Systematic review of effectiveness of bisphosphonates in treatment of low bone mineral density and fragility fractures in juvenile idiopathic arthritis

Bone Health in Children with Rheumatic Disorders: Focus on Molecular Mechanisms, Diagnosis, and Management

Bone is an extremely dynamic and adaptive tissue, whose metabolism and homeostasis is influenced by many different hormonal, mechanical, nutritional, immunological and pharmacological stimuli. Genetic factors significantly affect bone health, through their influence on bone cells function, cartilage quality, calcium and vitamin D homeostasis, sex hormone metabolism and pubertal timing. In addition, optimal nutrition and physical activity contribute to bone mass acquisition in the growing age. All these factors influence the attainment of peak bone mass, a critical determinant of bone health and fracture risk in adulthood. Secondary osteoporosis is an important issue of clinical care in children with acute and chronic diseases. Systemic autoimmune disorders, like juvenile idiopathic arthritis, can affect the skeletal system, causing reduced bone mineral density and high risk of fragility fractures during childhood. In these patients, multiple factors contribute to reduce bone strength, including systemic inflammation with elevated cytokines, reduced physical activity, malabsorption and nutritional deficiency, inadequate daily calcium and vitamin D intake, use of glucocorticoids, poor growth and pubertal delay. In juvenile arthritis, osteoporosis is more prominent at the femoral neck and radius compared to the lumbar spine. Nevertheless, vertebral fractures are an important, often asymptomatic manifestation, especially in glucocorticoid-treated patients. A standardized diagnostic approach to the musculoskeletal system, including prophylaxis, therapy and follow up, is therefore mandatory in at risk children. Here we discuss the molecular mechanisms involved in skeletal homeostasis and the influence of inflammation and chronic disease on bone metabolism.

Clinical practice guidelines for optimizing bone health in Korean children and adolescents

The Committee on Pediatric Bone Health of the Korean Society of Pediatric Endocrinology has newly developed evidence-based clinical practice guidelines for optimizing bone health in Korean children and adolescents. These guidelines present recommendations based on the Grading of Recommendations, which includes the quality of evidence. In the absence of sufficient evidence, conclusions were based on expert opinion. These guidelines include processes of bone acquisition, definition, and evaluation of low bone mineral density (BMD), causes of osteoporosis, methods for optimizing bone health, and pharmacological treatments for enhancing BMD in children and adolescents. While these guidelines provide current evidence-based recommendations, further research is required to strengthen these guidelines.

Effect of Bisphosphonates on Fracture Incidence in Young Adults With Low Bone Density

OBJECTIVE

To assess the effect of bisphosphonates on fracture incidence in young adults over a 5-year follow-up period.

METHODS

Based on the Kaiser Permanente electronic health record, this retrospective study investigated patients aged 19 to 40 years with abnormal bone density (either any Z-score of ≤-2 standard deviation [SD] or any T-score of ≤-2.5 SD). The incidence and time to fracture between the control (patients with <6 months of bisphosphonate exposure) and treatment (patients with ≥6 months of bisphosphonate use within 4 years of their first dual energy x-ray absorptiometry scan) groups were compared. Comparisons were analyzed with Χ² test for categorical variables and Wilcoxon rank sum test for continuous variables.

RESULTS

A total of 422 patients met the inclusion and exclusion criteria. Fractures occurred in 18 patients (5.0%) of the control group (n = 358) and 5 patients (7.8%) of the treatment group (n = 64; P = .37). T-scores were significantly lower in the treatment group (-2.53 ± 0.58 SD) than those in the control group (-2.30 ± 0.80 SD; P = .002) but did not correlate with fracture risk. No significant differences were found in total fracture incidence (hazard ratio = 1.54; 95% confidence interval, 0.26-6.26). Similarly, no correlation was noted between the length of bisphosphonate therapy and fracture incidence (odds ratio = 0.99; 95% confidence interval, 0.966-1.026).

CONCLUSION

In summary, we did not find a clear correlation of fracture incidence with the use of bisphosphonates in young adults. Further research into the pathophysiology, specific etiologies, and treatment options in this population is needed.

