperfecta (OI) has become an important symptomatic therapy, especially for severe forms of the disease, we found it important to investigate whether healing after surgical exposure of jaw bone was influenced by the bisphosponate treatment in our group of children, adolescents and young adults with OI.

SUBJECTS AND METHODS

Disodiumpamidronate was given as monthly intravenous infusion to 64 patients with OI aged 3 months to 20.9 years at the start of treatment (mean 8.1, median 7.7). During 0.5-12.5 years of treatment (mean 4.5, median 4.0), a total individual dose of 140-4020 mg/m(2) disodiumpamidronate was given (mean 1623 and median 1460). Ten patients continued with oral alendronate and two with zoledronic acid therapy. In 22 of these patients, 38 dental surgery procedures were performed at the age of 3.4-31.9 years (mean 12.2, median 12.3) after 0.03-7.9 years of treatment (mean 3.6, median 3.4).

RESULTS

Despite long-term intravenous monthly disodiumpamidronate treatment, none of the 64 patients had any clinical signs of ONJ.

CONCLUSIONS

The risk of ONJ in these patients must be considered so low that the patients with indications for treatment should be treated and get the chance to experience the well-documented beneficial effect for children with severe OI.

Osteoporosis in children with cancer

As increasing numbers of childhood cancer patients are surviving, the long-term complications of the disease and its treatment have become ever more increasingly important. Reduced bone mineral density and increased fracture risk have been reported during and after treatment of children with cancer. The causes of osteoporosis are multifactorial. Among others, the disease itself, chemotherapy, irradiation and genetic susceptibility play a role. Bone mineral density in later life depends largely on the peak bone mass achieved in adolescence or young adulthood. Therefore, optimizing peak bone mass is of clinical importance. Preventive and therapeutic strategies, such as calcium and vitamin D supplementation, physical activity and bisphosphonates, are considered.