Nutritional Disorders Review - Part 2 - And Primary Immunodeficiency Disorders

transcript

8/10/2019 Nutritional Disorders Review - Part 2 - And Primary Immunodeficiency Disorders

1/20

2013

NUTRITIONAL

DISORDERS

REVIEW

-Part

2

and

PRIMARY

IMMUNODEFICIENCY

DISORDERS

REVIEW

Barbara

D.

Bosch,

M.D.


2/20

2013

Nutritional

Disorders

Review

Part

2

and

Primary Immunodeficiency

Disorders

Review;

Barbara

D.

Bosch,

M.D page

2

References for

USMLE

Step

1

-format

questions

(with

modifications):

Catalano E.

Appleton

&

Lanqe

Review

of General

Pathology.

4th ed.

McGraw

Hill Medical,

2003.

Fenderson

BA,

Strayer

DS,

Rubin R, Rubin

E. Illustrated Q&A

Review

of Rubin 's

Pathology,

2nd

ed.

Lippincott

Williams

&

Wilkins, 201

1

.

Goldberg J.

Lanqe

Practice Tests

USMLE

Step

1,

2nd ed. McGraw

Hill

Medical,

2006.

Kettering JD,

Fletcher

HM .

PreTest

Microbiology,

12th

ed. McGraw

Hill

Medical,

2007.

King

MW. Lanae

Q&A

USMLE

Step

1.

6,h

ed . McGraw

Hill

Medical,

2008.

Klatt

EC,

Kumar V. Robbins and

Cotran

Review

of

Pathology,

3rd ed . Saunders

Elsevier,

2010.

Klein

RM,

Enders

GC. PreTest

Anatomy, Histology

&

Cell

Biology.

3rd ed.

McGraw Hill

Medical,

2007.

Le

T,

Klein

J,

Shivaram

A.

First Aid

Q&A

for

the

USMLE

Step

1

McGraw

Hill

Medical,

2007.

Le

T,

Krause

K, Klein

J,

Shivaram A. First

Aid

Cases

fo r the USMLE

Step

1.

McGraw

Hill

Medical,

2006.

Mufson M.

PreTest

Pathophysiology,

3rd

ed.

McGraw Hill Medical, 2005.

PreTest

Clinical

Vignettes

fo r the USMLE

Step

1,

4th

ed .

McGraw Hill

Medical,

2008.

Wilson

GN.

PreTest

Biochemistry

and

Genetics.

3rd

ed.

McGraw

Hill

Medical,

2007.


3/20

2013

Nutritional

Disorders Review

-

Part

2 and Primary

Immunodeficiency

Disorders

Review; Barbara D. Bosch,

M.D.

page 3

A

37 year-old woman

with a 20-year history of Crohn

disease

(a

chronic

inflammatory

bowel

disease which

frequently

affects the terminal

ileum)

presents

to

her

primary

care

physician

complaining of fatigue.

Physical examination reveals

tachycardia,

pale

conjunctivae,

and

a

sore,

smooth,

red

tongue.

Relevant

laboratory findings

include

a

hematocrit

of

21

(normal

36-

46 ), with a mean

corpuscular

volume

of

105

fL (normal

80-100

fL).

A

slide

of

her

peripheral

blood

smear is

provided

below.

Deficiency

of which of the following

vitamins is

most likely?

A.

ascorbic

acid

B.

calcitriol

C. cobalamin

D.

folic

acid

E.

niacin

F.

pyridoxine

G. retinol

H.

thiamine

I.

vitamin

K

So

.

o

&

If

this

patient's

vitamin deficiency is

not

corrected,

which

of the following neurological signs

/

symptoms

would be most

likely

to

develop?

A. confabulation

and

anterograde

amnesia

B.

horizontal

gaze

palsy and

nystagmus

C.

paresthesias

and

gait instability

D.

proximal

extremity

and facial muscleweakness

E.

upper

extremity

resting

tremor

and

rigidity


4/20

2013 Nutritional Disorders Review

Part

2 and

Primary

Immunodeficiency

Disorders

Review;

Barbara D.

Bosch,

M.D

page

4

What

pathologic

feature below is

associated with

the

neurological findings of

vitamin

B12

deficiency?

