Red cell enzymopathies and acquired hemolytic anemias

Question 1

Why do red cells need a continuous supply of energy

Answer 1

Maintenance of red cell flexibility and shape
regulation of sodium potassium pumps
Maintenance of Hb in its reduced state

Question 2

Function of G6PD

Answer 2

Reduces NADP to NADPH

Question 3

Function of NADPH

Answer 3

It is needed for the formation of glutathione, a compound that saved the red cell from oxidative stress leading to the formation of heinz bodies and RBC damage

Question 4

Variant of G6PD found in africans

Answer 4

G6PD A

Question 5

Main races affected by G6PD deficiency

Answer 5

Africans,mediterranean, Middle east, South east asia

Question 6

Presentation of G6PD deficiency

Answer 6

Asymptomatic usually
Neonatal jaundice
Triggers like drugs, oxidative stress, fava beans, infection cause hemolysis

Question 7

Diagnosis of G6PD deficiency

Answer 7

1. Methemoglobin reduction test/Direct enzyme assays on red cells
2. Normal blood count
3. Contracted and fragmented cells.
4. Hemolysis begins 1-3 days after exposure
5. Anemia at its peak after 7-10 days after exposure
6. Intravascular hemolysis

Question 8

Pyruvate kinase deficiency causes resistance against this infection

Answer 8

Infection with plasmodium falciparum

Question 9

Presentation of patients with pyruvate kinase deficiency

Answer 9

Chronic hemolytic anemia

Question 10

How are acquired hemolytic anemia caused

Answer 10

By production of antibodies against its own RBCs

Question 11

Test used to determine acquired hemolytic anemias

Answer 11

Coombs test

Question 12

Antibodies are divided into

Answer 12

warm and cold types depending on environment it works best in

Question 13

What happens in warm immune hemolytic anemia

Answer 13

Red cells are coated by IgG—> Undergoes partial phagocytosis in spleen—>Partial loss of coated membrane–> become spherocytes—> Spherocytes become permanently damaged

Question 14

Warm hemolytic anemia deals with this antibody

Answer 14

IgG

Question 15

Causes of warm reactive antibodies

Answer 15

Idiopathic
Some drugs
Lymphoma
SLE
Chronic lymphocytic leukemia

Question 16

Cold reactive hemolytic anemia

Answer 16

This occurs when antibody IgM agglutinates RBC below body temperature—-> Taken up by RE macrophages

Question 17

This antibody is associated with cold immune hemolytic anemia

Answer 17

IgM

Question 18

Presentation of cold immune hemolytic anemia

Answer 18

Various manifestations of hemolytic anemia

Question 19

Above this temperature cold hemolytic anemia does not occur

Answer 19

300 degrees

Question 20

Alloimune hemolytic anemia

Answer 20

A form of hemolytic anemia that occurs when your body makes antibodies against red cells gotten from blood transfusion

Question 21

2 types of alloimune hemolytic anemia

Answer 21

Hemolytic disease of newborn

Hemolytic transfusion reactions

Question 22

Drug induced hapten type of hemolytic anemia

Answer 22

Drug nonspecifically binds to RBC and is absorbed into it—> Antidrug antibodies reacts with cell membrane since drug is absorbed—> Destruction of RBC

Question 23

What drugs induce drug induced hapten type

Answer 23

Penicillin

Cephalosporins (rarely)

Question 24

Drug induced nonimmunological type

Answer 24

Drug alters membrane of RBC—> Antibodies IgG and compliment is absorbed on its surface—>Hemolytic anemia

Question 25

Drugs that cause Drug induced non immunological anemia

Answer 25

Cephalosporins

Question 26

Causes of AIHAs

Answer 26

1.Mechanical trauma to red cells
ie DIC, thrombocytic thrombocytopenic purpura, hemolytic uremic syndrome
2.Burns
3.Drugs
4. Schistocytes
5.Hypersplenism
6. PARAXOSYMAL NOCTURNAL HEAMOGLOBINURIA

Question 27

Diagnosis of paraxosymal nocturnal haemoglobinuria

Answer 27

Acidified serum test ( Hams test)