Immunology Practice Exam

Immunology Practice Exam

SELECT THE BEST ANSWER.

1. A young boy has had repeated infections with Staphylococcus aureus. His laboratory data reveals that he has normal numbers of white blood cells with a normal distribution by differential counting. His immunoglobulin levels are normal and he responds to candida skin test antigen with a positive DTH reaction. Which of the following types of immune deficiency do you suspect?

A. B cell deficiency

B. Granulocyte disorder

C. Combined immunodeficiency

D. T cell deficiency

2. A 27-year-old housewife presents to her family physician with a 3 month history of fatigue, and a facial rash which is aggravated by sun exposure. Laboratory tests reveal anemia of 10-gm/dl (normal is 12-14) and immune testing reveals auto-antibodies against DNA. What is the most likely diagnosis?

A. Rheumatoid Arthritis

B. Goodpasture's Syndrome

C. Systemic Lupus Erythematous

D. Graves Disease

E. Myasthenia Gravis

3. A mother is Rh-. Her first baby is Rh+. During the delivery, some of the fetal blood enters the mother's blood stream. She develops a strong response which includes isotype switching to IgG. These antibodies recognize the Rh molecules that were present on the baby's red blood cells. This is unfortunate for the second fetus because IgG antibodies can cross the placenta. Consequently, the IgG can harm the second fetus if it is also Rh+. The newborn second child is suspected of having "hemolytic disease of the newborn". A Coombs test is performed to determine if the cause of the anemia is the presence of the mother's antibodies to the Rh+ molecule on the RBC of this second child. A Coombs test would require:

A. a serum sample containing the mother's antibodies.

B. a blood sample containing the baby's red blood cells.

C. a labeled animal antibody that recognizes the Fc region of IgG.

D. a + b

E. b + c

4. A 24-year-old medical student is having some difficulty in understanding the role that antibodies play in the destruction of cells due to complement lysis. The professor decides that "seeing is believing" and so sends the student to the laboratory. The student is given two flasks. One flask contains antibodies isolated from an individual whose ABO phenotype is A. In the other flask there are red blood cells from an individual whose phenotype is unknown. The student is directed to put the red blood cells into the dish containing agar, and to add the isolated antibodies. In the second step, the student is directed to add all the complement proteins, required for cell lysis, to the agar dish. Following incubation of 37oC, the red blood cells are lysed. The phenotype of the individual from whom the red blood cells were isolated could have been:

A. only AB

B. only B

C. only A

D. either AB, B or A

E. either AB or B

5. A 17-year-old boy suffered an injury to his left eye when, during a car crash, a sharp silver of glass penetrated his eye, damaging his lens and uveal tract. The glass was removed and the injury repaired with complete recovery. However, 3 weeks later he noticed some redness in the left eye and photophobia, followed by pain and severe visual impairment. The left eye was removed and histologic examination showed an extensively infiltrated uveal tract with abundant lymphocutes and mononuclear cells. Two weeks later the other eye began to show the same symptoms. Since the lens was damaged the most likely scenario is that:

A. this is an example of immediate hypersensitivity.

B. sequestered antigen was released and initiated an immune response.

C. some of the glass must have penetrated the right eye as well.

D. the bacteria entered the damaged eye and is causing an infection in both eyes.

1. You are running a tissue typing laboratory and are faced with matching a potential kidney transplant recipient with one of several unrelated donors. Serology indicates 5/6 MHC matches. Which of the following would be the MOST judicious course of action?

A. Proceed with transplantation, with no immunosuppression.

B. Proceed with transplantation, using cyclosporin and prednisone.

C. Wait until you get 6/6 MHC matches.

D. Wait further matching data from MLR (72 hrs).

7. Which one of the following substances works to directly reverse bronchoconstriction and hence is the treatment of choice in severe allergic respiratory distress? (NOTE: ONLY FOUR CHOICES)

A. Cromolyn sodium

B. Antihistamines

C. Epinephrine

D. Blocking antibody

8. A new employee in the SPCA was bitten by a rabid dog. The worker was brought to the Emergency Department even though he had been inoculated for tetanus, only three days before he was bitten. The attending physician ordered treatment with anti-rabies immune human globulin. Which one of the following describes the type of immunization the patient received in the emergency unit?

