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63 Cards in this Set
- Front
- Back
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What are the different types of classification systems for acquired hemolytic anemias?
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Extrinsic factors vs. intrinsic
Location of hemolysis |
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What are the different types of extrinsic causes that can cause acquired hemolytic anemias?
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Immunohemolytic anemias
Traumatic Infectious Chemicals, drugs, toxins Physical agents Hypophosphatemia Paroxysmal nocturnal hemoglobinuria Spur cell anemia Vitamin E deficiency in newborns |
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What are some of the immunohsmolytic anemias?
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Transfusion of incompatible blood
Hemolytic disease of the newborn Warm-reactive autoimmune hemolytic anemia Cold-reactive autoimmune hemolytic anemia |
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What are some of the traumatic/microangiopathic causes of hemolytic anemia?
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Prosthetic valves
Hemolytic uremic syndrome Thrombotic thrombocytopenic purpura DIC Graft rejection |
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What are the lab findings of intravascular hemolytic anemias?
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Hemoglobinemia
Hemoglobinuria Hemosiderinuria Decreased haptoglobin |
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What are the clinical findings of intravascular acquired hemolytic anemias?
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Fever
Chills Tachycardia Backache |
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What are the laboratory findings of extravascular acquired hemolytic anemias?
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Haptoglobin levels normal, slightly decreased
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What are the clinical findings of extravascular acquired hemolytic anemias?
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Jaundice
Splenomegaly |
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What are some of the labs that you should order up if someone's hemolyzing?
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CBC: Hgb, hematocrit
MCV Reticulocyte count Peripheral blood smear Bone marrow aspiration Serum unconjugated bilirubin Serum LDH Plasma haptoglobin Plasma HGB Urine hemosiderin Cold agglutinin test Coomb's test Indirect antiglobulin test |
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Why is MCV often elevated in acquired hemolytic anemias?
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Increased RBC creation by bone marrow-->reticulocyte release, which are larger than normal RBCs
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What are findings in a peripheral blood smear in acquired hemolytic anemias?
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Polychomatophila
Fragmented RBCs (INTRAVASCULAR) Microspherocytes (EXTRAVASCULAR) |
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Fragmented RBCs are associated with intra or extravascular acquired hemolytic anemias?
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Intravascular
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Microspherocytes are associated with intra or extravascular acquired hemolytic anemias?
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Extravascular
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What type of antibodies are tested for in a cold agglutinin test?
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IgM
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How long does it take for urine hemosiderin test to become positive after hemolysis?
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7 days
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What does the direct antiblobulin test for look for? What kinds of anemias can this detect?
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IgG, C3
Looks for autoimmune hemolytic anemias |
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What is the use of the antiglobulin test?
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Incompatibility for blood tranfusions.
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What are the different types of anti-RBC antibodies?
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IgG warm autoantibodies
IgM cold agglutinins IgG donath-landsteiner antibodies |
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What are the properties of IgG Donath-Landsteiner antibodies?
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Bind to RBC membranes and activate the hemolytic complement cascade when the cells are warmed to 37
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What is the most common cause of the autoimmune hemolytic anemias?
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Warm antibodies (70%)
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What type of an antibody binds in warm antibody autoimmune hemolytic anemias?
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IgG
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What is the cause of RBC destruction in warm antibody autoimmune hemolytic anemias?
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Spleen recognizes RBC with IgG on the surface as pathologic, destroys the RBC
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What types of cells are seen in warm antibody autoimmune hemolytic anemias?
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Spherocytes: RBCs that have been partially digested by macrophages
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How are spherocytes cleared?
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Extravascular means
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What are the causes of warm antibody autoimmune hemolytic anemia?
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Idiopathic
Secondary |
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What are some of the secondary causes of warm antibody autoimmune hemolytic anemias?
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Lymphoproliferative diseases (CLL, NHL)
Connective tissue diseases (SLE) Immune deficiency disorders Drugs (alpha methyldopa) |
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What's the clinical presentation of warm antibody autoimmune hemolytic anemias?
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Symptoms:
Anemia Jaundice Splenomegaly Physical examination: Pallor Autoimmune signs Increased respiratory rate |
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What's the treatment for warm antibody autoimmune hemolytic anemias?
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-Generally, treat the cause
-If there aren't symptoms for people who are well-compensated, we don't do anything drastic -FOLIC ACID FOR EVERYONE -Transfuse if it's severe -Steroids if we can't find a cause -Splenectomy -IV IgG -Immunosupress -Danazol -Vinca alkaloids -Rituximab |
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What types of antibodies are found in cold agglutinin disease?
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IgM autoantibodies
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What autoantigen are the cold agglutinins directed against/
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I/i group antigen
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What system is activated by the cold agglutinin IgM antibodies?
