Life 28q

A 3-year-old boy with an X-linked defect in the Bruton tyrosine kinase (BTK) gene is impaired in which of the following mechanisms? ■ A. Antibody-mediated bacterial clearance ■ B. Formation of the membrane attack complex ■ C. Delayed (-type) hypersensitivity (DTH) responses ■ D. I FN-')' secretion by CD4 + T cells ■ E . T-cell precursor migration to the thymus

■ A. Antibody-mediated bacterial clearance

A 57-Year-Old man with autosomal dominant polycystic kidney disease develops end-stage kidney failure and undergoes renal allograft transplantation. During the operation, the surgeon notices that graft becomes cyanotic and mottled soon after its blood vessels are connected with those of the recipient. Blood flow to the graft ceases and no urine is produced. Which of the following immunologic mechanism best explains the findings observed by the surgeon? ■ A. Antibody-mediated hypersensitivity ■ B.Cell-Mediated Hypersensitivity ■ C. Graft-Versus-Host Disease ■ D. Immediate Hypersensitivity ■ E. Immune complex-mediated damage

■ A. Antibody-mediated hypersensitivity

Which of the following provides evidence of immune evasion by tumor cells? ■ A. Downregulation of MHC I molecules by tumor cells ■ B. Enhanced production of tumor necrosis factor by macrophages ■ C. I FN--y-mediated inhibition of tumor cell proliferation ■ D. Generation of antibodies against tumor-specific antigens ■ E. Stimulation of tumor cell apoptosis by increased Bax expression

■ A. Downregulation of MHC I molecules by tumor cells

An 8-year-old female with a known allergy to peanuts inadvertently ingests a cereal containing traces of peanuts. Within 1 hour, she develops diffuse erythema (redness of the skin) and urticaria associated with respiratory symptoms of shortness of breath and diffuse wheezing. These findings suggest which of the following events? ■ A. Type I hypersensitivity reaction ■ B. Arthus reaction ■ C. FeR-bearing cells binding to host cells coated with lgG ■ D. lgG binding to extracellular matrix of the respiratory passages ■ E. lgM-mediated interaction with cell membranes of lymphocytes

■ A. Type I hypersensitivity reaction

After receiving a kidney transplant from the most appropriate available donor, a 38-year-old female is administered immunosuppressive drugs, including cyclosporine, in order to ■ A. decrease T-cell production of I L-2. ■ B. destroy stem cells in her bone marrow. ■ C. induce involution of her thymus. ■ D. inhibit macrophage release of I FN-y ■ E . reduce plasma cell secretion of lgG antibodies.

■ A. decrease T-cell production of I L-2.

A 25-year-old female with a history of penicillin allergy unknown to her physician was given a single injection of penicillin for the treatment of syphilis. Within minutes, she developed diffuse urticaria (hives) , tachycardia (rapid heart rate) , and hypotension (decrease in blood pressure). This patient has experienced ■ A.anaphylaxis. ■ B. anergy. ■ C. antibody-mediated cytotoxicity. ■ D. asthma. ■ E . contact sensitivity.

■ A.anaphylaxis.

A 3-month-old male infant has recurrent infections and is found to have an impaired ability to kill microbes by the nitroblue tetrazolium test (which evaluates effectiveness of degradative enzymes) . Which of the following conditions is most likely responsible for the findings in this patient? ■ A. Chediak-Higashi syndrome ■ B. Chronic granulomatous disease ■ C. Hereditary angioedema ■ D. HIV/AIDS

■ B. Chronic granulomatous disease

A 15-year-old male suffe4rs severe cardiomyopathy following infective endocarditis from Coxsackie virus and is placed on the cardiac transplant list. Two weeks following cardiac transplantation from a matched donor, he is suffering dyspnea on exertion. Extensive evaluation is undertaken in this patient including cardiac catheterization and endomyocardial biopsy. Which of the following finding is most consistent with acute graft rejection? ■ A. Concentric coronary atherosclerosis ■ B. Dense interstitial lymphocytic infiltrate ■ C. Perivascular infiltrate with abundant eosinophils ■ D. Patchy necrosis with granulation tissue ■ E. Scant inflammatory cells and interstitial fibrosis

■ B. Dense interstitial lymphocytic infiltrate

A female neonate has a malformed jaw, cardiac abnormalities, and hypocalcemia, in addition to diminished cell-mediated and B-cell responses. Which of the following immune deficiencies should be included i n the differential diagnosis of this patient? ■ A. Adenosine deaminase (ADA) deficiency ■ B. DiGeorge syndrome ■ C. Hereditary angioedema ■ D. Severe combine immunodeficiency disease (SCI D) ■ E . Wiskott-Aidrich syndrome

