Mediators of inflammation and bone remodeling in rheumatic disease.

Remodeling of bone is a continuous process that occurs throughout life. Under normal physiologic conditions, bone-resorbing osteoclasts and bone-forming osteoblasts are tightly coupled and regulated to ensure proper balance, such that there is no net change in bone mass. However, inflammation perturbs normal bone homeostasis. The impact of inflammation on bone is dependent upon the anatomic site affected, cell types, factors and cytokines present in the local microenvironment, and local mechanical forces. Cytokines are central to the pathogenesis of inflammation-induced bone loss and contribute to the uncoupling of osteoclast-mediated bone resorption and osteoblast-mediated bone formation, thereby disrupting normal remodeling. In this review, we will discuss the effects of cytokines on bone in two settings, rheumatoid arthritis and spondyloarthritis, a disease category that includes ankylosing spondylitis, psoriatic arthritis, reactive arthritis, inflammatory bowel disease, and juvenile onset spondyloarthropathy. The outcome for bone in these disease settings is quite different, and an understanding of the pathogenic mechanisms leading to the net impact on bone has been essential in developing new therapeutic approaches to bone health in these diseases.

Design of a phase III efficacy, immunogenicity, and safety study of 9-valent human papillomavirus vaccine in prevention of oral persistent infection in men.

BACKGROUND: Seven high-risk human papillomavirus (HPV) types (16/18/31/33/45/52/58) covered by the 9-valent HPV (9vHPV) vaccine cause >90% of HPV-related head and neck cancers (HNCs). An ongoing clinical trial (NCT04199689) was designed to evaluate 9vHPV vaccine efficacy against HPV oral persistent infection, a surrogate endpoint for HPV-related HNCs. METHODS: In this double-blind, placebo-controlled, international trial, men aged 20-45 years (N = 6000) are randomized 1:1 to receive 9vHPV vaccine or placebo on day 1, month 2, and month 6. The primary objective is to demonstrate whether 9vHPV vaccination reduces incidence of HPV16/18/31/33/45/52/58-related 6-month oral persistent infection. Incidence of HPV6/11-related 6-month oral persistent infection will be evaluated as a secondary endpoint. Oral rinse and gargle samples will be collected on day 1, month 7, month 12, and every 6 months thereafter for HPV detection by PCR. Primary analyses will be performed in per-protocol populations. Efficacy in this case-driven study will be analyzed upon accrual of ≥20 primary efficacy endpoint cases. Serum will be collected at day 1 and months 7, 12, 24, 36, and 42; anti-HPV antibody titers will be measured by competitive Luminex immunoassay. Data will be summarized as geometric mean titers and seropositivity rates. Injection-site and systemic adverse events (AEs) will be collected for 15 days post-any vaccination and serious AEs through 6 months after the last vaccination; deaths and vaccine-related serious AEs will be collected throughout the study. DISCUSSION: This trial is expected to generate important data regarding the potential for 9vHPV vaccine to prevent HPV-related head and neck disease.

The National DNA Database on trial: engaging young people in South Wales with genetics.

While there has been research conducted on public views about ethical and social aspects of the National DNA Database (NDNAD), there is little which focuses on views of young people, in particular those whose details are held on the NDNAD. We describe an engagement activity developed in South Wales to engage young offenders with ethical and social issues surrounding the NDNAD--a Mock Trial--and how we facilitated the presentation of their views to policy makers. We discuss the successes and challenges we encountered with engaging young offenders, decisions that the young people reached about possible future policies for the NDNAD at the Mock Trial, and their contribution to the decision-making process.

IL-17A deficiency promotes periosteal bone formation in a model of inflammatory arthritis.

