Laboratory investigations in gout. Cutaneous small-vessel vasculitis. Oxford Medicine Online

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1 Oxford Medicine Online You are looking at 1-10 of 14 items for: UA MED00360 Laboratory investigations in gout Eliseo Pascual and Francisca Sivera Print Publication Year: 2016 Published Online: Nov 2016 ISBN: eisbn: DOI: /med/ Gout is a consequence of hyperuricaemia and the treatment goal is to dissolve the crystals by reducing serum urate levels. The first section of this chapter focuses on laboratory investigations on gout, reviewing serum urate levels and its determinants, methods of measurement, and urate renal handling. Additionally it reviews the use of inflammatory markers and synovial fluid cell counts. The second section of the chapter deals with the identification of monosodium urate and calcium pyrophosphate crystals in synovial fluid. It reviews the use of an optic microscope fitted with polarized filters and an analyser. A clear step-by-step process with useful tips is provided. Cutaneous small-vessel vasculitis Anna Haemel, Lindy Fox, and M. Kari Connolly DOI: /med/ Cutaneous small vessel vasculitis (CSVV) is an immune-complex-mediated disease targeting the postcapillary venules of the skin. Several classifications and synonyms have been proposed; however, simplified diagnostic criteria include palpable purpura with histopathology demonstrating leukocytoclastic vasculitis, in the absence of systemic small or medium-vessel vasculitis. CSVV is considered to be a reactive process, with underlying triggers (infection, drug, autoimmune disease, or neoplasm, though #40% of cases remain idiopathic). The triggers can be conceptualized as antigens to which antibodies are generated, with subsequent immune complex deposition, complement activation, neutrophil influx, and damage to the vessel wall. The inflammatory infiltrate contributes to the raised nature and erythema of the lesions, while vessel damage and haemorrhage result in non-blancheable purpura. The differential diagnosis includes macular purpura due to coagulation defects, other inflammatory skin diseases, and infections. While CSVV is generally limited to the skin, any site where immune complex could be filtered and deposited is potentially involved. Therefore, patients must be evaluated for both end-organ involvement/ systemic vasculitis syndromes and underlying triggers. Evaluation should Page 1 of 5

2 also include punch biopsy for histopathology and direct immunofluorescence. Treatment includes removal of triggers and empiric anti-inflammatory agents for more severe disease. Nuclear Medicine Imaging and Therapy in Rheumatology Adil Al-Nahhas and Imene Zerizer Print Publication Year: 2013 Published Online: Oct 2016 DOI: /med/ _update_001 The application of nuclear medicine techniques in the diagnosis and management of rheumatological conditions relies on its ability to detect physiological and pathological changes in vivo, usually at an earlier stage compared to structural changes visualized on conventional imaging. These techniques are based on the in-vivo administration of a gamma-emitting radionuclide whose distribution can be monitored externally using a gamma camera. To guide a radionuclide to the area of interest, it is usually bound to a chemical label to form a radiopharmaceutical. There are hundreds of radiopharmaceuticals in clinical use with different homing mechanisms, such as 99 mtc HDP for bone scan and 99 mtc MAA for lung scan. Comparing pre- and posttherapy scans can aid in monitoring response to treatment. More recently, positron emission tomography combined with simultaneous computed tomography (PET/CT) has been introduced into clinical practice. This technique provides superb spatial resolution and anatomical localization compared to gamma-camera imaging. The most widely used PET radiopharmaceutical, flurodeoxyglucose (18F-FDG), is a fluorinated glucose analogue, which can detect hypermetabolism and has therefore been used in imaging and monitoring response to treatment of a variety of cancers as well as inflammatory conditions such as vasculitis, myopathy, and arthritides. Other PET radiopharmaceuticals targeting inflammation and activated macrophages are becoming available and could open new frontiers in PET imaging in rheumatology. Nuclear medicine procedures can also be used therapeutically. Beta-emitting radiopharmaceuticals, such as yttrium-90, invoke localized tissue damage at the site of injection and can be used in the treatment of synovitis. Polymyositis and dermatomyositis Hector Chinoy and Robert G. Cooper Print Publication Year: 2013 Published Online: Oct 2015 DOI: /med/ _update_001 Polymyositis (PM), dermatomyositis (DM), and inclusion body myositis (IBM) form part of the idiopathic inflammatory myopathies (IIM), a heterogeneous group of rare autoimmune diseases characterized by an acquired proximal muscle weakness, raised muscle enzymes (including creatine kinase), inflammatory cell infiltrates in muscle biopsy tissue, electrophysiological abnormalities, and presence of circulating myositis-specific/ myositis-associated autoantibodies. The underlying aetiology of IIM is poorly understood, but likely involves interactions between environmental and genetic risk factors. Myositis Page 2 of 5