A.

cerebellar

atrophy

B. demyelination

of

the posterolateral

columns of

the

spinal

cord

C.

hemorrhage

in

the

mammillary bodies

D.

neuronal degeneration

of the

basal

ganglia

E. spinal

cord

compression

Which

of the

following

laboratory

results would support a

diagnosis

of

cobalamin (vitamin

B12)

deficiency?

A.

decreased

level

of

lactate

dehydrogenase

B.

elevated level of methylmalonic acid

C. elevated WBC count

D.

hypochromic

microcytic

anemia

E.

prolonged prothrombin

time

Another

frequent

cause of vitamin

Bi2

deficiency

is autoimmune

chronic atrophic gastritis,

which

results in

mucosal

destruction

of the fundus

and body

of

the

stomach. What is the function of

the

protein that

is

diminished in this disease process?

A.

binding free vitamin

Bi2

in

ileal

cells for transport

through

the

bloodstream

B. binding free vitamin

Bi2

in the small intestine

and then to

ileal

receptors

C.

binding

free

vitamin

Bi2

in

the stomach

D.

splitting

R-protein

/

vitamin

Bi2

complexes

in

the

duodenum

E.

splitting vitamin

B12

from its

exogenous

ingested

protein-bound form


5/20

2013 Nutritional Disorders

Review

-

Part 2 and

Primary

Immunodeficiency Disorders Review; Barbara D. Bosch,M.D.

page

5

Vitamin

B12

-

Cobalamin

(water-soluble

vitamin)

sources

(exclusively synthesized by

microorganisms)

meats,

eggs

and

dairy

products

absorption

and

transport

vitamin

Bi2

cleaved from its exogenous

protein-bound

form by

pepsin

and

complexed

with salivary

R-binders

(stomach)

complexes

lysed

by

pancreatic

proteases

and

vitamin

B12

bound

to

intrinsic

factor (duodenum)

IF

receptor-mediated

absorption

(distal

ileum)

=t>

vitamin

B12

bound to transcobalamin

II (plasma)

o

uptake by

cells of the

body

storage

liver

(amounts

can

last for several

years)

Dial


6/20

2013 Nutritional Disorders

Review -

Part

2

and

Primary

Immunodeficiency

Disorders

Review;

Barbara

D.

Bosch,

M.D.

page

6

major biologic functions

methylcobalamin

-

cofactor

for methionine synthase

(necessary to

convert

homocysteine into

methionine)

and, in

the

process,

loses

its

methyl

group

which

is

donated by

methyltetrahydrofolic

acid

to

form

tetrahydrofolic

acid

(active form of

folate)

adenosylcobalamin -

cofactor

for

methylmalonyl-CoA

mutase

causes of deficiency

*

I'd

absorption

(e.g., i d

gastric

or pancreatic exocrine

function; i d

production

of intrinsic

factor, such

as

with autoimmune

chronic

atrophic gastritis [pernicious anemia];

i leal resection or

disease)

i d

intake

(rare)

competition

for dietary

vitamin

B12

(e.g.,

fish

tapeworm

infestation)

t'd requirement (e.g.,

pregnancy)

pathogenesis of

megaloblastic

changes

vitamin

B12

deficiency

=>

trapping

of folate

in

its

methylated

form

=>

impairment

of

thymidine,

and

ultimately

DNA,

synthesis

=>

defective

nuclear

maturation

and delayed cell division

in

rapidly

proliferating

cell

types

(e.g.,

erythrocytes)

features

of

deficiency

megaloblastic anemia

and

megaloblastic changes

(epithelium)

CNS myelin

degeneration,

especially in

the

posterolateral

columns

of

the spinal cord

(subacute

combined

degeneration)

=>

paresthesias, loss of vibratory

/ position

sensation,

and

weakness, especially of

the

distal

extremities

dUMP

N5

10-Methylene

FH4

X

dTMP

Thymidylate

Synthetase

Homocysteine

Methionine

Synthase

Methionine


7/20


8/20

2013

Nutritional

Disorders

Review

- Part

2

and Primary

Immunodeficiency Disorders

Review:

Barbara

D.

