Immunodeficiency

Question 1

what is the difference between primary immunodeficiency and secondary immunodeficiency?

Answer 1

Primary is inherited immunodeficiency and secondary is aquired, this is more common and often due to drugs

Question 2

What happens when the apoptosis of neutrophils exceeds the ability of the body to remove them?

Answer 2

They release their contents and pus forms. This damages body tissues because they contain enzymes

Question 3

What are the main factors that normal neutrophil function depends upon?

Answer 3

Number of neutrophils - neutropenia counts as anything less than 1x10^9/L
Ability to migrate to tissues e.g. adhesion molecules and chemotaxis
Ability to destroy pathogens e.g. respiratory busrt and hydrolytic enzymes

Question 4

How does neutropenia present clinically?

Answer 4

With septicaemia due to bacteria or fungi

usually due to chemotherapy or autoimmune bone marrow failure

Question 5

How does Hyper IgE syndrome present?

Answer 5

Mucocutaneous candida and skin abscess

This is caused by a defective inflammatory response

Question 6

How does chronic granulomatous disease present?

Answer 6

Abscess due to staph/fungi

This is due to decreased respiratory burst

Question 7

How does leukocyte adhesion deficiency present?

Answer 7

Infection without pus however there are very high blood neutrophils
This is due to decreased adherence and phagocytosis

Question 8

How is profound neutropenia treated?

Answer 8

Treated with G-CSF , antifungals and antibiotics should also be given

Question 9

When does antibody deficiency tend to present and why?

Answer 9

Antibody deficiency presents 4-6 months after birth as this is when the maternal IgG antibodies start to disappear from the infant

Question 10

How are most cases of adult antibody deficiency aquired?

Answer 10

Through B cell malignancy such as CLL and multiple myeloma (plasma cell cancer in bone marrow)

Question 11

What are the four main manifestations of an antibody deficiency?

Answer 11

Recurrent infections from encapsulated bacteria e.g. S. Pneumoniae and H. Influenzae
Enterovirus infections such as ECHO of the CNS
Diarrhoea and malabsorption due to lack of IgA
Autoimmune disease such as pernicous anaemia

Question 12

What tests can be done to look at antibody deficiency?

Answer 12

Look at blood antibody levels

Measurement of functioning antibody levels against polysacharride and proteins

Question 13

What is C3 deficiency likely to present with?

Answer 13

Recurrent pyogenic bacerial infection

Question 14

How do deficiencies in complement 5-9 usually present?

Answer 14

Meningococcal meningitis

Question 15

How does C1 esterase inhibitor deficiency present?

Answer 15

It presents with spontaneous angioedema that is non itchy

Question 16

What is the most important cause of T cell deficiency?

Answer 16

HIV, will be CD4 deficiency

Question 17

What is the role of CD4 cells in the immune system?

Answer 17

Primed CD4 T cells provide help for B cell responses to protein antigens, inflammatory responses by release of the Th1 cytokines (IFN-γ, IL-4, and TNF), and priming of cytotoxic CD8 T-cells.

Question 18

What is the most important inherited cause of T cell deficiency?

Answer 18

DiGeorge syndrome

Question 19

How can functional assesment of CD4 cells be assessed?

Answer 19

by testing for delayed hypersensitivity to common antigens such as mumps