RBC and Bleeding Disorders

Question 1

Defects in membrane skeleton (spectrin, ankyrin, band 3, band 4.2) – less deformable red cells

EXTRAVASCULAR

increased MCHC
spherocytes

OSMOTIC FRAGILITY TESTING

Splenectomy

Answer 1

HEREDITARY SPHEROCYTOSIS

AD

Question 1

Defects in membrane skeleton (spectrin, ankyrin, band 3, band 4.2) – less deformable red cells

EXTRAVASCULAR

increased MCHC
spherocytes

OSMOTIC FRAGILITY TESTING

Answer 1

HEREDITARY SPHEROCYTOSIS

AD

Splenectomy

Question 2

Decreased NADPH needed for glutathione reduction – red cells vulnerable to lysis with OXIDATIVE STRESS

INTRAVASCULAR
EXTRAVASCULAR

HEINZ BODIES

BITE CELLS (Degmacytes)

Protective against malaria

Answer 2

G6PD DEFICIENCY

X-linked recessive

NBS
Aversion to triggers

Question 3

Mutation on the 6th codon of the B-globin gene
(GLU –> VAL)

Red cells become SICKLED when exposed to low pH and decreased oxygen tension

SICKLE CELLS (drepanocytes)
TARGET CELLS (codocytes)

HOWELL JOLLY BODIES - nuclear remnant in asplenic patients

Protective against malaria

Answer 3

SICKLE CELL DISEASE

AR

Hgb electrophoresis
Hydroxyurea

Question 4

Abnormalities in RNA splicing or decreased transcription

6-9 mos of age

HbF –> HbA synthesis

Answer 4

BETA THALASSEMIAS

B thalassemia major (COOLEY ANEMIA) - HbF (a2y2)
B thalassemia minor - HbA2

Question 5

Deletions

symptoms appear at BIRTH

newborns - HgB barts (y4)
older children and adults - HbH (B4)

Answer 5

ALPHA THALASSEMIAS

Question 6

PIGA mutations –> decreased complement regulatory proteins

CD55 (decay accelerating factor)
CD59 - most important
C8 binding protein

INTRINSIC

INTRAVASCULAR

Answer 6

PAROXYSMAL NOCTURNAL HEMOGLOBINURIA (PIGA)

nocturnal hemoglobinuria
thrombosis - MC disease related death
AML or MDS as sequelae

HSC transplantation
Eculizumab

Question 7

MC adverse transfusion reaction

temperature of 38 C or 1 C increase from pretransfusion temperature during or within 4 hrs

Answer 7

Febrile Non-Hemolytic Transfusion Reaction (FNHTR)

proinflammatory cytokines produced by donor leukocytes and platelets

antipyretics
avoid using old blood products, use of leukoreduced blood products

Question 8

MC reaction encountered in PLATELET transfusion

2nd MC reaction encountered in RBC transfusion

Allergic symptoms during or within 2 hrs after transfusion

Answer 8

Allergic Reaction

Question 9

Clinical and biochemical evidence of hemolysis and serologic evidence of RBC incompatibility during or within 24 hrs after transfusion

MCC - ABO incompatibility

LETHAL

fever - MC manifestation
flank or lower back pain
hemoglobinuria - tea colored urine
positive DAT

Answer 9

Acute Hemolytic Transfusion Reaction

preformed IgM antibodies against donor red cells that fix complement –> complement mediated lysis and intravascular hemolysis

Question 10

Positive DAT 24 hrs to 28 days after transfusion with either

(+) eluate or newly identified alloantibody
evidence of hemolysis

exposure to non-ABO antigens - COMMON CAUSE

Answer 10

Delayed Hemolytic or Serologic Transfusion Reaction

Question 11

Acute lung injury during or within 6 hrs after transfusion

fever, hypotension, hypoxemia, radiographic evidence of pulmonary edema

Answer 11

Transfusion Related Acute Lung Injury (TRALI)

antibodies or non-antibody compounds activate neutrophils

Question 12

Microangiopathic Hemolytic Anemia
Thrombocytopenia
Renal Failure
Fever
Neurologic manifestations

Answer 12

Thrombotic Thrombocytopenic Purpura