Effect of zoledronic acid on markers of bone turnover and mineral density in osteoporotic patients with beta-thalassaemia

Evaluation of Children and Adolescents with Thalassemia Major in Terms of Osteoporosis: A Single-Centre Experience

Background/Objectives: This study aimed to determine the frequency of osteoporosis in children and adolescents with thalassemia major (TM) and to identify risk factors for the early development of osteoporosis. Methods: This retrospective study included 27 patients under 18 years of age receiving regular blood transfusions and chelation therapy for TM at our hospital. Bone mineral density (BMD) was measured by dual-energy x-ray absorptiometry, and a lumbar spine Z-score <-2 was considered osteoporotic. Patients with osteoporosis were classified as Group 1 and those without osteoporosis as Group 2. Results: Osteoporosis was detected in 22.2% of the study population. The mean age was 13.83 ± 2.85 years in Group 1 and 7.95 ± 5.05 years in Group 2 (p = 0.012). Body weight and height were significantly lower in Group 1 (p = 0.012 and p = 0.004). Ferritin levels were 5306 ± 1506 ng/mL in Group 1 and 2020 ± 1205 ng/mL in Group 2, and the difference was significant (p = 0.001). Group 1 had significantly lower Ca and P levels (p < 0.001, p = 0.038). BMD was negatively correlated with ferritin (r = -0.791, p < 0.001) and positively correlated with calcium (r = 0.499, p = 0.008). Conclusions: Osteoporosis is a common condition in TM patients. Patients with risk factors should be followed more closely. These patients should be identified before BMD decreases. To prevent osteoporosis, regular BMD scans should be performed, calcium and vitamin D supplementation should be provided, and physical activity should be encouraged.

The role of bone in energy metabolism: A focus on osteocalcin

Understanding the mechanisms involved in whole body glucose regulation is key for the discovery of new treatments for type 2 diabetes (T2D). Historically, glucose regulation was largely focused on responses to insulin and glucagon. Impacts of incretin-based therapies, and importance of muscle mass, are also highly relevant. Recently, bone was recognized as an endocrine organ, with several bone proteins, known as osteokines, implicated in glucose metabolism through their effects on the liver, skeletal muscle, and adipose tissue. Research efforts mostly focused on osteocalcin (OC) as a leading example. This review will provide an overview on this role of bone by discussing bone turnover markers (BTMs), the receptor activator of nuclear factor kB ligand (RANKL), osteoprotegerin (OPG), sclerostin (SCL) and lipocalin 2 (LCN2), with a focus on OC. Since 2007, some, but not all, research using mostly OC genetically modified animal models suggested undercarboxylated (uc) OC acts as a hormone involved in energy metabolism. Most data generated from in vivo, ex vivo and in vitro models, indicate that exogenous ucOC administration improves whole-body and skeletal muscle glucose metabolism. Although data in humans are generally supportive, findings are often discordant likely due to methodological differences and observational nature of that research. Overall, evidence supports the concept that bone-derived factors are involved in energy metabolism, some having beneficial effects (ucOC, OPG) others negative (RANKL, SCL), with the role of some (LCN2, other BTMs) remaining unclear. Whether the effect of osteokines on glucose regulation is clinically significant and of therapeutic value for people with insulin resistance and T2D remains to be confirmed.

Identification of osteopenia and osteoporotic changes in pediatric thalassemia patients at thalassemia center, Misan city, Iraq; An intervention study

Background: Thalassemia syndrome is a heterogeneous group of hereditary disorders affecting the synthesis of globin chains of adult hemoglobin's, leading to ineffective erythropoiesis, hemolysis, and moderate to severe anemia. To identify the incidence of osteopenia and osteoporosis and it is relation to some of the probable risk factors of decreasing BMD among thalassemia patients attended Misan thalassemia center in Misan city in Iraq. Methods: A randomized cross-sectional study, applied through a period from September 2020 to September 2021, on 50 thalassemia patients attended thalassemia Center Amarah, Misan, Iraq. 24 were males and 26 were females, we divided them in to two groups according to age (10-14) years, (>14-18) years. They were scanned for bone mineral density (BMD) at lumbar spine. Results: 90% of patients had reduction in BMD patients mostly among THM patients. 40% had positive family history of thalassemia, Vitamin D3 level were low in (80%) of patients & DEXA studies were mostly between [(-1) -(-2.5)] before treatment that slightly improved after therapy in ranges of osteopenia but not in osteoporosis which increase severity as well. Conclusions:  Most thalassemia patient had severe anemia, corrected by frequent blood transfusion are complicated by increasing serum ferritin level and decreasing level of vitamin D3 in association with reduction in bone density mass in ranges of osteopenia and osteoporosis which correlates positively with increasing ages, early age at diagnosis and female gender  this altered bone mass density  require family awareness for better nutrition and optimum medical therapy and compliance to improve outcomes.     

