6 - Hemolytic Anemia - General and Acquired Causes

Question 1

key lab value that is increased across most forms of hemolytic anemia

Answer 1

retic count is usually up

Question 2

normal RBC lifespan

Answer 2

120 d

Question 3

how short does the average RBC lifespan have to be for increased hemolysis to cause anemia?

Answer 3

30 d

Question 4

only process in the body that makes CO

Answer 4

RBC destruction

Question 5

normal RBC destruction is extravascular/intravascular/both?

Answer 5

Extravascular only

Question 6

____ is converted to bilirubin when RBCs die

Answer 6

protoporphyrin

Question 7

cycle of bilirubin after being formed from RBC destruction

Answer 7

unconjugated bilirubin binds albumin (not soluble in this stage) > to liver
hepatocytes convert it to conjugated w/ glucuronyl transferase (now soluble)
excreted in bile
bacteria convert to stercobilinogen, can be resorbed and excreted in urine as urobilinogen

Question 8

____ hemolysis is assoc w/ hemoglobinemia, hemoglobinuria, and hemosidinuria

Answer 8

intravascular

Question 9

LDH and haptoglobin levels in intravascular hemolysis?

Answer 9

inc LDH

low haptoglobin

Question 10

hemolytic anemia will cause high direct or indirect bilirubin in the blood?

Answer 10

indirect

Question 11

what is the main consequence in terms of treatment of a hemolytic anemia having an intrinsic vs extrinsic cause?

Answer 11

intrinsic cause will mean that transfused cells will have a normal lifespan usually

Question 12

causes of reticulocytosis (4)

Answer 12

recovery from hypo-proliferative anemia
bleeding
myelophthisis (fibrosis or tumor)
hemolytic anemia

Question 13

3 categories of disorders that are congenital causes of hemolysis

Answer 13

membrane abnormalities
enzymopathies
hemoglobinopathies

Question 14

acute intravascular hemolytic events - examples

Answer 14

ABO incompatible transfusion
clostridial sepsis
PNH crisis

Question 15

acute intravascular hemolytic event symptoms

Answer 15

chills, fever
dark/red urine
back / abd pain
severe cases can lead to shock, DIC, acute renal failure

Question 16

complications of chronic hemolytic anemia

Answer 16

anemia
cholelithiasis (pigmented stones)
splenomegaly
leg ulcers
folate deficiency
worsened anemia with illnesses
iron deficiency
growth retardation in children
venous thromboembolic disease
aplastic crises w/ parvo B19 infection

Question 17

spherocytosis - give a acquired and congenital cause for hemolytic anemia

Answer 17

acquired - most auto-immune hemolytic anemias will show spherocytes
congenital - hereditary spherocytosis

Question 18

4 immune hemolytic anemias

Answer 18

warm-antibody induced
cold agglutinin dz
allo-immune hemolytic anemia
paroxysmal cold hemoglobinuria

Question 19

test to confirm warm antibody autoimmune hemolytic anemia

Answer 19

DAT (Coombs)

Question 20

how do you distinguish between Warm AIHA and cold agglutinin disease with lab tests?

Answer 20

Warm: DAT + IgG + C3 +/-
Cold: DAT + IgG - C3 +

Question 21

3 main causes of AIHA

Answer 21

idiopathic, lymphoproliferative disorders, SLE

Question 22

Tx of warm AIHA

Answer 22

corticosteroids (only about 60% respond)
splenectomy (effective in about 2/3)
immunosuppression/modulation (cyclophosphamide, IVIG, rituximab)
RBC transfusion (w/ caution - already prone to reacting to blood)

Question 23

what pathogen is cold agglutinin dz associated with for unknown reasons?

Answer 23

mycoplasma pneumoniae

Question 24

warm AIHA is an Ig_ response, cold AIHA is an Ig_ response

Answer 24

IgG

IgM

Question 25

tx of cold agglutinin dz

Answer 25

if 2/2 infection - usually transient, just try to keep warm (mittens, earmuffs)

corticosteroids and splenectomy not usually helpful

immunomodulation - cyclophosphamide, IVIG, anti CD20

Question 26

signs of hemolytic anemia + absence of platelets on PBS >

Answer 26

fragmentation syndrome - affects both RBCs and platelets

Question 27

causes of microangiopathic HA

Answer 27

TTP
HUS
DIC
disseminated carcinomatosis
obstetric complications
vasculitis
vascular malformations
inc shear stress
malignant hypertension

Question 28

paroxysmal nocturnal hemoglobinuria - general

Answer 28

rare acquired disorder characterized by episodic intravascular hemolysis

most morbidity/mortality related to thromboembolic complications