Microbiology-Hygiene Theory

Question 1

Hygiene hypothesis

Answer 1

Increased hygiene has contributed to the increasing rates of autoimmune diseases.

Question 2

In a large family, what child is most likely to have hay fever?

Answer 2

The oldest. It is possible that having lots of infections is protective against autoimmunity and youngest children will have less incidence of hay fever.

Question 3

Cytokines produces by T-cells when a person has worm infection

Answer 3

IL-4, IL-5, IL-13

Question 4

A 29 year old lived in Africa for 6 years. One of his friends had a worm crawl across the front of his eye and had microfilaria in his blood. He gets a blood test and results are shown below.

Answer 4

He has tons of microfilaria in his blood. When people are acutely infected with worms you get eosinophilia and release of IL-4 and IL-5 with allergic symptoms. Chronically, IgG4, IL-10 and TGF-beta that decrease allergic reactivity and T-cell responses.

Question 5

What type of immunity do worms develop

Answer 5

Type II with increased IgE and eosinophilia