Growth and puberty in children with juvenile idiopathic arthritis

Juvenile Idiopathic Arthritis is one of the most prevalent chronic diseases in children, with an annual incidence of 2-20 cases per 100,000 and a prevalence of 16-150 per 100,000. It is associated with several complications that can cause short-term or long-term disability and reduce the quality of life. Among these, growth and pubertal disorders play an important role. Chronic inflammatory conditions are often associated with growth failure ranging from slight decrease in height velocity to severe forms of short stature. The prevalence of short stature in JIA varies from 10.4% in children with polyarticular disease to 41% of patients with the systemic form, while oligoarthritis is mostly associated with localized excessive bone growth of the affected limb, leading to limb dissymmetry. The pathogenesis of growth disorders is multifactorial and includes the role of chronic inflammation, long-term use of corticosteroids, undernutrition, altered body composition, delay of pubertal onset or slow pubertal progression. These factors can exert a systemic effect on the GH/IGF-1 axis and on the GnRH-gonadotropin-gonadic axis, or a local influence on the growth plate homeostasis and function. Although new therapeutic options are available to control inflammation, there are still 10-20% of patients with severe forms of the disease who show continuous growth impairment, ending in a short final stature. Moreover, delayed puberty is associated with a reduction in the peak bone mass with the possibility of concomitant or future bone fragility. Monitoring of puberty and bone health is essential for a complete health assessment of adolescents with JIA. In these patients, an assessment of the pubertal stage every 6 months from the age of 9 years is recommended. Also, linear growth should be always evaluated considering the patient's bone age. The impact of rhGH therapy in children with JIA is still unclear, but it has been shown that if rhGH is added at high dose in a low-inflammatory condition, post steroids and on biologic therapy, it is able to favor a prepubertal growth acceleration, comparable with the catch-up growth response in GH-deficient patients. Here we provide a comprehensive review of the pathogenesis of puberty and growth disorders in children with JIA, which can help the pediatrician to properly and timely assess the presence of growth and pubertal disorders in JIA patients.

Expert panel consensus recommendations for diagnosis and treatment of secondary osteoporosis in children

BACKGROUND

Osteoporosis incidence in children is increasing due to the increased survival rate of patients suffering from chronic diseases and the increased use of drugs that can damage bones. Recent changes made to the definition of childhood osteoporosis, along with the lack of guidelines or national consensuses regarding its diagnosis and treatment, have resulted in a wide variability in the approaches used to treat this disease. For these reasons, the Osteogenesis Imperfecta and Childhood Osteoporosis Working Group of the Spanish Society of Pediatric Rheumatology has sounded the need for developing guidelines to standardize clinical practice with regard to this pathology.

METHODS

An expert panel comprised of 6 pediatricians and 5 rheumatologists carried out a qualitative literature review and provided recommendations based on evidence, when that was available, or on their own experience. The level of evidence was determined for each section using the Oxford Centre for Evidence-based Medicine (CEBM) system. A Delphi survey was conducted for those recommendations with an evidence level of IV or V. This survey was sent to all members of the SERPE. All recommendations that had a level of agreement higher or equal to 70% were included.

RESULTS

Fifty-one recommendations, categorized into eight sections, were obtained. Twenty-four of them presented an evidence level 4 or 5, and therefore a Delphi survey was conducted. This was submitted electronically and received a response rate of 40%. All recommendations submitted to the Delphi round obtained a level of agreement of 70% or higher and were therefore accepted.

CONCLUSION

In summary, we present herein guidelines for the prevention, diagnosis and treatment of secondary childhood osteoporosis based on the available evidence and expert clinical experience. We believe it can serve as a useful tool that will contribute to the standardization of clinical practice for this pathology. Prophylactic measures, early diagnosis and a proper therapeutic approach are essential to improving bone health, not only in children and adolescents, but also in the adults they will become in the future.

Protecting Bone Health in Pediatric Rheumatic Diseases: Pharmacological Considerations

Bone health in children with rheumatic conditions may be compromised due to several factors related to the inflammatory disease state, delayed puberty, altered life style, including decreased physical activities, sun avoidance, suboptimal calcium and vitamin D intake, and medical treatments, mainly glucocorticoids and possibly some disease-modifying anti-rheumatic drugs. Low bone density or even fragility fractures could be asymptomatic; therefore, children with diseases of high inflammatory load, such as systemic onset juvenile idiopathic arthritis, juvenile dermatomyositis, systemic lupus erythematosus, and those requiring chronic glucocorticoids may benefit from routine screening of bone health. Most commonly used assessment tools are laboratory testing including serum 25-OH-vitamin D measurement and bone mineral density measurement by a variety of methods, dual-energy X-ray absorptiometry as the most widely used. Early disease control, use of steroid-sparing medications such as disease-modifying anti-rheumatic drugs and biologics, supplemental vitamin D and calcium, and promotion of weight-bearing physical activities can help optimize bone health. Additional treatment options for osteoporosis such as bisphosphonates are still controversial in children with chronic rheumatic diseases, especially those with decreased bone density without fragility fractures. This article reviews common risk factors leading to compromised bone health in children with chronic rheumatic diseases and discusses the general approach to prevention and treatment of bone fragility.

