Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042384 (vasculitis)
 20,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fever of unknown origin (FUO) was originally defined as recurrent fever of 38.3 degrees C or higher, lasting 2-3 wk or longer, and undiagnosed after 1 wk of hospital evaluation. The last criterion has undergone modification and is now generally interpreted as no diagnosis after appropriate inpatient or outpatient evaluation. The 3 major categories that account for most FUOs are infections, malignancies, and noninfectious inflammatory diseases. The diagnostic approach in FUO includes repeated physical investigations and thorough history-taking combined with standardized laboratory tests and simple imaging procedures. Nevertheless, there is a need for more complex or invasive techniques if this strategy fails. This review describes the impact of (18)F-FDG PET in the diagnostic work-up of FUO. (18)F-FDG accumulates in malignant tissues but also at the sites of infection and inflammation and in autoimmune and granulomatous diseases by the overexpression of distinct facultative glucose transporter (GLUT) isotypes (mainly GLUT-1 and GLUT-3) and by an overproduction of glycolytic enzymes in cancer cells and inflammatory cells. The limited data of prospective studies indicate that (18)F-FDG PET has the potential to play a central role as a second-line procedure in the management of patients with FUO. In these studies, the PET scan contributed to the final diagnosis in 25%-69% of the patients. In the category of infectious diseases, a diagnosis of focal abdominal, thoracic, or soft-tissue infection, as well as chronic osteomyelitis, can be made with a high degree of certainty. Negative findings on (18)F-FDG PET essentially rule out orthopedic prosthetic infections. In patients with noninfectious inflammatory diseases, (18)F-FDG PET is of importance in the diagnosis of large-vessel vasculitis and seems to be useful in the visualization of other diseases, such as inflammatory bowel disease, sarcoidosis, and painless subacute thyroiditis. In patients with tumor fever, diseases commonly detected by (18)F-FDG PET include Hodgkin's disease and aggressive non-Hodgkin's lymphoma but also colorectal cancer and sarcoma. (18)F-FDG PET has the potential to replace other imaging techniques in the evaluation of patients with FUO. Compared with labeled white blood cells, (18)F-FDG PET allows diagnosis of a wider spectrum of diseases. Compared with (67)Ga-citrate scanning, (18)F-FDG PET seems to be more sensitive. It is expected that PET/CT technology will further improve the diagnostic impact of (18)F-FDG PET in the context of FUO, as already shown in the oncologic context, mainly by improving the specificity of the method.
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PMID:18F-FDG PET and PET/CT in fever of unknown origin. 1720 97

This review analyzes the impact of 2-[(18)F]fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET) in the diagnostic work-up of classic fever of unknown origin (FUO) according to the criteria first proposed by Petersorf in 1961 and later modified by Durack et al. in 1991. Algorithms currently used in this diagnostic process are not strictly evidence based up to now. FDG accumulates in malignant tissues, but also in inflammatory cells by the overexpression of facultative glucose transporter-isotypes (mainly GLUT-1 and GLUT-3) and by an overproduction of glycolytic enzymes. Therefore, this technique covers a broad spectrum of possible etiologies for FUO. Once imaged, these lesions can be further investigated by other (e.g. invasive) and more specific methods. Until now, four prospective studies using FDG-PET in patients with classic FUO, encompassing 167 patients in total are published. Three retrospective studies with 125 patients are also available. These studies are discussed and weighted according to the control of selection-bias that was performed. An interstudy-bias may also be present resulting from a considerable variability in causes of FUO. A low number of diagnostic scans in a study may sometimes be related to a high rate of fevers caused by miscellaneous disorders or to a high rate of undiagnosed patients. In these disease categories, focal pathologies that can be imaged with FDG-PET, are rare. A high number of diagnostic scans is always related to a high prevalence of patients with medium- and large-vessel vasculitis. Available data indicate that FDG-PET has the potential to play an important role as a second line procedure in the management of about 1/3 of patients with classic FUO. It is expected that hybrid imaging (PET/computed tomography [CT]; PET/magnetic resonance imaging [MRI]) will improve the diagnostic impact of FDG-PET further, but prospective data about the value of this methods are currently not available. The question as to how these new techniques can be implemented into an evidence based diagnostic algorithm, can only be resolved within a multidisciplinary setting, avoiding both selection- and interstudy-bias whenever possible.
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PMID:FDG-PET in patients with fever of unknown origin: the importance of diagnosing large vessel vasculitis. 1918 28