Skeletal fluorosis: an uncommon cause, yet a rescue treatment?

PURPOSE: Skeletal fluorosis (SF) results from chronic exposure to fluoride (F-) causing excessive aberrantly mineralized brittle bone tissue, fractures, and exostoses. There is no established treatment other than avoiding the source of F-. Still, excess F- can persist in bone for decades after exposure ceases. CASE PRESENTATION: A 50-year-old woman presented with multiple, recurrent, low AQ2 trauma fractures yet high radiologic bone mineral density. Serum F- was elevated, and osteomalacia was documented by non-decalcified transiliac biopsy. She reported intermittently "huffing" a keyboard cleaner containing F- (difluoroethane) for years. Following cessation of her F- exposure, we evaluated the administration of the parathyroid hormone analog, abaloparatide, hoping to increase bone remodeling and diminish her skeletal F- burden. CONCLUSION: Due to the prolonged half-life of F- in bone, SF can cause fracturing long after F- exposure stops. Anabolic therapy approved for osteoporosis, such as abaloparatide, may induce mineralized bone turnover to replace the poorly mineralized osteomalacic bone characteristic of SF and thereby diminish fracture risk. Following abaloparatide treatment for our patient, there was a decrease in bone density as well as a reduction in F- levels.

Severe magnitude of dental and skeletal fluorosis and its impact on society and environment in a part of Manbhum-Singhbhum Plateau, India.

BACKGROUND: Numerous approaches have been adopted to evaluate limited freshwater resources and the associated health hazards due to excessive amounts of fluoride in drinking water. The study aims to assess the degree and severity of dental and skeletal fluorosis and examine the broader effects of fluorosis on human health and society in the Manbhum-Singhbhum Plateau region, India. METHODS: The Community Fluorosis Index (CFI) and Dean's Index have been used to measure the magnitude and severity of dental and skeletal fluorosis. Questionnaire surveys, Focus Group Discussions (FGDs), and appropriate statistical methods have been applied to identify the social impacts. Risk-prone zones have been identified through overlay analysis using geoinformatics. RESULTS: About 54.60% of people in 67 villages of this part of the Manbhum-Singhbhum Plateau are affected in varying degrees of fluorosis ranging from very mild to mild, moderate, and severe dental fluorosis. Among these 67 villages, Janra (Manbazar I) and Hijla (Barabazar) have the most severely affected people. School dropout (n = 426), social isolation (n = 149), remarriage (n = 21), and physically disabled (n = 75) have also been reported. The study shows that about 414.29 km2 of the Manbhum-Singhbhum Plateau comes under the high-risk-prone category. CONCLUSIONS: The societal and environmental awareness of the fluorosis-affected individuals is almost absent in this region. Economic hardships, lack of education, inadequate health care facilities, water scarcity, and lack of awareness increase the magnitude of health hazards and societal vulnerability of the people in this region, who are largely dependent on natural resources.

Effect of Loratadine for Pegfilgrastim-Induced Bone Pain.

AIMS: Breast cancer patients on chemotherapy who receive pegfilgrastim to prevent neutropenia may experience severe bone pain as a side effect. Traditional treatment recommendations include nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, opioids, and/or antihistamine use. However, little research was found comparing these interventions. The study aim was to address the gaps in literature and to explore the use of and perceived effectiveness of loratadine versus acetaminophen or NSAIDs in women with breast cancer treated with pegfilgrastim. This study also sought to understand how patients became aware of loratadine or other treatments for management of bone pain. DESIGN/METHODS: This cross-sectional study used survey methods to collect data from 66 adult female breast cancer patients receiving chemotherapy with pegfilgrastim. RESULTS: The incidence of bone pain was 45% (n = 30) in our sample, but more than half (n = 45; 69%) of the women took either acetaminophen, NSAIDs, or loratadine alone or in combination to prevent bone pain. All medication were rated as effective by patients, with acetaminophen slightly more effective than loratadine, and loratadine more effective than NSAIDs. CONCLUSIONS: Acetaminophen, NSAIDs, and loratadine are easily available and inexpensive. However, unlike acetaminophen and NSAIDs, loratadine is dosed once a day and well tolerated with minimal adverse effects. CLINICAL IMPLICATIONS: Randomized controlled trials are needed to adequately assess the effectiveness of all three medication options. Because little is known about optimal use of any of these medications for pegfilgrastim-induced bone pain, it is also important to identify the optimal time to initiate treatment and ideal treatment duration.

