NBME Immunology Practice Test

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• Which antibody crosses the placenta?
• Anti-dsDNA antibodies are highly specific for which disease?
• Which cytokine is most closely associated with promoting IgE class switching in B cells?
• Antigen loading for MHC-II occurs in which compartment after removal of the invariant chain?
• In type IV hypersensitivity, which immune cell type is primarily involved?
• Which antibody is produced in the immediate (early) response to antigen exposure?
• Which immunoglobulin is primarily responsible for mucosal immunity and is produced as a dim er?
• Which T cell subset releases IL-4, IL-5, and IL-10, and what are the actions of these cytokines?
• In Hyper-IgM syndrome, which immunoglobulin is typically elevated?
• MHC class I molecules present endogenous peptides to which T cell population?
• Which immunoglobulin deficiency syndrome is caused by defective CD40 ligand, resulting in failure of class-switch recombination and high IgM with low other isotypes?
• What enzyme complex is essential for V(D)J recombination and is encoded by RAG genes?
• Which ligand interactions correctly match the following cell pairs: APC with CD4+ T cell, virus-infected cell with CD8+ T cell, and CD4+ T cell with B cell?
• Which antibody isotype provides most effective opsonization and activates complement via the classical pathway?
• IFN-γ has what main effect?
• Which receptor family recognizes pathogen-associated molecular patterns and activates innate immune responses upon binding microbial ligands?
• A patient has a malar rash with joint pain. Which diagnosis is most likely and what autoantibody targets?
• IFN-α and IFN-β exert antiviral effects by which mechanism?
• In which hypersensitivity reaction are immune complexes deposited in tissues, activating complement and causing inflammation?
• Which enzymes do NK cells use to kill their targets?
• Which molecule on antigen-presenting cells binds CD28 on T cells to provide the co-stimulatory signal for activation?
• Which cytokines promote Th1 differentiation and cell-mediated immunity?
• Which immunoglobulin requires the J chain to form its polymeric form in secretions?
• Which statement best distinguishes humoral immunity from cell-mediated immunity?
• Pemphigus vulgaris is a Type II hypersensitivity characterized by autoantibodies against which protein?
• What is the principal immunopathology of multiple sclerosis?
• Which MHC complex is expressed on all nucleated cells, and what does it bind?
• Common variable immunodeficiency is best described as which of the following?
• IL-8 primarily recruits which leukocyte?
• Asplenia increases susceptibility to infection with which group of pathogens?
• Which molecule presents endogenous peptides to CD8+ cytotoxic T cells?
• Distinguish humoral from cell-mediated immunity.
• Which cytokines promote B cell class switching to different Ig isotypes (e.g., IgG, IgA, IgE)?
• What is the function of IL-3?
• A patient presents with nervousness, heat intolerance, weight loss, bulging eyes, and stare. Which diagnosis is most likely?
• In mucosal secretions, which antibody is most abundant and typically secreted as a dimer?
• Pemphigus vulgaris is best described as which type of hypersensitivity?
• Chediak-Higashi syndrome is due to a defect in which cellular structure?
• Which cytokines activate NK cells?
• Which combination of markers is characteristic of helper T cells in flow cytometry?
• The polarization of T helper cells toward a Th1 phenotype is driven by which cytokines?
• Chronic rejection involves which components?
• Which statement best describes Hassall's corpuscles?
• Which molecule presents exogenous peptides to CD4+ helper T cells?
• Which statement best describes the clinical use of immune checkpoint inhibitors?
• Which organ absence markedly increases susceptibility to infections with encapsulated bacteria?
• Which antibody is found in secretions and breast milk?
• Which immunotherapy uses monoclonal antibodies to block PD-1/PD-L1 or CTLA-4 to enhance anti-tumor immunity?
• Which virus is the causative agent of AIDS?
• Which virus causes progressive loss of CD4+ T cells leading to AIDS?
• Which T cell subset releases IL-2 and IFN-γ, and what are the actions of these cytokines?
• Name a common intracellular pathogen that survives inside macrophages by inhibiting phagosome-lysosome fusion.
• Deficiency of C5-C8 predisposes to infections with which organism?
