A 48-year-man with chronic renal failure undergoes a cadaveric renal transplant. One week later, the patient has an elevated creatinine level. The surgical team is concerned about the possibility of acute transplant rejection. The cell type shown in the image is believed to be an important mediator of this process. In which of the following locations does this cell type complete maturation?
Thymus. Acute rejection is one complication of kidney transplantation. In acute rejection, the principal mediator is believed to be the cytotoxic T lymphocyte. Activated cytotoxic lymphocytes invade the tubular interstitium of the transplanted kidney, leading to tubulitis. In contrast, chronic rejection is mediated by antibody complex formation. Elevated creatinine levels allow early detection of acute rejection in the absence of clinical signs, which may include graft tenderness, oliguria, and fever. T lymphocytes mature in the thymus, where they undergo positive and negative selection.
A 23-year-old man comes to the physician with a bacterial infection. On questioning the patient reveals a history of recurrent bacterial, fungal, and viral infections. Blood is drawn and sent for laboratory analysis, which reveals all levels of immune cells (eg., T lymphocytes, B lymphocytes) are low. Which of the following conditions is most likely to have caused the patient’s symptoms?
Severe combined immunodeficiency is a defect in early stem cell differentiation that can have many causes and leads to a total lack of a cellular immune system. The typical presentation of this disease includes recurrent bacterial, viral, protozoal, and fungal infections.
A 13-year-old boy is diagnosed with a hyperactive immune system. Normally an antigen will activate the immune system to trigger a pro-inflammatory response. Following the proinflam-matory response, anti-inflammatory signals then dampen the immune response to prevent it from causing damage. This patient has trouble dampening the immune response after it is no longer needed. Decreased activity in which of the following anti-inflammatory cytokines is most likely the basis for this boy’s condition?
Transforming growth factor- β. Mounting a strong immune response is crucial for the body to be able to fight off infections. However, reducing this response once the infection has been warded off is critical in order for the body to maintain its normal balance. Transforming growth factor- βis the cytokine that is responsible for dampening the immune response after it is no longer needed.
A 19-year-old man comes to the physician with a bacterial infection. Without treatment, the patient’s immune system will most likely be able to fight off the infection within a few days. One of the tools the patient’s body uses against the organism is the membrane attack complex. The membrane attack complex functions as which of the following?
A proteinaceous pore in the plasma membrane.The C5b, 6, 7, 8 complex guides the polymerization of C9 molecules in lipid bilayer of the target cell’s plasma membrane. C9 polymers form pores in the membrane, allowing the passage of ions andsmall molecules into the cell, causing the cell to lyse
To assess the risk of erythroblastosis fetalis occurring during the future pregnancy of an Rh-negative woman, a clinician sends a sample of serum for detection of anti Rh-blood group antibodies. The laboratory performs an indirect Coombs’ test by mixing the patient’s serum with Rh-positive RBCs and then adding an anti-IgG antibody. In doing so, the laboratory technician observes agglutination of the RBCs. After receiving this test result, the clinician would be correct to conclude which of the following?
The presence of anti-Rh antibodies in the patient’s serum suggests that she has been pregnant with an Rh-positive fetus When an Rh-negative mother gives birth to an Rh-positive fetus, fetal RBCs may enter the mother’s circulation, and the body may recognize the Rh antigen as
foreign and produce antibodies against it. As
maternal IgG freely crosses the placenta, any
subsequent Rh-positive fetus is at risk for hemo-
lytic disease. Thus, the indirect Coombs’ test is
an important laboratory tool to monitor for Rh
incompatibilities that may complicate fetal
health. The test result given in this question in-
dicates that the patient possesses anti-Rh anti-
bodies in her serum. Therefore, it would be
logical for the clinician to suspect previous
pregnancy with an Rh-positive fetus.
