Infections in the Immunocompromised

Question 1

Innate defences in humans

Answer 1

Skin (barrier, sebum, normal flora)
Mucous membranes (tears, urine flow, phagocytes)
Lungs (goblet cells, muco-ciliary escalator)
Interferons
Complement
Lysozyme
Acute phase proteins
Normal commensal flora in gut

Question 2

Qualitative defects of neutrophils

Answer 2

Neutrophils lose ability to kill or chemotaxis
Chemotaxis defects are rare, usually congenital, e.g. inadequate signalling
Killing power defects are often inherited, e.g. Chronic Granulomatous Disease

Question 3

Quantitative defects of neutrophils

Answer 3

Less neutrophils present - neutropenia

Can be caused by things such as cancer treatment, bone marrow malignancy and aplastic anaemia from drugs

Question 4

Treatment for neutropenic patients

Answer 4

Broad spectrum antibiotics

Question 5

Common bacterial infections in neutropenic patients

Answer 5

E.coli
S. aureus
Often normal flora e.g. coagulase-negative staph