Whipple's disease overview: Difference between revisions
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==Pathophysiology== | ==Pathophysiology== | ||
Whipple’s disease is a very rare disease. Therefore, some aspects of [[pathogenesis]] have remained unclear. [[Tropheryma whipplei]] is usually transmitted through [[oral route]] to human [[Host (biology)|hosts]]. There is no known causative [[genetic]] factor for Whipple's disease. However, [[genetic]] and [[Immunological|immunologic]] factors play important roles in [[clinical]] manifestation of [[Tropheryma whipplei]] [[infection]]. Individuals with positive [[HLA-B27]] and defective [[cellular immunity]] including [[AIDS]] are at risk for Whipple's disease. Impaired [[macrophage]] function and [[cellular immunity]] are the main factors in replication of the [[bacteria]] and [[disease]] expansion to every [[tissue]]. There is a decreased activity of the [[T helper cells]] type 1 and increased activity of the [[T helper cells]] type 2. Defective [[phagocytic]] system is responsible for [[replication]] of [[bacteria]] in [[macrophages]] and spread of [[bacteria]] to other [[tissues]]. Characteristic of Whipple's disease is presence of foamy [[Macrophage|macrophages]] in the [[lamina propria]] that is [[periodic acid-Schiff stain]] positive. | |||
==Causes== | ==Causes== | ||
Revision as of 16:04, 16 November 2017
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sadaf Sharfaei M.D.[2]
Overview
Whipple's disease is a rare, systemic infectious disease caused by the bacterium Tropheryma whipplei.[1] Whipple's disease primarily causes malabsorption but may affect any part of the body including the heart, lungs, brain, joints, and eyes.
Historical Perspective
Whipple described the disease for the first time in 1907 as a gastrointestinal disorder and named it as "intestinal lipodystrophy." Light and electron microscopy on small bowel biopsy were used to detect bacilli inside the intestinal mucosa. In 1952, systemic antibiotics were used to treat the disease which confirmed the infective nature of the disease. It took almost 100 years for investigators to cultivate the bacterium and sequenced the genome.
Classification
Whipple’s disease may be classified into 2 groups of acute and chronic infection. It might be classified as systemic or localized based on the organ involvement. It has 4 different clinical manifestations: Acute infection, asymptomatic carrier state, the classic Whipple’s disease, and localized chronic infection.
Pathophysiology
Whipple’s disease is a very rare disease. Therefore, some aspects of pathogenesis have remained unclear. Tropheryma whipplei is usually transmitted through oral route to human hosts. There is no known causative genetic factor for Whipple's disease. However, genetic and immunologic factors play important roles in clinical manifestation of Tropheryma whipplei infection. Individuals with positive HLA-B27 and defective cellular immunity including AIDS are at risk for Whipple's disease. Impaired macrophage function and cellular immunity are the main factors in replication of the bacteria and disease expansion to every tissue. There is a decreased activity of the T helper cells type 1 and increased activity of the T helper cells type 2. Defective phagocytic system is responsible for replication of bacteria in macrophages and spread of bacteria to other tissues. Characteristic of Whipple's disease is presence of foamy macrophages in the lamina propria that is periodic acid-Schiff stain positive.