Immunodeficiencies

Question 1

What are the common neutrophil disorders?

Answer 1

Chronic granulomatous disease, Chediak-Higashi Syndrome, Leukocyte Adhesion Deficiency

Question 2

What are the common complement disorders?

Answer 2

Hereditary Angioedema, Complement Cascade Deficiencies

Question 3

What are the primary combined antibody and cellular immunodeficiencies (B & T cells)?

Answer 3

Severe Combined Immunodeficiency, Wiskott-Aldrich Syndrome, Ataxia-telangiectasia

Question 4

Severe combined immunodeficiency (SCID) is the most severe immunodeficiency. What is the pathophysiology?

Answer 4

Dysfunction of both cellular and humoral immune function due to multiple possible defects

Question 5

What is the clinical presentation of severe combined immunodeficiency disorder?

Answer 5

Small thymus, no lymphocytes in the thymus or lymph tissue, underdeveloped lymph nodes, infancy, opportunistic infections

Question 6

What is the treatment for severe combined immunodeficiency disorder?

Answer 6

Stem cell transplant

Question 7

What triad is often present with Wiskott-Aldrich Syndrome?

Answer 7

Atopic dermatitis, thrombocytopenia, susceptibility to encapsulated and opportunistic infections

Question 8

Wiskott-Aldrich Syndrome is an X-linked disorder. What is the pathophysiology?

Answer 8

Gene mutation that affects binding to adaptor molecules and cytoskeletal components in hemopoietic cells that prevents normal development of platelets and leukocytes

Question 9

When does Wiscott-Aldrich syndrome generally present?

Answer 9

During infancy - a baby that bleeds excessively after circumcision, bloody diarrhea, eosinophilia and increased IgE

Question 10

What triad is present with ataxia-telangiectasia?

Answer 10

Cerebellar ataxia, oculocutaneous telangiectasia (bloodshot eyes due to vasodilation), immunodeficiency

Question 11

ATM kinase defects are present in what immunodeficiency disorder?

Answer 11

Ataxia-telangiectasia

Question 12

Ataxia-telangiectasia is a progressive disorder. When does it typically present?

Answer 12

Around 1yr (soon after walking)

Question 13

A patient presents with cardiac abnormalities, abnormal facial features, cleft palate, and thymic hypoplasia. What is the diagnosis and cause of the disorder?

Answer 13

DiGeorge Syndrome due to deletion on chromosome 22

Question 14

From what embryonic structure do the thymus and inferior parathyroids develop?

Answer 14

Third pharyngeal pouch

Question 15

DiGeorge syndrome causes a defect of what immune cells?

Answer 15

T cells - B cells are OK but do not receive signaling from T cells so poorer antibody funcitoning

Question 16

MHC I deficiency affects what immune cells?

Answer 16

CD8+ T Cells - failure to transport molecules to the ER

Question 17

MHC II deficiency affects what immune cells?

Answer 17

CD4+ T cells - failure of MHC II expression

Question 18

True/False. MHC II is expressed on all nucleated cells.

Answer 18

False. MHC II is only expressed on APCs. MHC I is expressed on all nucleated cells

Question 19

MHC II Deficiency results in no effective CD4+ T cells. What is the clinical presentation?

Answer 19

Severe Combined Immunodeficiency - MHC II deficiency is much more severe than MHC I deficiency

Question 20

IL-12 cytokine receptor deficiency causes a loss of what T cell response?

Answer 20

Th1 response to intracellular and viral pathogens

Question 21

What is the clinical presentation of Hyper-IgE (Job) Syndrome?

Answer 21

Recurrent skin and respiratory infections, dermatitis, staph infections

Question 22

A male infant presents with recurrent bacterial infections. WBC reveals normal T cell levels, but no mature B cells and low IgG. What is the likely diagnosis?

Answer 22

X-Linked Agammaglobulinemia

Question 23

This immunodeficiency of B cells presents in teenage years with deficiency of all classes of Ig antibodies.

Answer 23

Common Variable Immunodeficiency - B cells are unable to differentiate into plasma cells

Question 24

This B cell disorder presents with normal or high levels of IgM, but deficiency of all other Ig classes.

Answer 24

Hyper IgM Syndrome

Question 25

What is the pathophysiology of Hyper IgM Syndrome?

Answer 25

Deficiency of CD40L on activated T cells needed for class switching

Question 26

Patients with IgA deficiency are often asymptomatic. What infections may recurrently present in these patients?

Answer 26

Sinopulmonary diseases, allergies, celiac disease

Question 27

What is the clinical presentation of transient hypogammaglobulinemia?

Answer 27

Gradual decline in maternal IgG during the first 6mo of life. IgG remains low for first year of life and then gradually increases

Question 28

This complement disorder is due to an autosomal dominant deficiency of C1-inhibitor.

Answer 28

Hereditary Angioedema

Question 29

What test is used to screen for complement cascade deficiencies?

Answer 29

CH50 or CH100

Question 30

Recurrent infections with encapsulated bacteria and N. meningitidis is often indicative of this immunodeficiency.

Answer 30

Complement cascade deficiencies

Question 31

What is the pathophysiology of chronic granulomatous disease?

Answer 31

Abnormal neutrophil function due to a deficiency of the NADPH oxidase and failure to generate ROS

Question 32

Patients with chronic granulomatous disease are most susceptible to what bacterial infections?

Answer 32

Catalase-positive bacteria and fungi (staph, aspergillus, candida)

Question 33

What is the clinical presentation of Chediak-Higashi Syndrome?

Answer 33

Oculocutaneous albinism, recurrent and serious staph and strep infections

Question 34

What is Chediak-Higashi Syndrome?

Answer 34

An inherited defect in lysosomal trafficking that causes giant granules in neutrophils and impairs phagocytosis

Question 35

What is the clinical hallmark of leukocyte adhesion deficiency?

Answer 35

Infections with NO PUS

Question 36

What is the pathophysiology of leukocyte adhesion deficiency type 1?

Answer 36

Absence of CD18, a subunit of integrin, that prevents neutrophils from exiting circulation and entering tissues

In LAD Type 2, sialyl-lewis X is absent and prevents leukocyte rolling

Question 37

Delayed separation of the umbilical stump may be indicative of this immunodeficiency.

Answer 37

Leukocyte Adhesion Deficiency

Question 38

Recurrent infections with encapsulated bacteria often point to what type of immunodeficiency?

Answer 38

Defect in antibody-mediated immunity

Question 39

Recurrent viral infections often point to what type of immunodeficiency?

Answer 39

T cell immunodeficiencies