Bone Abstracts

Osteoporosis and vertebral fractures are recognised complications of ankylosing spondylitis (AS) but the underlying causes are incompletely understood. Osteoprotegerin (OPG) is a decoy receptor for RANK-L and inhibits osteoclastogenesis. We have previously demonstrated that antibodies to OPG (OPG-Ab) are associated with osteoporosis and increased bone turnover in patients with autoimmune diseases. The aim of this study was to determine whether OPG-Abs were detectable in AS pat...

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Vertebral fractures are the most common complication of osteoporosis, but little is known about the genetic determinants of susceptibility. Here we present the results of a genome wide association study in 1553 postmenopausal women with clinical vertebral fractures and 4340 controls, with replication in 667 cases and 2105 controls. A locus tagged by a less frequent variant (rs10190845, A-allele MAF=0.05) was identified on chromosome 2q13 as a strong predictor of clinical verte...

Objective: Children with hypophosphatasia (HPP) treated with asfotase alfa in a Phase 2 study (NCT00952484) and its open-label extension (NCT01203826) experienced significant improvements in skeletal mineralization and physical function that were sustained through 5 years of treatment (1). Herein, we report data from these studies with a maximum of 7 years of treatment.Methods: Children with HPP aged 6–12 years at baseline received asfotase alfa (3 ...

Background: Mutations in the PLS3 gene, encoding plastin 3, cause X-linked osteoporosis. Osteoporosis is characterized by low bone mineral density (BMD) and increased susceptibility to fractures. Here we describe a 7-year-old boy with osteoporosis due to a novel PLS3 deletion.Presenting problem: The patient, born to non-consanguineous parents, had a history of one low-energy long-bone fracture, three vertebral fractures (T5, T6 T8) and kyphosis. DXA scan...

Background: Mutations in the ENPP1 gene have been identified in individuals with generalized arterial calcification of infancy (GACI), a life-threatening disorder characterized by calcification in the blood vessels, because of reduced availability of pyrophosphate. We describe a case of GACI due to a novel ENPP1 mutation.Presenting problem: The patient, born at term to non-consanguineous parents, was referred to us at birth with weak femoral pulses for e...

Objectives: Studies indicate that later puberty is associated with lower bone mineral density (BMD) in childhood. Less is known about effects of puberty timing on long-term bone accrual. We examined association between age at puberty and BMD accrual rate from 10 to 25 years.Methods: This was a prospective birth cohort of healthy largely European people born in southwest England in 1991–1992 and regularly follow-up from birth to mean age 25 years. Ag...

Objectives: Osteocytes play a major role in bone metabolism as mechanosensors, key regulators of osteoblast and osteoclast activity and of the mineral homeostasis. Therefore the assessment of osteocytes characteristics is important to understand bone pathology. We propose to study indirectly the osteocytes by performing quantitative backscattered electron imaging to quantify the sectioned osteocyte lacunae density and size in 2D on bone samples.Methods: ...

Background: Lean and bone mass are heritable traits with high phenotypic correlation (rho=0.44), likely reflecting the underlying mechanical and biochemical interactions between tissues.Aim: Estimate the shared heritability (genetic correlation) of both traits in children and identify genetic determinants displaying pleiotropic effects on lean mass and bone mass accrual.Methods: Participants make part of two prospective po...

Introduction: We recently showed that patients with primary Sjögren Syndrome (pSS) have significantly higher bone mineral density (BMD) in the lumbar spine and femoral neck compared with healthy controls. The majority of those patients (69%) were using hydroxychloroquine (HCQ), which may have favourable effects on BMD.Aim: To evaluate whether HCQ modulates human bone cells in vitro.Methods: Osteoblasts were differenti...