paroxysmal cold hemoglobinuria

(redirected from Paroxysmal cold haemoglobinuria)

hemoglobinuria

 [he″mo-glo″bĭ-nu´re-ah]
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 cold he·mo·glo·bi·nu·ri·a

a rare disorder in which acute severe hemolysis follows exposure to cold.

paroxysmal cold hemoglobinuria (PCH)

a rare autoimmune hemolytic anemia disorder marked by hemolysis minutes or hours after exposure to cold. Characterized by the presence of a biphasic hemolysin, called the Donath-Landsteiner antibody, which hemolyzes red cells after exposure to cool temperatures and then warming back to 37°C. Systemic symptoms include the passage of dark urine, severe pain in the back and legs, headache, vomiting, diarrhea, and moderate reticulocytosis. Temporary hepatosplenomegaly and mild hyperbilirubinemia may follow the onset of an attack.

paroxysmal cold hemoglobinuria

Hematology A disorder that is: (1) Rarely 'paroxysmal' clinically; (2) Not always precipitated by the cold; and (3) Not always associated with hemoglobinuria; PCH comprises 2-5% of autoimmune hemolytic anemias, and is caused by IgG–Donath-Landsteiner antibodies that react at < 15ºC and are directed against the ubiquitous P antigen on red cells; PCH may be transient, and 2º to viral exanthemas of childhood Clinical After exposure to the cold, the Pt may experience myalgia, abdominal cramping, headaches, hemoglobinuria, Raynaud phenomenon, cold urticaria, jaundice Lab Positive direct Coombs test–using anti-C3 antiserum, anemia, hemoglobinuria, ↓ haptoglobin, ↑ LD, ↑ BR; the antibody is a non-agglutinating IgG that binds to RBCs at cold temperatures and, when warmed to 37ºC, evokes complement-mediated hemolyses; antibody elutes from the red cells in vitro, and complement remains fixed, and thus is a 'biphasic' hemolysin; anti-P reacts with normal neutrophil antigens except for p and Pk Prevention Keep warm Management If chronic, corticosteroids, immunosuppressants

par·ox·ys·mal cold he·mo·glo·bi·nu·ri·a

(PCH) (par'ok-siz'măl kōld hē'mŏ-glō-bi-nyūr'ē-ă)
An autoimmune hemolytic anemia characterized by hemolysis and subsequent hemoglobinuria on exposure to cold. The hemolysis is caused by the Donath-Landsteiner antibody, which attaches to the red cell at temperatures below 15°C. On warming, the antibody dissociates from the cell, but the terminal complement components are activated, causing cell injury and hemolysis.
See also: Donath-Landsteiner antibody
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