Immunocompromise III

Question 1

What form of infx are patients who are deficient in immunoglobulin prone to? (esp IgG deficiency)

Answer 1

-pneumococcal (S. pneumoniae)

Question 2

What types of infections are people with cell-mediated immunocompromise most at risk for?

Answer 2

• viruses
• mycobacteria
• fungi
• protozoa

Question 3

what is the innate immune system designed to protect the host from mostly?

Answer 3

the microbiome.

Question 4

what is the adaptive immune system designed to protect the host against mostly?

Answer 4

the macrobiome (exogenous pathogens):

• viruses
• non-colonizing bacteria
• non-colonizing fungi
• parasites

Question 5

What do Igs protect the following from:

• Respiratory tract
• GI tract
• Skin

Answer 5

• Respiratory tract: pneumococcal infections
• GI tract: Giardia (parasite), Campylobacter (bacterium) and enteroviruses
• Skin: Group A Strep and Staphylococcal infections

Question 6

What is more common: hypogammaglobulinoemia (deficient in all Igs) or dysgammaglobulinoemia (deficient in some Igs)?

Answer 6

-hypogammaglobulinoemia (all Igs)

Question 7

List the acquired causes for Ig deficiency:

Answer 7

• nephrotic syndrome (due to renal loss)
• malabsorption or protein-losing enteropathy (due to GI)
• chronic lymphocytic leukoemia (CLL)

Question 8

What bacterial condition occurs in patients with cirrhosis (due to portal HTN and ‘lack of flow’ and lack of Igs in ascitic fluid)?

Answer 8

‘spontaneous bacterial peritonitis’

Question 9

What infections are patients with untreated CLL at risk of (due to Ig deficiency)?

Answer 9

• sinus infx
• respiratory infx
• bacteroemia (due to encapsulated organisms)

Question 10

What immune role does the spleen play?

Answer 10

-clearing encapsulated bacteria

Question 11

What types of asplenia are there?

Answer 11

• surgical

- functional (from Sickle Cell Disease)–> Howell-Jolly and Heinz bodies

Question 12

What are patients with asplenia at greatest risk for?

Which patients is the risk highest in?

What is the most likely causal pathogen?

Answer 12

OPSI: Overwhelming Post-Splenectomy Infection

highest risk: children esp with HbSS blood type.

S. pneumoniae (followed by N. meningitidis)

Question 13

Besides OPSI, what infections are asplenic patients at risk of?

Answer 13

• Babesia
• Malaria
• Capnocytophaga canimorsus (dog bites)

Question 14

List some opportunistic viruses that cause caner and those that are community-acquired.

Answer 14

herpesviruses and papillomaviruses can cause reactivation/cancer

-other CA viruses cauding OIs: influenza, hepatitis C

Question 15

List bacteria that cause OIs:

Answer 15

-mycobacteria : TB, MAI

Question 16

List fungi causing OIs:

Answer 16

• mucosal candidiasis
• pneuocystic jiroveccii
• dimorphic fungi

Question 17

List protozoa causing OIs:

Answer 17

• toxoplasma

- intestinal protozoa

Question 18

what are the most common causes of HIV-associated immunosuppression?

what else are they at risk for?

Answer 18

reactivation of latent viruses (and their associated cancers)

also: fungi, mycobacteria, protozoa infx