Nat Clin Pract Rheum
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Nat Clin Pract Rheum · Sep 2007
ReviewThe assessment of ankylosing spondylitis in clinical practice.
Ankylosing Spondylitis (AS) is a chronic inflammatory arthritis that predominantly affects the axial skeleton in adolescent patients causing spinal pain and stiffness. There is a marked delay, on average 8 years, between onset of disease symptoms and clinical diagnosis. The distinction between the symptoms of mechanical and inflammatory back pain remains one of the main contributing factors for the delay in diagnosis. ⋯ New therapies, such as the tumor necrosis factor (TNF) inhibitors, have transformed the treatment paradigm in AS, especially for those patients with aggressive disease. Thus, the definition of both patient selection criteria for these agents and the development of clinical methods to assess response to therapy have become a priority. This Review focuses on measuring the degree of disease activity, function and damage in patients with AS in an ambulatory care setting, and the assessment of suitability of various outcome measures for monitoring response to treatment with TNF inhibitors.
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Nat Clin Pract Rheum · Sep 2007
ReviewRegional pain syndrome: clinical characteristics, mechanisms and management.
Regional soft-tissue complaints are commonplace, and they usually relate to a disease process, such as strain, inflammation or degeneration of a muscle, tendon or related muscle-tendon unit. The clinical features and investigations of the causative processes of these complaints are characteristic, and outcomes to treatments are usually predictable and satisfactory. Regional pain syndromes are different: these syndromes present with regional pain and tenderness, and other sensory symptoms unaccounted for by a simple musculoskeletal mechanistic explanation. ⋯ Review of the epidemiology of regional pain syndromes combined with knowledge of other similar pain syndromes has enabled an evolving understanding of the condition. The musculoskeletal and central nervous systems both contribute to regional pain syndromes, through spine-related pain mechanisms and central sensitization, respectively. The patient's emotional state, particularly the effect on pain modulation, links these two systems.
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The identification of subgroups of patients from randomized clinical trials that are of specific interest for guiding clinical decisions can be an attractive idea; however, since such trials are designed for the comparison of groups of patients, performing subgroup analyses can result in misinterpretation of the data. Such analyses must, therefore, be performed and evaluated with caution: these should be pre-planned and included in the design of a suitably powered trial. ⋯ The caveats associated with this approach, such as the occurrence of false positive or false negative effects, chance differences in observed effects, lack of power to perform the analysis, floor or ceiling effects, issues relating to multiple statistical testing, and over-reporting and under-reporting are discussed in this review. Subgroup analyses can, however, provide valuable, albeit predominantly exploratory, information on which to base clinical decisions if they are performed in accordance with recommendations and guidelines, and do, therefore, have a legitimate place in rheumatology clinical trials.
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Nat Clin Pract Rheum · Jul 2007
ReviewMechanisms of disease: a 'DAMP' view of inflammatory arthritis.
Innate immunity achieves our primary host defense by recognizing invading microorganisms through pathogen-associated molecular patterns (PAMPs) and by reacting to tissue damage signals called damage-associated molecular patterns (DAMPs). DAMP molecules, including high mobility group box 1 protein (HMGB-1), heat-shock proteins (HSPs), uric acid, altered matrix proteins, and S100 proteins, represent important danger signals that mediate inflammatory responses through the receptor for advanced glycation end-products (RAGE, also known as AGER) and Toll-like receptors, after release from activated or necrotic cells. The terms 'alarmins' and 'endokines' have also been proposed for DAMP molecules. ⋯ They are rapidly secreted by activated monocytes or neutrophils, which are abundant in inflamed synovial tissue. HSPs are involved in the crosstalk between innate and adaptive immune systems, and primarily mediate immune regulatory functions. Multiple positive feedback loops between DAMPs and PAMPs and their overlapping receptors temporally and spatially drive these processes and may represent the molecular basis for the observation that infections, as well as nonspecific stress factors, can trigger flares in rheumatic diseases.