Effects of bisphosphonates on osteoporosis: Focus on zoledronate

Osteoporosis is a bone disease that mainly affects older people and postmenopausal women. Lack of proper treatment for this disease gives rise to many problems in patients and occasionally leads to death. Many drugs have been utilized to treat osteoporosis but the most effective one is the bisphosphonates (BPs) family. This family has several positive effects on bone tissue, including promoting bone healing, enhancing bone mineral density, reducing bone resorption, preventing pathologic fractures, suppressing bone turnover, and modulating bone remodeling. On the other hand, there have also been inconclusive reports that BPs might have a desirable or even adverse impact on osteoporotic patients. Therefore, we set out to examine the positive and negative effects of this family, with a focus on the most potent one that is zoledronate (Zol), in clinical usage. Zoledronate is an amino-BPs and nitrogen-containing drug which is the most powerful BPs on osteoporosis treatment or prevention. Many studies showed its effectiveness in the treatment of osteoporosis and bone healing. As Zol enjoys a considerable potential in treating and preventing osteoporosis, it can be used as one of the effective treatments in this field.

AZD3463, an IGF-1R inhibitor, suppresses breast cancer metastasis to bone via modulation of the PI3K-Akt pathway

Background

The bone-derived insulin-like growth factor I (IGF-1) and its receptor IGF-1R play a crucial role in promoting the survival and proliferation of cancer cells, and have thus been considered as prime targets for the development of novel antitumor therapeutics.

Methods

By using the MDA-MB-231BO cell line, which is the osteotropic metastatic variant of the human breast adenocarcinoma cell line MDA-MB-231, and an in vivo model of breast cancer metastasis to bone, the current study evaluated the effect of AZD3463, an IGF-1R inhibitor, used alone or in combination with zoledronic acid (ZA), on the regulation of IGF-1R associated signal pathway and treatment of bone metastases (BM). Cell proliferation and invasion were measured by methyl thiazolyl tetrazolium (MTT) and Transwell assay respectively. Apoptotic cell number was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL).

Results

AZD3463 was shown to alleviate IGF-1R phosphorylation promoted by IGF-1 treatment in MDA-MB-231BO cells in a dose-dependent manner. In both the cells and the mouse model, 5 nM of AZD3463 stimulated cell apoptosis and suppressed proliferation on a level similar to that of 100 µM of ZA. Remarkably, the combined use of AZD3463 and ZA exhibited a synergistic effect and greater antitumor activity compared to when they were employed individually. Mechanistic investigations indicated that the apoptosis-inducing activity of AZD3463 could be associated to its role in the activation of the phosphoinositide 3-kinase (PI3K)-Akt signaling pathway.

Conclusions

These findings suggested that AZD3463 could serve as a promising therapeutic molecule for treating BM in breast cancer patients, particularly when applied in conjunction with ZA or other antitumor agents.

Comparative effectiveness of alendronate and zoledronic acid on bone mass improvement in transfusion-dependent thalassemia patients

Thalassemia, as the most prevalent genetic blood disorder, has many associated comorbidities including low bone mass. We studied the comparative effectiveness of alendronate (AL) and zoledronic acid (ZOL) on bone mass improvement in transfusion-dependent thalassemia (TDT) patients a year after treatment. Three hundred seventy-five TDT patients with low bone mass were enrolled in this study. After a year of treatment with either AL or ZOL, a second bone mineral density (BMD) test was ordered to compare the effectiveness of the two aforementioned drugs. Body mass index (BMI), physical activity, sun exposure, and biochemical laboratory data were also considered as associated factors in this study. The BMD test of both groups was almost the same at the baseline and it increased comparably after a year of treatment with AL and ZOL. However, there was a significant difference in lumbar spine BMD delta Z score between both groups of female patients. ZOL was more effective in increasing the lumbar spine BMD of female patients. The choice of bisphosphonates therapy (oral versus parenteral) should be individually selected by considering patient's preference, compliance and the physician's decision. Given the longer administration interval, and TDT patients' compliance issue, it is justified to recommend ZOL as the drug of choice for patients suffering from low bone mass.

