Immunocompromsied

Question 1

What is an immunocompromised host?

Answer 1

State where the immune system is unable to respond appropriately and effectively against infectious microorganisms

Due to a defect in one or more components of the immune system

Question 2

What is primary immunodeficiency?

Answer 2

Intrinsic gene defect (congenital)

• missing protein/cell
• nonfunctional components (CGD: have neutrophils but can’t kill)

Question 3

What is secondary immunodeficiency?

Answer 3

Acquired (HIV/chemo/cancer cells invading lymphoid tissue)

• due to underlying disease/treatment
• reduced production/function of immune components
• loss of catabolism of immune components

Question 4

When do you suspect immunodeficiency?

Answer 4

SPUR

Severe
Persistent
Unusual (infections that shouldn’t occur in a normal individual)
Recurrent

Question 5

What are the 10 warning signs for PID’s?

Answer 5

Children

• 4 or more new ear infections within a year
• 2 or more serious sinus infections in a year
• 2 or more months on antibiotics with little effect
• 2 or more pneumonia’s within a year
• failure of an infant to gain weight

Adult

Question 6

What are some immunodeficiency diseases caused by antibody defects?

(65% of all PID’s)

Answer 6

Defect in B cell development
-Bruton’s disease (X linked agammaglobulinanemia)

Defect in antibody deficuiceny

• common variable immunodeficiency (most common, requires treatment)
• selective IgA deficiency (most common, without symptoms)
• IgG subclass deficiency
• hyper-IgM syndrome

Question 7

What are some immunodeficiency diseases caused by T cell defects?

Answer 7

B and T cell defects combined
-severe combined immunodeficiency

T cell defect
-Di George Syndrome (no thymus)

Question 8

What immunodeficiency diseases are caused by phagocytic effects?

Answer 8

Defects in respiratory bursts
-chronic granulomatous disease (CGD)

Defect in neutrophil production and chemotaxis

• cyclic neutropenia
• LAD protein deficiencies

Defect in fusion of lysosome/phagosome
-Chediak-Higashi syndrome

Question 9

What does age of symptom onset say abou the type of immunodeficicency disease?

Answer 9

<6 months: T cell/phagocyte defect (as baby has antibodies from mother still)

> 6 months, <5 years: B cell/antibody/phagocyte defects (not T cell defect as symptoms would’ve been seen earlier)

> 5 years: secondary immunodeficiency (malnutrition), B cell/antibody/complement defect

Question 10

What types of microbes and sites indicate the type of immunodeficiency disease?

Answer 10

Complement deficiency: Neiserria

Phagocytic defects: Staphylococcus aureus

Antibody deficiency: Streptococci

T cell defects: similar to antibody deficiency

Question 11

What symptom is typical for granulocyte deficiency?

Answer 11

Skin abscess

Question 12

How do you treat immunodeficiency?

Answer 12

IRT: immunoglobulin replacement therapy

Lifelong treatment

Question 13

What is the goal for serum IgG?

Answer 13

> 8 g/L

Question 14

What are some causes of decreased production of immune components in secondary immune deficiencies?

Answer 14

• malnutrition
• infection (HIV)
• liver disease
• haematological malignancies
• therapeutic treatment
• splenectomy

Question 15

Why do patients with haematological malignancies have increased susceptibility to infections?

Answer 15

• chemo induced neutropenia
• chemo induced damage to muscosal membrane (disruption to flora)
• vascular catheters