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Objective Bone loss in arthritis is a complex process characterized by bone erosions and periarticular and generalized bone loss. The antigen-induced arthritis (AIA) model is mainly used to study synovitis and joint destruction, including bone erosions; however, periarticular bone loss has been less extensively investigated. The objectives of this study were to characterize and establish AIA as a model for periarticular bone loss, and to determine the importance of NADPH oxidase 2 (NOX-2)-derived reactive oxygen species (ROS) in periarticular bone loss. Methods Arthritis was induced in mice by local injection of antigen in one knee; the other knee was used as a nonarthritis control. At study termination, the knees were collected for histologic assessment. Periarticular bone mineral density (BMD) was investigated by peripheral quantitative computed tomography. Flow cytometric analyses were performed using synovial and bone marrow cells. Results AIA resulted in decreased periarticular trabecular BMD and increased frequencies of preosteoclasts, neutrophils, and monocytes in the arthritic synovial tissue. Arthritis induction resulted in an increased capability to produce ROS. However, induction of arthritis in Ncf1*/* mice, which lack NOX-2-derived ROS, and control mice resulted in similar reductions in periarticular trabecular BMD. Conclusion The initiation of AIA resulted in periarticular bone loss associated with local effects on inflammatory cells and osteoclasts. Furthermore, based on our observations using this model, we conclude that NOX-2-derived ROS production is not essential for inflammation-mediated periarticular bone loss. Thus, AIA can be used as a model to investigate the pathogenesis of local inflammation-mediated bone loss. [ABSTRACT FROM AUTHOR]

Background: Cardiac conduction disturbances are common in spondyloarthropathies such as ankylosing spondylitis (AS). Whether their occurrence can be linked to signs and symptoms of rheumatic disease activity is an unsettled issue addressed in this study.Methods: In this cross-sectional study patients with AS according to modified New York criteria but without psoriasis, inflammatory bowel disease, dementia, pregnancy, other severe diseases such as malignancy and difficulties in answering questionnaires were invited; and 210 participated (120 men), mean age 49 years (SD 13; range: 16-77). Questionnaires, physical examination, ECG, and laboratory tests were performed at the same visit.Results: Cardiac conduction disturbances were common and diagnosed in 10-33%, depending on if conservative or less conservative predefined criteria were applied. They consisted mostly of 1st degree atrio-ventricular block and prolonged QRS duration, but one patient had a pacemaker and 7 more had complete bundle branch blocks. Conduction abnormalities were associated mainly with age, male gender and body weight, and not with laboratory measures of inflammation or with Bath Ankylosing Spondylitis Disease Activity Index. Neither were they associated with the presence of HLA B27, which was found in 87% of all patients; the subtype B270502 dominated in all patients.Conclusions: Cardiac conduction abnormalities are common in AS, but not associated with markers of disease activity or specific B27 subtypes. Even relatively mild conduction system abnormalities might, however, indirectly affect morbidity and mortality. [ABSTRACT FROM AUTHOR]

Introduction: Our objective was to determine the frequency of and factors associated with prevalent vertebral compression fractures in female systemic lupus erythematosus (SLE) patients attending rheumatologists in western Sweden., Methods: In this cross sectional study 150 women were included. They were examined with x-ray of thoracic and lumbar spine (Th4 to L4). A reduction of at least 20% of any vertebral height, assessed by Genant's semiquantitative method, was defined as a fracture. Bone mineral density (BMD) was measured by dual energy x-ray absorptiometry (DXA)., Results: Median patient age was 47 years (20 to 82) and disease duration 11 years (1 to 41). Only 6 (4%) women had a history of clinical compressions whereas 43 (29%) had at least one radiological fracture each. The patients with at least one fracture at any site were characterized by older age (P < 0.001), being postmenopausal (P < 0.01), higher Systemic Lupus International Collaborative Clinics Damage Index (P < 0.05), lower BMD total hip and femoral neck (P < 0.05), more peripheral fractures (P < 0.01), medication with bisphosphonates (P <0.05) and calcium and vitamin D3 (P < 0.05). There were no significant differences regarding current or cumulative glucocorticosteroid dose between the groups. In logistic regression analyses high age remained as a risk factor of at least one vertebral fracture at any site whereas low BMD in total hip was associated with vertebral fracture in the lumbar spine., Conclusions: Radiological compression fractures are common but seldom diagnosed in SLE patients. High age and low BMD in total hip, but not in spine, was associated with vertebral fractures.