Bisphosphonates use in children

The Mechanotransduction Signaling Pathways in the Regulation of Osteogenesis

Bones are constantly exposed to mechanical forces from both muscles and Earth's gravity to maintain bone homeostasis by stimulating bone formation. Mechanotransduction transforms external mechanical signals such as force, fluid flow shear, and gravity into intracellular responses to achieve force adaptation. However, the underlying molecular mechanisms on the conversion from mechanical signals into bone formation has not been completely defined yet. In the present review, we provide a comprehensive and systematic description of the mechanotransduction signaling pathways induced by mechanical stimuli during osteogenesis and address the different layers of interconnections between different signaling pathways. Further exploration of mechanotransduction would benefit patients with osteoporosis, including the aging population and postmenopausal women.

Safety and Efficacy of Alendronate to Treat Osteopenia in Children During Therapy for Acute Lymphoblastic Leukemia: A Retrospective Cohort Study of Sequential Outcomes

BACKGROUND

Low bone mineral density is encountered in children with acute lymphoblastic leukemia (ALL) before, during, and after treatment. Prior experience with alendronate, an oral bisphosphonate, demonstrated high tolerability and evident clinical efficacy. However, concerns have been expressed about the long-term safety and utility of such agents in children.

PROCEDURE

Sixty-nine children with ALL received alendronate for a mean of 87 weeks after dual-energy x-ray absorptiometry. Dual-energy x-ray absorptiometry was repeated following the completion of alendronate, and 5 to 9 years later in a subgroup of 32 children. Lumbar spine areal bone mineral density (LS aBMD) Z scores were obtained.

RESULTS

The mean LS aBMD Z score rose from -1.78 to-0.47 (P <0.0001). There was a modest median loss of LS aBMD subsequently in the 32 subjects on long-term follow-up. Almost 80% (N=172) of the children remain in continuous complete remission at a mean of 14.5 years from diagnosis. Of those who received alendronate, which was almost uniformly well tolerated, 7/69 (10.3%) relapsed compared with 19/89 (21.3%) who did not receive the drug.

DISCUSSION

Alendronate appears to be well tolerated and moderately effective in osteopenic children with ALL. Whether it offers protection against relapse of leukemia needs further study.

A Pragmatic Approach to Assessment of Chronic and Recurrent Pain in Children with Severe Neurologic Impairment

The term “severe neurologic impairment” (SNI) is used to describe a group of disorders of the central nervous system which arise in childhood, resulting in motor impairment, cognitive impairment and medical complexity. As a result, much assistance is required with activities of daily living. Since these patients are often unable to self-report pain, or they may exhibit uncommon behaviors when suffering, pain manifestations may go unrecognized. In this article, the basic principles of how to approach pain in children with SNI are discussed.

Can children be affected by bisphosphonate-related osteonecrosis of the jaw? A systematic review

Knowledge of bisphosphonate-related osteonecrosis of the jaw (BRONJ) is mostly based on adult cases, however bisphosphonates are also currently recommended for different paediatric diseases resulting in osteoporosis. The aim of this study was to review the literature on the risk of developing BRONJ in children and adolescents. The PubMed, LILACS, Web of Science, Scopus, and Cochrane databases were searched using the key words "bisphosphonates", "osteonecrosis", "jaw", and "children". Literature reviews, case reports, abstracts, theses, textbooks, and book chapters were excluded. Studies involving children and young adults (younger than 24 years of age) were included. A total of 56 publications were identified. After applying the eligibility criteria, only seven articles remained. Although no cases of osteonecrosis were identified, all studies had weaknesses such as a limited sample size or the absence of risk factors for the development of osteonecrosis. There is general consensus that this subject should be of concern and that further studies should be conducted before any definitive opinion is reached. It is believed that patients with secondary osteoporosis who use bisphosphonates continuously should be followed up during adulthood, since bone turnover decreases over the years.

Novel homozygous inactivating mutation of the calcium-sensing receptor gene in neonatal severe hyperparathyroidism responding to cinacalcet therapy: A case report and literature review

RATIONALE

Calcium-sensing receptor (CaSR) mutations can cause life-threatening neonatal severe hyperparathyroidism (NSHPT). The medical management of NSHPT is often challenging and complex. Here, we present a case of NSHPT caused by a novel homozygous CaSR mutation.