Administration of Intravenous Zoledronic Acid Every 3 Months vs. Annually in β-thalassemia Patients with Low Bone Mineral Density: a Retrospective Comparison of Efficacy

Introduction:

The benefit of annual administration of zoledronic acid in the management of thalassemia-associated osteoporosis is unknown.

Aim:

The aims of this study were to evaluate the efficacy of treatment with two different dosing regimens of IV zoledronic acid (annually versus every 3 months) for increasing low bone mineral density (BMD) in patients with osteoporosis associated with β-thalassemia as annually and 3-monthly on bone density in patients.

Materials and Methods:

This retrospective, single-center study analyzed patients’ clinical records and bone density measurements. Those enrolled in the study were 14 to 53 years of age, had documented β-thalassemia, and were treated with IV zoledronic acid on either an annual or every 3 months dosing regimen. Dual-energy X-ray absorptiometry was used to obtain the z-score for BMD in the lumbar spine and femoral neck.

Results:

Thirty-four patients were enrolled in the study; 15 (44.1%) had been treated annually, and 19 (55.9%) had been treated every month. In patients receiving treatment with the once-yearly dose of zoledronic acid, significant increases were observed in the lumbar spine BMD z-score, from -2.45 ± 0.69 to -1.97 ± 0.82 (P=0.02). When comparing BMD across the two treatment regimens, the mean lumbar spine BMD was 0.82 greater (95% CI 0.31, 1.33, P=0.003) and the mean femoral neck BMD 0.37 greater (95% CI -0.15, 0.87, P=0.1) in the group receiving annual zoledronic acid treatment.

Conclusions:

In patients with thalassemia-associated osteopenia, annual treatment with zoledronic acid increases lumbar spine bone density while being more effective, less expensive, and associated with fewer adverse events than dosing every 3 months.

Zoledronic Acid for Treatment of Low Bone Mineral Density in Patients with Beta Thalassemia Major

To determine the efficacy of zoledronic acid (ZA) in thalassemia major associated low bone mineral density. Prospective, open label, single arm trial. Bone mineral density (BMD) at lumbar, hip and forearm region were performed at baseline and after 1 year of therapy. Initial, 9 patients received a first dose of 4 mg. Due to severe adverse effects, further doses for these patients and all new recruited patients were 1 mg once every 3 months for 4 doses. All patients were receiving 500 mg of calcium carbonate twice daily and 0.25 μg alfacalcidol once daily before and during the entire study period. Dual energy X-ray absoptiometry was performed at baseline and after 1 year. Twenty-seven patients with transfusion dependent thalassemia with a median age 19.5 year (15-38 years) were eligible for ZA treatment. Seven patients had bony pains. Four patients developed grade 4 hypocalcemia (3 developed tetany) and 2 developed infusion related toxicity with initial dose of 4 mg. One mg dose was well tolerated. At the end of 1 year, bone pains had completely resolved. There was significant increase in BMD at lumbar (p = 0.002) and forearm regions (p = 0.04) and intertrochantric area (p = 0.041). The % change in BMD at 1 year was +3.7 ± 3.2%. ZA is an efficacious agent in treatment of low BMD in these patients. ZA produces significant adverse reactions at 4 mg dose but 1 mg dose is well tolerated and is efficacious.

The role of biphosphonates in the management of thalassemia-induced osteoporosis: a systematic review and meta-analysis

Thalassemia Major (TM) is a clinical entity with a high prevalence of low bone mass. The aim of the present study was to perform a meta-analysis of all available data on the role of bisphosphonates (BPs) in the therapy of thalassemia major-induced osteoporosis. The PRISMA recommendations for reporting systematic reviews and meta-analyses were used to guide the present study. We searched PubMed and the Cochrane Central Register of Controlled Trials (CENTRAL) through March 31, 2017 for articles related to thalassemia and BPs. To meta-analytically synthesize the primary endpoint, we used the standardized mean difference (SMD) after Hedges's g transformation under the scenario of a random effects model. Heterogeneity across studies was examined using the I² statistic. Nine randomized controlled trials (RCTs) containing original data were included in this review. Three studies were performed in Italy, one in Australia, three in Greece, one in Cyprus, and one in China. The BPs investigated included zoledronate, alendronate, pamidronate, clodronate, and neridronate. Zoledronate and alendronate showed a tendency to perform best as compared to neridronate and the placebo effect with respect to femoral neck, lumbar spine, total hip, and total body in terms of bone mass density (g/cm²). BPs and in particular, zolendronate, were quite effective in the treatment of osteoporosis. These findings suggested that bisphosphonates are still a front-line treatment of osteoporosis in TM. However, to draw more meaningful and significant conclusions for the use and efficacy of BP in TM, larger and more complete RCTs should be conducted.