■ B. DiGeorge syndrome

The principal difference between cytotoxic (type ll) and immune complex (type lll) hypersensitivity is: ■ A. The class (isotype) of antibody ■ B. Whether the antibody reacts with the antigen on the cell or reacts with antigen before it interacts with the cell ■ C. Participation of complement ■ D. Participation of T cells

■ B. Whether the antibody reacts with the antigen on the cell or reacts with antigen before it interacts with the cell

A 47-year-old-male has a history of end-stage renal failure and required a kidney transplant. Approximately 4 weeks after receiving his transplanted kidney, he developed oliguria (decreased production of urine), fever, hypertension, and pain or tenderness over the allograft. On the basis of these findings, the most likely underlying immunological process is ■ A. autoimmunity. ■ B. acute rejection . ■ C. chronic rejection. ■ D. hyperacute rejection. ■ E . peripheral tolerance.

■ B. acute rejection .

A 6-month-old male infant has diarrhea, extensive fungal infections, and skin rashes and has failed to gain weight. He is deficient in both T- and B-cell function. The thymus is of normal size. The most likely prospect for permanent restoration of normal immunity for this patient would be ■ A. an antibiotic "cocktail" given at regular intervals. ■ B. bone marrow transplantation. ■ C. exogenous immunoglobulins administered periodically. ■ D. isolation to an antiseptic environment. ■ E . thymic hormones given throughout his life.

■ B. bone marrow transplantation.

With no therapeutic intervention, the most likely outcome for a transplanted skin graft obtained from an unrelated donor who is H LA identical to the recipient is ■ A. acute rejection. ■ B. chronic rejection. ■ C. graft-versus-host disease. ■ D. hyperacute rejection. ■ E . long-term success

■ B. chronic rejection.

A 21 -year-old woman has a history since childhood of recurrent episodes of swelling of the submucosal and subcutaneous tissue of the gastrointestinal and respiratory tracts. Her C1 inhibitor level is less than 5% of the reference value. These findings support a diagnosis of ■ A. DiGeorge syndrome. ■ B. hereditary angioedema. ■ C. nutrition-based immune deficiency. ■ D. paroxysmal nocturnal hemoglobinuria. ■ E . Wiskott-Aidrich syndrome

■ B. hereditary angioedema.

A 5-year-old girl has a small deletion in chromosome 22. She has impaired thymus development with a significant deficiency in the number of functional T cells. The most likely etiology for these findings is ■ A. adenosine deami nase (ADA) deficiency. ■ B. Chediak-H igashi syndrome. ■ C. DiGeorge syndrome. ■ D. hereditary angioedema. ■ E . severe combined immunodeficiency (SCID) .

■ C. DiGeorge syndrome.

A 24-year-old male presents with fever, cough , and night sweats. Examination reveals an elevated temperature, increased respiratory rate, oral thrush (fungal infection) , and decreased breath sounds in the right mid lung field. Laboratory testing reveals aCD4 count of 60/m l (reference range: 400/ml). On the basis of these findings, the most likely underlying process is ■ A. autoimmune disease with pneumonia. ■ B. bacterial pneumonia. ■ C. HIV/AI DS with possible mycobacterium tuberculosis. ■ D. hypersensitivity pneumonitis. ■ E . Mycobacterium tuberculosis infection only.

■ C. HIV/AI DS with possible mycobacterium tuberculosis.

5-year old child is brought to the emergency department by his parents for night arm pain. The patient reports that he was playing hide and seek outside and felt a sharp pain on his arm while hiding in some thick bushes. His parents suspect something had stung him. Physical examination shows an edematous and erythematous plaque with mild central pallor. A residual stinger, located central to the lesion is readily extracted. The physical examination is otherwise not significant. Which of the following substances is most likely directly responsible for the skin findings observed in this patient? ■ A. C3b ■ B. IL-2 ■ C. Histamine ■ D. Lysozyme

■ C. Histamine

A 35-year-old male presents with symptoms of fatigue, paresthesia (numbness and tingling) of his arms and legs, and occasional blurred vision of 2 months' duration. Tests reveal several areas of demyelination within the central nervous system. Diagnosis of which of the following conditions is supported by these findings? ■ A. Ankylosing spondylitis ■ B. Hashimoto thyroiditis ■ C. Multiple sclerosis ■ D. Reactive arthritis ■ E . Systemic lupus erythematosus

