Infection - Immunocompromised Host Flashcards
What is an immunocompromised host?
A state in which the immune system is unable to respond appropriately and effectively to infectious microorganisms
What is the difference between primary and secondary immunodeficiency?
Primary immunodeficiency is congenital, and due to an intrinsic gene defect. Secondary immunodeficiency is acquired, and due to an underlying disease/treatment
What are the characteristic signs of an immunodeficiency?
Infections which are:
- severe
- persistent
- unusual
- recurrent
What are the ‘10 warning signs’ used for?
They are used to diagnose an immunodeficiency
Give some limitations of the ‘10 warning signs’ for diagnosing immunodeficiencies
- lack of population based evidence
- PID patients may have different defects/presentations
- PID patients may have non-infectious manifestations
What may be defective if the onset of ID symptoms comes younger than age 6 months?
A T-cell or phagocyte defect
What may be defective if the onset of ID symptoms comes between age 6 months and 5 years?
B-cell or antibody and phagocyte defect
What may be defective if the onset of ID symptoms comes when the patient is 5 years old or older?
B-cell/antibody/complement problem OR a secondary immunodeficiency
What is chronic granulomatous disease?
This is a hereditary disease where certain cells in the immune system are unable to form the reactive oxygen species (specifically the superoxide radical) which are used to kill ingested pathogens
Give some examples of supportive treatments for PID diseases
- infection prevention
- treat infections promptly and aggressively
- nutritional support
- no live vaccines!
Give some examples of specific treatments for primary immunodeficiency diseases
- immunoglobulin therapy
- in SCID, can do haematopoietic stem cell therapy
Give some causes of secondary immune deficiencies
Decreased production of immune components due to:
- malnutrition
- infection
- liver diseases
- lymphoproliferative diseases
- splenectomy
What are asplenic patients particularly at risk of?
Encapsulated bacteria infection and OPSI (overwhelming post-splenectomy infection)
How are asplenic patients protected from infection?
- penicillin prophylaxis (life-long)
- immunisation against encapsulated bacteria
- medic alert bracelet
What does it suggest if someone constantly has problems with viruses and fungi?
T cell deficiency
