Immunodeficiency

Question 1

Example of a disease that causes T cell deficiency?

Answer 1

HIV

Question 2

What viruses are people with T cell deficiencies susceptible to?

Answer 2

Herpes

Question 3

What bacteria are people with T cell deficiencies susceptible to?

Answer 3

Intracellular bacteria - because T cells’ main role is fighting intracellular bacteria

Strep. pneumonia, Mycobacteria species, Salmonella and more

Question 4

What fungi are people with T cell deficiencies susceptible to?

Answer 4

Yeasts: Candida, Cryptococcus

Pneumocystis jirovecii

Question 5

What parasites are people with T cell deficiencies susceptible to?

Answer 5

Spore forming Cryptosporidia

Intracellular Leishmania

Question 6

What malignancies are people with T cell deficiencies susceptible to?

Answer 6

EBV associated lymphoma: can’t fight off EBV

Cervical intraepithelial neoplasia: can’t fight of HPV?

Question 7

What autoimmune conditions are people with T cell deficiencies susceptible to?

Answer 7

Rheumatological & dermatological

They lose their Tregs function, nothing to stop immune responses getting out of hand

Question 8

Why does immunodeficiency mean you’re more susceptible to cancers?

Answer 8

If your immune system is weakened, then it will not be performing cancer immunosurveillance as effectively.

This is when your lymphocytes recognise mutated DNA in cells and induce cell apoptosis before the cell can divide and become a cancer

Question 9

What viruses & bacteria are people with B cell deficiencies susceptible to?

Answer 9

Encapsulated bacteria: Strep. pneumoniae, H. influenzae

Enteric pathogens

Chronic infections

Question 10

What parasites are people with B cell deficiencies susceptible to?

Answer 10

Giardia lamblia

Question 11

What malignancies are people with B cell deficiencies susceptible to?

Answer 11

Gastric

Lymphomas

Question 12

What are T cells required for?

Answer 12

Cell mediated immunity

T helper
T cytotoxic
T memory
T regulatory (make sure immune system does not get out of hand)

Question 13

What are B cells required for?

Answer 13

Antibody production

Question 14

What are phagocytes required for?

Answer 14

To kill bacteria and fungi

Phagocytosis

Question 15

What bacteria are people with phagocyte deficiencies susceptible to?

Answer 15

Generally gram negative

S. aureus, Klebsiella, E. coli

Question 16

What fungi are people with phagocyte deficiencies susceptible to?

Answer 16

Filamentous: Aspergillus fumigatus
Yeasts: Candida

Question 17

What is complement required for?

Answer 17

Opsonisation of encapsulated bacteria

Part of innate system

Question 18

What is hyposplenism?

Answer 18

Spleen dysfunction

Question 19

What is primary vs secondary immunodeficiency?

Answer 19

Primary: disorder of actual immune system

Secondary: disorder of supporting component of immune system or an external decreasing factor of it

Question 20

What are some clues to primary immunodefiency?

Answer 20

4 or more new ear infections per year

2 or more serious sinus infections per year

2 or more bouts of pneumonia per year

At least 2 months on antimicrobials in a year

Growth retardation in children

Recurrent deep skin or organ abscesses

Persistent oral thrush (candida) or fungal infection of skin

Need for intravenous antimicrobials to clear infections

2 or more deep seated infections or septicaemia

Family history

Question 21

What is SCID?

Answer 21

Severe combined immunodeficiency

Genetic condition caused by defects in a number of genes.

Dysfunction of T & B cells so no immune system at all

Usually die within 2 years unless they receive a haemopoetic stem cell transplant