Chap 21

Question 1

Treatment of Hereditary Spherocytosis?

Answer 1

Mild cases require no treatment usually.

Severe cases require regular transfusions.

Moderate-Severe Splenectomy, corrects anemia but membrane defect remains.

Question 2

What can be said of the prognosis for people W/ Hereditary Elliptocytosis?

Answer 2

Severity of anemia dictates prognosis and treatment options.

Question 3

Hereditary Spherocytosis (HS)

Answer 3

Defect in Ankyrin and Spectrin

Fragile Spherocytic RBCs

Inherited

Question 4

HS Clinical findings?

Answer 4

Varies in severity

Compensated Hemolytic Disease

Anemia varies W/ severity

Splenomegaly

Cholelithiasis (pigment bile stones, from increased Bilirubin breakdown).

Question 5

HS CBC?

Answer 5

Mild Anemia

MCV usually normal (77-87 fL)

MCH Normal

MCHC > 36% (only condition MCHC is truly increased).

RDW increased

Question 6

HS RBC Morph?

Answer 6

Spherocytes

Varying Polychromasia

Aniso

Poik

Question 7

HS BM?

Answer 7

Normoblastic Erythroid hyperplasia

Increased Iron storage

Question 8

Hs Chemistry

Answer 8

Increased: Bilirubin, Fecal Urobilinogen, LD/LDH

Decreased: Haptoglobin

Question 9

Immunohematology of HS?

Answer 9

DAT negative

Question 10

Diagnostic tests for HS?

Answer 10

Osmotic Fragility Increased

Auto-hemolysis test
RBCs incubated @ 37 Celcius for 48hrs
Degree of hemolysis increased
when spherocytes present.

RBC Membrane Studies- Membrane proteins analyzed W/ gel electrophoresis.

Question 11

Post-Splenectomy PB in HS?

Answer 11

Increased Poik

Increased Inclusions

Increased PLTs

Question 12

Osmotic Fragility

Answer 12

Measures RBC’s resistance to osmotic stress.

Normal, HE, HA: 0.30-0.45%

HS: 0.55-0.75 (Increased Fragility)

Hgb S & C Disorders, Thalas: 0.25-0.35 (Decreased fragility)

Question 13

Hereditary Elliptocytosis (HE)

Answer 13

Defect of skeletal proteins

Question 14

HE has fragile?

Answer 14

Ellipto RBCs to mechanical stress.

Question 15

Hereditary Pyropoikilocytosis (HPP)

Answer 15

Severe subtype of HE

Deficiency of a-spectrin (Mutant spectrin leads to disruption of skeletal lattice and destab).

HPP cells fragment @ 45-46 Celcius

Present @ birth
Hemolytic Anemia
Hyperbilirubinemia
Exchange Transfusion
Phototherapy
Serologic for HDN negative
Therapy: Spelenectomy

PB Smear:
Striking Poik (Budding, Frag,
Microspherocytes, Elliptos,
Triangulocytes, Bizarre forms

MCV decreased (25-55 fL(RBC Frag)

Question 16

Hereditary Stomatocytosis (H-Stoma)

Answer 16

Membrane defect, abnormally permeable to sodium and potassium.

Group of disorders

Mild-Severe Hemolytic anemia

Associated W/ Rh null individuals

Question 17

Paroxysmal Nocturnal Hemoglobinuria (PNH)

Answer 17

Rare acquired RBC membrane disorder.

Sleep-associated blood in the urine.

PTs often pancytopenic

Strongly associated W/ aplastic anemia

Significant # of PTs dev another clonal blood disorder: AML, CLL, CMD, MDS

Question 18

Etiology of PNH?

Answer 18

SC mutation leading to abnormal clones of differentiated HSCs.

Clones bind complement.

9 cell surface proteins that regulate complement missing.

Result RBC membrane sensitive to complement.

Question 19

Confirmation test for PNH?

Answer 19

Ham’s Test (Acidified Serum Lysis test)
PNH cells lyse in serum, Normal cells do not.

Question 20

PNH therapy?

Answer 20

Directed at the complications that arise from anemia and thromboses.

Question 21

Sugar water test

Answer 21

Blood incubated in a solution of sugar water.

Low ionic strength of the solution activates complement.

PNH cells are lysed.