Infection of the immunocompromised

Question 1

Common types of pathogens more prevalent during immunosuppression.

Answer 1

• Bacteria
• Viruses
• Fungi
• Parasites/Protozoa

Question 2

what functions can be disrupted if you are immnocompromised.

Answer 2

•Disruption of specific defence of an organ/system.
– Can be humoral- B cell and antibodies
– Can be cellular- T cells.

Question 3

innate defences

Answer 3

skin,
Interferons, complement, lysozyme, acute phase proteins
Mucous membrane e.g lungs

Question 4

2 types of immunodeficiences

Answer 4

congenital or acquired

Question 5

what is the second line of defence if the innate system is breached

Answer 5

neutrophils

Question 6

what are the 2 types of neutrophil defects

Answer 6

qualitative- rare

quantitative-common

Question 7

example of qualitative neutrophil defect

Answer 7

– Congenital,
– Inadequate signalling
– Abnormality in receptors or NE movement

Question 8

example of quantitative neutrophil defect

Answer 8

• eg - cancer treatment, bone marrow malignancy, aplastic anaemia caused by drugs
• Neutrophil level 50% will dvlp an infection.

Question 9

typical problems caused by lines

Answer 9

• Bacterial infections – Gram negative bacilli (e.g E. coli), Gram positive cocci (e.g. S. aureus ) - often normal flora which translocate from the blood to the gut. E.g. Coagulase negative staph
• Fungal infections – Candida spp. , Aspergillus spp.

Question 10

Common T cell deficiencies
1 congenital
2 acquired

Answer 10

• Congenital – rare e.g T helper cell disfucntion.
• Acquired – drugs e.g. ciclosporin after transplantation (decreases graft versus host disease and rejection), steroids
• Acquired – viruses e.g. HIV

Question 11

In T cells deficincnecy what types of opportunistic pathogenic organisms are present.

Answer 11

• BACTERIAL – Listeria monocytogenes (food- cheese) this is why it is not recommended in pregnant women, Mycobacteria – MTB, MAI
• VIRAL – e.g. leukaemia and transplanted pnts - HSV, CMV (pre–emptive treatment), VZV. Serological testing, prophylaxis and treatment with e.g. aciclovir and ganciclovir
• FUNGAL – e.g. Candida spp., Cryptococcus spp common in meningitis

Question 12

In T cell deficiency what ypes of parasitic/protazoan infections occur.

Answer 12

• Cryptosporidium parvum
• Toxoplasma gondii
• Strongyloides stercoralis.

Question 13

Is hypogammaglobulinaemia congenital or acquired

Answer 13

acquired- multiple myeloma, chronic lymphocytic leukaemia, burns

Question 14

what is hypoagammaglobinulinaemia

Answer 14

antobody deficency.

Question 15

what is the treatment for Hypogammaglobulinaemias

Answer 15

antibodies and immunoglobulins.

Question 16

Is complement deficiency congenital or acquired

Answer 16

congenital

Question 17

what infection frequently occurs in complement deficiency

Answer 17

S. pneumoniae infections

Question 18

removal of which organ can cause complement deficiency

Answer 18

spleen

source of complement and antibody producing, secondary lypkh organ

Question 19

What is process of organ transplantation and where can infections occur along this process.

Answer 19

• 1. The initial disease (e.g. HBV, liver transplant)
• 2. Surgery and hospital admission (e.g. ventilator acquired pneumonia, S. aureus wound infection)
• 3. Organ receipt (e.g. Toxoplasmosis, CMV), patient matching
• 4. Opportunistic infection during initial immunosuppression (initial 3/12, e.g. CMV, Aspergillus)
• 5. Later opportunistic infection (after 3/12, e.g. Zoster, Listeria)

Question 20

what is the main tests are used to investigate an infection

Answer 20

• Blood cultures. Occasionally bone marrow cultures.
respiratory samples
urine
histology (what is happening at a cellular level)
CT/imaging

Question 21

What methods are used to prevent infections

Answer 21

• Hand washing /aseptic technique / protective isolation / HEPA air filtration (allografts)
• Vaccines (avoid live vaccines in T-cell deficient)- for the 3 encapsulated bacteria.
• Prophylactic antimicrobials (e.g. penicillin, septrin, aciclovir) and passive immunoglobulin
• Special diet

Question 22

what types of infections affect you when you are immunocompromised

Answer 22

common

rare