BACKGROUND: Interleukin-17A (IL-17A) plays a pathogenic role in several rheumatic diseases including spondyloarthritis and, paradoxically, has been described to both promote and protect from bone formation. We therefore examined the effects of IL-17A on osteoblast differentiation in vitro and on periosteal bone formation in an in vivo model of inflammatory arthritis. METHODS: K/BxN serum transfer arthritis was induced in IL-17A-deficient and wild-type mice. Clinical and histologic inflammation was assessed and periosteal bone formation was quantitated. Murine calvarial osteoblasts were differentiated in the continuous presence of IL-17A with or without blockade of secreted frizzled related protein (sFRP)1 and effects on differentiation were determined by qRT-PCR and mineralization assays. The impact of IL-17A on expression of Wnt signaling pathway antagonists was also assessed by qRT-PCR. Finally, regulation of Dickkopf (DKK)1 expression in murine synovial fibroblasts was evaluated after treatment with IL-17A, TNF, or IL-17A plus TNF. RESULTS: IL-17A-deficient mice develop significantly more periosteal bone than wild-type mice at peak inflammation, despite comparable severity of inflammation and bone erosion. IL-17A inhibits calvarial osteoblast differentiation in vitro, inducing mRNA expression of the Wnt antagonist sFRP1 in osteoblasts, and suppressing sFRP3 expression, both potentially contributing to inhibition of osteoblast differentiation. Furthermore, a blocking antibody to sFRP1 reduced the inhibitory effect of IL-17A on differentiation. Although treatment with IL-17A suppresses DKK1 mRNA expression in osteoblasts, IL-17A plus TNF synergistically upregulate DKK1 mRNA expression in synovial fibroblasts. CONCLUSIONS: IL-17A may limit the extent of bone formation at inflamed periosteal sites in spondyloarthritis. IL-17A inhibits calvarial osteoblast differentiation, in part by regulating expression of Wnt signaling pathway components. These results demonstrate that additional studies focusing on the role of IL-17A in bone formation in spondyloarthritis are indicated.

Induction of bone loss in DBA/1J mice immunized with citrullinated autologous mouse type II collagen in the absence of adjuvant.

Joint damage in rheumatoid arthritis (RA) is characterized by cartilage and bone loss resulting in pain, deformity, and loss of joint function. Anti-citrullinated protein antibody (ACPA) has been implicated in RA pathogenesis and predicts radiographical joint damage and clinical severity. Therefore, the purpose of this study was to assess bone loss by micro-CT, histological joint damage, and ACPA levels using a mouse model of RA. Arthritis was induced by immunizing DBA/1 mice with autologous citrullinated type II mouse collagen (CIT-CII) weekly for 4 weeks. Mice immunized with autologous CII served as controls. At week 5, mice were killed, ACPA levels determined, and micro-CT performed to quantitatively analyze bone damage. Micro-CT analysis revealed significant loss of bone density, volume, and surface (p < 0.05) in bone peripheral to the inflamed joints of CIT-CII animals compared to CII controls. Histological staining demonstrated cartilage, proteoglycan, joint collagen, and bone collagen loss in the CIT-CII group compared to CII. Serum ACPA levels were increased (p = 0.03) in the CIT-CII group compared to CII, and these levels were inversely correlated with bone quantity and quality. In this study, we demonstrate that immunization with autologous CIT-CII initiates significant systemic bone and articular cartilage loss in the absence of adjuvant. Significant inverse correlations of circulating ACPA and bone quality/quantity were present. ACPA levels predict the adverse bone morphological changes in this model of early RA.

What choices should we be able to make about designer babies? A Citizens' Jury of young people in South Wales.

BACKGROUND: Young people will increasingly have the option of using new technologies for reproductive decision making but their voices are rarely heard in debates about acceptable public policy in this area. Capturing the views of young people about potentially esoteric topics, such as genetics, is difficult and methodologically challenging. DESIGN: A Citizens' Jury is a deliberative process that presents a question to a group of ordinary people, allows them to examine evidence given by expert witnesses and personal testimonies and arrive at a verdict. This Citizens' Jury explored designer babies in relation to inherited conditions, saviour siblings and sex selection with young people. PARTICIPANTS: Fourteen young people aged 16-19 in Wales. RESULTS: Acceptance of designer baby technology was purpose-specific; it was perceived by participants to be acceptable for preventing inherited conditions and to create a child to save a sibling, but was not recommended for sex selection. Jurors stated that permission should not depend on parents' age, although some measure of suitability should be assessed. Preventing potential parents from going abroad was considered impractical. These young people felt the Human Fertilisation and Embryology Authority should have members under 20 and that the term 'designer baby' was not useful. CONCLUSIONS: Perspectives on the acceptability of this technology were nuanced, and based on implicit value judgements about the extent of individual benefit derived. Young people have valuable and interesting contributions to make to the debate about genetics and reproductive decision making and a variety of innovative methods must be used to secure their involvement in decision-making processes.