A contemporary therapeutic approach to bone disease in beta-thalassemia - a review

Homozygous beta-thalassemia represents a serious hemoglobinopathy, in which an amazing prolongation in the survival rate of patients has been achieved over recent decades. A result of this otherwise positive evolution is the fact that bone problems have become a major issue in this group of patients. Through an in-depth review of the related literature, the purpose of this study is to present and comment on the totality of the data that have been published to date pertaining to the prevention and treatment of thalassemia bone-disease, focusing on: the contribution of diet and lifestyle, the treatment of hematologic disease and its complications, the management of hypercalciuria, the role of vitamins and minerals and the implementation of anti-osteoporosis medical regimen. In order to comprehensively gather the above information, we mainly reviewed the international literature through the PubMed database, searching for the preventive and therapeutic data that have been published pertaining to thalassemia bone-disease over the last twenty-nine years. There is no doubt that thalassemia bone-disease is a complication of a multi-factorial etiopathology, which does not follow the rules of classical postmenopausal osteoporosis. Bisphosphonates have been the first line of treatment for many years now, with varied and usually satisfactory results. In addition, over the last few years, more data have arisen for the use of denosumab, teriparatide, and other molecules that are in the clinical trial phase, in beta-thalassemia.

Thalassemia-associated osteoporosis: a systematic review on treatment and brief overview of the disease

Thalassemia-associated osteoporosis constitutes a major complication in patients with thalassemia. This review presents the existing studies on the treatment of thalassemia-associated osteoporosis and discusses the management of this debilitating complication. A brief presentation of the disease characteristics and pathogenetic mechanisms is also provided. The life expectancy of patients with thalassemia has increased markedly in recent years resulting in the aging of the population and the emergence of new comorbidities. The majority of patients with thalassemia have low bone mineral density and experience lifelong fracture rates as high as 71 %. The pathogenesis of thalassemia-associated osteoporosis (TAO) is multifactorial with anemia and iron overload playing crucial role in its development. Data concerning the prevention and treatment of TAO are extremely limited. We performed a literature research in Pubmed and Scopus to identify interventional studies evaluating the effects of various agents on TAO. Seventeen studies were retrieved. We present the results of these studies as well as a brief overview of TAO including presentation, pathogenesis, and management. Most of the studies identified are of poor quality, are not randomized controlled, and include small number of participants. There are no data concerning effects on fracture rates. Bisphosphonates are the most widely studied agents and among them zoledronic acid is the most well studied. Hormone replacement treatment (HRT) shows beneficial but small effects. Denosumab and strontium ranelate have each been evaluated in only a single study, while there are no data about the effects of anabolic agents. Given the increased life expectancy and the increase in fracture rates with age, more data about the management of TAO are warranted. Moreover, due to the need for lifelong management starting at young age, careful treatment plans which may include sequential treatment may often be required. However, currently, there are no relevant data available.

Vitamin D, osteoprotegerin/receptor activator of nuclear factor-kappaB ligand (OPG/RANKL) and inflammation with alendronate treatment in HIV-infected patients with reduced bone mineral density

OBJECTIVES

The aim of the study was to determine the effect of alendronate (ALN) on inflammatory markers and osteoprotegerin (OPG)/receptor activator of nuclear factor-kappaB ligand (RANKL), and to explore the associations of baseline systemic inflammation and vitamin D status on the bone mineral density (BMD) response to ALN.

METHODS

Eighty-two HIV-positive patients with lumbar spine T-score ≤ -1.5 were randomized to ALN 70 mg weekly or placebo for 48 weeks; all received calcium carbonate 500 mg/vitamin D3 200 IU twice daily. Serum C-telopeptide (CTx) and BMD were assessed at baseline and week 48. Stored plasma samples in 70 subjects were assayed for levels of 25-hydroxyvitamin D (25(OH)D), OPG, RANKL, interleukin (IL)-6 and soluble receptors for tumour necrosis factor (TNF)-α 1 and 2 (sTNFR 1 and 2).