A newborn child is exposed to
and subsequently develops meningi-
tis. Which of the following could have contrib-
uted to this child’s bacterial infection?
both possess a polysaccharide outer cap-
sule. Effective vaccination against these species
results in the generation of antibodies that rec-
ognize this polysaccharide capsule. Which of
the following best explains why the childhood
type B and
serogroup C are composed of a poly-
saccharide coat conjugated to a protein car-
A type B blood group, Rh-positive recipient is
mistakenly transplanted with a kidney from a
type A blood group, Rh-negative donor. Which
of the following best describes the mechanism
of transplant rejection that is most likely to en-
sue in this recipient?
A 12-year-old girl is brought to the pediatrician
by her mother because of a fever. The physi-
cian notes that the girl has features of albinism
and the mother states that her daughter has al-
ways looked the way she does. The physician
diagnoses the girl with a staphylococcal infec-
tion and prescribes a course of antibiotics.
Three months later, the child returns to the pe-
diatrician with another streptococcal infection.
The patient’s medical records indicate that she
has had repeated bouts of staphylococcal and
streptococcal infections for her entire life. This
patient most likely has which of the following
types of immune defi
A 60-year-old post-menopausal woman presents
with fatigue, mild jaundice, and tingling in the
lower extremities. Laboratory studies show ele-
vated serum levels of homocysteine and methyl
malonic acid, and complete blood cell count
shows a mild thrombocytopenia. Which of the
following fi ndings would be expected on a pe-
ripheral blood smear from this patient?
Antigen processing and presentation within the
context of a major histocompatibility complex
(MHC) class I molecule is essential to generat-
ing a CD8
T-lymphocyte response. In which of
the diagramed subcellular locations is the self-
peptide loaded onto MHC class I molecules?
A 7-year-old boy presents to the clinic with a
staphylococcal infection. He is well known at
the clinic because he has had recurrent staphy-
lococcal infections for most of his life. He is
started on an antibiotic regimen and the infec-
tion subsides. Three weeks later, the boy is di-
agnosed with pruritic papulovesicular dermati-
tis. Which of the following immune defi
syndromes would account for this patient’s re-
current staphylococcal infections and pruritic
Hyper-IgM syndrome usually presents with se-
vere pyogenic infections. The typical immuno-
globulin profi le in a patient with this disease
shows an elevated level of IgM in contrast to
the other immunoglobulin isotypes. Which of
the following is the etiology behind the in-
creased level of IgM in a patient with hyper-
A 40-year-old man presents to his physician
with numbness and tingling on the dorsal sur-
face of his right hand and forearm and raised
“varicose veins” that are fi rm to the touch
along the same distribution. He also complains
of weight loss. His serum creatinine level is 2.0
mg/dL. He has no previous medical history of
cance. An immune complex disease is
suspected, and assays for autoantibodies in
neutrophils are conducted. What diseases are
associated with the identifi cation of anti-my-
eloperoxidase and anti-proteinase-3 antibodies,
A 32-year-old man with Hodgkin’s lymphoma
is scheduled to undergo a bone marrow trans-
plant. HLA typing of his immediate family
shows that his identical twin brother is a suit-
able match for harvesting an allogenic bone
marrow graft. This type of graft can be classi-
fi ed as which of the following?
Patients sharing similar clinical symptoms and
disease pathology may nevertheless present dif-
ferently based upon age at disease onset. Adult-
onset rheumatoid arthritis (RA) and juvenile
rheumatoid arthritis (JRA) are both the result
of infl ammatory processes. How does the pre-
sentation of JRA differ from the presentation of
A 37-year-old man comes to the physician with
recurrent viral infections. Blood studies show
normal levels of circulating lymphocytes and
neutrophils. A defi ciency in which of the fol-
lowing cytokines would most likely lead to this
Cluster of differentiation (CD) antigens are
glycoproteins present on the cell surface of
many cell types involved in the immune sys-
tem. They are recognized by monoclonal anti-
bodies and aid in the identifi cation of various
cell types. Which of the following glycopro-
teins is present on the cell surface of all thymo-
cytes: helper T-cells, cytotoxic T-cells, and nat-
ural killer cells?
A 2-year-old girl with a lifelong history of mal-
absorptive and foul-smelling diarrhea, weak-
ness, and general failure to thrive has just un-
dergone a small intestine biopsy (see image).