Bosch,

M.D.

page

8

A

newborn

girl

is born with

a small

mouth,

rather

widely

spaced

eyes and low-set

ears.

Genetic

analysis

shows a

microdeletion

on

chromosome 22q1

1

.2

leading

to

a diagnosis

of an anomaly

which

results

from failure

of

the

normal development

of the third and

fourth

branchial

pouches

during

embryonic

development.

Which

of the following

could

also

be

expected

in

a

child with

this

anomaly?

A.

absence of

serum

immunoglobulins

B. excess

activity

of osteoclasts

C. increased numbers of cells

in

the

deep

cortex

of

the lymph nodes

D. increased

serum Ca2+

levels

E.

tetany

A

neonate

who

is

born with

a

cleft

palate

and

abnormal facies becomes cyanotic

and

hypoxic

soon after birth. On

physical examination,

the neonatologist

hears a crescendo-decrescendo

murmur with a harsh systolic ejection.

Further

investigation

shows tetralogy

of

Fallot.

Laboratory

tests reveal

that the

patient

is

hypocalcemic.

This

infant most likely

has

which o f the

following

conditions?

A. Bruton

agammaglobulinemia

B. chronic granulomatous

disease

C.

DiGeorge

syndrome

D.

severe

combined

immunodeficiency

E. Wiskott-Aldrich syndrome

If

you were to

look

at this newborn's

spleen,

which of the

following

regions

would

likely

be

sparsely

cellular?

A.

capsule

B. red pulp cords

C. red pulp sinuses

D.

white

pulp

follicles

E.

white

pulp periarteriolar

lymphoid

sheaths


9/20

2013

Nutritional

Disorders

Review

-

Part 2 and Primary

Immunodeficiency Disorders Review; Barbara D.

Bosch,

M.D. page 9

DiGeorge syndrome

Ithymic hypoplasia

(partial

or complete)

selective

deficiency

of

T

cells and

T

cell-mediated

immunity

due to

defective

development

of the 3rd

and

4th pharyngeal

pouches

(give rise

to

the

thymus,

parathyroid glands, parafollicular

[C ]

cells

of the

thyroid,

aortic

arch,

and

parts

of

the

lips

and ears)

majority due to chromosome

22q11

deletion

hypoplastic or absent

thymus

=t>

defective

T-cell

maturation

(low-normal

lymphocyte

count, paracortical

areas of

lymph

nodes

and

periarteriolar

lymphoid

sheaths

of

spleen

depleted)

=>

I d

cell-mediated

immunity

=>

recurrent

viral,

fungal

and

mycobacterial

infections

absent or rudimentary

parathyroid glands

>

hypocalcemia

=0

tetany

(often in

f irst few

days of life)

congenital

defects of the heart and

great

vessels,

as

well

as facial

abnormalities

occasionally

treated with

transplantation

of

fetal

thymus or thymic epithelium

(often

not

needed)

Splenic

Histology

Spleen

H&E

splenic

sinuses

>

**

Jo

:f,r:

.r

V*

f

j

splenic

cord

macrophage

endothc

\

*

white pulp

white

pulp


10/20

2013

Nutritional

Disorders

Review

-

Part

2 and

Primary

Immunodeficiency

Disorders

Review;

Barbara

D.

Bosch.

M.D.

page

10

A 12

year-old girl

is brought

to

the pediatrician by her

mother

because

of

a fe ver. The

physician

notes

that

the girl

has features of

albinism,

and the

mother states

that

her

daughter has

always

looked

the

way

she

does. The

physician diagnoses

the

girl

with

a

staphylococcal

infection and

prescribes

a

course of antibiotics.

Three

months

later,

the child returns to the

pediatrician

with

a

streptococcal

infection.

The patient's medical

records indicate that

she

has had repeated bouts

of

staphylococcal and streptococcal infections

for

he r entire

life.

Photomicrographs

of

he r

peripheral blood

smear

(left)

and

bone

marrow aspirate (right)

are

included

below.

St

A

,&s\

This

patient

most likely

has

which o f

the

following

types

of immune

deficiency?