• Which immunoglobulin is the first antibody produced during a primary immune response?
• Which autoantibody is most specific for the diagnosis of systemic lupus erythematosus?
• In chronic granulomatous disease, which laboratory finding is characteristic?
• What is the primary function of humoral immunity?
• RAG1/2 recombinases are essential for which process?
• Which fragment of the complement system is primarily responsible for opsonization?
• What is the principle of the Western blot test and what does it detect?
• Bruton’s agammaglobulinemia is caused by a mutation in which gene and what is the consequence?
• Deficiency of which component leads to severe, recurrent pyogenic sinus and respiratory tract infections?
• HIV infection primarily leads to immunodeficiency by which mechanism?
• Where do B cells undergo somatic hypermutation and affinity maturation?
• Which hypersensitivity reaction is mediated by IgE and results in immediate-type allergic responses?
• A patient presents with progressive muscle weakness, ptosis, and diplopia. Which diagnosis is most likely and what is the targeted molecule?
• Pemphigus vulgaris involves autoantibodies against desmoglein in the skin. Which Type II mechanism does this illustrate?
• Which class of molecules presents peptides to CD8+ T cells and is expressed on almost all nucleated cells?
• Which antibody isotype is predominant in secretions and is produced as a dimer?
• What is the primary function of MHC class I molecules in antigen presentation?
• Rituximab acts by targeting which cell surface molecule?
• Which gene is commonly mutated in X-linked agammaglobulinemia?
• What would result from an IL-12 receptor deficiency?
• Which T helper subset primarily provides cytokines that support humoral immunity and B cell responses?
• Which type of hypersensitivity is driven by immune complex deposition in tissues?
• In systemic lupus erythematosus, autoantibodies can target which cellular components?
• Deficiency of CD40 ligand (CD40L) causes which primary immunodeficiency?
• Which of the following forms the C5 convertase in the Lectin/Classic pathway?
• Which of the following statements correctly identifies the C3 convertase of the alternative pathway?
• Which laboratory assay assesses the overall functional activity of the classical complement pathway?
• Which statement correctly describes the structural features of MHC class I and II molecules?
• Which interaction is essential for T cell help to B cells and enables antibody class switching?
• Which cytokines drive class switching to IgE in B cells?
• Which hypersensitivity is primarily a T-cell–mediated delayed-type reaction?
• Scratch test looks for what type of hypersensitivity reaction?
• Negative selection in the thymus ensures central tolerance by eliminating T cells with which property?
• What is required for signal transduction in T cells?
• Hyperacute transplant rejection is characterized by which mechanism and timing?
• Chediak-Higashi syndrome presents with partial albinism, neuropathy, and recurrent infections due to which defect?
• In flow cytometry, which marker is used to identify helper T cells?
• What are the two signals required for class switching for CD4+ T cells, CD8+ T cells, and B cells?
• CH50 assay assesses the activity of which immune component?
• What is the role of C3b opsonization in bacterial clearance?
• Mechanism of superantigens?
• Which of the following forms the C5 convertase in the alternative pathway?
• What is the main function of natural killer (NK) cells in innate immunity?
• Which inheritance pattern is characteristic of Bruton's agammaglobulinemia?
• Abatacept is a fusion protein that inhibits T cell activation by blocking interaction between which molecules?
• What is the function of IL-8?
• Which type of hypersensitivity involves antibodies against cell-surface or matrix antigens leading to cytotoxic injury?
• Which statement about MHC class II molecules is true?
• Which immunoglobulin class triggers eosinophil activation in parasitic infections?
• Which surface marker is unique to natural killer cells?
• How do live attenuated vaccines differ from inactivated vaccines in terms of booster requirements?
• Bacteria producing superantigens?
• Which receptor on B cells binds EBV?
• Hyperacute rejection of a transplanted organ is mediated primarily by which immune mechanism?
• How do natural killer cells detect virally infected cells and mediate cytotoxicity?
• IgE-mediated and mast cell degranulation describe which type of hypersensitivity?
• Graft-versus-host disease occurs in which transplant settings and what are hallmark signs?
• What is the first-line treatment for anaphylaxis?