Bone histomorphometric changes in children with rheumatic disorders on chronic glucocorticoids

BACKGROUND

Rheumatic diseases are associated with an increased fracture risk. The tissue level characteristics of the bone involvement in children have not been well elucidated. Our objectives were to describe the bone micro-architectural characteristics in children with rheumatic diseases on chronic glucocorticoids, and to determine associations between micro-architectural findings with clinical and radiological variables.

METHODS

Children on chronic glucocorticoids for an underlying rheumatic disease were referred for evaluation of bone fragility given the presence of vertebral compression fractures. A trans-iliac bone biopsy was performed as part of the clinical assessment. Histomorphometric analysis and quantitative backscattered electron imaging (qBSE) of the biopsy samples were undertaken.

RESULTS

Data of 15 children (14.0 ± 3.2 years) with a duration of glucocorticoid exposure of 6.2 ± 4.1 years and average prednisone dose of 14.1 ± 6.2 mg/m²/day were assessed. Histomorphometric analyses demonstrated significant decrease in trabecular thickness (p = 0.01), osteoid thickness (p < 0.01), osteoblast surface (p = 0.02) and increase in trabecular separation (p = 0.04) compared to published age-matched normative data. Severity of the trabecular deficit was correlated to glucocorticoid dose, height and body mass index Z score, but not bone mineral density or measures of disease activity. Using qBSE to measure bone mineralization, the subjects were shown to have a heterogeneous and hypermineralized profile, with higher cumulative glucocorticoid dose being associated with greater mineralization (p < 0.01).

CONCLUSIONS

In children with rheumatic diseases presenting with vertebral fractures, there is evidence of abnormal bone matrix mineralization and impairments of bone micro-architecture that correlate to glucocorticoid dose.

Bisphosphonate therapy for osteogenesis imperfecta

BACKGROUND

Osteogenesis imperfecta is caused by a genetic defect resulting in an abnormal type I collagen bone matrix which typically results in multiple fractures with little or no trauma. Bisphosphonates are used in an attempt to increase bone mineral density and reduce these fractures in people with osteogenesis imperfecta. This is an update of a previously published Cochrane Review.

OBJECTIVES

To assess the effectiveness and safety of bisphosphonates in increasing bone mineral density, reducing fractures and improving clinical function in people with osteogenesis imperfecta.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Inborn Errors of Metabolism Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of journals and conference proceedings. We additionally searched PubMed and major conference proceedings.Date of the most recent search of the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Register: 28 April 2016.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing bisphosphonates to placebo, no treatment, or comparator interventions in all types of osteogenesis imperfecta.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed the risk of bias of the included trials.

MAIN RESULTS

Fourteen trials (819 participants) were included. Overall, the trials were mainly at a low risk of bias, although selective reporting was an issue in several of the trials. Data for oral bisphosphonates versus placebo could not be aggregated; a statistically significant difference favouring oral bisphosphonates in fracture risk reduction and number of fractures was noted in two trials. No differences were reported in the remaining three trials which commented on fracture incidence. Five trials reported data for spine bone mineral density; all found statistically significant increased lumbar spine density z scores for at least one time point studied. For intravenous bisphosphonates versus placebo, aggregated data from two trials showed no statistically significant difference for the number of participants with at least one fracture, risk ratio 0.56 (95% confidence interval 0.30 to 1.06). In the remaining trial no statistically significant difference was noted in fracture incidence. For spine bone mineral density, no statistically significant difference was noted in the aggregated data from two trials, mean difference 9.96 (95% confidence interval -2.51 to 22.43). In the remaining trial a statistically significant difference in mean per cent change in spine bone mineral density z score favoured intravenous bisphosphonates at six and 12 months. Data describing growth, bone pain, and functional outcomes after oral or intravenous bisphosphonate therapy, or both, as compared to placebo were incomplete among all studies, but do not show consistent improvements in these outcomes. Two studies compared different doses of bisphosphonates. No differences were found between doses when bone mineral density, fractures, and height or length z score were assessed. One trial compared oral versus intravenous bisphosphonates and found no differences in primary outcomes. Two studies compared the intravenous bisphosphonates zoledronic acid and pamidronate. There were no significant differences in primary outcome. However, the studies were at odds as to the relative benefit of zoledronic acid over pamidronate for lumbosacral bone mineral density at 12 months.