Skeletal pathology and bone mineral density changes in wild muskrats (Ondatra zibethicus) and red squirrels (Tamiasciurus hudsonicus) inhabiting arsenic polluted areas of Yellowknife, Northwest Territories (Canada): A radiographic densitometry study.

The City of Yellowknife is a known hotspot of arsenic contamination and there is a growing body of evidence suggesting that local wildlife in the vicinity of the abandoned Giant Mine site may be at risk of decreased bone mineralization and various bone disorders. The purpose of this study was to preliminarily measure bone mineral density (BMD) changes and investigate the incidence, pattern, and severity of bone lesions in wild muskrats and red squirrels breeding in three (3) catchment areas at different distances from the Giant Mine Site in Yellowknife, Northwest Territories (Canada): ~2 km (location 1), ~18 km (location 2), and ~40-100 km (location 3). Full femoral bones of 15 muskrats and 15 red squirrels were collected from the three sampling locations (5 from each location) and subjected to radiographic analysis and densitometric measurements. The patterns and severities of bone lesions, including changes in bone mineral density, were evaluated and compared between groups. As levels were significantly higher in the bones of muskrats caught from location 1 and 2, relative to location 3. Further, As and Cd levels were significantly higher in the bones of squirrels caught from locations 1 and 2 relative to squirrels caught from location 3. The preliminary results from bones revealed that radiographic abnormalities such as bone rarefaction, osteopenia, and thinning of the femoral shafts with significant ossific cystic lesions and bowing were the most common skeletal pathologies found in bones of red squirrels from the three locations. Radiographic appearances of massive sclerosis and dysplasia, including severe osteocondensation and osteopathia striata-like abnormalities, were found in the bones of muskrats from all the sampling locations. Densitometric evaluation showed no significant differences between the three locations in the bone parameters measured. However, there was a statistically significant correlation between As content in the bones of muskrats and percent fat content in the femur samples, which suggests that accumulation of As could have been a causal factor for a change in percent fat in femurs of muskrats.

Blood lead levels, calcium metabolism and bone-turnover among automobile technicians in Sagamu, Nigeria: Implications for elevated risk of susceptibility to bone diseases.

Lead is an occupational toxicant and a recognised health threat particularly in developing countries. Hence, this study explored the interaction of blood lead level (BLL), a conventional marker of lead exposure, with indices of calcium metabolism and biomarkers of bone-turnover in 120 adult male automobile technicians (AT) with ≥ 1 year duration in professional practice. The AT as well as the control group, which comprised 120 age, body-size and socio-economically matched male administrative workers, were recruited from Sagamu, South West Nigeria. Levels of blood lead, serum indices of calcium metabolism [total calcium (tCa), ionised calcium (iCa), phosphate, albumin, magnesium (Mg) and 25-Hydroxycholecalceferol (25-OHCC)], biomarkers of bone formation [bone alkaline phosphatase (BALP) and osteocalcin (OC)] and biomarkers of bone resorption [tartarate-resistant acid phosphatase-5b (TACRP-5b) and urinary hydroxyproline (UHYP)] were determined in all participants. The BLL, 25-OHCC, TRACP-5b and UHYP significantly increased while tCa and iCa significantly reduced in AT compared to control. However, no significant difference was observed in phosphate, albumin, Mg, BALP and OC in AT compared to control. Interestingly, BLL demonstrated a significant negative association with tCa and iCa but a significant positive association with 25-OHCC, TRACP-5b and UHYP. However, BLL did not show significant association with phosphate, albumin, Mg, BALP and OC. Increased lead exposure as well as altered calcium metabolism and bone-turnover demonstrated by the automobile technicians may be suggestive of lead-induced accelerated bone demineralisation. These workers may be predisposed to high risk of increased susceptibility to bone diseases if this sub-clinical picture is sustained.

Safety analysis of proposed pegfilgrastim biosimilar in Phase I and Phase III studies.