PATIENT CONCERNS

A Chinese female infant presented with poor feeding, constipation, severe hypotonia, and periodic bradycardia. Biochemistry tests revealed markedly elevated serum levels of Ca and parathyroid hormone (PTH).

DIAGNOSES

Genetic sequencing revealed a previously undescribed CaSR mutation in exon 3 (c.242T>A; p.I81K). A diagnosis of NSHPT secondary to homozygously inherited familial hypocalciuric hypercalcemia syndrome was established.

INTERVENTIONS

Cinacalcet was administered after the common treatments (low-calcium intake, hydration, and furosemide), calcitonin, and pamidronate therapy all failed.

OUTCOMES

Serum Ca decreased and stabilized with cinacalcet therapy. During a 10-month follow-up, total calcium was maintained within the high-normal range and PTH was normalized.

LESSONS

A trial of cinacalcet therapy might be undertaken in cases of NSHPT while definitive results of the genetic analysis are awaited.

Case report: acute clinical presentation and neonatal management of primary hyperparathyroidism due to a novel CaSR mutation

Background

Neonatal severe primary hyperparathyroidism (NSHPT) is a rare autosomal recessive disorder of calcium homeostasis, characterized by striking hyperparathyroidism, marked hypercalcemia and hyperparathyroid bone disease. We report the case of a newborn with a novel homozygous mutation of the CaSR, treated by successful subtotal parathyroidectomy, who had an acute presentation of the disease, i.e. out-of hospital cardiorespiratory arrest. .

Case presentation

A 8-day-old female newborn was admitted to the NICU of University of Bari “Aldo Moro” (Italy) after a cardiorespiratory arrest occurred at home. Severe hypercalcemia was found and different drug therapies were employed (Furosemide, Cinacalcet and bisphosphonate), as well as hyperhydration, until subtotal parathyroidectomy, was performed at day 32. Our patient’s mutation was never described before so that a strict and individualized long-term follow-up was started.

Conclusions

This case of NSHPT suggests that a near-miss event, labelled as a possible case of SIDS, could also be due to severe hypercalcemia and evidentiates the difficulties of the neonatal management of NSHPT. Furthermore, the identification of the specific CaSR mutation provides the substrate for prenatal diagnosis.

Hypercalcemia: a consultant's approach

Due to their daily involvement in mineral metabolism, nephrologists are often asked to consult on children with hypercalcemia. This might become even more pertinent when the hypercalcemia is associated with acute kidney injury and/or hypercalciuria and renal calcifications. The best way to assess the severity of hypercalcemia is by measurement of plasma ionized calcium, and if not available by adjusting serum total calcium to albumin concentration. The differential diagnosis of the possible etiologies of the disturbance in the mineral homeostasis starts with the assessment of serum parathyroid hormone concentration, followed by that of vitamin D metabolites in search of both genetic and acquired etiologies. Several tools are available to acutely treat hypercalcemia with the current main components being fluids, loop diuretics, and antiresorptive agents. This review will address the pathophysiologic mechanisms, clinical manifestations, and treatment modalities involved in hypercalcemia.

Risk factors for nonunion of bone fracture in pediatric patients: An inception cohort study of 237,033 fractures

Adult fracture nonunion risk is related to injury severity and surgical technique, yet nonunion is not fully explained by these risk factors alone; biological risk factors are also important. We test a hypothesis that risk factors associated with pediatric fracture nonunion are similar to adult nonunion risk factors.Inception cohort study in a large payer database of pediatric fracture patients (0-17 years) in the United States in calendar year 2011. Continuous enrollment in the database was required for 12 months, to allow time to capture a nonunion diagnosis. The final database collated demographic descriptors, treatment procedures as per Current Procedural Terminology (CPT) codes, comorbidities as per International Statistical Classification of Diseases and Related Health Problems (ICD-9) codes, and drug prescriptions as per National Drug Code Directory (Red Book) codes. Logistic regression was used to calculate odds ratios (ORs) for variables associated with nonunion.Among 237,033 pediatric fractures in 18 bones, the nonunion rate was 0.85%. Increased nonunion risk was associated with increasing age, male gender, high body-mass index, severe fracture (e.g., open fracture, multiple fractures), and tobacco smoking (all, P < .0001). Nonunion rate varied with fracture location; scaphoid, neck of femur, and tibia/fibula were most likely to go to nonunion. Nonunion ORs were significantly increased for risk factors including; surgical procedure, cardiovascular disease, Vitamin D deficiency, osteoarthritis, osteoporosis, and opioid prescription (all, multivariable P < .001).Nonunion is rare in pediatric patients, but nonunion risk increases with increasing age. We confirm a hypothesis that risk factors for pediatric nonunion are similar to adult nonunion risk factors. Scaphoid fractures in adolescents have nearly the same risk of nonunion as in adults. Opioids should be used cautiously in pediatric patients, as they are associated with a significant and substantial elevation of nonunion risk.

