Hemosiderin
3008032
224632939
2008-07-09T19:12:09Z
VolkovBot
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robot Adding: [[it:Emosiderina]]
[[image:hemosiderin.jpg|thumb|200px|right|'''Hemosiderin''' Image of a kidney viewed under a microscope. The brown areas contain hemosiderin]]
'''Hemosiderin''' or '''haemosiderin''' is an abnormal [[microscopic]] [[pigment]] found in the [[human]] body. Hemosiderin is composed of [[iron oxide]] and can accumulate in different [[Organ (anatomy)|organs]] in various [[disease]]s. Iron is required by many of the [[chemical reaction]]s in the body but is [[toxic]] when not properly contained. Thus, many methods of iron storage have developed.
Humans store [[iron]] within a [[protein]] called [[ferritin]]. The form of iron in ferritin is [[Iron(III) oxide-hydroxide]]. By complexing with ferritin, the iron is made [[water]] [[soluble]]. Several diseases result in deposition of Iron(III) oxide-hydroxide in tissues in an insoluble form. These deposits of iron are called hemosiderin. Although these deposits often cause no symptoms, they can lead to organ damage.
== Pathophysiology ==
Hemosiderin often forms after bleeding ([[hemorrhage]]) into an organ. When blood leaves a ruptured blood vessel, the cell dies and the [[hemoglobin]] of the [[red blood cells]] is released into the extracellular space. [[White blood cell]]s called [[macrophage]]s engulf ([[phagocytosis|phagocytose]]) the [[hemoglobin]] to degrade it, producing [[hemosiderin]] and [[porphyrin]].
== Diseases associated with hemosiderin deposition ==
Hemosiderin deposition in the [[lung]]s is often seen after [[diffuse alveolar hemorrhage]], which occurs in diseases such as [[Goodpasture's syndrome]], [[Wegener's granulomatosis]], and [[idiopathic pulmonary haemosiderosis]]. [[Mitral stenosis]] can also lead to pulmonary [[Transfusion hemosiderosis|hemosiderosis]]. Hemosiderin collects throughout the body in [[hemochromatosis]]. Hemosiderin deposition in the [[liver]] is a common feature of hemochromatosis and is the cause of liver failure in the disease. Deposition in the pancreas leads to [[diabetes mellitus|diabetes]] and in the skin leads to hyperpigmentation. Hemosiderin deposition in the brain is seen after bleeds from any source, including chronic [[subdural hemorrhage]], [[Cerebral arteriovenous malformation]]s, [[cavernous hemangioma|cavernous hemangiomata]]. Hemosiderin collects in the skin and is slowly removed after bruising; hemosiderin may remain in some conditions such as [[stasis dermatitis]]. Hemosiderin in the kidneys have been associated with marked hemolysis and a rare blood disorder called Paroxysmal Nocturnal Hemoglobinuria.
Hemosiderin may deposit in diseases associated with iron overload. These diseases are typically diseases in which chronic blood loss requires frequent [[blood transfusion]]s, such as [[sickle cell anemia]] and [[thalassemia]].
== Treatment ==
Treatment for hemosiderin focuses on limiting the effects of the underlying disease leading to continued deposition. In hemochromatosis, this entails frequent [[phlebotomy]]. In diseases such as Wegener's granulomatosis, immune suppression is required. Limiting blood transfusions and institution of iron [[chelation]] therapy when iron overload is detected are important when managing sickle-cell anemia and other chronic [[hemolytic anemia]]s.
[[Category:Hematology]]
[[Category:Iron oxide pigments]]
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[[ru:Гемосидерин]]