Aim: This analysis compares safety data for Sandoz proposed biosimilar (LA-EP2006) and reference pegfilgrastim from a Phase I pharmacokinetic/pharmacodynamic study in healthy volunteers (HVs) and two Phase III confirmatory studies in patients with breast cancer (BC; total n = 808). Patients & methods: Baseline characteristics were summarized, and event rates of bone pain and headache calculated. Results: HVs in the Phase I pharmacokinetic/pharmacodynamic study were generally younger, with lower mean body mass index, versus BC patients in PROTECT-1/-2. Bone pain was the most frequent adverse event with similar incidences with reference versus proposed biosimilar in all studies. Conclusion: No differences in adverse events were found between Sandoz proposed biosimilar and reference pegfilgrastim, notwithstanding some differences between HVs and BC patients.

Role of fluoride induced epigenetic alterations in the development of skeletal fluorosis.

Fluoride is an essential trace element required for proper bone and tooth development. Systemic high exposure to fluoride through environmental exposure (drinking water and food) may result in toxicity causing a disorder called fluorosis. In the present study, we investigated the alteration in DNA methylation profile with chronic exposure (30 days) to fluoride (8 mg/l) and its relevance in the development of fluorosis. Whole genome bisulfite sequencing (WGBS) was carried out in human osteosarcoma cells (HOS) exposed to fluoride. Whole genome bisulfite sequencing (WGBS) and functional annotation of differentially methylated genes indicate alterations in methylation status of genes involved in biological processes associated with bone development pathways. Combined analysis of promoter DNA hyper methylation, STRING: functional protein association networks and gene expression analysis revealed epigenetic alterations in BMP1, METAP2, MMP11 and BACH1 genes, which plays a role in the extracellular matrix disassembly, collagen catabolic/organization process, skeletal morphogenesis/development, ossification and osteoblast development. The present study shows that fluoride causes promoter DNA hypermethylation in BMP1, METAP2, MMP11 and BACH1 genes with subsequent down-regulation in their expression level (RNA level). The results implies that fluoride induced DNA hypermethylation of these genes may hamper extracellular matrix deposition, cartilage formation, angiogenesis, vascular system development and porosity of bone, thus promote skeletal fluorosis.

Aberrant methylation-induced dysfunction of p16 is associated with osteoblast activation caused by fluoride.

Chronic exposure to fluoride continues to be a public health problem worldwide, affecting thousands of people. Fluoride can cause abnormal proliferation and activation of osteoblast and osteoclast, leading to skeletal fluorosis that can cause pain and harm to joints and bones and even lead to permanent disability. Nevertheless, there is no recognized mechanism to explain the bone lesions of fluorosis. In this work, we performed a population study and in vitro experiments to investigate the pathogenic mechanism of skeletal fluorosis in relation to methylation of the promoter of p16. The protein coded by the p16 gene inhibits cdk (cyclin-dependent kinase) 4/cdk6-mediated phosphorylation4 of retinoblastoma gene product and induces cell cycle arrest. The results showed that hypermethylation of p16 and reduced gene expression was evident in peripheral blood mononuclear cells of patients with fluorosis and correlated with the level of fluoride exposure. Studies with cell cultures of osteoblasts revealed in response to sodium fluoride (NaF) treatment, there was an induction of p16 hypermethylation and decreased expression, leading to increased cell proliferation, a longer S-phase of the cell cycle, and development of skeletal fluorosis. Further, the methylation inhibitor, 5-aza-2-deoxycytidine, reversed the p16 hypermethylation and expression in response to NaF. These results reveal a regulatory role of p16 gene methylation on osteoblasts activation during the development of skeletal fluorosis.

FK228 recovers thiram-induced tibial dyschondroplasia in chicken via hypoxia inducible factor-1α.

Tibial dyschondroplasia (TD) is a disease of many avian species characterized by an enlarged and avascular lesion in the proximal tibiotarsal bone. The aim of present study was to evaluate the effects of hypoxia-inducible factor-1α(HIF-1α) inhibition on thiram- induced TD using synthetic medicine FK228 and the association between HIF-1α and heat-shock protein 90 (Hsp90). One hundred and fifty broiler chicks were equally divided into 3 groups: control; thiram fed; and FK228 treatment. Expressions of HIF-1α and Hsp90 genes were analyzed by real-time quantitative polymerase chain reaction (RT-qPCR) on day 10 and 14 post-hatch. Western blot analysis of HIF-1α and Hsp90 gene was performed to measure the protein levels at the end of the experiment. Results showed that HIF-1α and Hsp90 levels were significantly (P less than 0.05) up-regulated in the thiram group as compared to the control group. Meanwhile, FK228 (HIF-1α inhibitor) significantly (P less than 0.05) down- regulated the mRNA and protein levels of HIF-1α and Hsp90, restored the size of growth plate and diminished lameness. In conclusion, HIF-1α and Hsp90 play an important role in the formation of avascular growth plate and there is a direct relationship between HIF-1α and Hsp90 for the progression of TD pathogenesis. Therefore, HIF- 1α may prevent and control TD in broiler chickens.