AUTHORS' CONCLUSIONS

Bisphophonates are commonly prescribed to individuals with osteogenesis imperfecta. Current evidence, albeit limited, demonstrates oral or intravenous bisphosphonates increase bone mineral density in children and adults with this condition. These were not shown to be different in their ability to increase bone mineral density. It is unclear whether oral or intravenous bisphosphonate treatment consistently decreases fractures, though multiple studies report this independently and no studies report an increased fracture rate with treatment. The studies included here do not show bisphosphonates conclusively improve clinical status (reduce pain; improve growth and functional mobility) in people with osteogenesis imperfecta. Given their current widespread and expected continued use, the optimal method, duration of therapy and long-term safety of bisphosphonate therapy require further investigation. In addition, attention should be given to long-term fracture reduction and improvement in quality of life indicators.

The Child with Multiple Fractures, What Next?

Fractures are common during childhood; however, they can also be the presenting symptom of primary or secondary causes of bone fragility. The challenge is to identify those children who warrant further investigation. In children who present with multiple fractures that are not commonly associated with mild to moderate trauma or whose fracture count is greater than what is typically seen for their age, an initial evaluation, including history, physical examination, biochemistry, and spinal radiography, should be performed. In children with bone pain or evidence of more significant bone fragility, referral for specialist evaluation and consideration of pharmacologic treatment may be warranted.

Complications of systemic juvenile idiopathic arthritis: risk factors and management recommendations

Systemic juvenile idiopathic arthritis (SJIA) is an inflammatory condition characterized by fever, lymphadenopathy, arthritis, rash and serositis. Systemic inflammation has been associated with dysregulation of the innate immune system, suggesting that SJIA is an autoinflammatory disorder. IL-1 and IL-6 play a major role in the pathogenesis of SJIA, and treatment with IL-1 and IL-6 inhibitors has shown to be highly effective. However, complications of SJIA, including macrophage activation syndrome, limitations in functional outcome by arthritis and long-term damage from chronic inflammation, continue to be a major issue in SJIA patients' care. Translational research leading to a profound understanding of the cytokine crosstalk in SJIA and the identification of risk factors for SJIA complications will help to improve long-term outcome.

Preclinical evidence of potential craniofacial adverse effect of zoledronic acid in pediatric patients with bone malignancies

High doses of zoledronic acid (ZOL), one of the most potent inhibitors of bone resorption, are currently evaluated in phase III clinical trials in Europe for the treatment of malignant pediatric primary bone tumors. The impact of such an intensive treatment on the craniofacial skeleton growth is a critical question in the context of patients with actively growing skeleton; in particular, in light of our previous studies evidencing that endochondral bone formation was transiently disturbed by high doses of ZOL. Two protocols adapted from pediatric treatments were developed for newborn mice (a total of 5 or 10 injections of ZOL 50μg/kg every two days). Their impact on skull bones and teeth growth was analyzed by X-rays, microCT and histology up to 3months after the last injection. ZOL administrations induced a transient delay of skull bone growth and an irreversible delay in incisor, first molar eruption and root elongation. Other teeth were affected, but most were erupted by 3months. Root histogenesis was severely impacted for all molars and massive odontogenic tumor-like structures were observed in all mandibular incisors. High doses of ZOL irreversibly disturbed teeth eruption and elongation, and delayed skull bone formation. These preclinical observations are essential for the follow-up of onco-pediatric patients treated with ZOL.

Optimizing bone health in children and adolescents

The pediatrician plays a major role in helping optimize bone health in children and adolescents. This clinical report reviews normal bone acquisition in infants, children, and adolescents and discusses factors affecting bone health in this age group. Previous recommended daily allowances for calcium and vitamin D are updated, and clinical guidance is provided regarding weight-bearing activities and recommendations for calcium and vitamin D intake and supplementation. Routine calcium supplementation is not recommended for healthy children and adolescents, but increased dietary intake to meet daily requirements is encouraged. The American Academy of Pediatrics endorses the higher recommended dietary allowances for vitamin D advised by the Institute of Medicine and supports testing for vitamin D deficiency in children and adolescents with conditions associated with increased bone fragility. Universal screening for vitamin D deficiency is not routinely recommended in healthy children or in children with dark skin or obesity because there is insufficient evidence of the cost-benefit of such a practice in reducing fracture risk. The preferred test to assess bone health is dual-energy x-ray absorptiometry, but caution is advised when interpreting results in children and adolescents who may not yet have achieved peak bone mass. For analyses, z scores should be used instead of T scores, and corrections should be made for size. Office-based strategies for the pediatrician to optimize bone health are provided. This clinical report has been endorsed by American Bone Health.

