immunodeficiency

Question 1

manifestations of immunodeficiency

Answer 1

• reactivation of latent infection
• unusually persistent/frequent infection
• unusually severe/ widespread infection
• opportunistic infection

Question 2

primary immunodeficiency

Answer 2

• intrinsic defect in component of immune system (eg missing thymus)
• usually affects children

defective B&T cell maturation
- transplacental transfer of maternal IgG at 3rd trimester till birth
- deficiency manifests after 3-4 month since birth where levels of maternal IgG in child goes down to insignificant levels after 5.5 half lives and immunodeficient child unable to make IgG to respond to infection

Question 3

example of primary immunodeficiency

Answer 3

severe combined immunodeficiency
- genetic disorder resulting in impaired T, NK and B cell immunity
- present soon after birth (due to T cell because they cannot be transferred from placenta to child so child born without T cells)
- chronic inflammation, failure to thrive

neutrophil defects
- neutropenia: decreased production due to factors affecting bone marrow like chemo or radiotherapy or increased destruction (eg hyper active spleen)
- febrile neutropenia: low neutrophil count so prone to infection because cannot fight of pathogen -> bacteraemia -> septicaemia

Question 4

secondary immunodeficiency

Answer 4

• affect immunocompromised like elderly
• usually when you have another disease (eg asplenic, cancer, HIV)