LEVEL OF EVIDENCE

Prognostic study, Retrospective, Level II.

A network meta-analysis on the short-term efficacy and adverse events of different anti-osteoporosis drugs for the treatment of postmenopausal osteoporosis

A network meta-analysis was conducted to compare the short-term efficacy and adverse events of different drugs for the treatment of postmenopausal osteoporosis (PMO), providing a more effective treatment for PMO. We initially searched through various databases like PubMed, Cochrane Library, and EMBASE from inception till October 2016. All randomized controlled trials (RCTs) of drugs for the treatment of PMO were included for direct and indirect comparison. A combination of direct and indirect evidence of different inhibitors of anti-diabetic drugs for treatment of PMO were considered for calculating the weighted mean difference (WMD) value or odd ratio (OR) value and to draw surface under the cumulative ranking (SUCRA) curves. Twenty-seven RCTs were ultimately incorporated into this network meta-analysis comprising of 48 200 patients suffering from PMO. The network meta-analysis revealed that compared with placebo, alendronate had better efficacy on improving bone mineral density (BMD) at lumbar spine, femoral neck, and total hip. Risedronate and raloxifene had relatively lower incidence of new vertebral fractures. The SUCRA analysis showed that alendronate had better efficacy on improving BMD, risedronate could significantly decrease the incidence of fresh fracture and bazedoxifene was relatively safe. The available evidence suggested that alendronate and risedronate might be the superior choices for the treatment of PMO, while bazedoxifene was a comparatively safer option for patients.

Effect of Low-Magnitude, High-Frequency Mechanical Stimulation on BMD Among Young Childhood Cancer Survivors: A Randomized Clinical Trial

IMPORTANCE

Bone accrual during youth is critical to establish sufficient strength for lifelong skeletal health. Children with cancer may develop low bone mineral density (BMD) any time before or after diagnosis.

OBJECTIVE

To evaluate the ability of low-magnitude, high-frequency mechanical stimulation to enhance BMD among childhood cancer survivors.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind randomized clinical trial conducted at St Jude Children's Research Hospital from June 1, 2010, to January 22, 2013, using cancer survivors, ages 7 to 17 years, who were previously treated at St Jude Children's Research Hospital, were in remission, and at least 5 years from diagnosis, with whole-body or lumbar spine BMD z scores of -1.0 or lower. Participants were randomized (stratified by sex and Tanner stage) to either a placebo device or low-magnitude, high-frequency mechanical stimulation device, which was used at home.

INTERVENTIONS

Placebo or low-magnitude, high-frequency mechanical stimulation (0.3 g; 32-37 Hz) for 2 sessions lasting 10 minutes each, 7 days per week for 1 year. All participants were prescribed daily cholecalciferol (vitamin D) and calcium.

MAIN OUTCOMES AND MEASURES

Changes in areal and volumetric BMD and bone biomarkers were compared by analysis of variance, adjusted for strata.

