Immunology

Question 1

What cells give the GI trat surface it’s characteristic membrane ruffles?

Answer 1

M cells

Question 2

What is the process of uptake up antigen by M cells?

Answer 2

The M cells take up the antigens by endocytosis and phagocytosis. The antigen is transported across the M cells in vesicles and released at the basal surface. The antigen is then bound by dendritic cells, which activate T cells
Dendritic cells also have the ability to extend processes across the epithelial layer to capture antigens from the lumen of the gut

Question 3

What immunoglobulin is produced in the GI tract?

What is it’s function?

Answer 3

IgA

Can bind and neutralize pathogens and toxins

Question 4

How does selective IgA deficiency present?

Answer 4

2/3 asymptomatic, remainder get recurrent sinopulmonary infections

Question 5

What is common variable immunodeficiency?

How does it present?

Answer 5

Failure to differentiate into Ig secreting cells - low IgG, IgA, IgM, IgE
Recurrent sinopulmonary and GI infections

Question 6

X-linked agammaglobulinaemia
What is it?
How does it present?

Answer 6

Genetic condition causing very few B cells

Sinopulmonary and GI infections + devastating systemic manifestations of chronic enteroviral infections

Question 7

Chronic granulomatous disease

How does it present?

Answer 7

Staphlococcus aureus/inflammatory granulomas- pneumona, liver abscess, perianal abscess and skin abscess

Question 8

SCID

How does it present?

Answer 8

Oral candidiasis/chronic diarrhoea/interstitial pneumonitis
GI- CMV/rotavirus/EBV
Prevents within the first 6 months of life