A. Chediak-Higashi

syndrome

B.

chronic granulomatous

disease

C.

hyper-IgM syndrome

D. Job

syndrome

E.

selective

IgA

deficiency

F. severe

combined

immunodeficiency

G. Wiskott-Aldrich syndrome

i


11/20

2013 Nutritional

Disorders Review

-

Part

2 and


Disorders

Review;

Barbara D.

Bosch,

M.D. page 11

Chediak-Higashi

syndrome

rare,

autosomal

recessive disease

characterized

by

a defective

membrane-associated,

lysosomal

trafficking

regulator

protein

= >

abnormal organellar synthesis,

trafficking

&/or

fusion

generalized

t'd

fusion

of

cytoplasmic granules in leukocytes (especially

neutrophils),

NK

cells,

melanocytes,

platelets,

and

cells of the nervous

system

enlarged lysosomes

=>

neutropenia

and

impaired

neutrophil

function

(e.g., chemotaxis,

phagocytosis,

phagolysosome

fusion,

microbial

killing)

recurrent

infections,

especially

by

pyogenic

bacteria

partial

oculocutaneous albinism

(due

to

melanin

trapping

in

giant melanosomes)

mild bleeding tendency

(abnormal

dense bodies

in

platelets)

progressive

neurologic

dysfunction

and

eventual accelerated

phase

with

lymphoproliferative

infiltrates

A

7 month-old male infant is

admitted to the

hospital with

chronic diarrhea and an overall

failure

to

thr ive. Review

of his

medical

records

reveals that he

has

had several

episodes

of

bacterial

pneumonia

and oti tis

media,

along with

oral

candidiasis

and herpes

simplex

virus

gingivostomatitis.

Chest

X-ray

reveals

the

absence of

a thymic

shadow,

and both B

and

T

lymphocytes

are

decreased

in

number

in

the

peripheral

blood. Serum

calc ium levels

are within

normal l imi ts . Which

one of

the

following listed

defects

is

associated with the X-linked recessive

form of this infant's

immunodeficiency

disease?

A.

decreased

production

of

NADPH

oxidase

B.

decreased

synthesis

of

adenosine

deaminase in lymphocytes

C.

defects in

the

common gamma

chain

subunit of

interleukin

receptors

D.

mutation

in

the

gene

coding

for

CD40L

E.

mutation

in the

gene

coding

for the Wiskott-Aldrich

syndrome protein

(WASp)

Which

of

the

following

is

the best

therapy for

the

infant

described

above?

A.

bone marrow transplant

B.

IgG

from

pooled

random donors

C. immunization

with

attenuated vaccines

D.

infusion of the

deficient

enzyme

E. thymic

grafting


12/20

2013

Nutritional

Disorders Review - Part

2 and

Primary

Immunodeficiency

Disorders

Review;

Barbara

D.

Bosch,

M.D.

page

12

Severe combined

immunodeficiency diseases

(SCID)

-

heterogeneous

group

profound

deficiency

of BOTH cell-mediated

and

humoral immunity

(although

T-cell

immunity

is

usually

more

severely

affected) due

to

abnormal development &/or

activation

of

both

T

and

B lymphocytes

X-linked recessive form is

the

most common

(50-60 of

cases)

due

to

an

abnormal

gamma chain

shared

by

several

interleukin

receptors

autosomal

recessive fo rms are due to other

abnormal receptor

or

signaling

proteins,

impaired

expression

of

class II MHC molecules

(bare

lymphocyte

syndrome),

or

PNP

or

*

adenosine deaminase (ADA)

deficiencies

(which

result

in

the

accumulation

of

metabolites

toxic to

developing

T

cells)

typical findings

include

virtual

absence of

systemic lymphoid

tissue,

severe

lymphopenia

and

scant

immunoglobulins

if

untreated,

patients generally

die

by 1

year

of age

due

to

multiple,

severe,

recurrent

infections

with al l types

of

pathogens (bacterial,

fungal,

viral,

protozoan)

individuals are

also

extremely

susceptible to graft-versus-host disease

treated

with early

allogeneic stem cell

transplantation

Which one

of the

following complement

component

deficiencies

is associated

with

frequent

pyogenic bacterial

infections?

A. C1q

B.

C1

inhibitor

C. C2

D.

