autoimmune disease &
immunodeficiency

autoimmune disease

Signs

lost of immunity to self antigen

tissue damage/physiological dysfunction

Rare Single Gene Defects
Associated with Autoimmune Disease

AIRE

Foxp3⭐

no need to know the exact mechanism,

women are more prone
to autoimmune diseases

example: systemic lupus erythematous (SLE)⭐
- from the learning outcomes, you should have a comprehensive overview of SLE

what

  • immune system attacks its own tissues and causes widespread inflammation and tissue damage in the affected organs
  • presents as fatigue, skin rashes, pain and swelling in the joints

Treatment

  • immunosuppressive drugs that inhibit the activity of the immune system

immunodeficiency

categories of immunity

primary immunodeficiency (rare)

  • Intrinsic defect in the immune system

secondary immunodeficiency

  • Underlying disease adversely affects immune system

clinical manifestations
of immunodeficiency

infections

increased incidence of certain cancers (eg cancers associated with viral infections)
(because the immune system cannot identify the malignant cells to prevent the tumour)

insert the photo with the summary of immune mechanisms of microbial defence (search this in whatsapp)

examples of primary
immunodeficiency conditions

primary immunodeficiency: Severe combined immunodeficiency (SCID)

  • group of genetically determined disorders resulting in impairment of both the B anc T cell arms of the adaptive immune system

secondary (acquired) immunodeficiency:

  • basically just any virus/illness
  • HIV, removal of spleen

go through the cases in the notes

Specific example: HIV infections

  • infects CD4+ cells and causes progressive destruction of these cells
  • the CD4 cells are initially able to mitigate the immune response, but over time the CD4 cells deplete and hence they cannot fight the virus
  • from the graph, CD4 cells will never be able to reduce the virus to zero, only to set point
    • the immune system is not strong enought
    • this is because the HIV 1 is has an antigenic coat --> meaning that its coat constantly mutates to give different antigens to evade the immune system response

insert the photo for the graph on the HIV infections

insert the photo for the text on clinical phases of the infection

opportunistic infections

  • in immunodeficient individuals, microbes will seize the opportunity to cause infection
    • mycobacteria, pneumocystis jirovecii
  • rupture in the wall of GI tract --> flora in GI tract will escape into cavities where the flora is not normally found --> sepsis