Glucocorticoid-associated osteoporosis in chronic inflammatory diseases: epidemiology, mechanisms, diagnosis, and treatment

Children with chronic illnesses such as Juvenile Idiopathic Arthritis and Crohn's disease, particularly when taking glucocorticoids, are at significant risk for bone fragility. Furthermore, when childhood illness interferes with achieving normal peak bone mass, life-long fracture risk is increased. Osteopenia and osteoporosis, which is increasingly recognized in pediatric chronic disease, likely results from numerous disease- and treatment-related factors, including glucocorticoid exposure. Diagnosing osteoporosis in childhood is complicated by the limitations of current noninvasive techniques such as DXA, which despite its limitations remains the gold standard. The risk:benefit ratio of treatment is confounded by the potential for spontaneous restitution of bone mass deficits and reshaping of previously fractured vertebral bodies. Bisphosphonates have been used to treat secondary osteoporosis in children, but limited experience and potential long-term toxicity warrant caution in routine use. This article reviews the factors that influence loss of normal bone strength and evidence for effective treatments, in particular in patients with gastrointestinal and rheumatologic disorders who are receiving chronic glucocorticoid therapy.

Bisphosphonate therapy for osteogenesis imperfecta

BACKGROUND

Osteogenesis imperfecta is caused by a genetic defect resulting in an abnormal type I collagen bone matrix which typically results in multiple fractures with little or no trauma. Bisphosphonates are used in an attempt to increase bone mineral density and reduce these fractures in people with osteogenesis imperfecta.

OBJECTIVES

To assess the effectiveness and safety of bisphosphonates in increasing bone mineral density, reducing fractures and improving clinical function in people with osteogenesis imperfecta.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Inborn Errors of Metabolism Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of journals and conference proceedings. We additionally searched PubMed and major conference proceedings.Date of the most recent search: 07 April 2014.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing bisphosphonates to placebo, no treatment, or comparator interventions in all types of osteogenesis imperfecta.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed the risk of bias of the included trials.

MAIN RESULTS

Fourteen trials (819 participants) were included. Overall, the trials were mainly at a low risk of bias, although selective reporting was an issue in several of the trials. Data for oral bisphosphonates versus placebo could not be aggregated; a statistically significant difference favouring oral bisphosphonates in fracture risk reduction and number of fractures was noted in two trials. No differences were reported in the remaining three trials which commented on fracture incidence. Five trials reported data for spine bone mineral density; all found statistically significant increased lumbar spine density z scores for at least one time point studied. For intravenous bisphosphonates versus placebo, aggregated data from two trials showed no statistically significant difference for the number of participants with at least one fracture, risk ratio 0.56 (95% confidence interval 0.30 to 1.06). In the remaining trial no statistically significant difference was noted in fracture incidence. For spine bone mineral density, no statistically significant difference was noted in the aggregated data from two trials, mean difference 9.96 (95% confidence interval -2.51 to 22.43). In the remaining trial a statistically significant difference in mean per cent change in spine bone mineral density z score favoured intravenous bisphosphonates at six and 12 months. Data describing growth, bone pain, and functional outcomes after oral or intravenous bisphosphonate therapy, or both, as compared to placebo were incomplete among all studies, but do not show consistent improvements in these outcomes. Two studies compared different doses of bisphosphonates. No differences were found between doses when bone mineral density, fractures, and height or length z score were assessed. One study compared oral versus intravenous bisphosphonates and found no differences in primary outcomes. Two studies compared the intravenous bisphosphonates zoledronic acid and pamidronate. There were no significant differences in primary outcome. However, the studies were at odds as to the relative benefit of zoledronic acid over pamidronate for lumbosacral bone mineral density at 12 months.

AUTHORS' CONCLUSIONS

Bisphophonates are commonly prescribed to individuals with osteogenesis imperfecta. Current evidence, albeit limited, demonstrates oral or intravenous bisphosphonates increase bone mineral density in children and adults with this condition. These were not shown to be different in their ability to increase bone mineral density. It is unclear whether oral or intravenous bisphosphonate treatment consistently decreases fractures, though multiple studies report this independently and no studies report an increased fracture rate with treatment. The studies included here do not show bisphosphonates conclusively improve clinical status (reduce pain; improve growth and functional mobility) in people with osteogenesis imperfecta. Given their current widespread and expected continued use, the optimal method, duration of therapy and long-term safety of bisphosphonate therapy require further investigation. In addition, attention should be given to long-term fracture reduction and improvement in quality of life indicators.

Association between juvenile idiopathic arthritis and osteogenesis imperfecta: case report

The authors report a rare association case of juvenile idiopathic arthritis (JIA) and osteogenesis imperfecta (OI) in a 53 years-old female patient, present a literature review and discuss the radiological aspects of the temporo-mandibular joint involvement. To our knowledge, this is the first case report of JIA an OI association.