RESULTS

Of the 65 participants, 32 were randomized to the intervention group (mean [SD] age was 13.6 [3.7] years, 18 [56.2%] were male, and 27 [84.4%] were white), and 33 were randomized to the placebo group (mean [SD] age was 13.6 [2.9] years, 17 [51.5%] were male, and 26 [78.8%] were white). Forty-eight participants completed the trial, 22 in the intervention group and 26 in the placebo group with median adherence of 70.1% for intervention and 63.7% for placebo groups. With intention-to-treat analysis, mean (SD) whole-body BMD z score by dual x-ray absorptiometry improved by 0.25 (0.78) in the intervention (n = 22), but decreased by -0.19 (0.79) in the placebo group (n = 26, P = .05). Circulating osteocalcin at 12 months correlated with change in total body BMD (r = 0.35, P = .02). Tibial trabecular bone among participants completing 70% or more of the prescribed sessions increased by a mean of 11.2% (95% CI, 5.2 to 17.2%) compared with those completing less than 70% who decreased by a mean of -1.3% (95% CI, -7.3 to 4.7%; P = .02). Change in circulating receptor activator of nuclear factor κ-B ligand was higher in the intervention than in the placebo group (0.06 [0.16] vs -0.04 [0.17] pmol/L) (P = .04).

CONCLUSIONS AND RELEVANCE

Pediatric cancer survivors with low BMD may benefit from low-magnitude, high-frequency mechanical stimulation as a novel and safe intervention to optimize peak bone mass during youth, alone or in conjunction with other therapies.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01010230.

Life-Threatening Hypercalcemia During Prodrome of Pneumocystis jiroveci Pneumonia in an Immunocompetent Infant

Severe hypercalcemia in infants is usually attributed to genetic etiologies and less commonly to acquired ones. An 8-week-old girl presented with failure to thrive, mild respiratory distress, and life-threatening hypercalcemia (23.5 mg/dL). Serum 1,25(OH)₂-vitamin D (1,25(OH)₂-D) level was elevated and parathyroid hormone undetectable. Evaluation for genetic mutations and malignant etiologies of hypercalcemia was negative. Treatment with intravenous hydration, loop diuretic, and calcitonin failed to correct the hypercalcemia, which was subsequently controlled with bisphosphonate therapy. Due to progressive respiratory deterioration, a bronchopulmonary lavage was done on day 17 of her hospitalization disclosing Pneumocystis jiroveci infection. The subsequent immunological investigation showed no abnormalities. She was treated with trimethoprim/sulfamethoxazole resulting in gradual clearing of her lungs and normalization of serum 1,25(OH)₂-D level. A year later, she remains healthy with normal biochemical parameters of mineral metabolism. We conclude that in a child with hypercalcemia with suppressed parathyroid hormone and elevated 1,25(OH)₂-D, once the genetic etiology for elevated 1,25(OH)₂-D and malignancy are ruled out, one should investigate closely for a chronic granulomatous disease. Among the latter Pneumocystis jiroveci pneumonia infection should be considered even in an immunocompetent child.

Intra-tumor delivery of zoledronate mitigates metastasis-induced osteolysis superior to systemic administration

Bisphosphonates (BPs) have recently been shown to have direct anti-tumor properties. Systemic treatment with BPs can have multiple adverse effects such as osteonecrosis of the jaw and BP induced bone fracturing and spine instability. While benefits of systemic BP treatments may outweigh risks, local treatment with BPs has been explored as an alternate strategy to reduce unwarranted risk. In the present study, we examined whether local delivery of BPs inhibits tumor-induced osteolysis and tumor growth more effectively than systemic treatment in an animal model of tumor-induced bone disease. Following establishment of an intra-tibial model of bone metastases in athymic mice, the experimental group was treated by local administration of zoledronate into the tibial lesion. A comparison of the effect of local versus systemic delivery of zoledronate on the formation of tumor-induced osteolysis was also carried out. A significant increase in mean bone volume/tissue volume % (BV/TV) of the locally treated group (12.30±2.80%) compared to the control group (7.13±1.22%) (P<0.001). Additionally, there was a significant increase in the BV/TV (10.90±1.25%) in the locally treated group compared to the systemically treated group (7.53±0.75%) (P=0.005). These preliminary results suggest that local delivery of BPs outperforms both systemic and control treatments to inhibit tumor-induced osteolysis.

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.

Efficacy and safety of pamidronate in children with vitamin D intoxication

BACKGROUND

Bisphosphonates are used in the treatment of vitamin D intoxication (VDI) after failure of conventional therapy including prednisolone. Safety concerns restrict the use of bisphosphonates from being used as first-line therapy for VDI in children. The aim of this study was to evaluate the efficacy and safety of pamidronate in comparison with prednisolone in children with VDI.

METHODS

We reviewed the hospital records of children consecutively diagnosed with VDI at two medical centers in a 15 year period.