3 may also manifest in association with other connective tissue disorders. The predominant clinical presentation of IIM is skeletal muscle weakness, but many extramuscular features can also occur. Access to good neuropathological support is essential in securing an accurate IIM diagnosis and excluding non-inflammatory myopathies, although IBM is often difficult to distinguish from PM. Antibody testing can help define IIM clinical subtypes, including cancer-associated myositis, predict prognosis, and help in optimizing treatment decisions. MRI can be invaluable for differentiating disease activity from damage, and detecting treatment-induced interval changes. Therapeutic effectiveness of new and existing treatments (where the evidence base remains poor) depends on making a prompt diagnosis and initiating early and appropriately aggressive treatment to prevent establishment of muscle damage. This chapter attempts to summarize the salient features of IIM and update the reader about currently used diagnostics and treatment paradigms in this rare and understudied disease. Paediatric vasculitis Despina Eleftheriou and Paul A. Brogan Print Publication Year: 2013 Published Online: Oct 2014 DOI: /med/ _update_001 Systemic vasculitis is characterized by blood vessel inflammation which may lead to tissue injury from vascular stenosis, occlusion, aneurysm, and/or rupture. Apart from relatively common vasculitides such as IgA vasculitis (Henoch Schönlein purpura (HSP)) and Kawasaki s disease (KD), most of the primary vasculitic syndromes are rare in childhood, but are associated with significant morbidity and mortality. New classification criteria for childhood vasculitis have recently been proposed and validated. The cause of most vasculitides is unknown, although it is likely that a complex interaction between environmental factors such as infections and inherited host responses trigger the disease and determine the vasculitis phenotype. Several genetic polymorphisms in vasculitis have now been described that may be relevant in terms of disease predisposition or development of disease complications. Treatment regimens continue to improve, with the use of different immunosuppressive medications and newer therapeutic approaches such as biologic agents. We provide an overview of paediatric vasculitides focusing on HSP, KD, and polyarteritis nodosa (PAN). Key differences (where relevant) between paediatric and adult vasculitis are highlighted. In addition we discuss new emerging challenges particularly in respect to the long-term cardiovascular morbidity for children with systemic vasculitis, and emphasize the importance of future international multicentre collaborative studies to further increase and standardize the scientific base of investigating and treating childhood vasculitis. Approach to the diagnosis of vasculitis in adult patients Barri J. Fessler DOI: /med/ Page 3 of 5

