Heme/onc Lec 4 - Hyperproliferative Anemia

Front 1

what happens to haptoglobin in hemolytic anemia? urobilin/urobilinogen?

Back 1

- haptoglobin salvages heme b/c heme can be toxic so this decreases

- increased breakdown products such as urobilin & urobilinogen

Front 2

what is intra vs extravascular hemolysis?

Back 2

- extravascular = reticuloendothelial system = liver + spleen

- intravascular = heme released into circulation complexing with haptoglobin & excreeted in urine & stool

Front 3

what are some clinical manifestations of hemolytic anemia?

Back 3

- pallor, jaundice, enlarged spleen, dark urine

- pigment gallstones, skin ulcers (leg), aplastic crises (associated w/ parvovirus) --> get high fever & low recticulocyte count

Front 4

what are some lab findings in hemolytic anemia?

Back 4

- increased reticulocyte count, abnormal peripheral blood smear (red cells w/ nuclei)

- low haptoglobin, increased LDH, increased bilirubin in serum

- increased urine hemosiderin in intravascular crisis

Front 5

what happens in hereditary spherocytosis? what is the defect?

Back 5

- defects in spectrin, ankyrin, band 3, pallidin --> defective bilayer --> cells become spherocytes

- AD 75%, AR 25%

- most common inherited membrane defect

Front 6

what are the labs like in hereditary spherocytosis?

Back 6

- increased reticulocyte count

- increased MCHC (ONLY DISORDER THAT DOES THIS)

- spherocytes on peripheral smear

- abnormal osmotic fragility test (lyse @ low [ ] saline)

Front 7

what happens in hereditary elliptocytosis? what is the defect?

Back 7

- AD, defect in spectrin, protein 4.1, glycophorin C --> weakness of RBC cytoskeleton

- milder than HS

Front 8

what happens in G6PD? what is the defect?

Back 8

- X-linked

- African variant = milder & only older RBCs effected, Med variant = all RBCs defective

- G6PD deficiency fails to generated enough NADPH to salvage reduced glutathione --> lots of oxidative stress to cell

Front 9

what labs do you see with G6PD?

Back 9

- ghost cells & bite cells on peripheral smears

- positive heinz body w/ supravital stain

- for african variant will come back false neg b/c young red cells have adequate G6PD

Front 10

what happens with pyruvate kinase deficiency?

Back 10

- AR, most common defect in glycolysis

- diagnosis is made by enzyme assay

Front 11

what is the difference between G6PD & pyruvate kinase deficiency hemolyic anemia?

Back 11

- chronic hemolysis rather than G6PD deficiency which is triggered by something (ie drugs)

Front 12

what is the difference between warm & cold AIHA?

Back 12

- warm AIHA: caused by IgG antibodies, more likely idiopathic, can fix complement but does not easily activate it

- cold AIHA: caused by IgM antibodies, more likely due to infections or malignancy, fix & activate complement more readily

Front 13

what is the direct coombs test vs indirect coombs test?

Back 13

- direct coombs: autoantibodies detected on RBC surface --> red cells agglutinate due to cross linking

- indirect coombs: alloantibodies in serum

Front 14

what coombs test do you use for cold agglutination?

Back 14

- C3 positive by not IgG

Front 15

which AIHA is responsive to steroids & splenectomy?

Back 15

- warm AIHA is responsive, cold AIHA not responsive

Front 16

what is a hapten? innocent bystander? autoimmune?

Back 16

- hapten: IgG against RBC/drug complex

- innocent bystander: Ab against drug, but cross reacts w/ RBCs

- autoimmune: drug induces Abs against RBC antigen

Front 17

what are some non-immune causes of acquired hemolytic anemia?

Back 17

- march hemoglobinuria, infections, burns, microangiopathic hemolysis (see schisocytes on blood smear)

Front 18

what are microangiopathic hemolysis?

Back 18

- RBC damage occurs as they transverse abnormal surfaces

- see shistocytes on peripheral blood smear

- hemangioma, artifical valves, DIC (most common cause), TTP (second most common cause)