Langerhans cell histiocytosis (LCH) is a rare disease of not well-defined etiology that involves immune cell activation and frequently affects the skeleton. Bone involvement in LCH usually presents in the form of osteolytic lesions along with low bone mineral density. Various molecules involved in bone metabolism are implicated in the pathogenesis of LCH or may be affected during the course of the disease, including interleukins (ILs), tumor necrosis factor α, receptor activator of NF-κB (RANK) and its soluble ligand RANKL, osteoprotegerin (OPG), periostin and sclerostin. Among them IL-17A, periostin and RANKL have been proposed as potential serum biomarkers for LCH, particularly as the interaction between RANK, RANKL and OPG not only regulates bone homeostasis through its effects on the osteoclasts but also affects the activation and survival of immune cells. Significant changes in circulating and lesional RANKL levels have been observed in LCH patients irrespective of bone involvement. Standard LCH management includes local or systematic administration of corticosteroids and chemotherapy. Given the implication of RANK, RANKL and OPG in the pathogenesis of the disease and the osteolytic nature of bone lesions, agents aiming at inhibiting the RANKL pathway and/or osteoclastic activation, such as bisphosphonates and denosumab, may have a role in the therapeutic approach of LCH although further clinical investigation is warranted.
Athanasios D Anastasilakis, Marina Tsoli, Gregory Kaltsas, and Polyzois Makras
Alessandro Brancatella and Claudio Marcocci
Thyroid hormones stimulate bone turnover in adults by increasing osteoclastic bone resorption. TSH suppressive therapy is usually applied in patients with differentiated thyroid cancer (DTC) to improve the disease outcome. Over the last decades several authors have closely monitored the potential harm suffered by the skeletal system. Several studies and meta-analyses have shown that chronic TSH suppressive therapy is safe in premenopausal women and men. Conversely, in postmenopausal women TSH suppressive therapy is associated with a decrease of bone mineral density, deterioration of bone architecture (quantitative CT, QCT; trabecular bone score, TBS), and, possibly, an increased risk of fractures. The TSH receptor is expressed in bone cells and the results of experimental studies in TSH receptor knockout mice and humans on whether low TSH levels, as opposed to solely high thyroid hormone levels, might contribute to bone loss in endogenous or exogenous thyrotoxicosis remain controversial. Recent guidelines on the use of TSH suppressive therapy in patients with DTC give value not only to its benefit on the outcome of the disease, but also to the risks associated with exogenous thyrotoxicosis, namely menopause, osteopenia or osteoporosis, age >60 years, and history of atrial fibrillation. Bone health (BMD and/or preferably TBS) should be evaluated in postmenopausal women under chronic TSH suppressive therapy or in those patients planning to be treated for several years. Antiresorptive therapy could also be considered in selected cases (increased risk of fracture or significant decline of BMD/TBS during therapy) to prevent bone loss.
Keina Nishio, Akiko Tanabe, Risa Maruoka, Kiyoko Nakamura, Masaaki Takai, Tatsuharu Sekijima, Satoshi Tunetoh, Yoshito Terai, and Masahide Ohmichi
Although surgical menopause may increase the risks of osteoporosis, few studies have investigated the influence of chemotherapy and radiation therapy. The aim of this study is to evaluate the effects of treatments for gynecological malignancies on bone mineral density (BMD).
This study enrolled 35 premenopausal women (15 ovarian cancers (OCs), 9 endometrial cancers (ECs), and 11 cervical cancers (CCs)) who underwent surgical treatment that included bilateral oophorectomy with or without adjuvant platinum-based chemotherapy in OC and EC patients, or concurrent chemo-radiation therapy (CCRT) in CC patients according to the established protocols at the Osaka Medical College Hospital between 2006 and 2008. The BMD of the lumbar spine (L1–L4) was measured by dual-energy X-ray absorptiometry, and urine cross-linked telopeptides of type I collagen (NTx) and bone alkaline phosphatase (BAP) were assessed for evaluation of bone resorption and bone formation respectively. These assessments were performed at baseline and 12 months after treatment.
Although the serum BAP was significantly increased only in the CC group, a rapid increase in the bone resorption marker urinary NTx was observed in all groups. The BMD, 12 months after CCRT was significantly decreased in the CC group at 91.9±5.9% (P<0.05 in comparison to the baseline).
This research suggests that anticancer therapies for premenopausal women with gynecological malignancies increase bone resorption and may reduce BMD, particularly in CC patients who have received CCRT. Therefore, gynecologic cancer survivors should be educated about these potential risks and complications.