NOLAN: a randomized, phase 2 study to estimate the effect of prophylactic naproxen or loratadine vs no prophylactic treatment on bone pain in patients with early-stage breast cancer receiving chemotherapy and pegfilgrastim.

PURPOSE: Mild-to-moderate bone pain is a commonly reported adverse event (AE) associated with pegfilgrastim. We evaluated the effect of prophylactic naproxen or loratadine vs no prophylactic treatment on pegfilgrastim-associated bone pain. METHODS: In this open-label study (NCT01712009), women ≥ 18 years of age with newly diagnosed stage I-III breast cancer and an ECOG performance status ≤ 2 who were planning ≥ 4 cycles of adjuvant or neoadjuvant chemotherapy with pegfilgrastim support starting in cycle 1 were randomized 1:1:1 to receive naproxen, loratadine, or no treatment to prevent pegfilgrastim-associated bone pain. The primary endpoint was all-grade bone pain in cycle 1 from AE reporting. Secondary endpoints included bone pain in cycles 2-4 and across all cycles from AE reporting and patient-reported bone pain by cycle and across all cycles. RESULTS: Six hundred patients were enrolled. Most patients (83.0%) were white, and mean (SD) age was 54.2 (11.1) years. The percentage of patients with all-grade bone pain in cycle 1 from AE reporting in the naproxen, loratadine, and no prophylaxis groups was 40.3, 42.5, and 46.6%, respectively; differences between the treatment groups were not statistically significant. Maximum, mean, and area under the curve for patient-reported bone pain were consistently lower in the naproxen and loratadine groups than in the no prophylaxis group; some of these differences were significant. Loratadine was associated with fewer treatment-related AEs and discontinuations than naproxen. CONCLUSIONS: Given its tolerability, its ease of administration, and its potential benefit, treatment with loratadine should be considered to help prevent bone pain in patients receiving chemotherapy and pegfilgrastim. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov ; NCT01712009.

Adenine-induced chronic kidney disease in rats.

Many animal models have been developed to study the causes and treatments of chronic kidney disease (CKD) in humans, an insidious disease resulting from kidney injury and characterized by persistent functional decline for more than 3 months, with or without evidence of structural deficit. The eventual outcome of CKD may be end-stage kidney disease (ESKD), where patients need dialysis or transplantation to survive. Cardiovascular disease is accelerated in patients with CKD and contributes to increased mortality, with the relationship between CKD and cardiovascular disease being bi-directional. Most animal models do not mimic the complexity of the human disease as many do not develop CKD-associated cardiovascular disease. The adenine diet model of CKD in rodents is an exception. The original adenine diet model produced rapid-onset kidney disease with extensive tubulointerstitial fibrosis, tubular atrophy, crystal formation and marked vessel calcification. Since then, lower adenine intake in rats has been found to induce slowly progressive kidney damage and cardiovascular disease. These chronic adenine diet models allow the characterization of relatively stable kidney and cardiovascular disease, similar to CKD in humans. In addition, interventions for reversal can be tested. Here the key features of the adenine diet model of CKD are noted, along with some limitations of other available models. In summary, the data presented here support the use of chronic low-dose adenine diet in rats as an easy and effective model for understanding human CKD, especially the links with cardiovascular disease, and developing potential therapeutic interventions.

Retrospective Review of Atypical Femoral Fracture in Metastatic Bone Disease Patients Receiving Denosumab Therapy.