Her parents believe her problems began at 6
months of age, when she started eating solid
foods, but have signifi cantly worsened over the
past few months. The only recent change in
her diet is that she eats a bowl of cereal every
morning with her parents before they go to
work. She tried a dairy-free diet a month ago,
but it did not improve her symptoms. Which of
the following is the most likely diagnosis
A pediatrician becomes concerned after learn-
ing the family and medical history of an infant
who is currently suffering from pneumonia,
with a presumed diagnosis of
infection. Over the past year, the
patient has suffered from erysipelas as well as a
previous bout of pneumococcal pneumonia;
both were treated successfully with antibiotics.
The patient’s mother says that her son’s mater-
nal uncle also suffered from repeated bacterial
infections and was successfully treated with an-
tibiotics. On physical examination, it appears
that the patient does not have tonsils. His
mother denies a previous tonsillectomy. Analy-
sis of the boy’s serum would most likely yield
which of the following results?
A 25-year-old man presents to his doctor with a
2-day history of blood in his urine. A kidney bi-
opsy is obtained. When the tissue is stained
with fl uorescent anti-IgG antibodies, the stain-
ing reveals a linear pattern. Which of the fol-
lowing is the most likely diagnosis?
A clinician is concerned that an Rh-negative
mother may be pregnant with an Rh-positive
fetus. The potential pathology that the clini-
cian is concerned about is classifi ed as which
of the following immune reactions?
A 14-year-old boy presents to the physician with
recurrent pyogenic infections. Physical exami-
nation shows that the boy has pruritic papulo-
vesicular dermatitis. Blood is drawn and sent for
laboratory evaluation of platelets and immuno-
globulin levels. The results show a markedly low
platelet count, a low serum IgM level, and an
elevated IgA level. This patient most likely has
which of the following conditions?
A 32-year-old woman comes to the emergency
department complaining of sudden blindness.
On obtaining a thorough history, it is learned
that the patient’s right leg has “given out” from
time to time, causing the patient to have epi-
sodes of weakness and falling. Periventricular
white matter plaques are found on MRI.
Which of the following cells are primarily
damaged in this disease?
Women have about a 2.7 times greater lifetime
risk of developing at least one autoimmune dis-
ease than men. Which of the following state-
ments, if true, would support the higher rate of
systemic lupus erythematosus in women than
A 2-year-old boy is brought to the physician by
his parents because of recurrent sinus infec-
tions. The parents also state that the boy has
had multiple lung infections. Which of the fol-
lowing results would most likely be found on
A 50-year-old man presents to his clinician be-
cause of bilateral itching, burning, and redness
of the lower extremities. He states that he wore
shorts while gardening outside his house re-
cently and could have come in contact with
poison ivy. Which of the following statements
regarding this patient’s immune response is
Antibodies are one of the major players in the
adaptive immune response. All antibody mole-
cules consist of two heavy chains and two light
chains, and the specifi
c type of heavy and light
chain will determine the antigen binding site.
In all antibodies, the two heavy chains and the
two light chains are identical. Like most pro-
teins, much of their functional capabilities and
antigen binding characteristics stem from their
three-dimensional structure. Which of the fol-
lowing holds the heavy and light chains to-
gether to make the three-dimensional structure
of the antibody?
A 23-year-old woman comes to the physician
for a routine checkup. She has generally been
well over the past year, although she notes that
she has “had a few falls lately.” On physical ex-
amination, the lesion shown in the image is
found on her skin. Blood is drawn for labora-
tory evaluation. The results show that the
woman has very low levels of IgA. Based on her
presentation, this patient will most likely also
present with which of the following symptoms?
A 50-year-old man comes to the physician with
hemoptysis and diffuse joint pain. He states
that both his father and cousin had similar
symptoms and were diagnosed with micro-
scopic polyangiitis, a disease affecting medium-
to small-sized arteries that is believed to have
an autoimmune component to its pathogene-
sis. Which of the following autoantibodies
might be present in this patient?