■ C. Multiple sclerosis

A 45-year-old man with renal failure undergoes kidney transplantation. His postoperative course is unremarkable with normal functioning of the renal allograft. Four years later, the patient develops hypertension. Laboratory studies shows a progressive increase in serum creatinine levels over last few months. Urinalysis is within normal limits. On ultrasonography, the transplanted kidney is reduced in the size. A biopsy of graft is most likely to show which of the following? ■ A. Dense mononuclear interstitial infiltrate ■ B. Glomerular crescent formation ■ C. Obliterative vascular fibrosis ■ D. Vascular fibrinoid necrosis and neutrophil infiltration

■ C. Obliterative vascular fibrosis

A previously healthy 45-year-old male presents with rhinorrhea, nasal congestion, and persistent respiratory symptoms several months after returning to his home i n New Orleans after Hurricane Katrina. He has noticed mold growing along the walls of his house. Skin testing for sensitivity to common mold spores gave positive resu lts to several of them in less than 30 minutes. These findings indicate an example of ■ A. contact dermatitis. ■ B. delayed (-type) hypersensitivity. ■ C. immediate hypersensitivity. ■ D. serum sickness. ■ E. type II hypersensitivity.

■ C. immediate hypersensitivity.

According to the immune surveillance theory, ■ A. antibodies arise during fetal development that can destroy tumors. ■ B. cancer cells rarely arise within a normal individual. ■ C. innate immune responses eliminate specific tumor cell antigens. ■ D. tumors arise only if malignant cells escape immune detection. ■ E. tumor-infiltrating lymphocytes prevent malignant transformations

■ C. innate immune responses eliminate specific tumor cell antigens.

The process that is synergistically enhanced by the binding of both antibodies and complement fragments such as C3b by phagocytes is known as ■ A. agglutination. ■ B. complement activation. ■ C. neutralization . ■ D . opsonization.

■ D . opsonization

A 5-month-old Caucasian male who suffers from chronic diarrhea and failure to thrive is found to have a low blood T lymphocyte count and severely decreased serum immunoglobulin level. After thorough evaluation, an experiment treatment is offered to the patient's parents. The therapy consists of infecting his cells with a retroviral vector coding the gene for his deficient protein. The gene most likely codes for: ■ A. Myeloperoxidase ■ B. Reverse transcriptase ■ C. NAPH Oxidase ■ D. Adenosine Deaminase

■ D. Adenosine Deaminase

A 19-year old woman is brought to the emergency department after a motor vehicle collision. The patient's medical history includes celiac disease and 3 episodes of pneumonia. His blood pressure is 80/45 Hg and pulse is 130/min. Physical examination reveals pallor, and ultrasound shows a splenic laceration. She receives a blood transfusion with O-negative packed red blood cells. During transfusion, the patient develops facial swelling, generalized hives and shortness of breath. Which of the following is most likely diagnosis in this patient? ■ A. ABO Incompatibility ■ B. C1 inhibitor deficiency ■ C. Leukocyte adhesion deficiency ■ D. Selective IgA deficiency

■ D. Selective IgA deficiency

A 6-year-old male receives a bone marrow transplant from his father during treatment for acute myelogenous leukemia. Of primary concern will be the potential development of ■ A. acute rejection . ■ B. an allergic reaction. ■ C. autoimmune responses. ■ D. graft-versus-host disease. ■ E . immediate hypersensitivity.

■ D. graft-versus-host disease.

Lymphocytes expressing both the CD4 and CD25 markers on their surfaces function as ■ A. antigen-presenting cells. ■ B. autoantibody-secreting B cells. ■ C. cytotoxic T cells. ■ D. natural killer-like T cells. ■ E . T regulatory cells

■ E . T regulatory cells

Failure of the immune system to respond against an epitope in an aggressive way is termed ■ A. autoimmunity. ■ B. positive selection. ■ C. negative selection. ■ D. suppression. ■ E . tolerance

■ E . tolerance

A previously healthy 65-year-old female presents with complaints of frequent bowel movements, weight loss, and nervousness. Her physical examination was remarkable for slight exophthalmos (protrusion of the eyeball) and atrial fibrillation (abnormal heart rhythm).Laboratory findings supported a diagnosis of G raves disease. Which of the following tissues/organs will be most affected by the ensuing immune reactions? ■ A. Connective tissue ■ B. Joints of lower extremities ■ C. Heart valves ■ D. Kidneys ■ E. Thyroid gland

■ E. Thyroid gland