Adding to complexity: comorbidity in paediatric rheumatic disease

Novel therapies including biologic agents offer paediatric rheumatologists significant opportunity to improve long-term prognosis for children with rheumatic disease. However, comorbidities related to the diseases themselves and their treatments pose specific challenges to be overcome. Prompt recognition and appropriate management will improve quality of life, effectiveness of treatment and overall prognosis. In this review, we discuss key areas of comorbidity frequently encountered in paediatric rheumatology including cardiovascular, renal, genito-urinary and visual comorbidity, bone health, drug-related issues and the influence of rheumatic disease on growth and puberty.

Skeletal health of children and adolescents with inflammatory bowel disease

Current evidence points to suboptimal bone health in children and adolescents with inflammatory bowel disease (IBD) when compared with their healthy peers. This compromise is evident from diagnosis. The clinical consequences and long-term outcome of this finding are still unknown. The mechanism of suboptimal bone health in children and adolescents with IBD lays mainly in reduced bone formation, but also reduced bone resorption, processes necessary for bone growth. Factors contributing to this derangement are inflammation, delayed growth and puberty, lean mass deficits, and use of glucocorticoids. We recognize that evidence is sparse on the topic of bone health in children and adolescents with IBD. In this clinical guideline, based on current evidence, we provide recommendations on screening and monitoring bone health in children and adolescents with IBD, including modalities to achieve this and their limitations; monitoring of parameters of growth, pubertal development, and reasons for concern; evaluation of vitamin D status and vitamin D and calcium intake; exercise; and nutritional support. We also report on the current evidence of the effect of biologics on bone health in children and adolescents with IBD, as well as the role of bone active medications such as bisphosphonates. Finally, we summarize the existing numerous gaps in knowledge and potential subjects for future research endeavors.

Osteopenia and osteoporosis in epidermolysis bullosa

Patients with the more severe forms of epidermolysis bullosa (EB) are at risk of developing osteopenia, osteoporosis and fractures. The cause is likely to be multifactorial and includes reduced mobility, a generally proinflammatory state, poor nutrition and hormonal factors. Monitoring this group with dual energy X-ray absorptiometry (DEXA) scans and plain radiographs is necessary to detect these changes. Data are lacking about the optimal approach to managing poor bone health in EB, although it seems that encouraging mobility, supplementation of calcium and vitamin D where necessary, with the addition of a bisphosphonate when there is evidence of fractures, may be helpful.

[New treatments for idiopathic juvenile arthritis]

Immunosuppressants, including methotrexate and more recently anti-TNF alpha, anti-IL1 and anti-IL6 receptor, have modified the prognosis of juvenile idiopathic arthritis. Growth hormone was shown to limit growth retardation due to general corticotherapy.

Nephrotoxicity as a cause of acute kidney injury in children

Many different drugs and agents may cause nephrotoxic acute kidney injury (AKI) in children. Predisposing factors such as age, pharmacogenetics, underlying disease, the dosage of the toxin, and concomitant medication determine and influence the severity of nephrotoxic insult. In childhood AKI, incidence, prevalence, and etiology are not well defined. Pediatric retrospective studies have reported incidences of AKI in pediatric intensive care units (PICU) of between 8% and 30%. It is widely recognized that neonates have higher rates of AKI, especially following cardiac surgery, severe asphyxia, or premature birth. The only two prospective studies in children found incidence rates of 4.5% and 2.5% of AKI in children admitted to PICU, respectively. Nephrotoxic drugs account for about 16% of all AKIs most commonly associated with AKI in older children and adolescents. Nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, amphotericin B, antiviral agents, angiotensin-converting enzyme (ACE) inhibitors, calcineurin inhibitors, radiocontrast media, and cytostatics are the most important drugs to indicate AKI as significant risk factor in children. Direct pathophysiological mechanisms of nephrotoxicity include constriction of intrarenal vessels, acute tubular necrosis, acute interstitial nephritis, and-more infrequently-tubular obstruction. Furthermore, AKI may also be caused indirectly by rhabdomyolysis. Frequent therapeutic measures consist of avoiding dehydration and concomitant nephrotoxic medication, especially in children with preexisting impaired renal function.

Bisphosphonate therapy for osteogenesis imperfecta

BACKGROUND

In osteogenesis imperfecta (OI) a genetic defect in type I collagen results in multiple fractures with little or no trauma. Bisphosphonates are used to attempt to reduce these fractures.