A. Active natural immunity.

B. Active artificial immunity.

C. Passive natural immunity.

D. Passive artifical immunity.

E. None of the above.

9. You see a young man in the later stages of HIV infection with a markedly decreased CD4+ T-cell count, diarrhea and weight loss, fever and oral candidiasis. Which one of the following is NOT necessarily an anticipated infection in this man?

A. Intestinal and pulmonary cytomegalovirus infection.

B. Systemic herpes virus infection.

C. Pneumococcal pneumonia.

D. Fungal infection

10. A 3-year-old boy has a history of repeated pyogenic (pus-forming) infections. He had normal antibody responses following childhood immunizations and normal recovery from chickenpox and measles. Decreased numbers or functional defects in which of the following cells best explains the cause of his infections?

A. Eosinophils

B. Neutrophils

C. T lymphocytes

D. B lymphocytes

11. A positive DTH skin reaction involves the interaction of:

A. antigen, complement, and lymphokines.

B. antigen-antibody complexes, complement and neutrophils.

C. Memory T cells, cytokines and macrophages.

D. IgE antibody, antigen, and mast cells

E. Antigen, macrophages and complement.

12. A 24-year-old known atopic patient presented to the out patient medical clinic on a quiet spring afternoon with history of dry cough, wheeze and breathlessness. Upon examination, the patient was found to be under to moderate respiratory distress with bilateral lung wheezes. The patient's previous health records revealed that he was treated several times for acute allergic bronchial asthma. All of the following are correct concerning the immunological disorder presented in the above patient EXCEPT:

A. it is immunological E (IgE) mediated reaction.

B. the IgE antibodies that had developed during the initial exposures are bound to the mast cells and basophils.

C. The present clinical symptoms are due to the release of vasoactive amines from the mast cells and basophils.

D. The complement factors 'B' and 'D' have an active role in the release of various immunological mediators of the Type I hypersensitivity.

E. Antihistamines, Epinephrine and Corticosteroids are life saving drugs that are commonly used for above immunological disorder.

13. A patient who is allergic to ragweed developed IgE myeloma (plasma cell that secretes IgE). The myeloma IgE does not react with the ragweed pollen. What would be the effect of his myeloma on the severity of his allergic symptoms during hayfever season?

A. Increased due to his having more IgE.

B. No change

C. Decrease due to the displacement of IgE anti-ragweed on mast cell by myeloma IgE.

D. Increase due to the blocking effect of the myeloma.

14. An Rh-negative mother had an anti-Rh response following the birth of her Rh-positive child. The second fetus was also Rh+ so the maternal anti-Rh antibodies coated the fetus's erythrocytes with antibody. The isotype of these antibodies is

1. IgA
2. IgD
3. IgG
4. IgE
5. IgM

1. With reference to the clonal selection theory, the following are true EXCEPT:

A. B and T lymphocytes of all antigenic specificities exist prior to contact with antigen.

B. each lymphocyte carries an antigen receptor on its surface of only a single specificity.

C. lymphocytes can be stimulated by antigen under appropriate conditions to give rise to progeny with identical antigenic specificity.

D. lymphocytes bear multipotential receptors which become specific after contact with antigen.

16. You are called to assess a patient in the midst of a rapid blood transfusion for an acute blood loss. She has spiked a fever and feels terribly unwell. You stop the transfusion, infuse saline, and draw blood for typing. This patient is O positive. The most likely cause of the reaction is:

A. anti-A reactivity in the recipient.

B. anti-B reactivity in the recipient.

C. anti-A and anti-B reactivity in the donor.

D. could be any of the above

17. A precocious kindergarten child, decided to take her three week old baby brother out of the carriage so that she could play "mother". Unfortunately she tripped, and the baby fell onto an old tin can which the dog had dragged onto the front lawn. Since the baby received a laceration, the mother rushed him to the doctor. Which of the following would be the preferred treatment?

A. A tetanus immune globulin (human) injection this visit, with an injection of tetanus toxoid several weeks later.

B. A mixture of tetanus toxoid and tetanus immune globulin (human) as one injection.

C. A tetanus immune globulin (human) infection this visit, with an injection of tetanus toxiod the following week.

D. Separate injections of tetanus toxoid and tetanus immune globulin in different sites on this one visit.

E. A tetanus toxoid injection this visit, with an injection of tetanus immune globulin (human) approximately one week later.

