Infection in the immunocompromised host Flashcards
Innate defences
- Skin
- Mucous membranes
- Normal gut flora
Definition of immuncompromised
Disruption of specific defence of an organ/system
Neutrophil qualitative defects
Chemotaxis - inadequate signalling
Neutrophil quantitative defects
- Lack of neutrophils
- Leads to patient becoming Neutropenic
Neutropenic patients
- More susceptible to infections by pathogens
- E.Coli, S.aureus
- Candida + Aspergillus ssp
How are neutropenic patients treated
Empirical therapy
- Broad spectrum antibiotics given to treat until tests confirm invasive species
T cell deficiences
- T helper cell dysfunction
- Can be congenital - RARE
Acquired: - Drugs - circlosporin
- Viruses such as HIV
Cryptosporidium parvum
- Protozoan infection
- Oocyte excreted and consumed is route
- Recovery takes much longer in T-cell deficients
Hypogammaglobulinemia’s
- Low antibody count
- Congenital rare
- Acquired - multiple myeloma/burns
- Usually caused by encapsulated bacteria
Hypogammaglobulinemia’s treatment
Immunoglobulin long term and antibiotics short term for infection
Complement deficiency
- Encapsulated bacteria need complement to kill bacteria
- C5-8 deficiency leads to Neisseria Meningiditis
Role of spleen in immune system
A source of complement and antibody producing B cells
What is splenectomy
removal of the spleen
- Can be caused by trauma during surgery
- EBV = removal
Splenectomy risk
- At risk from encapsulated bacteria - malaria, pneumonia, influenza etc
Biologics
- Drugs from biological sources
- Antibodies that inhibit inflammatory cytokine signals