OBJECTIVES

To assess the effectiveness and safety of bisphosphonates in increasing bone mineral density (BMD), reducing fractures and improving clinical function in people with OI.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearches of journals and conference proceedings. We searched PubMed and major conference proceedings.Register last searched: August 2008.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing bisphosphonates to placebo, no treatment, or comparator interventions in all types of OI.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed trial quality.

MAIN RESULTS

Eight studies (403 participants) were included. Data for oral bisphosphonates versus placebo could not be aggregated. A significant difference favouring bisphosphonates in fracture risk reduction and number of fractures was noted in one trial. No differences were reported in the remaining three trials. Two trials reported data for spine BMD; one found significantly increased lumbar spine density z scores at 12 months and one reported a significant increase in lumbar spine BMD at 12, 24 and 36 months; both favouring bisphosphonates. For intravenous bisphosphonates versus placebo, aggregated data from two trials showed no significant difference for the number of participants with at least one fracture, RR 0.56 (95% CI 0.30 to 1.06). In the remaining trial no significant difference was noted in fracture incidence. For spine BMD, no significant difference was noted in the aggregated data from two trials, MD 9.96 (95%CI -2.51 to 22.43). In the remaining trial a significant difference in mean per cent change in spine BMD z score favoured intravenous bisphosphonates at 6 and 12 months. One trial compared oral versus intravenous bisphosphonates and found no differences in primary outcomes. Data describing growth, bone pain, and functional outcomes after bisphosphonate therapy were incomplete.

AUTHORS' CONCLUSIONS

Evidence suggests oral or intravenous bisphosphonates increase BMD in children and adults with OI. These were not shown to be different in their ability to increase BMD; it is unclear whether either treatment decreases fractures. Additional studies may determine whether bisphosphonates improve clinical status (reduce fractures and pain; improve growth and functional mobility) in this population. Optimal method, duration of therapy and long-term safety of bisphosphonate therapy requires further investigation.

Dual-energy X-ray aborptiometry assessment in children and adolescents with diseases that may affect the skeleton: the 2007 ISCD Pediatric Official Positions

The Task Force focusing on the use of dual energy X-ray absorptiometry (DXA) in children and adolescents with diseases that may affect the skeleton reviewed over 300 articles to establish the basis for the Official Positions. A significant number of studies used DXA-based outcome measures to assess the effects of specific interventions and charted the natural history of incremental changes in bone size and mass in specific disease states in children. However, the utility of DXA in clinical practice has not been evaluated systematically, in large part due to the lack of a workable definition for childhood osteoporosis. Thus, in combination with the Official Positions addressing the diagnosis of osteoporosis in children, and the reporting of DXA results in children, this document presents clear guidelines from which clinicians and researchers alike can work. This report delineates a set of disorders in which it is appropriate to use DXA as part of the comprehensive assessment of skeletal health in children and adolescents, and provides guidance concerning the initiation of assessment and the frequency of monitoring. Importantly, this document also highlights significant gaps in our knowledge, emphasizing areas for future research.

Chronic pediatric inflammatory diseases: effects on bone

In children, chronic inflammatory diseases present a significant challenge to long-term skeletal health. These conditions are often associated with poor appetite and suboptimal overall nutrition, altered nutrient utilization, delayed puberty, inactivity, and reduced muscle mass, all of which can alter bone metabolism. In addition, bone cell activity is susceptible to the effects of the immune response that characterizes these diseases. Moreover, drugs used to treat these maladies, notably glucocorticoids, may have negative effects on bone formation and on linear growth in developing children. As a result, predicted peak bone mass may not be achieved, and fracture risk may be increased in the short term or in the future. Studies using primarily dual energy X-ray absorptiometry have documented that deficits in bone mass are common in these diseases. However, there are wide variations in the prevalence of low bone mass, largely due to differences in the characteristics of each study population. Recent studies provide insight into the pathogenesis of decreased bone mass in these conditions. In this paper we will provide an overview of the effects of chronic inflammatory conditions on bone mass in children. We will also present relevant data from adult patients, when pediatric data are scant or not available.

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.

Osteoporosis in juvenile idiopathic arthritis--a practical approach to diagnosis and therapy

In all subgroups of juvenile idiopathic arthritis, a decrease in bone mass has been described in a high percentage of children. Recently, new pathogenetic concepts have identified muscle mass as the strongest predictor of bone mass and bone is now recognized as part of the musculoskeletal system. In addition, the sophisticated use of bone densitometry in pediatrics, including new measurement techniques, has provided the tools for a reliable assessment. A standardized diagnostic approach to the musculoskeletal system, including prophylaxis and therapy, is, therefore, mandatory in all children with JIA who do not achieve rapid remission. In this review, diagnostic and therapeutic options are being described and possibilities to incorporate them into clinical practice are suggested.