RESULTS

The subjects consisted of 21 children (age, 0.3-4.2 years) who were treated with prednisolone and/or bisphosphonates. Pamidronate (n = 18) or alendronate (n = 3) was used in six patients after unsuccessful prednisolone treatment, and in 15 patients from baseline. Initial serum calcium and 25-hydroxyvitamin D were 16.1 ± 1.9 mg/dL and 493 ± 219 ng/mL, respectively. The median time to reach normocalcemia in the pamidronate, alendronate and prednisolone groups was 3 days (range, 2-12 days), 4 days (range, 3-6 days) and 17 days (range, 12-26 days), respectively (P = 0.013). The pamidronate group had a fivefold shorter hospital stay than the prednisolone group. Three patients initially treated with prednisolone developed nephrocalcinosis but this did not occur in any patient treated with bisphosphonates from baseline. Apart from transient fever and moderate hypophosphatemia, no side-effect of bisphosphonate treatment was observed.

CONCLUSIONS

Pamidronate is efficient and safe for the treatment of VDI in children. Pamidronate use significantly shortens the duration of treatment, and thereby may prevent the development of nephrocalcinosis. Instead of prednisolone, pamidronate should be used together with hydration and furosemide as the first-line therapy for VDI.

Efficacy of pamidronate in pediatric osteosarcoma patients with low bone mineral density

PURPOSE

Most surviving pediatric osteosarcoma patients experience osteoporosis, bone pain, and pathologic fracture during and after therapy. The aim of this study was to evaluate the efficacy and side effects of pamidronate therapy in these patients.

METHODS

Nine osteosarcoma patients (12.8±1.6 years of age; 5 boys and 4 girls) who had a history of nontraumatic fracture or severe pain after completing chemotherapy were included. Intravenous pamidronate (1.5 mg/kg) was given every 6 weeks for 4 to 6 cycles. Bone mineral density (BMD) of the lumbar spine was measured by dual-energy x-ray absorptiometry. Clinical outcomes including acute side effects were also evaluated.

RESULTS

After pamidronate treatments, all patients experienced decreased pain. Seven of 9 patients could walk without a crutch. The BMD of lumbar spine was increased by 0.108±0.062 mg/cm(2) after 8.4±1.0 months (n=8, P=0.017) and the mean z-score improved from -2.14±0.94 to -1.76±0.95 (P=0.161). Six patients (67%) had an acute-phase reaction, and 2 patients had symptomatic hypocalcemia.

CONCLUSION

Pamidronate appears to be safe and effective for the treatment of osteosarcoma in children with low BMD and bone pain.

Effect of alendronate on the mandible and long bones: an experimental study in vivo

BACKGROUND

Bisphosphonates are anticatabolic agents that inhibit bone resorption and are widely used to treat osteoporosis and bone metastases in adults. They are also used in young patients with diseases like osteogenesis imperfecta or juvenile osteoporosis. Bone modeling/remodeling is elevated in growing subjects, and inhibition of osteoclastic activity has been shown to interfere with growth. Thus, our objective was to evaluate the effect of alendronate (ALN) on growing animals.

METHODS

Healthy male Wistar rats, aged 1 mo, received ALN or vehicle for 8 wk. Serum levels (calcemia, phosphatemia, and total alkaline phosphatase) were determined. Morphometric (rat: femur and tibia weight and length and hemimandible growth) and histomorphometric parameters (thickness of tibial epiphyseal cartilage and each cartilage zone, interradicular bone volume in the first lower molar, trabeculae volume, percentage of bone and cartilage, and osteoclast number in mandibular condyles) were assessed.

RESULTS

ALN caused a significant decrease in femur and tibia length, tibial cartilage thickness, and longitudinal growth of hemimandibles. It increased interradicular bone volume and mandibular condyle trabeculae volume, increasing the percentage of cartilage and osteoclast number.

CONCLUSION

These findings indicate that administration of ALN to growing animals alters the endochondral ossification process, and thus alters growth.

