Normocytic Anemia With Intravascular Hemolysis Flashcards
How does DAF protect cells from complement mediated cell damage?
Decay Accelerating Factor is secured to the cell membrane by GPI and protects the cells by inhibiting C3 convertase.
What is paroxysmal nocturnal hemogobinuria?which ecells does it affect?
It is an acquired defect in myeloid stem cells resulting in absent glycosylphosphqtidylinositol (GPI) which renders cells susceptible to destruction by complement.
When does intra vascular hemolysis occur and what does it lead to?
It occurs often at night due to shallow breathing which activates complement and loses RBCs, WBCs and platelets. It leads to hemoglobinemia and hemoglobinuria in the morning and hemosiderinuria DAYS after hemolysis.
How is paroxysmal nocturnal hemoglobinuria screened for? How is this test confirmed? What marker is used? What is the main cause of death and what are some complications?
It is screened via sucrose test. Confirmatory test is the acidified sum test or flow cytometry to detect lack of CD55 (DAF) on blood cells. Main cause of death is thrombosis of hepatic, portal or cerebral veins from destroyed platelets. Complications include iron deficiency anemia due to hemoglobinuria and AML in 10% of patients.
How does glucose 6 phosphate dehydrogenase (G6PD) deficiency cause intra vascular hemolysis? What type of disorder is it? What are its major variants?
G6PD is an X linked recessive disorder resulting in reduced half life of G6PD. It’s byproduct NADPH is needed to regenerate reduced gluthatione, which is an antioxidant that neutralizes hydrogen peroxide which damages the cells. During this process, glutathione becomes oxidized. The African and Mediterranean variants lead to mildly and markedly intra vascular hemolysis respectively. High carrier frequency due to protective role against falciparum malaria.
A 25 year old coach presents to your heme onc clinic with complaints of severe back pain. On further questioning, she mentioned that she had travelled to Italy recently and had cut her leg at the beach which caused a serious infection. The only thing that cheered her up was her stash of favs beans which she uses to make favs soup. Her medication list includes some sulfa drugs. Urine analysis shows the presence of hemoglobin. What does this patient have? What caused it? How and when would you screen for this disease? What would you see under the microscope?
She has G6PD deficiency. Her presentation is caused by oxidative stress from infection,drugs or favs beans. On the scope, you will see bite cells which are due to the removal of Heinz bodies from the cells by the spleen mqcrophages. The Heinz bodies are due to the precipitation of hemoglobin. You can do enzyme studies weeks After hemolytic episode resolves.
Which type of organism causes malaria? What are some symptoms and physical findings? If you have daily fever which organism caused it? If fever every other day?
Female anopheles mosquito. Intra vascular hemolysis and cyclical fever. Daily fever is P falciparum and the other one is p vivax and p ovale. Splenomegaly with mild extra vascular hemolysis.
A 68 year old retired bus driver comes to your clinic. On history, she has a history of heart disease and aortic stenosis. She had undergone open heart surgery to replace her aortic valves with some prosthetics. What type of anemia does she have? What caused it in her case? What would you see on blood smear? What are other cause of this anemia?
She has microangiopathic hemolytic anemia from vascular pathology. RBCs are destroyed as they pass through the circulation and form schistocytes. Aortic stenosis and prosthetic valves are the cause in her case. It also ovcurs with micro thrombi (TTP-HUS, DIC, HELLP)
How is immune hemolytic anemia diagnosed? Which antibodies are usually involved?What are the two variations of this test? And what do they tell you?
Coombs test. Direct or indirect. IgM or IgG. Direct Coombs test confirms the presence of antibody or complement coated red blood cells. When anti-IgG/complement is added, there is agglutination if they are coated with IgG or complement. Indirect Coombs confirms the presence of antibodies in patient serum.
Where does IgG bind RBCs? What is associated with this disease? What kind of cells do you get? What is it associated with? What is the treatment for IgG anemia?
Binds in the relatively warm temperature of the central body (warm agglutinin). Extra vascular hemolysis is associated with it. Spherocytes are formed. Associated with SLE, chronic lymphocytic leukemia and drugs. Tx involves drug cessation, steroids, IVIG, splenectomy is necessary.
Where does IgM bind RBCs? What is associated with this disease? What kind of cells do you get? Which organisms are associated with this disease?
Binds in the relatively cold temperature of the central body (cold agglutinin). Extra vascular hemolysis is associated with it. Spherocytes are formed when residual C3b serves as opsonin for splenic macrophages. Associated with Mycoplasma pneumoniae and infectious mononucleosis.