BACKGROUND: Denosumab therapy is used to reduce skeletal-related events in metastatic bone disease (MBD). There have been reports of atypical femoral fracture (AFF) in osteoporotic patients treated with denosumab but none in the context of higher dose and more frequent denosumab therapy for MBD. The goal of this study was to assess the incidence of AFF in MBD. PATIENTS AND METHODS: We conducted a retrospective review of 253 patients who received a minimum of 12 doses of denosumab at 120 mg each for MBD. To identify patients with asymptomatic atypical stress reactions in the lateral subtrochanteric femur (which precede fractures), we reviewed the skeletal images of 66 patients who had received at least 21 doses of denosumab for AFF features. RESULTS: These patients received a median of 17 doses, with a median treatment duration of 23 months. There was 1 case of undiagnosed clinical AFF detected after chart review and 2 cases of subclinical atypical femoral stress reaction observed on imaging review after 23 doses of denosumab over 33 months, 28 doses over 27 months, and 21 doses over 21 months, respectively. Scout computed tomography films showed diffuse cortical thickening of diaphysis with localized periosteal reaction of lateral femoral cortex. Bone scan and magnetic resonance imaging scan of 2 patients with stress reactions confirmed the diagnosis. CONCLUSION: The incidence of clinical AFF in this context is 0.4% (1/253; 95% confidence interval [CI] 0.1%-2.2%), and the incidence of atypical femoral stress reaction based on imaging review is 4.5% (3/66; 95% CI 1.6%-12.5%). Clinicians should be aware of the clinical prodrome (which may or may not be present) and antecedent imaging changes associated with AFF. The Oncologist 2017;22:438-444Implications for Practice: Among patients with metastatic bone disease treated with denosumab, cases of clinical and subclinical atypical femoral fracture (AFF) are rare. The one detected case of clinical fracture went unrecognized despite prodromic symptoms. Clinicians should be aware of (a) the potential prodrome of anterior thigh/groin pain and (b) subclinical imaging changes in the lateral femur, both of which may precede clinical AFF.

A PET/MR Imaging Approach for the Integrated Assessment of Chemotherapy-induced Brain, Heart, and Bone Injuries in Pediatric Cancer Survivors: A Pilot Study.

Purpose To develop a positron emission tomography (PET)/magnetic resonance (MR) imaging protocol for evaluation of the brain, heart, and joints of pediatric cancer survivors for chemotherapy-induced injuries in one session. Materials and Methods Three teams of experts in neuroimaging, cardiac imaging, and bone imaging were tasked to develop a 20-30-minute PET/MR imaging protocol for detection of chemotherapy-induced tissue injuries of the brain, heart, and bone. In an institutional review board-approved, HIPAA-compliant, prospective study from April to July 2016, 10 pediatric cancer survivors who completed chemotherapy underwent imaging of the brain, heart, and bone with a 3-T PET/MR imager. Cumulative chemotherapy doses and clinical symptoms were correlated with the severity of MR imaging abnormalities by using linear regression analyses. MR imaging measures of brain perfusion and metabolism were compared among eight patients who were treated with methotrexate and eight untreated age-matched control subjects by using Wilcoxon rank-sum tests. Results Combined brain, heart, and bone examinations were completed within 90 minutes. Eight of 10 cancer survivors had abnormal findings on brain, heart, and bone images, including six patients with and two patients without clinical symptoms. Cumulative chemotherapy doses correlated significantly with MR imaging measures of left ventricular ejection fraction and end-systolic volume, but not with the severity of brain or bone abnormalities. Methotrexate-treated cancer survivors had significantly lower cerebral blood flow and metabolic activity in key brain areas compared with control subjects. Conclusion The feasibility of a single examination for assessment of chemotherapy-induced injuries of the brain, heart, and joints was shown. Earlier detection of tissue injuries may enable initiation of timely interventions and help to preserve long-term health of pediatric cancer survivors. © RSNA, 2017 Online supplemental material is available for this article.

Drug-induced Physeal Abnormalities in Preclinical Toxicity Studies.

Most toxic physeal changes are characterized microscopically by altered chondrocyte development, proliferation, or maturation in the growth plate and eventually result in disordered appositional bone growth. Many therapeutic drugs directly or indirectly target proteins involved in chondrocytic differentiation and maturation pathways, so toxic physeal injury has become increasingly common in preclinical toxicologic pathology. While physeal dysplasia has been associated with several different drug classes including bisphosphonates, vascular endothelial growth factor receptor inhibitors, fibroblast growth factor receptor inhibitors, transforming growth factor beta receptor inhibitors, and vascular targeting agents, physeal changes often share similar morphologic features including thickening and disorganization of the hypertrophic layer, increased numbers of hypertrophic chondrocytes, altered mineralization of endochondral ossification, and/or increased thickness of subphyseal bone. Knowledge of genetic and nutritional diseases affecting bone growth has been important in helping to determine which specific target drugs may be affecting that could result in toxic physeal lesions. A pathophysiologic mechanism for most physeal toxicants has been determined in detail using a variety of investigative techniques. However, due to the signaling cross talk and the tight regulation required for chondrocyte maturation in the physis, several growth factor pathways are likely to be affected simultaneously with pharmacologic disruption of physeal homeostasis and inhibition of one factor necessary for chondrocyte function often affects others.