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Complement cascade/C3b-->phagocytosis by hepatic macrophages
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What kinds of diseases cause cold agglutinin disease?
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Chronically: B-lymphocyte neoplasms
Acutely: infectious causes |
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What are some B-lymphocytics causes of cold agglutinin disease?
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CLL
Lymphoma Waldenstrom's macrogobulinema |
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What are some of the infectious causes of cold agglutinin disease?
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Mycoplasma pneumoniae
Mono |
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What are the symptoms of cold agglutinin disease?
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Cold-induced acrocyanosis (IgM binding to the RBCs in he cold areas of the body)
Anemia Cold-associated hemoglobinuria |
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What are the laboratory findings of cold agglutinin disease?
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Decreased Hgb
Hemolysis findings Peripheral blood smear: RBC agglutination DAT: C3 ONLY! Cold agglutinins: positive |
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What's the treatment for cold agglutinin disease?
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AVOID THE COLD!
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Who get paroxysmal cold hemoglobinuria?
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Kids following viruses
Tertiary, congenital syphilis |
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What are the clinical manifestations of paroxysmal cold hemoglobinuria?
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Symptoms following the cold:
-Fever -Leg pain -Rigors -Back pain -Hemoglobinuria -Cramps |
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What antibodies cause paroxysmal cold hemoglobinuria?
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IgG that binds to RBCs in the cold but falls of at 37C
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What labs should you do for paroxysmal cold hemoglobinuria?
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Incubate the serum with normal RBCs at 4 C, then at 37. You should see lysis
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What is the prognosis for paroxysmal cold hemoglobinuria?
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Self-limited; ends within2-3 weeks
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What are the different mechanisms that underlie drug-induced hemolytic anemia?
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-Hapten
-Immune complex -Autoantibody mechanism -In vivo sensitization mechanism |
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How does the hapten mechanism work in drug-induced hemolytic anemia?
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1. Drug binds to RBC
2. Immune system reacts against drug-RBC complex via IgGs 3. Hemolysis |
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What are drugs that can cause drug-induced hemolytic anemia?
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Penicillins
Cephalosporins |
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How does the immune complex mechanism work in drug-induced hemolytic anemia?
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1. Drug binds to protein/antibody and form complex
2. Complex binds to RBCs-->complement activation via IgM 3. Intravascular hemolysis |
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What are the findings on the DAT for hapten mediated drug-induced hemolytic anemia?
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+ for IgG
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What are the findings on the DAT for immune-complex mediated drug-induced hemolytic anemia?
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Complement ONLY
MOST COMMON! |
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What are some drugs that can cause immune-complex mediated drug-induced hemolytic anemia?
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Quinidine
Phenacetin Sulfasalazine |
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How does the autoantibody mechanism lead to drug-induced hemolytic anemia?
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1. Drug induces autoantibody formation against Rh antigen
2. Autoantibody binds, kills the RBCs via IgG |
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What kind of drug causes autoantibody drug-induced hemolytic anemia?
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Alpha-methyldopa
Ibuprofin |
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How does the in Vivo sensitization mechanism cause drug-induced hemolytic anemia?
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1. Drug binds to RBC membrane
2. Antigen that's created-->IgG Ab directed against the combination of the drug next to the RBC antigen Only happens when the drug is present |
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What is the main cause of fragmentation hemolysis?
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Mechanical stress on the RBCs.
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What's the treatment for fragmentation hemolysis?
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Supportive care
Folic acid |
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What is the definition of hypersplenism?
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Overactive spleen--> too many red cells removed.
You can have a case where the blood is spending too much time in the spleen-->destruction |
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What are some infectious causes of non-immune hemolytic anemias?
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Direct infection: malaria
Strep: toxins Binding to membranes |
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What is the cause of paroxysmal nocturnal hemoglobinuria?
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Acquired, intrinsic acquiring of a hematopoietic stem cell that result in production of defective blood cells.
Somatic mutation in pig-a gene; linker protein problems |
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What kind of destruction happensin paroxysmal nocturnal hemoglibinuria?
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Complement mediated -you don't have the GPI "force field" against complement
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What's the clinical picture of paroxysmal nocturnal hemoglobinuria?
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2nd decade onward
Associated with cancers |
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What are people with PNH at increased risk for?
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Venous thrombosis
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What are the lab findings of PNH?
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Evidence of anemia due to intravascular hemolysis
Ham's acid hemolysis Leukocyte alkaline phosphatase score is low Flow cytometry for PIG-linked antigens |
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What's the treatment for PNH?
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Correct the anemia
Put them on blood thinners Bone marrow transplant Eculizumab: Ab against C5-->less hemolysis, thrombosis |
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What are some other causes of non-immune hemolytic anemias?
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Liver disease
Severe burns Copper excess Drug-induced oxidative damage |