18. Three- year-old Johnny gets burned in a home accident and requires extensive skin grafting. The attending physician believes that Johnny will tolerate the graft with little, (or no) immunosuppressive drugs since the child has an immunodeficiency disorder. Johnny most likely has:

A. DiGeorge's Syndrome

B. Chronic Mucocutaneous Candidiasis

C. X-linked Agammaglobulinemia

D. Chediak-Higashi Syndrome

E. Chronic Granulomatous Disease

19. Positive skin tests to Candida albicans or tuberculoprotein have certain aspects in common with a reaction to poison ivy. These similarities include the following:

A. They both are chemical responses to caustic irritants.

B. They both are due to IgE antibody.

C. They both occur within 1 hour of antigen exposure.

D. They both are T cell-mediated.

20. A 25-year-old man who recently sustained a severe, dirty laceration of his right foot is brought to you. He has never received any immunizations. At age 7 he had tetanus. He was treated with penicillin and tetanus immune globulin (human). Fortunately, he recovered. Which of the following would you do to prevent tetanus now?

A. Immunize with tetanus toxoid, which will stimulate a secondary antibody response.

B. Administer tetanus immune globulin (human) to passively immunize the patient.

C. Administer tetanus immune globulin (human) in addition to tetanus toxoid, because you cannot depend on a secondary immune response after 18 years.

D. Administer tetanus immune globulin (human) plus tetanus toxoid, because the patient has absolutely no immunity to tetanus.

E. Give no injection, because the residual immunity from the clinical tetanus will protect the patient.

1. You prescribe penicillin for your patient. The patient develops a severe allergic reaction and dies. In this case, the penicillin molecule was probably acting as a (an):

A. adjuvant.

B. hapten.

C. immunologic carrier.

D. immunotoxin

22. Infantile X-linked agammaglobulinemia occurs in male infants, who begin to suffer from recurrent bacterial infections at about 6-12 months of age. Patients have virtually no B lymphocytes. Which of the following is TRUE?

A. The B cell response is intact, but the defect is in antigen processing.

B. The defect may be in stem cell differentiation, as indicated by the occurrence of global immunodeficiency.

C. The disease is most easily diagnosed by measuring CD4+ lymphocytes in the patient's peripheral blood.

D. The age of onset of infections is due to disappearance of maternal antibody.

23. A 57-year-old female complains of cold intolerance and undue fatigue. Her hemoglobin is 13-gm/dl (normal 12-14). Tests indicate auto-antibodies to thyroglobulin, and to microsomal antigens from thyroid epithelial cells. This patient most likely has:

A. Rheumatoid Arthritis

B. Goodpasture's Syndrome

C. Hashimoto's Thyroiditis

D. Systemic Lupus Erythematosus

E. Graves' Disease

24. Which of the following best describes the differences between the classic and alternate complement pathways?

A. The classic pathway results in the lysis of the target cell, which is not the case with the alternate pathway.

B. The alternate pathway requires antibody for initiation, and the classic pathway is antibody-independent.

C. The classic pathway is more active than the alternate pathway.

D. The alternate pathway typically requires C3b for activation, while the classical pathway typically requires antigen-antibody complexes.

25. In the developmental pathway of B lymphocytes, the sequence of events is as follows:

A. Rearrangement of heavy chain, rearrangement of light chain, surface IgM, surface IgD.

B. Rearrangement of light chain, rearrangement of the heavy chain, surface IgM, surface IgD.

C. Rearrangement of light chain, rearrangement of the heavy chain, surface IgD, surface IgM.

D. Rearrangement of heavy chain, surface IgM, rearrangement of the light chain, surface IgD.

E. Rearrangement of heavy chain, rearrangement of the light chain, surface IgD, surface IgM.

1. An antibody directed against the idiotypic determinants of a human IgG antibody would react with:

A. the Fc part of the IgG.

B. an IgM antibody produced by the same plasma cell that produced the IgG.

C. all human kappa chains

D. all human gamma chains

1. "Isotype switching" of immunoglobulin classes by B cells involves:

A. simultaneous insertion of VH genes adjacent to each CH gene.

B. insertion of a single VH gene adjacent to different CH gene.

C. activation of homologous genes on chromosome 6.

D. switching of light-chain types (kappa and lambda)

28. Multiple myeloma is a disease that affects primarily the elderly. It is characterized by the proliferation of a single clone of Ig secreting plasma cells. Sam, a retired engineer has been diagnosed with multiple myeloma in which the plasma cells secrete IgG. In Sam, which of the following would be competitively inhibited due to the multiple myeloma? (Assume that the specificity of the IgG is to an antigen to which Sam would never be exposed.)

