0417 - Infections in Immunocompromised Hosts

Question 1

What are some important aspects of secondary immunodeficiency, classified immunologically?

Answer 1

Macro (things you can see/assess at bedside)

• Skin (surgical wounds, eczema)
• Mucous membranes (mucositis from chemotherapy)
• Foreign materials (IV catheters)

Micro

• Surface barriers (stomach acid, mucociliary elevator, flora in genitals, skin desquamation etc)
• Innate immunity (immunodeficiency, splenectomy)
• Adaptive immunity (lack of memory, immune naievety, splenectomy)

Question 2

What are some aspects of an otherwise normal immune system that could expose a person to infection?

Answer 2

Genetic risk

Physiologic risk (very young, pregnant, very old)

Immunologic risk (unvaccinated/no natural immunity)

Question 3

Which elements of the immune system respond to extracellular bacteria?

Answer 3

Mostly phagocytes and B cells, with some CD4 T-cells.

Question 4

Which elements of the immune system respond to intracellular bacteria?

Answer 4

Huge numbers of phagocytes, with some CD4 T-cells.

(I would also argue CD8’s)

Question 5

Which elements of the immune system respond to fungi?

Answer 5

Large numbers of phagocytes and some CD4 T-cells, with a few B-cells.

Question 6

Which elements of the immune system respond to viruses?

Answer 6

Large numbers of CD8 T-cells and NK cells, with a few CD4 cells, B-cells, and phagocytes.