Pegfilgrastim-Induced Bone Pain: A Review on Incidence, Risk Factors, and Evidence-Based Management.

OBJECTIVE: To review the incidence, risk factors, and management of pegfilgrastim-induced bone pain (PIBP). DATA SOURCES: PubMed was searched from 1980 to March 31, 2017, using the terms pegfilgrastim and bone pain. STUDY SELECTION AND DATA EXTRACTION: English-language, human studies and reviews assessing the incidence, risk factors, and management of PIBP were incorporated. DATA SYNTHESIS: A total of 3 randomized, prospective studies and 2 retrospective studies evaluated pharmacological management of PIBP. Naproxen compared with placebo demonstrated a reduction in the degree, incidence, and duration of bone pain secondary to pegfilgrastim. Loratadine was not effective in reducing the incidence of bone pain prophylactically, but a retrospective study evaluating dual antihistamine blockade with loratadine and famotidine demonstrated a decreased incidence in bone pain when administered before pegfilgrastim. CONCLUSION: Naproxen is effective at managing PIBP. Although commonly used, antihistamines have a paucity of data supporting their use. Dose reductions of pegfilgrastim and opioids may also be potential management options; however, data supporting these treatment modalities are scarce.

Prevention of granulocyte-colony stimulating factor (G-CSF) induced bone pain using double histamine blockade.

PURPOSE: Febrile neutropenia (FN) is an oncological emergency that may reduce patient survival due to chemotherapy dose delays or reductions. It is recommended that patients at risk for FN receive prophylaxis with granulocyte-colony stimulating factor (G-CSF). Bone pain is a common side effect through a mechanism not fully understood. It is thought to be due to histamine release from an inflammatory response. METHODS: This was a retrospective cohort from January to November 2015. Oncology patients receiving an initial dose of G-CSFs rated their bone pain on a 0-10 scale prior to starting each cycle of chemotherapy and at least 1 day after G-CSF had been given. Those who developed bone pain received prophylaxis at their next G-CSF dose with a combination of famotidine and loratadine. The primary endpoint was to determine the analgesic effects of double histamine blockade for G-CSF induced bone pain. The secondary endpoint was to determine potential risk factors for the development of bone pain. RESULTS: Thirty percent of patients developed bone pain within this cohort, and 17 patients were included in the final analysis. Bone pain scores were lower by a mean of 1.21[(0.20-2.23), p = 0.019] in patients who were prophylaxed with the double histamine blockade. Type of cancer, treatment, age, and BMI were not significant predictors of bone pain. CONCLUSION: The use of a double histamine blockade is an inexpensive, safe, and effective way to alleviate bone pain symptoms secondary to G-CSF agents. Further investigation is warranted for prospective larger studies to confirm these results.

Development and validation of a fluoride bone injury risk prediction model.

BACKGROUND: Fluoride bone injury affects millions of people exposed to fluoride worldwide, and has no treatment - prevention is the only solution. OBJECTIVES: A risk prediction model was developed to identify workers at high risk for fluoride bone injury in aluminum production. METHODS: We collected data from the Molecular Epidemiology Study of Fluoride Bone Injury. 120 fluoride bone injury cases and 120 controls were involved in the study. Logistic regression was used to determine variables in the risk prediction model. Predictive accuracy was validated with bootstrap method. Potential risk cut-offs was evaluated with receiver operating characteristic curve. RESULTS: Working history, urinary fluoride, osteocalcin, bone alkaline phosphatase and calcitonin receptor gene polymorphism were included in the final prediction model. The model had very good calibration and discrimination (C index=0.986; Brier score 0.014). CONCLUSIONS: Our fluoride bone injury risk prediction model performed well in the present data, and the working history, urinary fluoride, osteocalcin, bone alkaline phosphatase, and calcitonin receptor gene polymorphism were identified as predictors. The model could be used to assess the fluoride bone injury risk, and identify the susceptible workers.

[Drugs induced osteopathies]. / Syndromes iatrogènes : les ostéopathies induites.

