Immunology

Question 1

A 3 year old boy presents with the following history: Pneumonia at 10 months and 27 months of age 4 episodes of acute otitis media Enteroviral meninoencephalitis at 29 months of age Maternal uncle died from pneumonia at 2 years of age Which of the following is the most helpful investigation to establish the diagnosis in this patient?

1. Flow cytometry for T cell numbers
2. Immunoglobulin levels
3. Alpha fetoprotein level
4. Flow cytometry for CD11/CD18
5. Total hemolytic complement

Answer 1

2. Immunoglobulin levels

Question 2

The following may be associated with IgA deficiency except:

1. Wiskott-Aldrich syndrome
2. X-linked hypogammaglobulinemia
3. No clinical symptoms
4. Severe combined immunodeficiency
5. Ataxia telangiectasia

Answer 2

1. Wiskott-Aldrich syndrome

Question 3

Which of the following statements is FALSE regarding immunoglobulin (Ig) replacement therapy?

1. Serious adverse reactions are less frequent with SC Ig than with IV Ig
2. Minor adverse reactions to IV Ig are often related to infusion rate
3. Aseptic meningitis is a serious adverse reaction to IV Ig that is a contraindication to future doses
4. The risk of known blood-borne infections from IVIg is less than 1/1,000,000 – 1/10,000,000

Answer 3

3. Aseptic meningitis is a serious adverse reaction to IV Ig that is a contraindication to future doses

Question 4

A 6 month old boy was brought to the emergency department with a second episode of pneumonia. He has had intermittent thrush and diarrhea for the past 2 months. On examination, he is in respiratory distress and hypoxic. His weight was < 3rd %ile and height was at 25%ile. His bloodwork shows: Neutrophils 10.8 x 109/L IgG 0.4 g/L Basophils 0.02x 109/L IgA < 0.1 g/L Eosinophils 0.03x 109/L IgM < 0.1 g/L Lymphocytes 0.5 x 109/L IgE < 25 IU/mL What is the most likely diagnosis?

1. X-linked agammaglobulinemia
2. Common variable immunodeficiency
3. Severe combined immunodeficiency
4. Complement deficiency

Answer 4

3. Severe combined immunodeficiency

Question 5

A 7 year old girl is newly diagnosed with ovarian Burkitt lymphoma. She has no prior history of significant infections. There is a strong family history of breast cancer. As you are taking the history, you notice that she sways from side to side while sitting and has oculomotor apraxia. An MRI of her brain demonstrates diffuse cerebellar volume loss. What is the most appropriate screening test for the suspected immunodeficiency?

1. ADA level
2. Vitamin B12 levels
3. Alpha fetoprotein level
4. Blood smear

Answer 5

3. Alpha fetoprotein level

Question 6

A 4 month old female has recurrent viral infections following cardiac surgery. She has a history of seizures and a cleft palate. Her labs reveal: Lymphocytes 1.5 x 109/L (normal range 2.5-8.99 x 109/L) IgG 0.9 g/L (normal range 1.1-7.0 g/L) What would be the most appropriate immunological recommendation?

1. Delay live vaccines until T cells are evaluated
2. Delay killed vaccines until the IgG normalizes
3. Start immunoglobulin replacement therapy
4. Start prophylactic antibiotics

Answer 6

1. Delay live vaccines until T cells are evaluated

Question 7

A 3 year old male is admitted for pulmonary aspergillosis and hemophagocytic lymphohistiocytosis. He has a history of cervical adenitis at 16 months of age that required drainage and IV antimicrobials. Pus was obtained from the drainage and the culture was positive for S. aureus. What is the most likely diagnosis?

1. Hyper IgE syndrome
2. Complement deficiency
3. Leukocyte adhesion defect
4. Chronic granulomatous disease

Answer 7

4. Chronic granulomatous disease

Question 8

Immunoglobulin replacement therapy is indicated in the following IEI, except:

1. X-linked agammaglobulinemia
2. Chronic granulomatous disease
3. Common variable immunodeficiency
4. Severe combined immunodeficiency
5. Hyper IgM syndrome

Answer 8

2. Chronic granulomatous disease

Question 9

Pneumocystis jirovecii prophylaxis is recommended in which IEI below?

1. Chronic granulomatous disease
2. DiGeorge syndrome
3. Wiskott-Aldrich syndrome
4. Common variable immunodeficiency
5. Complement deficiency

Answer 9

3. Wiskott-Aldrich syndrome