Welcome to your 6. ⚠️ Hypersensitivity, Immune Tolerance, Autoimmunity, Immunodeficiency & Immunomodulatory Drugs
1.
A 6-month-old infant develops recurrent severe infections caused by several types of microorganisms. Investigation shows marked impairment of both antibody-mediated and cell-mediated immune responses. Which category best fits this disorder?
2.
A genetically susceptible patient develops an autoimmune disorder after recovery from an infection. The immune response generated against microbial antigens cross-reacts with structurally similar host antigens. Which mechanism best explains this event?
3.
A 20-year-old student develops generalized urticaria, wheezing and hypotension within minutes of receiving an antibiotic. Which immune mechanism best explains this reaction?
4.
A patient receiving prolonged corticosteroid therapy for an autoimmune disease is at increased risk of which adverse effect because of immunosuppression?
5.
A patient develops skin rash, diarrhea and liver dysfunction after hematopoietic stem-cell transplantation. Which mechanism best explains these findings?
6.
A transplant patient receives a corticosteroid, a calcineurin inhibitor and an antimetabolite rather than a very high dose of one immunosuppressive drug. What is the main therapeutic rationale for this strategy?
7.
An HIV virion attaches to CD4 on a susceptible host cell through its envelope glycoprotein. Interaction with which additional host molecules facilitates viral entry?
8.
Mycophenolate mofetil suppresses lymphocyte proliferation mainly by inhibiting which enzyme?
9.
Which immune cell is progressively depleted and functionally impaired during untreated HIV infection?
10.
Which condition is an example of an acquired immunodeficiency?
11.
A child has recurrent bacterial respiratory infections due to markedly impaired antibody production. Which category of immunodeficiency is most directly involved?
12.
A renal transplant gradually loses function over a prolonged period. Histology shows vascular narrowing and interstitial fibrosis. Which process best explains these findings?
13.
Which abnormality is the fundamental immunological basis of autoimmune disease?
14.
A 19-year-old man with allergic asthma develops a second wave of wheezing and airway inflammation several hours after exposure to house dust. The early bronchospasm has already subsided. Which process most strongly contributes to this later inflammatory phase?
15.
A patient receiving treatment for malignancy develops marked neutropenia because of bone-marrow suppression. The therapeutic aim is to stimulate recovery of circulating neutrophils rather than suppress immune activity further. Which immunomodulatory approach is most appropriate?
16.
During development in the thymus, a strongly self-reactive T lymphocyte undergoes apoptosis. Which immunological process is being demonstrated?
17.
A transplant recipient receives cyclosporine to reduce T-cell activation. Which intracellular enzyme is inhibited by this drug?
18.
Which hypersensitivity mechanism is responsible for tissue injury caused by deposition of circulating antigen-antibody complexes?
19.
A patient with metastatic malignancy receives an immune checkpoint inhibitor. Several weeks later, he develops inflammatory colitis and dermatitis despite having no previous autoimmune disease. Which mechanism best explains these adverse effects?
20.
A 32-year-old woman presents with weight loss, palpitations and tremor. Thyroid hormone levels are elevated, and antibodies against the TSH receptor are detected. Which immune effect best explains the abnormal thyroid function?
21.
Following renal transplantation, recipient T lymphocytes become activated after recognizing intact donor MHC molecules displayed by antigen-presenting cells originating within the graft. Which mechanism of antigen recognition is occurring?
22.
A patient develops an itchy erythematous rash 48 hours after skin exposure to nickel. Which immune component is mainly responsible for this reaction?
23.
Months after transplantation, donor proteins released from a graft are taken up and processed by recipient antigen-presenting cells. Peptides derived from these proteins are then presented to recipient T lymphocytes. Which pathway is responsible?
24.
Rituximab is used in selected autoimmune diseases and B-cell malignancies. Which cellular target best explains its action?
25.
During B-lymphocyte development in the bone marrow, an immature cell strongly recognizes a self-antigen. Instead of undergoing deletion, it changes its antigen-receptor specificity and is no longer self-reactive. Which tolerance mechanism has occurred?
26.
Which cell population plays an important role in suppressing potentially harmful self-reactive lymphocytes in peripheral tissues?
27.
After HIV enters a CD4-positive lymphocyte, reverse transcriptase generates viral DNA. Which subsequent event is most important for establishing persistent infection within that cell?
28.
A kidney transplant recipient develops worsening renal function and new disturbances of glucose metabolism while receiving an immunophilin-binding immunosuppressant. Which drug most closely matches this adverse-effect pattern?
29.
A renal transplant recipient receives a potent antibody preparation that depletes T lymphocytes. During treatment, the patient develops an infusion reaction, leukopenia and increased susceptibility to infection. Which agent most likely produced these effects?
30.
A child has recurrent infections despite preserved immunoglobulin production and functional T lymphocytes. Neutrophils are present in adequate numbers but fail to kill ingested microorganisms effectively. Which immune-system defect is most likely?
31.
A patient receiving azathioprine for immune suppression develops severe bone-marrow toxicity soon after another medication that inhibits xanthine oxidase is added. Which pharmacological change best explains the increased toxicity?
32.
A transplanted kidney becomes cyanotic and fails almost immediately after restoration of blood flow. Pre-existing antibodies against donor antigens are detected. Which type of rejection is most likely?
33.
A patient with recurrent infections has normal lymphocyte numbers and normal phagocyte function. Further testing demonstrates defective formation of the membrane attack complex and impaired complement-mediated microbial killing. Which category of immunodeficiency is most likely?
34.
Two siblings carry a particular HLA allele associated with increased susceptibility to an autoimmune disorder. What property of HLA molecules most directly explains such genetic associations?
35.
Which combination best contributes to the development of many autoimmune diseases?
36.
Which immunosuppressive drug acts mainly by inhibiting mTOR and reducing IL-2-driven lymphocyte proliferation?
37.
A mature self-reactive lymphocyte recognizes a self-antigen but does not receive adequate co-stimulatory signals and becomes functionally inactive. Which mechanism has occurred?
38.
A woman with a severe autoimmune inflammatory disorder improves after treatment with a systemic corticosteroid. The drug suppresses several inflammatory cytokines and reduces leukocyte activity. Which cellular action best explains these broad effects?
39.
A 46-year-old renal transplant recipient develops graft tenderness and rising serum creatinine 10 days after transplantation. Biopsy shows a prominent lymphocytic infiltrate with injury to graft cells, without widespread intravascular thrombosis. Which process is most likely responsible?
40.
A patient with myasthenia gravis has antibodies that interfere with acetylcholine receptor function. This disease is best classified as which type of hypersensitivity?