Cristina Lamas, Elena Navarro, Anna Casterás, Paloma Portillo, Victoria Alcázar, María Calatayud, Cristina Álvarez-Escolá, Julia Sastre, Evangelina Boix, Lluis Forga, Almudena Vicente, Josep Oriola, Jordi Mesa, and Nuria Valdés
Primary hyperparathyroidism is the most frequent manifestation of multiple endocrine neoplasia type 1 (MEN1) syndrome. Bone and renal complications are common. Surgery is the treatment of choice, but the best timing for surgery is controversial and predictors of persistence and recurrence are not well known. Our study describes the clinical characteristics and the surgical outcomes, after surgery and in the long term, of the patients with MEN1 and primary hyperparathyroidism included in the Spanish Registry of Multiple Endocrine Neoplasia, Pheochromocytomas and Paragangliomas (REGMEN). Eighty-nine patients (49 men and 40 women, 34.2 ± 13 years old) were included. Sixty-four out of the 89 underwent surgery: a total parathyroidectomy was done in 13 patients, a subtotal parathyroidectomy in 34 and a less than subtotal parathyroidectomy in 15. Remission rates were higher after a total or a subtotal parathyroidectomy than after a less than subtotal (3/4 and 20/22 vs 7/12, P < 0.05), without significant differences in permanent hypoparathyroidism (1/5, 9/23 and 0/11, N.S.). After a median follow-up of 111 months, 20 of the 41 operated patients with long-term follow-up had persistent or recurrent hyperparathyroidism. We did not find differences in disease-free survival rates between different techniques, patients with or without permanent hypoparathyroidism and patients with different mutated exons, but a second surgery was more frequent after a less than subtotal parathyroidectomy.
Emmanuelle Noirrit, Mélissa Buscato, Marion Dupuis, Bernard Payrastre, Coralie Fontaine, Jean-François Arnal, and Marie-Cécile Valera
Estrogen–progestin therapy was previously considered as the standard of care for managing bothersome symptoms associated with menopause, but it increases risks of breast cancer and of thromboembolism. The combination of conjugated estrogen (CE) with bazedoxifene (BZA) named tissue-selective estrogen complex (TSEC) was designed to minimize or even abrogate the undesirable effects on breast, while maintaining the beneficial effects such as prevention of osteoporosis and suppression of climacteric symptoms. The risk on thromboembolism associated with TSEC is unknown, although the clinical available data are reassuring. The aim of this study was to define the impact of a chronic administration of CE, BZA or CE + BZA on hemostasis and thrombosis in ovariectomized mice. As expected, CE, but not BZA neither CE + BZA, induced uterine and vagina hypertrophy. As previously demonstrated for 17β-estradiol (E2), we found that CE (i) increased tail-bleeding time, (ii) prevented occlusive thrombus formation in injured carotid artery and (iii) protected against collagen/epinephrine-induced thromboembolism. Thus, whereas BZA antagonized CE action on reproductive tissues, it had no impact on the effect of CE on hemostasis, thromboembolism and arterial thrombosis in mice. CE + BZA shared the anti-thrombotic actions of CE in these mouse models. If a similar process is at work in women, CE combined with BZA could contribute to minimize the risk of thrombosis associated with hormone replacement therapy.
Petar Milovanovic and Björn Busse
An increasing number of patients worldwide suffer from bone fractures that occur after low intensity trauma. Such fragility fractures are usually associated with advanced age and osteoporosis but also with long-term immobilization, corticosteroid therapy, diabetes mellitus, and other endocrine disorders. It is important to understand the skeletal origins of increased bone fragility in these conditions for preventive and therapeutic strategies to combat one of the most common health problems of the aged population. This review summarizes current knowledge pertaining to the phenomenon of micropetrosis (osteocyte lacunar mineralization). As an indicator of former osteocyte death, micropetrosis is more common in aged bone and osteoporotic bone. Considering that the number of mineralized osteocyte lacunae per bone area can distinguish healthy, untreated osteoporotic and bisphosphonate-treated osteoporotic patients, it could be regarded as a novel structural marker of impaired bone quality. Further research is needed to clarify the mechanism of lacunar mineralization and to explore whether it could be an additional target for preventing or treating bone fragility related to aging and various endocrine diseases.
Raja Padidela, Moira S Cheung, Vrinda Saraff, and Poonam Dharmaraj
X-linked hypophosphataemia (XLH) is caused by a pathogenic variant in the PHEX gene, which leads to elevated circulating FGF23. High FGF23 causes hypophosphataemia, reduced active vitamin D concentration and clinically manifests as rickets in children and osteomalacia in children and adults. Conventional therapy for XLH includes oral phosphate and active vitamin D analogues but does not specifically treat the underlying pathophysiology of elevated FGF23-induced hypophosphataemia. In addition, adherence to conventional therapy is limited by frequent daily dosing and side effects such as gastrointestinal symptoms, secondary hyperparathyroidism and nephrocalcinosis. Burosumab, a recombinant human IgG1 MAB that binds to and inhibits the activity of FGF23, is administered subcutaneously every 2 weeks. In clinical trials (phase 2 and 3) burosumab was shown to improve phosphate homeostasis that consequently resolves the skeletal/non-skeletal manifestations of XLH. Burosumab was licensed in Europe (February 2018) with the National Institute for Health and Care Excellence, UK approving use within its marketing authorisation in October 2018. In this publication, the British Paediatric and Adolescent Bone Group (BPABG) reviewed current evidence and provide expert recommendations for care pathway and management of XLH with burosumab.
