paroxysmal nocturnal hemoglobinuria(redirected from Marchiafava-Micheli anemia)
the presence of free hemoglobin in the urine. adj., adj hemoglobinu´ric.
march hemoglobinuria hemolysis caused by repeated uncushioned shocks or trauma to some body part, such as in some soldiers on long marches, in marathon runners, and in karate practitioners.
paroxysmal cold hemoglobinuria an autoimmune or postviral disease in which there is a biphasic IgG antibody directed against the P blood group antigen. It is marked by episodes of hemoglobinemia and hemoglobinuria after exposure to cold and is detected by the Donath-Landsteiner test. The condition is treated with prednisone and cyclophosphamide and by protection from exposure to cold.
paroxysmal nocturnal hemoglobinuria (PNH) an acquired blood cell abnormality with proliferation of abnormal red blood cells (PNH cells) that are readily hemolyzed by complement, and episodes of severe hemolysis and thrombosis, particularly of the hepatic veins. It is detected by the ham test. Treatment is with androgens or prednisone and, during thrombotic episodes, with heparin.
par·ox·ys·mal noc·tur·nal he·mo·glo·bi·nu·ri·a
an infrequent disorder with insidious onset (usually in the third or fourth decade) and chronic course, characterized by episodes of hemolytic anemia, hemoglobinuria (chiefly at night), pallor, icterus or bronzing of the skin, a moderate degree of splenomegaly, and sometimes hepatomegaly; red blood cells are usually macrocytic and vary considerably in size, but there is no evidence of spherocytosis, erythrophagocytosis, or abnormal leukocytes. The disorder is a result of an abnormality of the red blood cell membrane, which makes the red blood cell unusually sensitive to lysis by complement.
paroxysmal nocturnal hemoglobinuria
A rare hemolytic disorder caused by an acquired genetic mutation affecting hematopoietic stem cells, characterized by hemolytic anemia and hemoglobinuria, primarily at night.
paroxysmal nocturnal hemoglobinuria (PNH)
an acquired hemolytic anemia caused by a clonal stem cell mutation that results in an absence of glycosylphosphatidylinositol-anchored proteins, including decay-accelerating factor (DAF) and CD55. Red cells lacking DAF and CD55 have an increased susceptibility to complement activation and lysis, resulting in intravascular hemolysis and hemoglobinuria, especially during sleep.
paroxysmal nocturnal hemoglobinuriaAn acquired hemolytic disease, due to proliferation of an abnormal clone(s) of myeloid stem cells, the progeny of which are susceptible to complement-mediated membrane damage and hemolysis–CMH Clinical Thromboses, ↑ infections; PNH may evolve into aplastic or sideroblastic anemia, myelofibrosis, AML Lab Leukopenia, thrombocytopenia, dimorphic RBC population, iron-deficiency, ↓ leukocyte alk phos, ↓ RBC acetylcholinesterase, altered properdin–alternate pathway of complement lysis, hemoglobinuria, hemosiderinuria, positive Ham test, positive sucrose lysis test; negative direct Coombs' test, ↑ susceptibility of RBCs to CMH
par·ox·ys·mal noc·tur·nal he·mo·glo·bi·nu·ri·a(PNH) (par'ok-siz'măl nok-tŭr'năl hē'mŏ-glō'bi-nyūr'ē-ă)
A hemolytic anemia in which the red blood cell membrane is abnormal, rendering the cell more susceptible to hemolysis by complement. The membrane defects include a lack of decay-accelerating factor (DAF) and C8 binding protein (C8bp) due to lack of glycosyl phosphatidyl inositol (GPI). GPI is a membrane glycolipid that attaches proteins to the cell membrane. Hemolysis is intravascular and intermittent, characterized by passage of reddish urine.
Paroxysmal nocturnal hemoglobinuria (PNH)
A rare complement disorder characterized by episodes of red blood cell destruction (hemolysis) and blood in the urine (hemoglobinuria) that is worse at night.
Mentioned in: Complement Deficiencies
Marchiafava,Ettore, Italian pathologist, 1847-1935.
Marchiafava syndrome - Synonym(s): Marchiafava-Bignami syndrome
Marchiafava-Bignami disease - a disorder consisting of demyelination of the corpus callosum and cortical laminar necrosis involving the frontal and temporal lobes. Synonym(s): Marchiafava syndrome
Marchiafava-Micheli anemia - Synonym(s): Marchiafava-Micheli syndrome
Marchiafava-Micheli syndrome - an infrequent disorder with insidious onset and chronic course, characterized by episodes of hemolytic anemia, hemoglobinuria, pallor, icterus or bronzing of the skin, a moderate degree of splenomegaly, and sometimes hepatomegaly. Synonym(s): Marchiafava-Micheli anemia; paroxysmal nocturnal hemoglobinuria