RESULTS

ALN increased BMD more than placebo at both the lumbar spine (difference ALN - placebo 2.64%; P = 0.011) and the total hip (difference 2.27%; P = 0.016). No within- or between-arm differences in OPG, RANKL or inflammatory markers were observed over 48 weeks. High baseline CTx and sTNFR2 were associated with a more robust BMD response to ALN over 48 weeks at the lumbar spine [difference 5.66%; 95% confidence interval (CI) 3.50, 7.82; P < 0.0001] and total hip (difference 4.99%; 95% CI 2.40, 7.57; P = 0.0002), respectively. Baseline 25(OH)D < 32 ng/mL was associated with larger increases in total hip BMD over 48 weeks, independent of ALN treatment (P = 0.014).

CONCLUSIONS

Among HIV-positive patients, higher baseline bone resorption and TNF-α activity were associated with an increased BMD response to ALN. The greater BMD response in those with lower vitamin D reinforces the importance of vitamin D supplementation with bisphosphonate treatment.

The use of alendronate is associated with a decreased incidence of type 2 diabetes mellitus--a population-based cohort study in Taiwan

Purpose

Bone remodeling has been linked to glucose metabolism in animal studies, but the results of human trials were inconclusive. Bisphosphonates may play a role in glucose metabolism through their impacts on bone remodeling enzymes. In this study, we aimed to examine the influence of alendronate usage on the incidence of type 2 diabetes mellitus (DM) among osteoporotic patients.

Methods

A retrospective cohort study was designed to include osteoporotic patients without DM from a population-based cohort containing 1,000,000 subjects. Patients treated with alendronate (exposed group, N=1,011) were compared with those who received no treatment (age and gender matched non-exposed group, N=3,033). Newly diagnosed DM was identified from medical records by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9CM) code. The incidence of DM in both groups was calculated for comparison.

Results

The non-exposed group had a significantly higher incidence of DM (Odds ratio 1.21, 95% confidence interval 1.03~1.41) when compared with the exposed group. In subgroup analysis, the DM risk reduction in exposed group was only significant among those younger than 65 years and those without hypertension or dyslipidemia. Patients who were prescribed alendronate more than or equal to 3 times had demonstrated a significant reduction in DM risk.

Conclusions

Our study showed alendronate might yield a protective effect for incident DM. This effect became insignificant in patients with older age, dyslipidemia or hypertension. The underlying mechanism needs further exploration with prospective data for confirmation of the observed findings.

Bisphosphonates in the adjuvant treatment of young women with breast cancer: the estrogen rich is a poor candidate!

During the last 2 decades the role of bisphosphonates (BPs) to reduce skeletal-related events from bone metastases in breast cancer has been well defined. Several preclinical studies have strongly suggested that BPs may also provide an anti-cancer effect in early breast cancer. Indeed, the use of adjuvant BPs represents a unique approach that attempts at eradicating occult tumor micro-metastases residing in the bone marrow via targeting the bone microenvironment to render it less favorable for cancer cell growth. Although, this concept has been tested clinically for more than 15 years, no final consensus has been reached as for the routine use of BPs in the adjuvant phase of breast cancer, owing to conflicting results of randomized studies. Nevertheless, accumulating evidence from recent trials has indicated a therapeutic benefit of adjuvant BPs-particularly zoledronic acid-in women with established menopause, with no or perhaps detrimental effects in premenopausal women. Indeed, this hypothesis has opened a new chapter on the role of estrogen-poor microenvironment as a potential pre-requisite for the anti-tumor effects of BPs in the adjuvant phase of breast cancer. In this review, we will emphasize the biological rational of using BPs to target bone microenvironment in patients with early breast cancer and we will explore mechanistic differences; related to bisphosphonates effects in premenopausal versus postmenopausal women and how the endocrine environment would influence the anticancer potential of these compounds.

The spine in β-thalassemia syndromes

STUDY DESIGN

Literature review.

OBJECTIVE

To present a comprehensive overview of spinal involvement in patients with β-thalassemia, aiming to orient the spinal surgeon to these potentially disabling complications.

