August 25, 2015 - Introduction to the Immune System

Question 1

Cardinal Signs of Inflammation

Answer 1

1. Redness
2. Swelling
3. Heat
4. Pain

Question 2

Primary Lymphoid Organs

Answer 2

1. Bone marrow
2. Thymus

Question 3

Secondary Lymphoid Organs

Answer 3

1. Spleen
2. Lymph nodes

Question 4

Feeling “Full” and Spleen Size

Answer 4

With an enlarged spleen (splenomegaly), it may press on the stomache and cause the patient to feel “fuller”.

Question 5

White Pulp

Answer 5

Contains the B and T cells and is where they encounter antigens. In the marginal zone is the area where macrophages hang out and where B cells mature.

Question 6

Red Pulp

Answer 6

The area where macrophages remove old and damaged RBCs. This can also be the site of extramedullary hematopoiesis, which is the creation of new RBCs when the bone marrow is overloaded.

This is also the storage site for iron, RBCs, platelets, and plasma cells.

Question 7

Asplenic and Infections

Answer 7

At increased risk for infections, particularly encapsulated organisms.

Common ones that you should be vaccinated against are…

• Streptococcus pneumonianiae*
• Neisseria meningitidis*
• Hemophilus influenzae*

Question 8

Leukocyte Adhesion Deficiency

Answer 8

Missing adhesins or integrins so the neutrophils cannot leave the circulation.

This can result in a lack of pus at the sites of infection.

Question 9

Myeloperoxidase Deficiency

Answer 9

Relatively common.

Almost always asymptomatic. May cause worse fungal infections.

Question 10

Chronic Granulomatous Disease

Answer 10

Lack the enzymes that are responsible for generating superoxide radicals. Catalase-positive organisms can cause significant infections. H2O2 is not enough to kill these.

~75% is X-linked, ~25% is AR.

Question 11

Dihydrorhodamine Test (Oxidative Burst)

Answer 11

Used to test for chronic granulomatous disease. Neutrophils are stimulated with a substance that causes activation and then are incubated with dihydrorhodamine dye. If oxidative radicals are generated, it will change colour.

Normally, you will see a movement of the peak.

Question 12

Complement Deficiency

Answer 12

A patient is unable to create the MAC. This can present with infections in otherwise healthy individuals.

If you see patients with bacteremia, sepsis, or pneumonia that should not typically have it, you may want to consider a complement deficiency.

Perform a CH50/Total Hemolytic Complement test

Question 13

Complement Deficiency Test

Answer 13

CH50 / Total Hemolytic Complement

C3 and C4 levels

Other proteins