Primary Immune Deficiencies

Question 1

What kind of signs should make you suspect a patient has a primary immune deficiency?

Answer 1

• 2x+ pneumonias
• odd locations of infections and uncommon types
• Early onset of autoimmunity syndrome

Question 2

What are common causes of secondary immune deficiencies/

Answer 2

• Infections (TB, HIV, Measles)
• Malnutrition
• Immunesuppression via glucocorticoids
• Metabolic
• Malignancies

Question 3

If a young patient has poor wound healing and is found to have a hepatic liver abscess, what should be investigated?

Answer 3

Neutrophil Defect

Question 4

What test is used to assess if neutraphil are functioning properly?

Answer 4

Oxidative Burst testing, DHR test

CBC w/ Diff (look at amount present)

Question 5

What are the risk factors of having an early complement defect?

Answer 5

Increased Strep susceptibility

Increases chance of Systemic Lupus and Glomerulonephritis

Question 6

If a patient has been diagnosed with meningitis more than one time and the most recent was found to Neisseria, what is likely the cause?

Answer 6

Late C5-C9 Complement Deficit
-- Increases infection chance of Neisseria class bacteria

Question 7

How do you test for a complement defect?

Answer 7

Test for a CH50, if it is low, then it is either being consumed or deficient. Usually Deficient is still lower than being consumed.

Question 8

What is the most common primary immune deficiency?

Answer 8

B-cell or Antibody Defects

XLA and CVID

Question 9

What is unique to B-cell defects?

Answer 9

• Agammaglobulinemia beginning of life
• increased risk of pulmonary infections
• enteroviral meningitis
• Recurrent / Chronic GI infections

Question 10

What is the most important test in ruling out a B-cell defect?

Answer 10

Quantitative Immunoglobin - See the Amount of B-cells present, there is no need for amount of each class.

Question 11

If a patient from the being born gets recurrent infections including opportunistic with chronic diarrhea, what is the likely cause?

Answer 11

SCID - “bubble baby” syndome

Question 12

How would you diagnose SCID?

Answer 12

• CBD w/ Diff
• Flow cytometry of T, B, and NK cells (enumerate)
  **In SCID, there would only be memory cells from mother
• Mitogens, looking at T-cell proliferation
  EARLY DETECTION IS KEY for SURVIVAL

Question 13

What is the etiology of SCID?

Answer 13

There is a mutation in the common gamma chain of IL-2 receptor, preventing the immune cells from proliferating.

Question 14

How can you screen for the SCID at birth?

Answer 14

rt-PCR of TRECs - nonreplicating piece of circular DNA present in almost all naive T-cells generated when producing their receptors.
All forms of SCID have low TRECs present

Question 15

With a defect in the pharyngeal pouches what is the common immune syndrome?

Answer 15

DiGeorge Syndrome. Deletion of part of Chromosome 22

Question 16

DiGeorge Syndrome has a wide spectrum of symptoms, what are the symptoms and how can it be tested for?

Answer 16

CATCH22 - 
Cardiac Defects
Abnormal Faces
Thymic Hypoplasia
Cleft Palate
Hypocalcemia
22nd chromosome abnormality
\+ Autoimmune disorders
**Fish + Chromosome Microarray**

Question 17

What is the most common cause of XLA (X-linked agammaglobulinemia)?

Answer 17

Mutation of the BTK gene preventing differentiation of the B-cells. (Dysfunctional Tyrosine Kinase receptor)
Males Only

Question 18

If a middle aged female has chronic sinusitis and cough with history of multiple pneumonias. Lab tests reveal low quantitative immunoglobulin.

Answer 18

Common Variable Immunodeficiency CVID
*Most common immune deficiency
Characteristic: Chronic pulmonary disease, poor response to vaccines.

Question 19

What is the most common antibody deficiency?

Answer 19

IgA Deficiency - Extremely Low, but normal IgG and IgM

• -Can cause heterophile antibodies, that recognize antigens that have never been seen by the body–
• *Typically not many more infections**

Question 20

How would lab tests be different between XLA and CVID?

Answer 20

If tested for isotypes:
XLA – decrease in all types of B-cells
CVID – will have decreased IgG and another, but others could be normal

Question 21

What is the etiology of Chronic Granulomatous Disease?

Answer 21

Dysfunction of the NADPH Oxidase and it X-linked
Most common in males (not always) who are young.
Innate immune system does not work well without a working respiratory burst.

Question 22

How would you test for and treat Chronic Granulomatous?

Answer 22

DHR - looks for respiratory burst
Prophylaxis Antibiotics
Bone Marrow Transplant

Question 23

What is a key finding of a patient who has a type of Leukocyte Adhesion deficit, but above average amounts of WBCs?

Answer 23

–Nonhealing wounds without purulence–
Peridental disease
Recurrent fevers and respiratory disease