Immune

Question 1

Complement crosses the placenta (T/F)

Answer 1

False. They don’t cross

Question 2

Role of neutrophils

Answer 2

Phagocytic, chemotaxis, and bacterial killing

Question 3

Macrophages present which cells?

Answer 3

T cells and B cells

Question 4

Adaptive immune system has which type of response?

Answer 4

Antigen specific

Takes 4-7 days to develop

Question 5

Which immunoglobulin crosses placenta? How? What age does Maternal IgG disappear?

Answer 5

IgG
Placental transport by endocytosis
By 9 months

Question 6

Chronic granulomatous disease- genetics, cause, clinical presentation, diagnosis

Answer 6

• X linked recessive in majority
• Deficiency or absent NADPH oxidase function in phagocytic cells- neutrophils can’t generate superoxide (necessary for killing bacteria)
• Severe, recurrent infections with catalase-positive bacteria or fungi
• Diagnosis made by Nitroblue tetrazolium Test (NBT) –> remains colorless = absent/severely deficient respiratory burst activity in phagocytes

Question 7

Leukocyte Adhesion Deficiency- cause, clinical presentation

Answer 7

AR, mutation in B2 integrin gene
Adhesion abnormality- no pus formation

Recurrent bacterial infections
Delayed separation of umbilical
stump >21 days
Leukocytosis

Question 8

Peri rectal abscess and neutropenia in a boy?

Answer 8

Hyper IgM syndrome

Question 9

Absent thymic tissue, interrupted aortic arch, problems with Ca retention. Dx?

Answer 9

Chromosome 22q11 deletion

Question 10

Boy with eczema, thrombocytopenia and infections. Dx?

Answer 10

Wiskott-Aldrich Syndrome
X-linked
Clinical- Eczema, thrombocytopenia, and susceptibility to infection

• Platelets are small, defective, and abnormally shaped
• Lymphocyte numbers are decreased and T cell function is abnormal

Question 11

Lymphadenopathy on vignette. MCC Dx?

Answer 11

HIV

Question 12

How do you diagnosis SCID?

Answer 12

Absence of TREC

SCID - Deficiency of both antibody and cell-mediated immunity
(low/normal # B cells, decreased T cells/NK cells)
* Diarrhea, pneumonia, otitis, sepsis, cutaneous infections,
eosinophilia
20-30% risk of maternal cell-mediated GVHD (placental transfer of maternal T cells)

Question 13

Highest sensitivity for maternal chorio

Answer 13

Maternal fever (80%)

Question 14

What grows in Thayer Martin medium

Answer 14

Gonorrhea

Question 15

Name single stranded DNA virus

Answer 15

Parvo

Question 16

Single stranded RNA

Answer 16

Enterovirus

Question 17

What is associated with
Celery stalking long bone
Salt and pepper retina

Answer 17

Rubella

Question 18

If low TREC on NBS, what is next test?

Answer 18

Flow cytometry of lymphocyte subset

IgG levels not indicated until after 6 mo (bc of maternal antibodies)

Think SCID or Di George or false positive in premie.

Question 19

What is the MOA of interferon alpha?

Answer 19

Activated in response to infection and act via toll like teceptors.
Limit viral replication

Question 20

Development of T cell (weeks and location)

Answer 20

8.5 weeks fetal liver
10 weeks thymus becomes lymphoid
11-12 weeks T cells emigrate from thymus to spleen, nodes
16-18 weeks hassall’s bodies in the thymus

Question 21

B cell development (location and weeks)

Answer 21

8 weeks pre-B cells in fetal liver
8-10 weeks in fetal bone marrow
18-22 weeks in liver lung and kidney
>30 weeks Solely in bone marrow

Question 22

Natural immune system comprises of?

Answer 22

Neutrophils for chemotaxis, phagocytosis, bacterial killing

Monocytes for chemotaxis, phagocytosis, bacterial killing, wound repair

Complement for opsonization, chemoattraction

Question 23

Infant with recurrent infections, eczema, coarse facial features and broad nasal bridge. Etiology of this disorder?

Answer 23

Abnormality in neutrophil chemotaxis

Hyperimmunoglobulin E (Jobs syndrome)

Question 24

Neonate with omphalitis without pus formation and delayed separation of cord. What is the underlying reason for this disorder?

Answer 24

Leukocyte adhesion deficiency

Defective neutrophil adhesion and migration

Mutation in the B2 integrin gene

Question 25

Infant with partial oculocutaneous albinism, nystagmus, Peripheral neuropathy and recurrent infections. Whats the underlying problem?

Answer 25

Chediak-Higashi Abnormal neutrophil degranulation (afecta intracellular killing) and monocyte chemotaxis

Question 26

Infant with recurrent abscesses, poor wound healing and granulomas. What is the underlying cause of this disease?

Answer 26

Chronic granulomatous disease Dysfunctional NADPH oxidase and abnormal phagocytic microbial ability X-linked Test: nitroblue tetrazolium test (neutrophils in pts with CGD cannot produce superoxide and thus test negative(

Question 27

Pale infant with steatorrhea, failure to thrive, and generalized bone marrow dysfunction. Dx?

