11-25 L3 Anemia Increased destruction

Question 1

Define

Hemolytic anemia

Answer 1

anemia caused by increased rate of RBC destruction

Question 2

What is increased with red cell breakdown

Answer 2

• indirect or unconjugated bilirubin
• leads to jaundice

Question 3

What enzyme is present in many tissues, (sensitive) but not specific for hemolysis

Answer 3

LDH

(lactate dehydrogenase)

Question 4

What protein in the plasma binds to free hemoglobin so it may be removed by reticuloendothelial system>

Answer 4

Haptoglobin

Question 5

What is the difference b/t Coombs direct vs indirect testing?

Answer 5

• direct: testing against the pt’s RBC
• Indirect: using Pt serum to test on std RBC.

Question 6

extravascular hemolysis

Answer 6

• more common than intravascular hemolysis
• splenogmegaly (due to hyperplasia of macrophages)

Question 7

Intravascular hemolysis

Answer 7

• Mechanical injury
  
  • defective cardiac valves, thrombi withint he microcirculatoin, or repetivtive physical trauma
• Completment fixation
• infeciton (falciparum malaria)
• Exogenous toxin injury
• Results in hemoglobinemia, hemoglobinure, jaundice, hemosiderinuria and decreased haptoglobin

Question 8

HS

(hereditary spherocytosis)

Answer 8

• inheritable
• cuased by mutatoin in RBC membrane proteins resulting in less deformable RBCs that become trapped and phagocytosed in splenic cords
• **Labs: **spherocytes, increaed MCHC, and osmotic fragility

Question 9

PNH

(Paroxysmal Nocturnal Hemoglobinuria)

Answer 9

• GPI liken protens has a mutation
• results:
  
  • CD59 (membrane inhibitor of reactive lysis)
  • CD55 (daf: decay accelerating factor)
  • C8 binding protein

Question 10

what are the 2

Intrinsic hemolysis enzymes

Answer 10

• G6PD def: >90% of cases
• Pyruvate kinase def

Question 11

G6PD deficiency

Answer 11

• X-linked recessive inherited enzyme def resulting in increaed RBC susceptibility
  
  • drugs (antimalarials, sulfonamides)
  • Foods (fava beens)
  • Oxidant free radicals (produced by WBCs during infections)

Question 12

G6PD A-

(which one of the 2 ethicities is the most common as well)

Answer 12

• 10% of African americans
• Mediterranean are the most common varients

Question 13

What 2 histological features are present with G6PD?

Answer 13

• Heinz bodies
• Bite cells

Question 14

Warm Ab hemolytic anemia

Answer 14

• most common form of immune-mediate HA
• causative Ab is **IgG **acting at body temperature

Question 15

Cold agglutinin HA

Answer 15

• Caused by IgM Abs that bind RBC fixing complement–>agglutination

Question 16

TTP (thrombotic thrombocytopenic purpura)

is associated wiht what abnormal levels?