Update Review and Clinical Presentation in Congenital Insensitivity to Pain and Anhidrosis

Introduction. Congenital insensitivity to pain and anhidrosis (CIPA) or hereditary sensory and autonomic neuropathy type IV is an extremely rare syndrome. Three clinical findings define the syndrome: insensitivity to pain, impossibility to sweat, and mental retardation. This pathology is caused by a genetic mutation in the NTRK1 gene, which encodes a tyrosine receptor (TrkA) for nerve growth factor (NGF). Methods. The consultation of a child female in our center with CIPA and a tibia fracture in pseudoarthrosis encouraged us to carefully review literature and examine the therapeutic possibilities. A thorough review of literature published in Pubmed was done about CIPA and other connected medical issues mentioned in the paper. Conclusions. The therapeutic approach of CIPA remains unclear. The preventive approach remains the only possible treatment of CIPA. We propose two new important concepts in the therapeutic approach for these patients: (1) early surgical treatment for long bone fractures to prevent pseudoarthrosis and to allow early weight bearing, decreasing the risk of further osteopenia, and (2) bisphosphonates to avoid the progression of osteopenia and to reduce the number of consecutive fractures.

Zoledronic Acid for the Treatment of Children With Refractory Central Giant Cell Granuloma

There are no approved medical therapies for the treatment of pediatric central giant cell granuloma (CGCG), a benign but potentially aggressive tumor of the jaw. Zoledronic acid (ZA), a third-generation bisphosphonate, has been used in CGCG occurring in adults. We describe 4 patients with CGCG treated with ZA, 3 of whom achieved resolution of disease up to 4 years of follow-up. Our experience suggests that ZA may be considered as treatment for pediatric CGCG.

The use of bisphosphonates in pediatrics

Bisphosphonates are widely used for the prevention and treatment of osteoporosis in adulthood. In the last years, bisphosphonates have been increasingly used in pediatric patients for the treatment of a growing number of disorders associated with osteoporosis, resistant hypercalcemia or heterotopic calcifications. The use of bisphosphonates in pediatric patients has been proven safe; however, the risk of potential severe consequences into adulthood should be kept in mind. Well-defined criteria for bisphosphonates treatment in pediatric patients are not specified, therefore an accurate selection of patients who could benefit from bisphosphonates is mandatory. A strict follow-up of pediatric patients receiving long-term bisphosphonate therapy is strongly recommended. The purpose of this mini review is to provide a summary of current knowledge on some main general aspects of the structure, mechanisms of action, pharmacokinetics, and bioavailability of bisphosphonates, and to focus on the latest advances of bisphosphonate treatment in pediatric patients. Particular attention has been paid to the common and potential adverse effects of bisphosphonate treatment, and some suggestions concerning the clinical approach and general measures for bisphosphonate treatment in pediatric patients are reported.

Effects of antiepileptic drugs on bone health and growth potential in children with epilepsy

BACKGROUND

Bone health may be impaired in children with epilepsy.

OBJECTIVES

Our objective was to characterize bone mineral density (BMD) and bone growth in children receiving antiepileptic drugs (AEDs) and to assess the effects of co-morbidity, vitamin D deficiency, and type of drugs used.

DATA SOURCES

Data were sourced from PubMed, Embase, and Web of Science.

ELIGIBILITY CRITERIA

Cross-sectional, cohort, case-control, or randomized controlled trials reporting BMD or parameters of bone growth.

PARTICIPANTS

Children with epilepsy compared with controls.

INTERVENTIONS

AEDS or ketogenic diet.

STUDY APPRAISAL

The studies were evaluated by one author.

SYNTHESIS METHODS

Studies were categorized as reporting reduced BMD or not at any skeletal site as outcome. A logistic regression was performed for age, percent boys, study design, type of AED, co-morbidity or not, and signs of vitamin D deficiency/osteomalacia or not.

RESULTS

Carbamazepine and valproate were analyzed as monotherapy in 11 studies, and for both drugs a limited decrease in BMD seemed present. For oxcarbazepine, levetiracetam, phenytoin, phenobarbital, and topiramate, only one study with monotherapy was found for each drug, none of which reported decreased bone density. Polytherapy with AEDs seemed to be associated with a larger decrease in bone density than was monotherapy. Although few studies were available on bone growth, these did indicate that bone growth may be impaired among users of AEDs. Ketogenic diet may be associated with decreased bone density. The main determinant of normal BMD was absence of vitamin D deficiency/osteomalacia.