Answer 27

Schwachman Diamond Syndrome AR- decreased neutrophil production May also have skeletal defects and dysmorphic features Increased risk for myelodysplastic syndrome

Question 28

Infant noted with severe neutropenia since 1 month of life with recurrent infections. Dx?

Answer 28

Kostman syndrome AR

Question 29

Most neonates reach adult complement levels by what age?

Answer 29

3-6 months

Question 30

Early (C1-4) components vs late (C5-9) component deficiencies of the complement system are associated with which infections?

Answer 30

Early C1-4 pneumococcal Late C5-9 neiserria

Question 31

IL 1 and TNF alpha role

Answer 31

Cytokines involved in leukocyte adhesions and mediating fever response

Question 32

Infant with h/o pneumonia, multiple bouts of itits, diarrhea, sinusitis between 4-12 months of life. Dx?

Answer 32

X linked agammaglobulinemia Severe deficiency of B cells leading to hypogamma-globulinemia

Question 33

Infant with episodic fever triggered by immunizations with athralgias, rash, diarrhea, vomiting, oral ulcers. Dx?

Answer 33

Hyperimmunoglobulin D Syndrome Mutation in mevalonate kinase gene Treatment with 3 hydroxy 3 methylglutaryl co enzyme A reductase inhibitors or TNF inhibitors or IL 1 inhibitors Severe form is mevalonic aciduria

Question 34

Neonate born to a mother w lupus and now 7 days old w renal vein thrombosis. Mother with prior pregnancy losses. Which is the most common autoantibody associated with neonate’s condition?

Answer 34

Antiphospholipid syndrome Neonate without other findings of SLE and 30% of mother’s w SLE have antiphospholipid antibodies which increases risk for clots and pregnancy loss.

Question 35

Most common thoracic duct anatomy involves a

Answer 35

Single duct

Question 36

When does the stratum corneum keratinization begin?

Answer 36

32-34 weeks gestation and matures within 2 weeks after birth Skin keratinization is delayed is delayed in premies because of this

Question 37

Most common manifestation of primary infantile systemic lupus erythematosus?

Answer 37

Glomerulonephritis, then pneumonitis

Question 38

What is the initial event in pathogenesis of congenital heart block in neonatal lupus syndrome?

Answer 38

Cardiocyte apoptosis

Question 39

Most common cause of neutropenia in early neonatal period is

Answer 39

Pregnancy-induced hypertension

Question 40

The most common manifestation of neonatal SLE is?

Answer 40

Thrombocytopenia (MC) | then rash and direct hyperbilirubinemia

Question 41

MCC of apnea after immunizations in preemies

Answer 41

Having apneic episodes before immunization

Question 42

How can phagocytosis be more effective?

Answer 42

By complement component 3 and IgG coating

Question 43

Patients with X linked agammaglobulinemia is characterized by mutation in which enzyme?

Answer 43

Beuton tyrosine kinase Near abscence of all immunoglobulins Present after 2 months as maternal IgG is still present in newborn period

Question 44

By what postnatal age does maternal IgG typically disappear in neonatal circulation?

Answer 44

9 months

Question 45

Neutrophils of term neonates compared to adults

Answer 45

Decreased migration Poor adherence to endothelium Decreased chemotactic response Comparable phagocytosis and de granulation

Question 46

Most common complement decifiency

Answer 46

C2

Question 47

Where do the classical and alternative pathways converge ?

Answer 47

C3

Question 48

Differences between classical and alternative pathways?

Answer 48

Classical complement pathway requires Ag-Ab reaction (immune complex formation) Alternative pathway may be Ab independent

Question 49

Patients with splenic dysfunction show a peripheral blood smear with

Answer 49

Howell jolly bodies

Question 50

Name 4 collectins

Answer 50

Surfactant protein A, SP-D, conglutinin, mannose binding lectin

Question 51

B cell levels after birth

Answer 51

Proportion of b cell similar to adult Absolute number of b cell higher Number of b cells peak at 3-4 mo declines to adult level by 6-7 yo Preterm=term levels

Question 52

Does the fetus produce IgA?

Answer 52

No fetal production of IgA Levels at 1 yo 20% of adult

Question 53

Does the fetus produce IgM?

Answer 53

Some fetal production- only antibody produced by fetus Levels at 1 yo 75% of adult

Question 54

Hyperimmunoglobulin E (hyper IgE) = Job syndrome- cause, clinical presentation

Answer 54

STAT3 mutation alters PMN chemotaxis Recurrent infections involving skin coarse facial features, broad nasal bridge, eczema

Question 55

Chediak-Higashi Syndrome

Answer 55

Abnormal degranulation Recurrent infections, oculocutaneous albinism, WBC inclusions/giant intracellular granules

Question 56

Complete DiGeorge syndrome (athymia) triad Treatment

Answer 56

Lymphadenopathy, rash, Oligoclonal T cells in blood Treatment: immuno-reconstitution, thymus transplantation, might need systemic corticosteroid therapy to suppress oligoclonal T cells