Immune Deficiencies

Question 1

True or False:

Immunodeficiencies may arise at any age.

Answer 1

True

Question 2

List the typical features of infections that are associated with immunodeficiencies?

Answer 2

• Often chronic, severe, or recurrent.
• Not responsive well to an antibiotic therapy.
• Microbes involved may be atypical or opportunistic.

Question 3

Opportunistic organisms are often involved in immunodeficiencies. What are opportunistic organisms?

Answer 3

Pathogens of low virulence that are easily held in check by an intact immune system but that take their moment to invade when the host’s guard is lowered.

Question 4

When do primary immune deficiencies (PIDs) typically manifest?

Answer 4

Often clinically manifested during the first years of life (> 5-6 months).

because of maternal IgG (about 6 months), immune deficiencies are not detected in the newborn.

Question 5

What do patients with primary immune deficiencies (PIDs) suffer from, leading to the diagnosis of PIDs?

Answer 5

Suffer from recurrent, protracted infections.

Question 6

In the USA, how many infants are born annually with primary immune deficiency?

Answer 6

350-400 infants

Question 7

What are primary immune deficiencies (PIDs) classified on?

Answer 7

Based on host-defense mechanism affected.

Question 8

What are the different classifications of PIDs?

Answer 8

• antibody deficiencies (B cells)
• deficiencies of T-cells
• combined T- and B-cell deficiencies
• deficiencies of phagocytosis
• deficiencies of complement

Question 9

How long do maternal antibodies protect the child?

Answer 9

6 months

Question 10

True or False:

Maternal IgG in the infant disappears after birth with a half-life of 25-30 days.

Answer 10

True

Immune deficiencies are usually detected early in infant’s life after maternal Ab titer is dropped after 6 months.

Question 11

When taking a medical history, what are the warning signs of immnodeficiency disorder?

Answer 11

• 8 or more ear infections in one year
• 2 or more serious sinus infections in one year
• 2 or more bouts of pneumonia in one year
• 2 or more deep-seated infections, or infections in unusual areas
• Recurrent deep skin or organ abscesses
• Need for IV antibiotic therapy to clear infection
• Infections with unusual or opportunistic organisms
• Family history of primary immunodeficiency

Question 12

List examples of diseases for B lymphocyte deficiency.

Answer 12

• X-linked agammaglobulinaemia (XLA)
• Common variable immunodeficiency (CVID)
• Selective IgA deficiency
• IgG subclass deficiency

Question 13

List examples of diseases for T lymphocyte deficiency.

Answer 13

• DiGeroge syndrome
• Acquired immunodeficiency syndrome (HIV)
• T cell activation defects (e.g., CD3-gamma chain mutation)
• X-linked hyper-IgM syndrome (XHIM)

Question 14

List examples of diseases for T cell-APC interactions.

Answer 14

• IFN-gamma receptor deficiency

- IL-12 and IL-12 receptor deficiency

Question 15

List examples of diseases for neutrophil defects.

Answer 15

• chronic grannulomatous disease (CGD)

- leukocyte adhesion deficiency (LAD)

Question 16

List examples of diseases for deficiency of complement components.

Answer 16

• classical pathway
• alternative pathway
• common pathway
• regulatory proteins
• mannan binding lectin