Clarissa Souza Barthem, Camila Lüdke Rossetti, Denise P Carvalho, and Wagner Seixas da-Silva
Estradiol has been used to prevent metabolic diseases, bone loss and menopausal symptoms, even though it might raise the risk of cancer. Metformin is usually prescribed for type 2 diabetes mellitus and lowers food intake and body mass while improving insulin resistance and the lipid profile. Ovariectomized rats show increased body mass, insulin resistance and changes in the lipid profile. Thus, the aim of this work was to evaluate whether metformin could prevent the early metabolic dysfunction that occurs early after ovariectomy. Female Wistar rats were divided into the following groups: SHAM-operated (SHAM), ovariectomized (OVX), ovariectomized + estradiol (OVX + E2) and ovariectomized + metformin (OVX + M). Treatment with metformin diminished approximately 50% of the mass gain observed in ovariectomized animals and reduced both the serum and hepatic triglyceride levels. The hepatic levels of phosphorylated AMP-activated protein kinase (pAMPK) decreased after OVX, and the expression of the inactive form of hepatic acetyl-CoA carboxylase (ACC) was also reduced. Metformin was able to increase the levels of pAMPK in the liver of OVX animals, sustaining the balance between the inactive and total forms of ACC. Estradiol effects were similar to those of metformin but with different proportions. Our results suggest that metformin ameliorates the early alterations of metabolic parameters and rescues hepatic AMPK phosphorylation and ACC inactivation observed in ovariectomized rats.
Karoline Winckler, Lise Tarnow, Louise Lundby-Christensen, Thomas P Almdal, Niels Wiinberg, Pia Eiken, Trine W Boesgaard, and the CIMT trial group
Despite aggressive treatment of cardiovascular disease (CVD) risk factors individuals with type 2 diabetes (T2D) still have increased risk of cardiovascular morbidity and mortality. The primary aim of this study was to examine the cross-sectional association between total (25-hydroxy vitamin D (25(OH)D)) and risk of CVD in patients with T2D. Secondary objective was to examine the association between 25(OH)D and bone health. A Danish cohort of patients with T2D participating in a randomised clinical trial were analysed. In total 415 patients (68% men, age 60±9 years (mean±s.d.), duration of diabetes 12±6 years), including 294 patients (71%) treated with insulin. Carotid intima–media thickness (IMT) and arterial stiffness (carotid artery distensibility coefficient (DC) and Young's elastic modulus (YEM)) were measured by ultrasound scan as indicators of CVD. Bone health was assessed by bone mineral density and trabecular bone score measured by dual energy X-ray absorptiometry. In this cohort, 214 patients (52%) were vitamin D deficient (25(OH)D <50 nmol/l). Carotid IMT was 0.793±0.137 mm, DC was 0.0030±0.001 mmHg, YEM was 2354±1038 mmHg and 13 (3%) of the patients were diagnosed with osteoporosis. A 25(OH)D level was not associated with carotid IMT or arterial stiffness (P>0.3) or bone health (P>0.6) after adjustment for CVD risk factors. In conclusion, 25(OH)D status was not associated with carotid IMT, arterial stiffness or bone health in this cohort of patients with T2D. To explore these associations and the association with other biomarkers further, multicentre studies with large numbers of patients are required.
Agnès Linglart, Martin Biosse-Duplan, Karine Briot, Catherine Chaussain, Laure Esterle, Séverine Guillaume-Czitrom, Peter Kamenicky, Jerome Nevoux, Dominique Prié, Anya Rothenbuhler, Philippe Wicart, and Pol Harvengt
In children, hypophosphatemic rickets (HR) is revealed by delayed walking, waddling gait, leg bowing, enlarged cartilages, bone pain, craniostenosis, spontaneous dental abscesses, and growth failure. If undiagnosed during childhood, patients with hypophosphatemia present with bone and/or joint pain, fractures, mineralization defects such as osteomalacia, entesopathy, severe dental anomalies, hearing loss, and fatigue. Healing rickets is the initial endpoint of treatment in children. Therapy aims at counteracting consequences of FGF23 excess, i.e. oral phosphorus supplementation with multiple daily intakes to compensate for renal phosphate wasting and active vitamin D analogs (alfacalcidol or calcitriol) to counter the 1,25-diOH-vitamin D deficiency. Corrective surgeries for residual leg bowing at the end of growth are occasionally performed. In absence of consensus regarding indications of the treatment in adults, it is generally accepted that medical treatment should be reinitiated (or maintained) in symptomatic patients to reduce pain, which may be due to bone microfractures and/or osteomalacia. In addition to the conventional treatment, optimal care of symptomatic patients requires pharmacological and non-pharmacological management of pain and joint stiffness, through appropriated rehabilitation. Much attention should be given to the dental and periodontal manifestations of HR. Besides vitamin D analogs and phosphate supplements that improve tooth mineralization, rigorous oral hygiene, active endodontic treatment of root abscesses and preventive protection of teeth surfaces are recommended. Current outcomes of this therapy are still not optimal, and therapies targeting the pathophysiology of the disease, i.e. FGF23 excess, are desirable. In this review, medical, dental, surgical, and contributions of various expertises to the treatment of HR are described, with an effort to highlight the importance of coordinated care.