Drug induced bone diseases concerns : induced osteoporosis, induced osteomalacia (by loss of calcium, phosphate or vitamin D) and induced sarcopenia. Some of these drugs are well known, such as anti-hormones, corticotherapy (which could induce all of osteoporosis, osteomalacia and sarcopenia). In the present article, we will focus on 3 others less known but frequently used drugs : iron replacement, proton pump inhibitors therapy, and serotonin reuptake inhibitor antidepressants treatment. For each of them we will discuss the pathophysiological mechanism leading to bone fragility as well as the recommendations of prevention / management to be proposed in case of absolute necessity of the treatment.

Les pathologies osseuses induites par les médicaments regroupent : les ostéoporoses induites et les ostéomalacies sur carence ou pertes induites du calcium, du phosphate ou de la vitamine D. On peut aussi y ajouter les sarcopénies iatrogéniques. Certains de ces médicaments sont bien connus, comme les antihormones ou la cortisone qui, à elle seule, agit sur les 3 entités. Dans cet article, nous aborderons 3 autres familles de médicaments provoquant des pathologies osseuses, probablement moins connus mais pourtant très prescrits : les traitements substitutifs en fer, les inhibiteurs de la pompe à protons et les antidépresseurs sélectifs de la recapture de la sérotonine. Pour chacun d'entre eux, nous verrons le mécanisme physiopathologique conduisant à la fragilité osseuse ainsi que les règles de prévention/prise en charge à proposer en cas de nécessité absolue du traitement.

The Epi-TAF for Tenofovir Disoproxil Fumarate?

Approximately 84% of human immunodeficiency virus (HIV)-infected US residents on antiretroviral therapy currently receive some form of tenofovir disoproxil fumarate (TDF) as part of their HIV treatment regimen. The TDF analogue tenofovir alafenamide (TAF) has demonstrated equal efficacy but with decreased renal injury and bone mineral density loss compared with TDF. We examine how much more society ought to be willing to pay for TAF over TDF, in exchange for its improved toxicity profile. Using cost-effectiveness methods, we find that current conditions warrant an annual premium of up to $1000 over the average wholesale price (AWP) of TDF. Once generic coformulations of tenofovir/lamivudine become accessible, however, the appropriate premium for TAF will likely merit a downward adjustment, using generic TDF-based costs as the benchmark.

Randomized phase II study of loratadine for the prevention of bone pain caused by pegfilgrastim.

PURPOSE: Bone pain is a common side effect of pegfilgrastim and can interfere with quality of life and treatment adherence. This study investigated the impact of antihistamine prophylaxis on pegfilgrastim-induced bone pain. METHODS: This is a two-stage enrichment trial design. Patients receiving an initial dose of pegfilgrastim after chemotherapy were enrolled into the observation (OBS) stage. Those who developed significant back or leg bone pain (SP) were enrolled into the treatment (TRT) stage and randomized to daily loratadine 10 mg or placebo for 7 days. SP was defined by Brief Pain Inventory as back or leg pain score ≥5 and a 2-point increase after pegfilgrastim. The primary end point of TRT was reduction of worst back or leg bone pain with loratadine, defined as a 2-point decrease after treatment compared to OBS. RESULTS: Two hundred thirteen patients were included in the final analysis. Incidence of SP was 30.5 %. The SP subset had a worse overall Functional Assessment of Cancer Therapy-Bone Pain score (33.9 vs. 51.7, p < 0.001) and a higher mean white blood cell count (15.4 vs. 8.4 K/cm(3), p = 0.013) following pegfilgrastim than those without SP. Forty-six patients were randomized in the TRT. Benefit was 77.3 % with loratadine and 62.5 % with placebo (p = 0.35). Baseline NSAID use was documented in four patients (18.2 %) in loratadine arm and two patients (8.3 %) in placebo arm, with baseline non-NSAID use documented in five (22.7 %) and six (25 %) patients, respectively. Eight additional patients used NSAIDS by day 8 compared to day 1 (six in the loratadine and two in the placebo arm). A total of six additional patients used non-NSAIDS by day 8 compared to day 1 (four in the loratadine and two in the placebo arm). CONCLUSIONS: Administration of prophylactic loratadine does not decrease the incidence of severe bone pain or improve quality of life in a high-risk patient population. ClinicalTrials.gov identifier: NCT01311336.