SUMMARY OF BACKGROUND DATA

β-thalassemia, an inherited disorder of hemoglobin synthesis, is the most common monogenetic disease worldwide. Patients with thalassemia major (TM) suffer a severe anemia that requires regular blood transfusions for survival and iron chelation therapy to control transfusional iron overload. Thalassemia intermedia is a phenotype of thalassemia with a milder course and anemia, wherein most patients remain transfusion independent. Spinal involvement related to disease course and treatment is common in patients with thalassemia syndromes, yet it has not been constructively reviewed in the literature.

METHODS

Potentially relevant studies were identified from an electronic search of MEDLINE (1966 to the second week of May 2010).

RESULTS

In patients with TM, genetic and acquired risk factors lead to osteoporosis, pathologic fractures of the spine, and back pain. Osteoporosis in TM patients is progressive; thus, early diagnosis and treatment are recommended. Bisphosphonates are relatively safe and effective in this patient population. Characteristic intervertebral disc degeneration is also seen in patients with TM who have evidence of severe iron overload or those who receive the subcutaneous iron chelator deferoxamine. Spinal asymmetry and overt scoliosis are common in patients with TM. The prognosis seems favorable, with many patients showing spontaneous resolution without the need for intervention. In patients with thalassemia intermedia, ineffective erythropoiesis drives extramedullary hematopoietic tissue formation, which is mostly evident on magnetic resonance imaging. Paraspinal involvement is of greatest concern because of the associated spinal cord compression. Several treatment options have been described, including transfusion therapy, laminectomy, radiotherapy, and the use of fetal hemoglobin-inducing agents that decrease the hematopoietic drive.

CONCLUSION

Current knowledge supports that spinal involvement in patients with β-thalassemia is common and diverse yet still requires further prospective evaluation.

Bone disease and skeletal complications in patients with β thalassemia major

Increased survival in patients with β thalassemia major (TM) allowed for several complications of the disease and its treatment to manifest, one of which is bone disease. Osteoporosis in this patient population results from a variety of genetic and acquired factors. Early diagnosis and prevention are essential and several measures have been evaluated for management including bisphosphonates. Fracture prevalence in TM patients seems to be clustered in mid adulthood, and is related to vitamin D deficiency and low bone mineral density. Fracture healing in patients with TM does not seem to be different from that in normal individuals. Bone and joint pain are a common manifestation of the underlying pathophysiology or may be related to iron chelator intake. Intervertebral disc changes are seen in patients who are heavily iron overloaded or those who are chelated with deferoxamine. Spinal deformity is common in TM, yet the prognosis is benign with spontaneous resolution frequently observed. Further research is warranted to evaluate the mechanisms, clinical implications, and optimal management of bone disease in this patient population.

Zoledronic acid: clinical utility and patient considerations in osteoporosis and low bone mass

The availability of a once-a-year zoledronic acid infusion heralds a new era in the management of osteoporosis. It virtually eliminates the problem of poor compliance with orally administered bisphosphonates and, because it bypasses the gastrointestinal tract, it is not associated with gastrointestinal side effects. Zoledronic acid is effective for the treatment and prevention of postmenopausal osteoporosis, and for the treatment of osteoporosis in men, and glucocorticoid-induced osteoporosis. When administered within three months of a hip fracture, it reduces mortality and the risk of subsequent fractures. It is remarkably free of serious adverse effects. After administration of the intravenous infusion, about 18% of bisphosphonate-naïve patients experience an acute-phase reaction, including low-grade temperature, aches, and pains. This is reduced to about 9% in those who have been treated with oral bisphosphonates, and is further reduced by the concomitant and subsequent administration of acetaminophen. The likelihood and magnitude of the acute-phase reaction is less after the second infusion. Other adverse effects are similar to those encountered with other bisphosphonates. Because it is mostly excreted by the kidneys, zoledronic acid should not be administered to patients with a creatinine clearance less than 35 mL/min. It should not be administered to patients with hypocalcemia.

