2023 FEBRUARY SUMMATIVE

A patient was undergoing a series of surgical procedures requiring general anesthetic. At the third procedure, he suddenly became hypotensive with marked cardiac arrhythmia. In addition, his breathing became difficult due to extensive bronchoconstriction and obstructive laryngeal edema. Despite the efforts of the surgical team, the patient developed severe and permanent brain damage due to hypoxemia. It was subsequently discovered that the patient had developed IgG antibodies to the anesthetic gas and this had resulted in an anaphylactoid response to the anesthetic. What type of reaction caused this condition?

• a. Type I

             

             

             

• b. Type II

• c. Type III

• d. Type IV

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. The ability of this organism to cause disease is related to it’s ability to infect, persist  in, and replicate within macrophages. The lepromin skin test is used to determine what type of leprosy a person has. In this test, inactivated Mycobacterium leprae organisms are injected just beneath the skin. At the site of injection, a person with a positive test will develop an area of induration with erythema peaking around 48 hours after the injection. If this test measures a hypersensitivity reaction against the organism, what type of hypersensitivity reaction is it intended to detect?

• Type I

• Type IV

• Type II

• Type II or III

• Type III

13. The principle difference between type II and type III hypersensitivity is

           

           

           

           

• a. the class (isotype of antibody)

• b. whether the anticody reacts with the antigen on the cell or reacts with antigen before it interacts with the cell

• c. the participation of complement

• d. the participation of T cells

How is this reaction probably mediated by? A child stung by a bee experiences respiratory distress within minutes and lapses into unconsciousness.

           

           

           

           

           

• a. IgE antibody

• b. IgG antibody

• c. sensitized T cells

• d. complement

• e. IgM antibody

15. A patient with severe asthma gets no relief from antihistamines. The symptoms are MOST likely to be caused by:

           

           

           

           

• a. IL-2

• b. leukotrienes

• c. serotonin

• d. bradykinin

16. Hypersensitivity to penicillin and hypersensitivity to poison oak are both:

           

           

           

           

• a. mediated by IgE antibody

• b. mediated by IgG and IgM antibody

• c. initiated by haptens

• d. initiated by Th2 cells

Your patient has been treated for endocarditis with Penicillin G for the past 2 weeks. She now has fever and maculopapular erythematous rash over her chest and abdomen. A urinalysis shows significant protein in the urine. If the fever, rash and proteinuria are immunologic in origin, which one of the following is MOST likely to be involved?

           

           

           

           

           

• a. IgG and complement

• b. IgE and histamine

• c. IL-2 and cytotoxic T cells

• d. Gamma interferon and macrophages

• e. latex gloves were used

A child disturbs a wasp nest, is stung repeatedly, and goes into shock within minutes, manifesting respiratory failure and vascular collapse. This is MOST likely due to;

         

       

         

          

         

•    a. systemic anaphylaxis

•      b. serum sickness

•    c. an arthus reaction

•   d. cytotoxic hypersensitivity

•    e. spheksophobia

In Henoch-Schonlein purpura, what is the reason for the purpuric rash?

                      

                      

     

• a. bacteria that adhere to vascular walls including necrosis

• b. IgM immune complexes that induce vasculitis

• c. immune-mediated destruction of bacteria, releasing endotoxin

• d. the disease is the result of superantigen activity by the infectious agent

• e. IgA immune complexes that induce vasculitis

. A delayed hypersensitivity reaction is characterized by:

           

           

           

           

 

• a. edema without a cellular infiltrate

• b. an infiltrate composed of neutrophils

• c. an infiltrate composed of helper T cells and macrophages

• d. an infiltrate composed of eosinophils