Bone Abstracts

Purpose: Denosumab is commonly used as an anti-resorptive agent to treat osteoporosis. After discontinuation of denosumab, however, bone resorption increases again, and the bone mass gained during therapy is lost within a year.Methods: We present a case report of asymptomatic hypoparathyroid hypercalcemia in a patient who discontinued long-term treatment with denosumab.Results: A 67-year old women with osteoporosis was treated with...

Background: Osteogenesis imperfecta [OI] is a disorder of bone fragility with a variable spectrum of severity and poor correlation of antenatal findings with postnatal outcome. We present two antenatal diagnosed cases with a mild postnatal course significant for the absence of fractures and progressive remodelling of the long bones. A novel heterozygous pathogenic mutation predicted to replace glycine with aspartic acid at position 913 in exon 42 of the COL1A2 gene has been id...

Background: Hyperphosphatemic familial tumoral calcinosis (HFTC) is characterized by hyperphosphatemia and the formation of tumor-like extra-osseous calcifications. Tumors often necessitate surgical management although medical treatment may limit the need for surgical intervention. We present two cases of HFTC successfully managed with combination acetazolamide (ACTZ) and sevelamer carbonate.Case Report #1: A 5-year-old African boy with a loss-of-functio...

Osteogenesis Imperfecta (OI) is a rare congenital disorder of bone fragility. Majority of OI cases are caused by loss of function or missense pathogenic variants in the COL1A1/2 genes. In addition to fractures, patients suffer from different, mainly long bone, skeletal deformities. OI patients might develop chest deformities (pectus carinatum (PC) or excavatum (PE)) of different severity, which can tend to formation of cardiopulmonary complications. The main aim of current stu...

Objectives: Fibroblast growth factor 23 (FGF23) is a bone-derived phosphaturic hormone. The main target organ is the kidney, where FGF23 suppresses renal phosphate reabsorption and vitamin D synthesis. It also stimulates calcium reabsorption in the kidney. FGF23 secretion is stimulated by 1,25(OH)2D and by increased extracellular phosphate concentration, thus forming a feedback loop between kidney and bone. The bioactive intact FGF23 contains 251 amino acids and is glycosylate...

Preterm infants develop reduced bone mass and fragility fractures. Nevertheless, normal ranges in preterm infants are poorly defined for concentrations of vitamin D; its isomers (C3α-epimer of 25(OH)D3) and metabolites (24, 25(OH)2D3, 1, 24(OH)2D); and other mineral-regulating hormones, including FGF23 in both intact (iFRG23) and inactive (C- terminal) forms.Objective: To clarify normal concentrations of minerals and hormones in healthy, preterm inf...

Objectives: Hypophosphatasia (HPP) is a rare metabolic disease caused by loss-of-function mutation(s) in the gene encoding tissue-nonspecific alkaline phosphatase (TNSALP). HPP in infants is characterized by poor skeletal mineralization, respiratory compromise, and a high risk of mortality. We previously reported improved mineralization and respiratory function in 15 patients enrolled in this second study of asfotase alfa, a bone-targeted recombinant human TNSALP, in infants a...

Aims: Using an extensive bioinformatic approach we identified integrin α5 subunit as a novel potential target to treat bone dissemination from breast cancer. Aim of this study is to confirm the value of this target.Methods: Integrin α5 mRNA expression levels were quantified by qRT-PCR, using radically resected primary tumors of 427 breast cancer patients. α5 expression at protein level by IHC on primary tumor was correlated, in an addition...

Background: Rickets is a disorder of the growing child arising from impaired mineralisation of the growth plate and osteoid. The most common cause of NR in the UK is thought to be secondary to vitamin D deficiency [VDD; serum 25-hydroxyvitamin D (25OHD) <25 nmol/l], although in some African & South Asian countries dietary calcium deficiency (DCaD) by itself, or together with VDD is an important cause of NR (Ann Trop Paediatr. 2006;26:1–16). Currently, the data on ...

Objective: We evaluated the long-term efficacy of burosumab, a monoclonal antibody against FGF23, in a Phase 2 Study (NCT02163577) in children with XLH.Methods: Fifty-two children with XLH (5-12 years-old, Tanner ≤ 2) were randomized 1:1 to receive subcutaneous burosumab Q2W or Q4W for 64 weeks. Doses were titrated up to 2 mg/kg/dose targeting serum phosphorus levels within 1.1–1.6 mmol/l. All subjects entered the long-term extension at Week 6...