C3

E.

C4

Patients with C5-9

(membrane

attack

complex)

complement

deficiencies

are most

susceptible

to

infections

with

which

of

the following pathogens?

A.

Aspergillus

sp .

B.

Giardia lamblia

C. Neisseria sp .

D.

Staphylococcus

aureus

E,

Streptococcus

sp.


13/20

Genetic deficiencies of

the

complement system

- rare disorders

C1(q, r or

s),

*

C2

and

C4 deficiencies

autoimmune

&/or

immune

complex

diseases

(e.g.,

lupus-like

disorder,

glomerulonephritis)

C3

deficiency

frequent,

serious,

pyogenic bacterial

infections

C5-9

deficiencies

recurrent

disseminated

infections

by Neisseria

Suspecting an

immune

dysfunction,

further

testing

is

performed.

A

defect

in

which

of the following

would be

most

likely

in

this

patient?

A.

adenosine

deaminase

B.

CD40

ligand

on CD4+

T-helper

cells

C. DNA

repair

enzyme

D.

interferon-y

E.

LFA-1

adhesion proteins

on phagocytes

F.

tyrosine kinase

A 2 year-old

girl

is

brought

to the

pediatrician

for

a routine

visit.

History

reveals recurrent infections and

more

falls

than usual lately.

(Physical

findings

seen

in

this condition

are shown

in

the accompanying

images.)


14/20

2013

Nutritional Disorders

Review

-

Part

2 and


Disorders

Review;

Barbara

D.

Bosch,

M D. page

14

Ataxia-telangiectasia

autosomal

recessive,

multisystem disorder

(due

to

ATM

gene

mutations

and

resultant

chromosomal instability)

ATM protein

plays an

important role in the

recognition

of damaged

DNA

and the

coordination

of its

repair,

in

addition

to

functions related to cell

proliferation

and

normal development

/

activity

of

the nervous and

immune systems

characterized

by

progressive neurologic

dysfunction,

cerebellar

ataxia,

oculocutaneous

telangiectasia,

abnormal

sensitivity

to radiation,

impaired

organ

development,

variable

types

of

immunodeficiency, and

an

T'd

frequency

of

malignancies

A

2

year-old boy has

had

almost continuous

infections since

he was

6 months

old. These

infections have

included otitis

media,

pneumonia

and impetigo.

Organisms cultured

have been

Haemophilus

influenzae,

Streptococcus pneumoniae,

and

Staphylococcus

aureus.

He has a lso

had

diarrhea,

with Giardia

lamblia

cysts identified

in stool specimens.

The family

history

indicates

that an older brother

with

a similar condition

d ied because of

overwhelming

infections.

The

boy's five

sisters

and

both

parents are normal.

Which

o f the

following

laboratory

findings

would

most

like ly be seen in

this boy?

A.

variable loss of cellular immunity

commonly

I'd

IgM,

normal

IgG, T'd IgA and

IgE

characterized

by

recurrent

infections,

bleeding

complications

and

malignancies

(especially lymphomas)

can be treated with

stem

cell

transplantation

Parents of

an

18 month-old

boy

bring

their

child

to a

pediatrician as they are concerned

about

their

son's

recurring skin

and

lung

infections.

Biopsy

of

one

of

the boy's

current

skin

lesions

reveals aggregates of

neutrophils

surrounded

by

a rim

of

large,

eosinophilic, epithelioid

macrophages

(depicted in

the

image below).

Culture

of

the

les ion is positive for

Staphylococcus

aureus.

Which o f the

following

would best account for this

patient's

condition?

A.

absence

of

T-helper

cell

activity

B.

adenosine

deaminase

enzyme

deficiency

C. complement

C3b

opsonization

abnormality

D.

decreased hydrogen

peroxide production

E. defective

macrophage phagocytosis

What

is the

name

of this

disease?

Which of the

following

neutrophil

functions

is

severely

impaired

in

this disorder?

A. adhesion to endothelial

cells

B.

chemotaxis

C.

phagocytosis of

bacteria

D.

phagosome-lysosome fusion

E.

microbial killing

i


17/20

2013

Nutritional

DisordersReview

-

Part

2

and

Primary


Review;

Barbara

D. Bosch,M.D.

page 17

Name the

enzyme that is

deficient in

this

disorder.

