Lecture 9: Issues in Immunology

Question 1

What are the types of immune deficiencies?

Answer 1

Primary Immune Deficiencies
-Genetic
Secondary Immune Deficiencies
-Acquired

Question 2

What is a Type I Hypersensitivity?

Answer 2

Allergy and Atopy

-Ag causes IgE bound to MAST cells to release histamines

Question 3

What is a Type II Hypersensitivity?

Answer 3

Antibody-Mediated Hypersensitivity

-IgG or IgM antibodies attack cell surface antigens and kill cells via complement or ADCC

Question 4

What is Type III Hypersensitivity?

Answer 4

Immune Complexes

-Ag-Ab complexes deposit in tissues and induce complement activation and inflammation in that tissue

Question 5

What is Type IV Hypersensitivity?

Answer 5

Delayed Type Hypersensitivity

-Th Cells release cytokines which activate Macrophages or Tc Cells that cause cellular damage

Question 6

What kind of hypersensitivity is a cat allergy and what is involved?

Answer 6

Type I Hypersenstivity

• Caused by Fel d 1 antigen protein
• Th2 and IgE induced responses
• Cause MAST/Basophils to release histamine

Question 7

What kind of hypersensitivity is a transfusion reaction? What about Erythroblastosis Fetalis?

Answer 7

Both Type II Hypersensitivity

-ABO compatibility

Question 8

What is ABO blood typing?

Answer 8

ABO Blood Groups

Have 1 of the following antigens attached to RBCs:

1) Type A antigen
2) Type B antigen
3) Type AB antigen (both A and B)
4) Type O Antigen (neither A or B)

You have antibodies for the other antigens

Question 9

What kinds of antibodies do you have and who are your potential donors for all the blood types?

Answer 9

Type O

• Antibodies for A, B and AB
• Potential Donors: Type O

Type A

• Antibodies for B and AB
• Potential Donors: Type O or A

Type B

• Antibodies for A and AB
• Potential Donors: Type O or B

Type AB

• No Antibodies b/c these RBCs have both A&B
• Potential Donors: Type O, A, B, or AB

Question 10

How does Erythroblastosis Fetalis develop?

Answer 10

Antigen D (AKA Rh) is found on RBCs of developing fetus

If mom is Rh negative but fetus is positive then its okay b/c this is the 1st time seeing antigens

Mom gives birth, is exposed to baby’s Rh, mounts B Cell response and develops memory B Cells

If 2nd pregnancy is Rh positive then mom has memory B cells that release IgG that cross placental barrier and destroy fetal blood supply

Question 11

What is RhoGAM?

Answer 11

If mom is Rh negative but baby is Rh Positive then mom can take this medication during pregnancy which prevents Mom’s B Cell activation and memory cell formation

Question 12

What kind of Hypersensitivity is transplant rejection?

Answer 12

Type IV Hypersensitivity

-Tissue rejection due to HLA Incompatibility

Question 13

What is the most successful type of transplant?

Answer 13

Bone Marrow transplant to cure genetic immune disorders

Question 14

What is PGD?

Answer 14

Preimplantation Genetic Diagnosis (PGD)
-select for proper embryo to ensure bone marrow/HLA match before implantation

Destroy bad bone marrow w/ chemo then implant donor marrow and let regrow

Question 15

What blood type is the universal donor and which is the universal recipient?

Answer 15

Universal Donor is Type O

Universal Recipient is Type AB