Can bisphosphonate treatment be stopped in a growing child with skeletal fragility?

Cyclical pamidronate therapy in a 2-year-old child with skeletal fragility resulted in remodelling of vertebral fractures and improvement in bone mineral density (BMD) at distal radial and spinal sites. The BMD at both sites decreased precipitously within 24 months of stopping treatment, raising the question as to whether bisphosphonates can be stopped in a growing child with skeletal fragility.

INTRODUCTION

At age 23 months, a male toddler sustained a low trauma fracture of his right femur. Skeletal radiographs revealed generalised osteopenia with multiple vertebral body fractures. He was diagnosed with type IV osteogenesis imperfecta; however, no mutations were found in COL1A1 or COL1A2 genes.

METHODS

This case report presents bone densitometry data before, during and after bisphosphonate treatment. Axial QCT was main outcome from 2 years of age; DXA and pQCT were taken after age 5.

RESULTS

QCT confirmed that he had low spinal trabecular volumetric BMD (Z-score -2.4). After 4 years of treatment his vertebral fractures had been remodelled and all bone densitometry values (QCT, DXA and pQCT) were within normal range and therefore treatment was discontinued. Shortly after this he suffered stress fractures of his left mid tibia and at the sclerotic metaphyseal line corresponding to his first APD treatment. He had marked reduction in spinal trabecular and distal radial vBMD; change in BMAD was less marked.

CONCLUSION

The patient has been restarted on IV APD therapy. This case has led us to consider whether bisphosphonate therapy can be discontinued in a child with fragility fractures before his/her linear growth has ceased?

Bisphosphonate therapy for reduced bone mineral density in children with chronic graft-versus-host disease

Reduced bone mineral density (BMD) occurs frequently in children after hematopoietic cell transplantation (HCT), but therapy for this complication is undefined. To determine the impact of bisphosphonate therapy on reduced BMD after HCT, we compared baseline and follow-up dual energy X-ray absorptiometry (DEXA) scans of 48 patients (controls) who received calcium and vitamin D to 18 patients who also received bisphosphonate therapy. Among the controls, median annualized increase in standardized BMD (sBMD) was 10% (range, -26% to +41%), but the deviation of sBMD from normal, as indicated by the Z-score, did not improve from baseline, -2.46 (range: -5.15 to -1.16) compared to follow-up, -2.79 (range: -5.76 to +0.07). For the bisphosphonate-treated patients, the median annualized increase in sBMD was 33% (range 3% to 147%, P = .0002) and the median Z-score improved from -3.57 (range: -5.13 to -0.86) at baseline, to -1.80 (-4.89 to +0.47) at follow-up (P = .06). The annualized median change in BMD Z-scores per year was +0.12 (-2.28 to +4.24) among the controls and +1.43 (-0.29 to +3.72) for the bisphosphonate group (P = .0002). The greatest improvement in BMD was observed in children who received therapy with bisphosphonates.

Bone health in children and adolescents after allogeneic stem cell transplantation

BACKGROUND

This cross-sectional study evaluated the overall bone health and the prevalence of vertebral complications after stem cell transplantation (SCT) in prepubertal children and adolescents.

METHODS

A total of 44 children and adolescents (median age, 10 years) were evaluated at a median of 3.8 years after SCT for areal bone mineral density (aBMD) with dual-energy X-ray absoptiometry and for vertebral fractures with instant vertebral assessment. Pretransplant and posttransplant medications and nutritional parameters were recorded, and plasma levels of vitamin D, calcium, phosphate, and parathormone were measured.

RESULTS

Of the 44 patients, 16 (36%) had a BMD Z-score of <-1.0. The patients with low BMD did not differ from the others with regard to their clinical or biochemical characteristics. Prepubertal patients had better BMD Z-scores at all sites compared with pubertal or postpubertal subjects. This was evident especially at the hip, in which the median aBMD Z-score in prepubertal patients (-0.2; range, -0.5 to +1.7) was found to be significantly higher than in pubertal (-1.1; range, -1.5 to +0.4) and postpubertal (-1.1; range, -2.6 to +0.5) patients (P = .03). Five patients (11%) had a history of peripheral fractures. Nine patients (20%) had vertebral compression fractures, which were asymptomatic in 7 patients.

CONCLUSIONS

Approximately one-third of patients who had undergone allogeneic SCT in childhood were found to have a reduced BMD before reaching adulthood. This was due in part to inadequate BMD gain during the pubertal years. The high prevalence of asymptomatic vertebral compression fractures calls for the systematic assessment of spinal health during the posttransplantation follow-up.