A. ADCC mediated lysis of target cells (e.g. virally infected cells) by natural killer cells.

B. Opsonization by phagocytes when the opsonin is IgG.

C. Neutralization of both viruses and toxin

D. Only a and b

E. None of the above

29. Immune surveillance should provide the mechanism for the elimination of tumors that express tumor specific antigens. However, the presence of tumors in patients indicate that there are factors that enable the tumor to escape the immune system, as listed below. Which one of the following is INCORRECT?

A. Tumors may be in privileged sites.

B. Tumors may change their surface antigens (antigenic modulation).

C. Tumor antigens may be recognized by T-cells in the absence of MHC.

D. There may be a hole in the T cell repertoire.

E. There may be blocking antibodies present which bind to soluble tumor antigens.

30. You are a cardiologist and are asked to see a 28-year-old female patient in regards to palpitations and hyperactivity. Her GP tells her she is merely "overanxious", but she is afraid she is having intermittent symptoms of a heart attack! When you see her you are struck by her thick neck and marked protuberance of the eyes (exophthalmos). TSH levels are low. Cariological work-up is normal. Which one of the following tests might you perform to elucidate the basic mechanism that underlies the patient's symptoms?

A. Biopsy of tissue in the neck.

B. Assay immunoglobulin and/or complement activity.

C. Assay for antibody to TSH-receptor.

D. Assay for anti-thyroxin antibody.

31. A 24-year-old primigravida after an uneventful pregnancy delivered a male baby at term. Upon neonatal examination, the baby was found to have low set ears, microcephaly (small head), rock bottom feet, cynosis (bluish discoloration) of the body due to severe congenital anomaly of the heart. Within 24 hours, the child died of severe hypocalcemic convulsions. Autopsy findings revealed redimentary thymus, total agenesis of parathyroid glands and severe ventricular and atrial defects of the heart. Based on the history, what is the most presumptive diagnosis?

A. Bruton's syndrome

B. X-linked agammaglobulinemia

C. Severe combined immunoglobulin deficiency (SCID)

D. DiGeorge's syndrome

E. Selective variable immunoglobulin deficiency

32. A 52-year-old patient returns for a routine follow-up to an Oncology Clinic six months after surgical removal of a tumor. Physical examination and functional inquiry were within the normal limits. However, laboratory results revealed an elevated level of serum carcinoembryonic antigen (CEA). Which is the LEAST likely diagnosis?

A. Cancer of the colon.

B. Stomach cancer.

C. Breast cancer.

D. Testicular teratocarcinoma.

E. Lung cancer.

33. An intern working on your medical service accidentally pricks himself with a needle used to draw blood from a patient believed to be Hepatitis B positive. Optimal post exposure treatment for this person would be:

A. begin vaccination with recombinant Hepatitis B vaccine only.

B. administration of Hepatitis B immune globulin only.

C. administration of Hepatitis B immune globulin and immunization at different sites.

E. none of the above is required if the person is healthy

34. An individual's finger was caught in a car door and as a result sustained significant tissue damage and internal bleeding without breaking the skin or infecting the wound with foreign material. Which of the following is the MOST likely explanation for the resulting inflammation?

A. The inflammation must be the result of nonimmunologic mechanisms because there are no foreign antigens present.

B. The inflammation must be attributable to natural killer (NK) cells because they do not have a unique antigen receptor.

C. The inflammation is related to an increase in the amount of C4bC2a on the surface of the damaged tissue.

D. The inflammation is related to an increased constitutive production of C3b by clotting factors.

35. Three weeks after a bone marrow transplant, the patient began to experience diarrhea and a skin rash on the palms and soles of the feet spreading to the trunk. This is highly suggestive of graft versus (GVHD) host disease. All the following are correct regarding GVHD EXCEPT: