CP5-6 infection in immunocompromised host Flashcards
What does immunocompromised mean?
A disruption of a specific defence of an organ/system - either humoral or cellular immune system
What are examples of innate defences?
Skin
Mucous membranes
Goblet cells and muco-cilary escalator of the lungs
Interferons, complement, lysosomes and acute phase proteins
Normal gut flora/microbiome
What extremes affect the healthy innate defences?
Age
Pregnancy
Malnutrition
What white blood cell is the second line of defence/ important after initial breach of innate defences?
Neutrophils
What are two types of defects with neutrophils?
Qualitative defects e.g. neutrophils lose ability to kill or perform chemotaxis
Quantitative defects e.g. reduction in number of cells
What inherited disease causes increase in risk of staph aureus infection due to reduction in killing power of neutrophils?
Chronic Granulomatous Disease
What can cause quantitive defects in neutrophils?
Cancer treatment
Bone marrow malignancy
Aplastic anaemia (caused by drugs)
Stem cell transplant
What is the medical term for low neutrophil count?
Neutropenic
At what quantity is neutrophil number dangerous if prolonged?
0.5 x 10^9/L
How are neutropenic patients treated?
With broad spectrum antibiotics - 1st line anti pseudomonal penicillin +/- gentamicin or 2nd line with carbapenem
Sometimes with granulocyte stimulating factors if antibiotics not working.
What does GCSF stand for?
Granulocyte stimulating factors
If a patient is neutropenic, what infection causes death within 24 hours in 50% of patients infected?
Pseudomonal infection
Apart from pseudomonal infection, what other infections are neutropenic patients at risk of?
Bacterial like e.coli, staph aureus and coagulase negative staph
Fungal like candida and aspergillus species
Viruses
What can congenital t-cell deficiencies cause?
T helper dysfunction +/- hypogammaglobulinaemia
What is an example of a drug that can cause acquired T cell deficiencies?
Ciclosporin after transplantation
What is an example of a virus that can cause acquired T cell deficiency?
HIV
What are some examples of opportunistic pathogens that are dangerous in patients with T cell deficiencies?
Bacterial = listeria monoctyogenes and mycobacteria
Viral = in transplants e.g. HSV, CMV and VZV
Fungal = candida species, pmeumocystis species and cryptococcus species
How are recipients of transplants who have viral infections treated?
With aciclovir and ganciclovir
What is a protozoan/parasite that causes prolonged illness in patients with t-cell deficiencies? What is the route of transmission?
Cryptosporidium parvum
Oocytes she’d by cattle/humans and spread via faecal oral route
What is a protozoan infection that is dangerous in pregnancy?
Toxoplasma gondii
What can cause hypogammaglobulinaemia?
X-linked agammaglobulinaemia
Multiple myeloma
Burns
Encapsulated bacteria e.g. s. Pneumoniae
Parasites e.g. giardia lamblia
How is hypogammaglobulinaemia treated?
With immunoglobulins
What causes complement deficiency?
Genetics
What infections are dangerous in those with complement deficiency?
Encapsulated bacteria (needs complement to be killed)
S. Pneumoniae