Why are

streptococcal

infections not

usually found in patients

with

this

disorder?

Chronic

granulomatous

disease

(CGD)

rare disorder

of

neutrophils

characterized

by

a

lack

of respiratoryburst with

phagocytosis

defective

activation

of

membrane NADPH-oxidase

impaired production

of

superoxide

anion during

phagocytosis

deficient

H202

production

in

the

phagolysosome

o

failure

of

H202-MP0-halide

killing

system

(converts

H202

to HOCI

[powerful

oxidant])

-2/3 are X-linked

recessive

(neutrophils

deficient

in

neutrophil

cytochrome b); rest are

autosomal recessive

(other

components

of

NADPH-oxidase

system

affected)

frequent, severe,

chronic bacterial

infections

with

granulomatous

abscesses

of multiple

organs

(including

the subcutaneous

tissue,

lymph

nodes,

lungs,

liver)

infectious pathogens are typically

catalase-positive

bacteria

(e.g.,

Staphylococcus

aureus

,

Serratia,

Salmonella

,

Escherichia

coli)

and

fungi

An 18

year-old

woman

presents

to

your

clinic with a recurrent sinus

infection.

She has also

suffered from

bronchitis,

otitis media

complicated

by meningitis,

diarrhea,

and

pneumonia

over

the

last

year.

You

order serum

studies,

which demonstrate a

markedly

depressed

IgG

level and

subnormal serum

IgA

and IgM

levels.

You

treat the

sinusitis with

antibiotics

and

suggest

IV

gamma

globulin

therapy

for treatment

of

her

underlying condi tion. Which

of

the following would

most

likely

also

be found

in

this

patient?

A.

absence of

lymphoid

germinal centers

B.

failure of phagosome-lysosome fusion within macrophages

C.

lymphadenopathy

D.

lymphocytopenia

E.

negative

nitroblue tetrazolium

dye

reduction test

treatment

includes

y-interferon


18/20

2013

Nutritional

Disorders Review

-

Part

2

and

Primary


Review;

Barbara

D.

Bosch,

M.D.

page

18

Common variable immunodeficiency disease

(CVID)

-

relatively common, heterogeneous

characterized by

hypogammaglobulinemia

(usually

all immunoglobulins, occasionally

only

IgG)

Sc-Vo .

often

diagnosed

irK{eenagers and

young

adults)

congenital

or

acquired

usually due to an intrinsic B-cell defect

(B

cells can proliferate

in

response

to antigens,

but fail

to

differentiate

into

plasma

cells); occasionally also T-cell

dysfunction

typically a normal

number

of

circulating

B cells with markedly

~ce areas

(lymphoid

follicles)

in

lymph

nodes,

spleen and

Gl

tract (due to

persistent

antigen stimulation),

bu t no

plasma

cells;

non-necrotizing granulomas may also

be seen

recurrent

infections

by

pyogenic

bacteria,

as

well

as

intestinal

infections with Giardia

lambliaCX=*\

\

treated

with

periodic

immunoglobulin

infusions

COMMON VARIABLE

IMMUNODEFICIENCY

DUODENAL

NODULAR LYMPHOID

HYPERPLASIA

(ENDOSCOPY)

S>

associated

with

an T'd f requency of autoimmune diseases

and

lymphoma P

exrakoe

A

x

V.o m

u?\KVifceL.

Bonus questions:

What

is

the

most common primary immunodeficiency in the U.S.?

A 22

year-old man is evaluated

for repeated

episodes

of pulmonary

infections, including

a

recent

one productive of

foul, purulent

sputum

and accompanied

by

shortness

of

breath . Pas t

medical

history

is also significant for chronic

sinus

infections

with

mucopurulent

discharge.

Physical examination

is

remarkable

for

scattered

rhonchi

and

rales

throughout all lung

fields.

Imaging

studies show

abnormally

dilated

and

thickened

airways extending close

to the pleural

surface and

a cardiac

silhouette

in

the right thorax. Bronchoscopy demonstrates

numerous

mucopurulent plugs.