LIMITATIONS

The studies differed in skeletal sites studied and most were cross-sectional. No head-to-head comparisons of AEDs were performed. Children treated with polytherapy or ketogenic diet may have more complicated and severe disease than those treated with monotherapy. The underlying cause of epilepsy and vitamin D deficiency may contribute to impaired bone growth and density.

CONCLUSIONS

Reduced bone density, impaired bone growth, and vitamin D deficiency may be seen in children treated with drugs against epilepsy.

IMPLICATIONS

Measures to correct vitamin D deficiency, calcium intake should be taken.

Radiographic and MR Imaging Findings of the Spine after Bisphosphonate Treatment, in a Child with Idiopathic Juvenile Osteoporosis

Bisphosphonates are employed with increasing frequency in various pediatric disorders, mainly associated with osteoporosis. After cessation of bisphosphonate treatment in children, skeletal radiologic changes have been documented including dense metaphyseal lines of the long bones and "bone in bone" appearance of the vertebrae. However, the evolution of these radiographic changes has not been fully explored. We describe the MR imaging appearance of the spine that, to our knowledge, has not been previously addressed in a child with idiopathic juvenile osteoporosis who had received bisphosphonates and emphasize the evolution of the radiographic findings of the spine and pelvis over a four-year period.

Body composition and bone health in long-term survivors of acute lymphoblastic leukaemia in childhood and adolescence: the protocol for a cross-sectional cohort study

INTRODUCTION

Success in the treatment of young people with cancer, as measured conventionally by survival rates, is mitigated by late effects of therapy that impose a burden of morbidity and limit life expectancy. Among these adverse sequelae are altered body composition, especially obesity, and compromised bone health in the form of osteoporosis and increased fragility. These outcomes are potentially reversible and even preventable. This study will examine measures of body composition and bone health in long-term survivors of acute lymphoblastic leukaemia (ALL) in childhood and adolescence. These measures will be complemented by measures of physical activity and health-related quality of life (HRQL).

METHODS AND ANALYSIS

Survivors of ALL who are at least 10 years from diagnosis, following treatment on uniform protocols, will undergo measurements of body mass index; triceps skin fold thickness and mid-upper arm circumference; fat mass, lean body mass, skeletal muscle mass and bone mineral density by dual energy X-ray absorptiometry; trabecular and cortical bone indices and muscle density by peripheral quantitative CT; physical activity by the Habitual Activity Estimation Scale; and HRQL by Health Utilities Index instruments. Descriptive measures will be used for continuous variables and number (percent) for categorical variables. Associations between variables will be assessed using Fisher's exact t test and the χ(2) test; correlations will be tested by the Pearson correlation coefficient.

ETHICS AND DISSEMINATION

The study is approved by the institutional research ethics board and is supported by a competitive funding award. Dissemination of the results will occur by presentations to scientific meetings and publications in peer-reviewed journals, and by posting summaries of the results on websites accessed by adolescent and young adult survivors of cancer.

Implications of high-dosage bisphosphonate treatment on bone tissue in the jaw and knee joint

Bisphosphonates are bone antiresorptive agents traditionally used on a relatively large scale for treatment of bone metabolic diseases and on a smaller scale for bone metastasis treatment. A study on the effects of bisphosphonate treatment on healthy instead of diseased animals will give more insight into the basic mechanisms of bisphosphonates and their effects on different bone sites. We aimed to assess the effect of BP on the mouse knee and jaw joint. Three-month old female C57BL/6 mice were used (twenty-four and eighteen control and experimental group, respectively). At baseline and after treatment with zoledronic acid (ZA) for one, three or six months, we combined bone assessment via µCT and additional histology. Our results showed that, in the knee joint, ZA treatment increased TMD, bone volume, trabecular thickness but did not influence cortical thickness. In both control and ZA group, a higher trabecular TMD compared to cortical TMD was seen. Unseen in the knee joint, ZA treatment in the jaw joint resulted in bone-site specific changes in mineralization; a significant time-dependent higher TMD was evident in the subchondral bone compared to the most distal region of the condyle. MicroCT images revealed the presence of mineral in this region and histology showed that this region did not contain mature bone tissue but cartilage-like tissue. Our data indicate the possibility of site-specific negative side effects, i.e., disturbing normal mandibular development under the influence of bisphosphonate therapy.