• Which process allows B cells to change the antibody isotype they produce while preserving antigen specificity?
• Chronic rejection after transplantation is characterized by which features?
• Which cell is the primary professional antigen-presenting cell that primes naive T cells?
• Which cells are the first responders in acute inflammation and are primarily responsible for phagocytosis of bacteria?
• X-linked agammaglobulinemia is due to a defect in which protein?
• Which statement best describes clonal expansion?
• Which complement pathway is initiated by antibody binding to antigen?
• Which immunosuppressive drug inhibits calcineurin, reducing IL-2 production and T cell activation?
• How is the alternative complement pathway activated?
• Autoimmune hemolytic anemia involves which hypersensitivity mechanism?
• Where is the antigen loaded for MHC-I and MHC-II?
• Which sequence correctly describes the major steps of antigen processing for MHC class I presentation?
• Thymus-dependent antigens differ from thymus-independent antigens in that thymus-dependent antigens contain peptide and can be presented by MHC to T cells, enabling class switching and memory.
• Which portion of the antibody determines its isotype?
• Selective IgA deficiency most commonly presents with which feature?
• Which immunodeficiency is characterized by severe combined immunodeficiency with defective thymic T-cell development, often requiring stem cell transplantation for survival?
• Which immunoglobulin isotype is the first produced during a primary immune response?
• Which complement component acts as a potent chemotactic factor for neutrophils?
• What is the role of maternal IgG in immunity?
• What is the role of regulatory T cells (CD4+ CD25+ FOXP3+) in the immune system?
• Absence of MHC-I makes a cell more susceptible to attack by which immune cells?
• Which autoantibodies are commonly associated with systemic lupus erythematosus and lupus nephritis?
• In the thymus, which processes occur?
• Which statement correctly describes MHC class I function?
• Goodpasture syndrome is associated with autoantibodies against which structure?
• A patient’s blood sample returns a negative nitroblue tetrazolium dye test. What is the most likely diagnosis?
• Graft-versus-host disease is best described as which of the following?
• What is the function of TNF-α?
• Deficiency of C3 leads to increased susceptibility to which type of hypersensitivity?
• Which immunoglobulin class predominantly exists as a pentamer in the serum?
• What is the function of IL-1?
• C1 esterase inhibitor's role in the complement system is to:
• B cells localize and proliferate primarily in which site?
• Which cytokine is the key growth factor driving T cell proliferation?
• Which immunoglobulin is deficient in selective IgA deficiency?
• Which encapsulated bacterium is commonly used as an example of risk for individuals without a spleen?
• Which autoimmune disease is associated with anti-dsDNA and anti-Smith antibodies and lupus nephritis?
• Which immunoglobulin is most closely associated with eosinophil activation in parasitic infections?
• Name a primary immunodeficiency characterized by absent B cells and agammaglobulinemia in males due to BTK mutation.
• What is a function of IFN-α, IFN-β, IFN-γ?
• Which statement about central tolerance and peripheral tolerance is correct?
• Class switch recombination to IgG, IgA, and IgE is promoted by cytokines produced by helper T cells.
• Which T cell subset is primarily involved in delayed-type (Type IV) hypersensitivity responses?
• MHC class II molecules are expressed on which cells?
• How do live attenuated vaccines differ from inactivated vaccines in terms of booster requirements?
• Which component is central to all three complement pathways (classical, lectin, and alternative)?
• IL-12 receptor deficiency leads to reduced production of which cytokine?
• Common variable immunodeficiency is characterized by what immunologic defect?
• The membrane attack complex (MAC) is most effective against which type of organisms?
• Which cytokine is primarily produced by activated T cells to promote expansion of the T cell population?
• Which disease is characterized by autoantibodies against desmoglein causing loss of keratinocyte adhesion?
• Which antibody is primarily responsible for type I hypersensitivity reactions?
• What is the function of the C3 convertase in the complement cascade?
• What is the role of positive and negative selection in T cell development, and where do they occur?
• Which function best describes dendritic cells in initiating adaptive immunity?
• HIV infection primarily targets which immune cells?
• Which cells primarily recognize bacterial PAMPs through Toll-like receptors and coordinate early innate immune responses?
