A. INTRINSIC & EXTRINSIC HA

Question 1

Defect of red cell itself, usually hereditary & grouped as membrane, metabolic or hgb defects.

Answer 1

Intrinsic HA

Question 2

• Congenital Hemolytic Jaundice or Anemia
• Inherited as a non-sex-linked dominant trait
• Most common in North Europeans
• Spherocytes die prematurely
• Splenomegaly

Answer 2

HEREDITARY SPHEROCYTOSIS

Question 3

• Chronic intravascular hemolysis
• Nocturnal hemoglobinuria occurs during sleep or after awakening
• Rare chronic acquired red cell membrane defect
• ↓ plasma pH due to red cells
• Acidosis

Answer 3

Paroxysmal Nocturnal Hemoglobinuria (PNH) / Machiafava-Micheli Syndrome (MMS)

Question 4

• Lab findings:
  o (+) sucrose hemolysis test or Ham’s acidified serum test or sugar water test.
  o ↓WBC ct., ↓plt ct.
  o Hemosiderinuria is a feature.
• PBS:
  o ↑retic ct.
  o Normocytic-normochromic anemia is present.

Answer 4

PNH (MMS)

Question 5

• Associated w/ severe HA in infants
• Defect involves the impaired association of spectrin dimers resulting in free, unconnected dimers.

Answer 5

HEREDITARY ELLIPTOCYTOSIS / OVALOCYTOSIS

Question 6

• Lab findings:
  o ↑Osmotic Fragility test
  o Autohemolysis of red cells is present
• PBS:
  o Non-hypochromic elliptocytes are abundant on blood films.
  o Normal shape of retics & nRBCs

Answer 6

HEREDITARY ELLIPTOCYTOSIS / OVALOCYTOSIS

Question 7

• Rare, moderately severe congenital HA
• Inherited as recessive autosomal traits
• Occurs in blacks
• PBS:
  o Microcytosis, striking micrpoikilocytosus, &
  fragmentation (common among black ppol)

Answer 7

HEREDITARY PYROPOIKILOCYTOSIS

Question 8

• Rare congenital anemia
• Inherited as recessive autosomal trait caused by as
  recessive autosomal trait caused by ↑Na & ↓K due to
  ↑permeability of membrane
• 10-30% red cells appear as mouth-like

Answer 8

HEREDITARY STOMATOCYTOSIS (HYDROCYTOSIS)

Question 9

• Causes by absence of beta-lipoprotein
• Associated w/ plasma lipid abnormalities
• ↓total lipid, cholesterol, & phospholipids
• Autohemolysis occurs (so EDTA is preferred)
• Presence of mild anemia

Answer 9

HEREDITARY ACANTHOCYTOSIS (ABETALIPOPROTEINEMIA)

Question 10

• Inherited due to gene suppression or presence of
  silent Rh gene (Xo)
• Membrane abnormalities due to absence of all Rh-Hr
  Ags on the red cells

Answer 10

RHnull DISEASE

Question 11

• Lab findings:
  o ↑retic ct.
  o Autohemolysis & Osmotic Fragility test
• PBS:
  o Mild, chronic normocytic normochromic HA
  o Smear shows stomatocytes & spherocytes

Answer 11

RHnull DISEASE

Question 12

• Inherited
• Represents an imbalance in the membrane
  phospholipids in the red cells
• Anemia may ↑ due to infx or under condition of stress
• PBS:
  o Causes mild anemia w/ morphologically
  normal cells

Answer 12

HIGH PHOSPHATIDYLCHOLINE HA

Question 13

▪ A factor outside the red cell & acting upon it. Almost always acquired.

Answer 13

Extrinsic HA:

Question 14

EXTRINSIC DEFECTS
Causes:

Answer 14

1. Chemical agents – drugs & chemicals
2. Physical agents – heat, trauma
3. Vegetable & animal poisons
4. Infectious agents – malarial parasite, bacteria
5. Presence of autoAbs, isoAbs or drug-related Ab causes

Question 15

Congenital HAs

Answer 15

Refer to handout page 5