[Advances in the treatment of secondary osteoporosis]

Osteoporosis is being increasingly recognised in paediatric practice as a consequence of the increasing life expectancy of children who suffer from chronic diseases and other factors. There are many non-pharmacological measures that can improve children' bone health, for example, avoiding inflammatory activity and osteotoxic treatments; increasing sun exposure and weight-bearing exercise, and maintaining an adequate nutritional status. Vitamin D and calcium supplements have been proposed as a measure to increase bone mass, but their effect and therapeutic indications are not completely clear. On the other hand, bisphosphonates are currently the only pharmacological alternative for the patients with infantile secondary osteoporosis. However, more studies are required on the therapeutic indications, posology, and long term secondary effects of biphosphonates. The aim of this article is to analyze the scientific evidence of the effectiveness of the therapeutic alternatives for childhood secondary osteoporosis and their safety in children.

Use of bisphosphonates in orthopedic surgery: pearls and pitfalls

Bisphosphonates are medications known to decrease bone resorption by inhibiting osteoclastic activity. They are the first-line therapy for the treatment of osteoporosis because a significant body of literature has proved their efficacy in reducing the risk of fracture in the hip, spine and other nonvertebral osseous sites. In addition, the use of bisphosphonates has significantly decreased morbidity and increased survival, and they have also proved to be cost-effective. Unexpected adverse effects have been reported recently, but the benefit of bisphosphonates use outweighs the risks. This article reviews the current use of bisphosphonates in orthopedic surgery.

Novel homozygous inactivating mutation of the calcium-sensing receptor gene (CASR) in neonatal severe hyperparathyroidism-lack of effect of cinacalcet

BACKGROUND

NSHPT is a life-threatening disorder caused by homozygous inactivating calcium-sensing receptor (CASR) mutations. In some cases, the CaSR allosteric activator, cinacalcet, may reduce serum PTH and calcium levels, but surgery is the treatment of choice.

OBJECTIVE

To describe a case of NSHPT unresponsive to cinacalcet.

PATIENT AND RESULTS

A 23-day-old girl was admitted with hypercalcemia, hypotonia, bell-shaped chest and respiratory distress. The parents were first-degree cousins once removed. Serum Ca was 4.75 mmol/l (N: 2.10-2.62), P: 0.83 mmol/l (1.55-2.64), PTH: 1096 pg/ml (9-52) and urinary Ca/Cr ratio: 0.5mg/mg. First, calcitonin was given (10 IU/kg × 4/day), and then 2 days later, pamidronate (0.5mg/kg) for 2 days. Doses of cinacalcet were given daily from day 28 of life starting at 30 mg/m2 and increasing to 90 mg/m2 on day 43. On day 33, 6 days after pamidronate, serum Ca levels had fallen to 2.5 mmol/l but, thereafter, rose to 5 mmol/l despite the cinacalcet. Total parathyroidectomy was performed at day 45. Hungry bone disease after surgery required daily Ca replacement and calcitriol for 18 days. At 3 months, the girl was mildly hypercalcemic, with no supplementation, and at 6 months, she developed hypocalcemia and has since been maintained on Ca and calcitriol. By CASR mutation analysis, the infant was homozygous and both parents heterozygous for a deletion-frameshift mutation.

CONCLUSION

The predicted nonfunctional CaSR is consistent with lack of response to cinacalcet, but total parathyroidectomy was successful. An empiric trial of the drug and/or prompt mutation testing should help minimize the period of unnecessary pharmacotherapy.

Bone mineral density deficits and fractures in survivors of childhood cancer

Although substantial increases in survival rates among children diagnosed with cancer have been observed in recent decades, survivors are at risk of developing therapy-related chronic health conditions. Among children and adolescents treated for cancer, acquisition of peak bone mass may be compromised by cancer therapies, nutritional deficiencies, and reduced physical activity. Accordingly, failure to accrue optimal bone mass during childhood may place survivors at increased risk for deficits in bone density and fracture in later life. Current recommendations for the treatment of bone density decrements among cancer survivors include dietary counseling and supplementation to ensure adequate calcium and vitamin D intake. Few strategies exist to prevent or treat bone loss. Moving forward, studies characterizing the trajectory of changes in bone density over time will facilitate the development of interventions and novel therapies aimed at minimizing bone loss among survivors of childhood cancer.