Which

of

the

following

is

most

likely

responsible

for these

findings?

A.

abnormal

neutrophilic function resulting in

impaired degranulation

B.

alpha-1

antiprotease deficiency

(PiZZ

phenotype)

C. cell

membrane

defect

resulting in abnormally

viscous

glandular secretions

D.

defect in ciliary motility

due to the

absence

of

dynein

arms

E.

hypersensitivity

reaction

associated with

c-ANCA

and granuloma

formation

i


19/20

2013 Nutritional

Disorders

Review

-

Part

2 and

Primary


Review;

Barbara

D.

Bosch.

M.D. page

19

A

5 year-old

boy

has had

multiple

recurrent

infections,

including Pneumocystis jiroveci

pneumonia,

Streptococcus

pneumoniae

otitis media and

Pseudomonas

aeruginosa

urinary

tract

infections. On

physical

examination,

he

is

now

noted

to

have

pharyngeal

erythema

with

an

exudate. Laboratory

studies show

hemoglobin 9.1 g/dL (nl 13.5-17.5);

platelet

count

130,900/mm3

(nl 150,000-400,000);

and

WBC

count 3440/mm3

(nl

4500-11,000)

with

47

segmented

neutrophils,

3

bands,

40

lymphocytes,

and 10

monocytes.

Serum

immunoglobulin

levels

are

IgG

88

mg/dL

(nl 650-1500);

IgM

721

mg/dL

(nl

40-345);

and

IgA

undetectable

(nl 76-390 mg/dL).

A

peripheral

blood smear

shows

nucleated

RBCs.

Which of

the

following

immunological

defects is most

likely in

this

patient?

A.

a defect

in DNA

repair

enzymes

B.

a defect

in

LFA-1

adhesion

proteins

on

phagocytes

C. abnormal CD40-CD40L interaction

D.

absence

of

adenosine deaminase

E.

deletion

of

chromosome

22q1

1

F.

failure

of interferon-y

production

G.

lack

of

IgA production

by

B

lymphocytes

H.

mutation

in

the

BTKgene

Where

does

immunoglobulin

switching from IgM to

IgG

primarily

occur?

A.

bone

marrow

B.

germinal

centers

C.

peripheral

blood

D.

splenic

red

pulp

E.

thymus

A

24

year-old woman with a

history of

allergic

rhinitis is involved

in

an automobile accident and

sustains

a

splenic

laceration.

She

undergoes

abdominal

surgery

and is then

transfused with

four

units

of blood of

the

appropriate

ABO

and

Rh type.

As the

transfusion

progresses,

she

becomes

rapidly hypotensive

and

develops airway

edema,

consistent with

anaphylaxis.

Which

of the

following pre-existing

conditions best

accounts fo r these symptoms?

A.

C1 esterase

inhibitor

deficiency

B.

common

variable

immunodeficiency

C.

DiGeorge

syndrome

D.

hyper-IgM syndrome

E. selective

IgA

deficiency

F.

Wiskott-Aldrich

syndrome


20/20

2013

Nutritional Disorders

Review

-

Part

2

and


Disorders

Review:

Barbara

D.

Bosch,

M

D. page 20

A

15

year-old boy

is

brought

to the emergency

department because

of

the

acute

onset

of fever,

chills and

a

productive cough.

Samples

taken

of

the

sputum

show

a-hemolytic

gram-positive

diplococci

that show

a

positive quellung

reaction.

The patient

says

that

he has had

similar

infections over the past

year. A

peripheral

blood smear is

done,

and results

show

several

sickle-shaped

RBCs.

Which of

the

following

explains

why

this

patient

is

susceptible

to

this

particular

type of infection?

A.

bone

marrow

infiltration

resulting in neutropenia and compromised immune

function

B.

large

vessel occlusions

in

the

cerebral vasculature

resulting

in neurologic

events

and

aspiration pneumonia

C.

microvascular

infarcts

resulting in pulmonary

failure

D.

microvascular

infarcts

resulting in splenic

dysfunction

E. vaso-occlusion in

the

renal medulla resulting

in

renal

failure

and uremia

Nutritional Disorders Review - Part 2 - And Primary Immunodeficiency Disorders

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