Iron chelation therapy in Upper Egyptian transfusion-dependent pediatric homozygous beta-thalassemia major: impact on serum L-carnitine/free fatty acids, osteoprotegerin/the soluble receptor activator of nuclear factor-kappabeta ligand systems, and bone mineral density

Bone disease in beta-thalassemia major (betaTM) remains poorly understood. Receptor activator of nuclear factor-kappabeta ligand (RANKL) regulates osteoclast formation and function. RANKL activity is balanced by interaction with its receptor (RANK) and binding to osteoprotegerin (OPG). L-Carnitine (LC) enhances osteoblastic activity by furnishing fuel. This study hypothesized that abnormal bone metabolism in betaTM involves imbalanced RANKL/OPG and LC/free fatty acids (FFAs) metabolism. Sixty-nine transfusion-dependent betaTM patients and 15 healthy controls were enrolled. One group of patients (n=34) received desferrioxamine (DFO) and the other (n=35) did not. Serum OPG, soluble RANKL (sRANKL), FFAs, LC [total LC (TC), free LC (FC), and esterified LC (EC)], calcium, and inorganic phosphate were measured by specific immuno and colorimetric assays; bone mineral density was examined by dual x-ray absorptiometry. Patients showed lower levels of OPG, TC, FC, EC and higher levels of sRANKL, sRANKL/OPG ratio, and FFAs than controls. Patients on DFO showed lower levels of OPG, TC, FC and higher levels of sRANKL, sRANKL/OPG ratio, and FFAs than those without chelation. In patients, sRANKL correlated negatively with TC and OPG and FC correlated positively with OPG and negatively with sRANKL, sRANKL/OPG ratio, and FFAs. In conclusion, altered bone metabolism owing to imbalanced osteoclastic bone resorption versus constructive osteoblastic activities in betaTM pediatric patients could be due to abnormal sRANKL-OPG and LC-FFAs systems that were worsened by DFO.

RANKL inhibition for the management of patients with benign metabolic bone disorders

The receptor activator of NF-kappaB ligand (RANKL) is a member of the TNF receptor superfamily, essential for osteoclastogenesis. It binds to its receptor activator of NF-kappaB on the surface of osteoclast precursors and enhances their differentiation, survival and fusion, while it activates mature osteoclasts and inhibits their apoptosis. The effects of RANKL are counteracted by osteoprotegerin (OPG), a neutralizing decoy receptor. Derangement of the balance in RANKL/OPG action is implicated in the pathophysiology of metabolic bone diseases, including osteoporosis. Current therapies used to prevent or treat metabolic bone diseases are thought to act, at least in part, through modification of the RANKL/OPG dipole. The idea of using a molecule that could specifically bind and neutralize RANKL to decrease bone resorption and subsequent bone loss is appealing. Recombinant OPG was initially tested. Denosumab, a fully human monoclonal antibody against RANKL, is a promising antiresorptive agent under investigation. It rapidly decreases bone turnover markers resulting in a significant increase in bone mineral density and reduction in fracture risk. However, because receptor activator of NF-kappaB activation by RANKL is also essential for T-cell growth and dendritic-cell function, inhibition of its action could simultaneously affect the immune system, leading to susceptibility in infections or malignancies.

Long-term effects of pamidronate in thalassemic patients with severe bone mineral density deficits

Osteoporosis is a common complication in thalassemia major (TM). Our previous study demonstrated severe bone mineral density (BMD) deficits at spine and hip in 62 and 35% of TM patients. This study assessed the effects of different treatments (calcium, vitamin D and bisphosphonate) on patients' BMD, which was measured at baseline and after 3-year treatments by dual energy X-ray absorptiometry (DEXA). Twenty-one untreated patients, 11 patients on calcium/vitamin D and seven patients on additional pamidronate, were recruited. They were comparable for gender (p = 0.630) and serum ferritin levels (p = 0.412). The median BMD Z-scores at lumbar spine and left hip improved only in patients with standard plus pamidronate treatments (baseline: -3.01 and -3.05, end-of-study: -2.12 and -2.09; p = 0.018 and 0.028, respectively). In contrast, BMD Z-scores at hip worsened in untreated patients (p = 0.034). In conclusion, long-term improvement in BMD in TM patients was observed with bisphosphonate but not calcium and vitamin D treatment.

Bone recovery after zoledronate therapy in thalassemia-induced osteoporosis: a meta-analysis and systematic review

Zoledronate is a promising bisphosphonate that improves the bone mineral density by 0.69 standard deviations in thalassemia-induced osteoporosis, but the entire range of its actions and side effects is currently not fully understood.

INTRODUCTION

Zoledronate is a promising bisphosphonate for the treatment of thalassemia-induced osteoporosis; however, a quantitative summary of its beneficial effect and its effects on the markers of bone turnover are not established.

