Lecture 5: Blood groups

Question 1

RBC membranes have _____________ on their external surfaces

Answer 1

glycoprotein antigens

Question 2

These antigens are:

Answer 2

Unique to the individual
Recognized as foreign if transfused into another individual
Promoters of agglutination and are referred to as agglutinogens

Question 3

used to classify blood groups

Answer 3

Presence or absence of these antigens

Question 4

Humans have ____ varieties of naturally occurring RBC antigens

Answer 4

30

Question 5

cause vigorous transfusion reactions when they are improperly transfused

Answer 5

The antigens of the ABO and Rh blood groups

Question 6

https://www.youtube.com/watch?v=L06TJTMVkBo

Question 7

The ABO blood groups consists of:

Answer 7

Two antigens (A and B) on the surface of the RBCs
Two antibodies in the plasma (anti-A and anti-B)

Question 8

________ (ANTIGENS) and their corresponding antibodies cannot be mixed without serious ___________

Answer 8

Agglutinogens
hemolytic reactions

Question 9

Question 10

2 kinds of antibodies

Answer 10

= anti-A and anti-B

Question 11

2 kinds of antibodies = anti-A and anti-B

Answer 11

> Thus 4 possibilities in the plasma as well
- alpha, beta
- Alpha and beta
- O
Alpha antibody interacts (agglutinates) with the A antigen
Beta-antibody agglutinates with the B antigen
People with antigen A in their RBCs always have B-antibody in
their plasma
They cannot have alpha-antibody because this will agglutinate
with their own RBC and destroy them

Question 12

Individuals with antigen B

Answer 12

have alpha-antibody

Question 13

If a patients is given the wrong blood type

Answer 13

• antibodies in patients own plasma react with antigens of donor
• Clumping of donor blood – death
  Remember: it is the plasma antibodies of the recipient that react with the antigens (RBCs) of the donor
• Group 0 can donate blood to anyone
• Group 0 can receive only 0 blood

Question 14

Question 15

Rh Blood groups

Answer 15

• Rh agglutinogens are in SOME blood
• Presence of the Rh agglutinogens on RBCs is indicated as Rh+
• Anti-Rh+ antibodies are not spontaneously formed in Rh–
  individuals
• However, if an Rh– individual receives Rh+ blood, anti-Rh antibodies
  form
• A second exposure to Rh+ blood will result in a typical transfusion
  reaction

Question 16

Rh Blood groups and birth

Answer 16

• Rh- mother bears Rh+ positive child conceived from positive
  father
• At birth some of the child’s RBCs pass through plasenta into
  mother’s circulation
• Rh antigens promote formation of Rh antibodies in maternal blood
• First child = normal
• Future pregnancies cause haemolytic disease of newborn or
  erythorblastosis foetalis
• Rh antibody concentration rise in blood of mother shortly after birth
  of Rh-positive baby = need to desensitize mother

Question 17

Transfusion reactions

Answer 17

• RBC antigens encounter their antibodies
• Binding
• This coating of antibody have several effects:
  > Make cell adhere to each other (agglutinate)
  > Activate the compliment system - break open (lyses) the cell =
  release haemoglobin and potassium (affects nerve and muscle
  function)
  > Expose the cell for attack by macrophages (reduced blood
  pressure; overall shock)
  > Life threatening

Question 18

How is the CBC test used?

Answer 18

The complete blood count (CBC) is often used as a broad screening test to determine your general health status. A CBC may be used to:
Screen for a wide range of conditions and diseases
Help diagnose various diseases and conditions, such asanemia,infection,inflammation,bleeding disorderorleukemia, to name just a few
Monitor the status of a disease or condition and the effectiveness of treatment after a diagnosis is established
Monitor treatment that is known to adversely affect blood cells, such aschemotherapyor radiation therapy

Question 19

What diseases can be detected with a CBC?

Answer 19

A CBC can help detect a number of conditions. Some examples include:
Anemiaof various etiologies
Autoimmune disorders
Bone marrow disorders
Dehydration
Inflammation
Hemoglobin abnormalities
Leukemia
Low platelets
Lymphoma
Myeloproliferative neoplasms
Myelodysplastic syndrome
Sickle cell disease
Thalassemia

Question 20

What does an elevated RDW mean?

Answer 20

An increased variation in red blood cell size, a condition known asanisocytosis.