4 Diagnosis of vasculitis is challenging due to non-specific symptoms, overlapping syndromes, lack of specific diagnostic tests, and the absence of generally accepted diagnostic criteria. While progress is being made in establishment of classification criteria for the different vasculitic syndromes (as published by the 2012 Chapel Hill Consensus Conference on nomenclature of vasculitides), there remains a strong need for classification and diagnostic criteria to aid in the early diagnosis of vasculitis and facilitate research studies. The initial, essential step in diagnosis is a comprehensive history and physical examination. The next step is selection of appropriate tests to delineate areas of disease involvement, either through tissue biopsy or imaging studies. At the same time, secondary causes of vasculitis and mimics of vasculitis must be excluded. The demonstration of vasculitis on tissue biopsy remains the gold standard for diagnosis. However, this is often not straightforward and diagnosis of a specific form of vasculitis requires familiarity with the features of the different syndromes and narrowing down the differential diagnosis based on histological, laboratory, and imaging findings in the context of the clinical pattern. Angiography and percutaneous interventions Souheil Saddekni and Rachel F. Oser DOI: /med/ Patients undergo angiography either to establish a diagnosis, to document the extent of involvement, or to treat the disease. Diagnosis of vascular inflammatory disorders is sometimes difficult and the occlusive process is not unique to these disorders. Therefore, the clinical presentation, laboratory results, type and pattern of vascular involvement, and angiographic features are all important for definitive diagnosis and treatment. Certain angiographic findings are highly specific and have an important role in diagnosis. Examples are stenoses or occlusions of the aortic arch or arch vessels in giant cell arteritis or Takayasu s arteritis of adults, and multiple pulmonary aneurysms with large-vein thrombosis in Behçet s syndrome. Endovascular therapies are more applicable to large and medium-vessel diseases than to the small-vessel varieties. Techniques include the use of various balloons, stents, atherectomy devices, and lasers. Novel interventions under development, such as local delivery of novel immunosuppressive drugs or monoclonal antibodies, offer potential for improvements in treating this set of disorders. This chapter focuses on current angiography and intervention techniques in large and medium-vessel vasculitis syndromes as encountered in a university practice. Inflammatory joint diseases Susan M. Oliver (ed.) Print Publication Year: 2009 Published Online: Aug 2010 ISBN: eisbn: DOI: /med/ Abstracts and keywords to be supplied. Page 4 of 5

5 Systemic sclerosis Christopher P. Denton and Pia Moinzadeh Print Publication Year: 2013 Published Online: Oct 2013 DOI: /med/ The term scleroderma describes a group of conditions in which the development of thickened, fibrotic skin is a cardinal feature. This includes localized forms of scleroderma (e.g. morphoea) and also systemic forms of the disease that are more correctly termed systemic sclerosis. Systemic sclerosis (SSc) is a multiorgan, autoimmune disease that has a high clinical burden and mortality, due to affecting the skin as well as internal organs. As with other related diseases there is a female predominance and marked clinical diversity. The pathogenesis of SSc is not fully elucidated; it includes endothelial cell injury fibroblast activation and autoimmunity that lead to skin and internal organ manifestations. The majority of cases exhibit characteristic serum autoantibodies. Some of these antibodies are scleroderma-specific reactivities including anti-centromere (ACA), anti-topoisomerase-1 (ATA or Scl 70) or anti-rna polymerase III antibodies. These anti-nuclear antibody (ANA) patterns are generally mutually exclusive and serve as useful clinical markers of disease subgroups. Additional subsetting of scleroderma cases, based on the extent of skin sclerosis, permits classification into limited and diffuse subsets. Because of the heterogeneity of the disease patients may suffer from different organ manifestations, such as lung fibrosis, hypertensive renal crisis, severe cardiac disease, gastrointestinal involvement, and pulmonary arterial hypertension. Although outcomes have improved recently, systemic sclerosis still has the highest case-specific mortality of any of the autoimmune rheumatic diseases and requires careful and systematic investigation, management and follow-up. Treatment includes symptomatic strategies with attention to each involved organ system; it is still an area where therapeutic progress and better understanding of pathogenesis is increasingly anticipated. Osteomalacia and rickets Roger Smith and Paul Wordsworth Print Publication Year: 2016 Published Online: May 2016 ISBN: eisbn: DOI: /med/ Lack of vitamin D is the most common cause of rickets and osteomalacia. Insufficiency also contributes to osteoporosis. Vitamin D has important non-skeletal actions. This chapter also deals with recently described forms of renal tubular rickets, with oncogenic osteomalacia, with vitamin D-dependent rickets, and with the effects of renal glomerular failure on the skeleton. Changes in FGF23 occur in osteomalacia/rickets. Page 5 of 5