METHODS

We conducted a meta-analysis of the published randomized controlled trials using standardized mean difference and a random effects model for improvement in bone mineral density (BMD). We also conducted a systematic review for the influence of zoledronate on markers of bone turnover and bone pain.

RESULTS

We found that zoledronate improves the baseline BMD by 0.69 (95% confidence interval 0.47-0.90) standard deviations-an effect that was more pronounced when BMD was measured at the lumbar spine. However, the mechanistic interpretations of the effects on the markers of bone turnover are not completely clear.

CONCLUSION

Sufficient evidence exists to demonstrate that 4 mg zoledronate given every 3 months markedly improves the BMD; however, more qualitative and quantitative evidence is required to understand the mechanisms of its action and the potential side effects.

Serum Dickkopf-1 is increased and correlates with reduced bone mineral density in patients with thalassemia-induced osteoporosis. Reduction post-zoledronic acid administration

Dickkopf-1 is an inhibitor of Wnt signaling, which is crucial for osteoblast differentiation. We evaluated serum levels of Dickkopf-1 in 66 patients with thalassemia-induced osteoporosis who received therapy with zoledronic acid in a placebo-controlled, randomized trial. At baseline, thalassemia patients had increased serum levels of Dickkopf-1 that correlated with reduced bone mineral density of the lumbar spine and the distal radius. High Dickkopf-1 also correlated with increased bone resorption and reduced bone formation markers. Zoledronic acid produced a reduction in serum Dickkopf-1, which was associated with bone mineral density increase after 12 months of therapy. On the contrary, placebo group showed a borderline increase of Dickkopf-1, which was higher in patients who showed deterioration in pain scores. These results suggest that Dickkopf-1 is implicated in the pathogenesis of osteoporosis in thalassemia and reveal Dickkopf-1 as a possible target for the development of novel agents for the management of thalassemia-induced osteoporosis.

Clinical efficacy and safety of zoledronic acid in osteoporosis and Paget's bone disease

Osteoporosis and Paget's bone disease are the most common diseases of the bone. In addition to glucocorticoid treatment, there are many other secondary causes of osteoporosis. Bisphosphonates are used to treat these bone conditions. Zoledronic acid is the most potent bisphosphonate at inhibiting bone resorption. In osteoporosis, zoledronic acid increases bone mineral density for at least 1 year following a single intravenous administration. The efficacy and safety of zoledronic acid in the treatment of osteoporosis and Paget's bone disease are reviewed. This article also covers the studies of the effects of zoledronic acid in the bone loss associated with the secondary osteoporosis.

EFFECTS OF ZOLEDRONIC ACID ON OOFORECTOMIZED RATS' TIBIAE: A PROSPECTIVE AND RANDOMIZED STUDY

To investigate clinical, biomechanic and histomorphometric effects of zoledronic acid on osteoporotic rats' tibiae after bilateral ooforectomy.

METHODS

40 female Wistar (Rattus novergicus albinus) rats were prospectively studied. On the 60th day of life, the animals were randomized into two groups according to the surgical procedure: bilateral ooforectomy (O) (n=20) and sham surgery ("sham") (P) (n=20). After 30 days, the animals were divided into four groups, according to the administration of zoledronic acid (ZA) 0.1mg/kg or distilled water (DW): OZA (n=10), ODW (n=10), PZA (n=10) and PDW (n=10). After 12 months, the animals were sacrificed, and had their tibiae assessed. In the clinical study, animals' weight was considered; in the biomechanical study, compressive assays were applied and, in the histomorphometric analysis, the bone trabecular area was determined.

RESULTS

"O" groups showed a significantly greater weight gain than "P" groups (p=0.005). Groups OZA and PZA showed an insignificant weight gain when compared to ODW (p=0.47) and PDW (p=0.68). The groups receiving zoledronic acid and distilled water were able to bear maximum load, similar (p=0.2), at the moment of fracture. In the groups receiving zoledronic acid, an insignificant increase of the bone trabecular area was found when compared to the groups receiving distilled water (p=0.21). There was a positive correlation between trabecular area and maximum load (p=0.04; r=0.95).

CONCLUSION

Zoledronic acid did not significantly influence animals' weight. The results showed an insignificant increase both of the tibial shaft bone resistance and the bone trabecular area.