12 Hemolytic anemias

Question 0

Intravascular hemolytic anemias

Answer 0

PNH
Mechanical Shearing
Malaria

Question 1

Extravascular hemolytic anemias

Answer 1

RBC membrane disoders (Hereditary Spherocytosis)

Thalassemias

Question 2

Intra and extravascularly hemolytic anemias

Answer 2

RBC enzyme disorders (i.e. G6PD and bite cells)
Sickle cell anemia
Autoimmune hemolysis (intra complement, Extra AB)

Question 3

Labs to evaluate hemolysis

Answer 3

Normocytic?
Reticulocytosis?
^LDH, K, AST
^indirect bilirubinemia (conjugated in liver DZ)
Hemoglobinemia/hemosiderinuria/ Decr. Haptoglobin (intravascular)
DAT (direct antiglobin test)

Question 4

Hemolytic anemias clinical findings

Answer 4

Acute Symptoms:
based on severity and acuity of anemia-
* i.e. young patients with chronic hemolytic anemias can be at Hb of 6-7g/dL without significant symptomology

Chronic symptoms:

• Splenmegaly/hepatomegaly from extramedullary hematopoiesis (thalassemia, PK D, Hereditaryspherocytosis)
• Skeletal changes from expansion of marrow- B Thal Major
• Asplenia: Sickle cell

Question 5

Clinical features of acute hemolysis

Answer 5

40%, <8g/dL, confusion/shock

Question 6

Hemolytic Hyperbilirubinemia

Answer 6

Hemolytic anemia ^ indirect bilirubin

>5mg/dL of indirect bilirubin (unless liver dz) is hemolytic anemia

Question 7

Rare hemolytic complications

Answer 7

• Pigment induced renal dmg
  
  • tubular obstruction, cell injury and vasoconstriction
  • UA with hemoglobinuria WO CELLS
• Folate D
• Increased thrombosis

Question 8

Hemolytic anemia with underlying disease process

Answer 8

Microangiopathic hemolytic anemia

• TTP, HUS, DIC, Malignant HTN, CREST syndrome, vasculitis, HELLP syndrome
• Microvascular infarction causing AKI, Liver Dz, abd pain, fever, mentalstatus change, thrombocytopenia, rash, hemorrhagic diarrhea.

Question 9

Hereditary spherocytosis

Answer 9

*Spherocytes due to defect in Ankyrin, spectrin, or Band 3 75% autosomal dominant
*Normocytic, hyperchromic anemia
*Extravascular hemolysis in spleen due to Decr. deformability
*Variable hemolysis and splenomegaly, gallstones, aplastic crises
may treat with splenectomy.

Question 10

Autoimmune Hemolytic anemias

Answer 10

• Cause spherocytosis and polychromasia
• shortened RBC life span
• Normocytic hyperchromic

Warm: Idiopathic, lymphoproliferative, autoimmune, some drugs: IgG associated intravascular hemolysis (complement) and Extravascular (ab complexes)
Cold: Post infectious(mononucleosis, TB), IgM related intravascular hemolysis, Raynaud?

DIRECT ANTIGLOBIN/COOMBS TEST: ab to complement and IgG added- does it pprecipitate?

Question 11

G6PDH D

Answer 11

• ***X LINKED - labile G6PDH- breakdown after time
• Hemolytic anemia due to breakdown of pentose phosphate pathway and REDUCED GSH –> Causes increased succeptability to oxidant stressors (fava beans, infecction, drugs:dapson sulfonamindes, quinalones, nitrofurantonin, primaquine)
• Precipitated denatured Hb(intravascular hemolysis) forms Heinz bodies- which are ingested by macs in spleen- (Extravascular hemolysis)

Question 12

G6PDH screens

Answer 12

NADPH Fluorescence- can be Normal, Low(heterozygous females), or very low(males)

Question 13

Mechanical RBC damage

Answer 13

Schistocytosis
Caused by:
Defective heart valves
Extreme heat/burns
Microangiopathic hemolytic anemias:
-TTP
-Malignant HTN
-Antiphospholipid antibody syndrome
-DIC
-Disseminated cancer

Question 15

PNH

Answer 15

Paroxysmal Nocturnal Hemoglobinurea 
PANCYTOPENIA- Complement mediated intravascular hemolysis
*X LINKED PIGA gene disorder
*Lacking GPI linker- used with anticomplement proteins
*UNUSUAL UNEXPLAINED THROMBOSIS
*S/S
acute intravascular hemolysis 
chronic low level hemolysis
Hemoglobinurea

Test by looking for
CD55, CD59- GPI linked proteins on WBC and RBCs