• In autoimmune thyroid disease like Graves’ disease, which receptor is targeted by stimulating antibodies?
• What is the initial receptor/co-receptor interaction exploited by HIV to enter CD4+ T cells?
• Which molecule commonly acts as an opsonin?
• A patient presents with glomerulonephritis and pulmonary hemorrhage. What is the likely diagnosis, and what is the targeted molecule?
• Differentiate between Type II and Type III hypersensitivities.
• After splenectomy, the patient is particularly susceptible to infections by which type of organisms?
• Where does central tolerance of B cells primarily occur?
• Which MHC complex is expressed only on professional antigen-presenting cells, and what does it bind?
• What happens when there is defective Th1 responses or a Th2-dominant response?
• Which immune cells kill virally infected cells by releasing perforin and granzyme?
• Which genes encode MHC class I and class II proteins?
• Differentiate between DiGeorge and Omenn syndromes.
• Superantigen exposure causes uncoordinated release of cytokines from which cells?
• Which enzyme rearranges immunoglobulin gene segments in developing B cells to generate diverse antibodies?
• Which cytokine is primarily responsible for driving inflammatory responses and fever during infection?
• Which interaction provides the co-stimulatory signal necessary for naive T cell activation?
• In graft-versus-host disease, which cells are typically responsible for attacking host tissues after bone marrow transplant?
• Which complement pathway is activated by antibodies bound to antigen?
• Autoantibodies stimulating the TSH receptor lead to what effect on the thyroid?
• Which cells kill virus-infected cells and tumor cells via perforin/granzyme pathways?
• Which virus causes progressive loss of CD4+ T cells leading to AIDS?
• CD14 binds LPS and is found on which cells?
• NK cells mediate antibody-dependent cellular cytotoxicity primarily through which surface receptor?
• What is the main difference between hyperacute and acute rejection after transplantation?
• Which vaccine type contains live, attenuated pathogens that replicate in the host but are not disease-causing in healthy individuals?
• What is antibody class switching and what prompts it?
• What is the mechanism of action of rituximab in autoimmune diseases?
• Which mechanism primarily generates antigen receptor diversity during lymphocyte development?
• Which molecule forms the C3 convertase of the Lectin/Classic pathway?
• In flow cytometry, which physical property is assessed by forward scatter?
• Pemphigus vulgaris demonstrates which hypersensitivity type?
• Which antibody class crosses the placenta to provide passive immunity to the fetus/neonate?
• Decay Accelerating Factor (DAF) in the complement system primarily serves to:
• CD8+ T cell–mediated destruction of pancreatic beta cells is a hallmark of which disease?
• What is the role of the alternative complement pathway in host defense?
• Which of the following best distinguishes MHC class II antigen presentation from MHC class I?
• Guillain-Barre syndrome is best categorized as which type of hypersensitivity?
• Autoantibodies in myasthenia gravis target which molecule?
• Which statement accurately describes MHC-I?
• Which of the following is NOT a step in MHC class I antigen processing?
• In X-linked SCID caused by IL2RG deficiency, which immune cell populations are severely reduced?
• Which T cell subset is activated when exogenous antigens are presented on MHC class II molecules?
• Acute cellular rejection of a transplanted organ is primarily mediated by which cells?
• Which antibody forms a pentamer in circulation?
• Which cytokine produced by Th1 cells activates macrophages and promotes IgG class switching?
• In acute cellular rejection of a transplanted organ, which cells are the primary mediators that recognize donor antigens?
• Which receptor on phagocytes recognizes C3b to promote phagocytosis?
• Which statement describes the difference between clonal selection and clonal expansion in adaptive immunity?
• Hassall's corpuscles are located in which organ?
• Which laboratory test is commonly used to detect specific antibodies or antigens in serum and can be confirmed by Western blot?
• Which of the following describes a role of interferon-gamma in immunity?
• Which transcription factor is essential for regulatory T cell development?
• Anti-CCP antibodies are most associated with which disease?
• What is the hallmark of Type IV hypersensitivity?
• The J chain in immunoglobulins is primarily responsible for which function?
• Acute rejection after transplantation is primarily mediated by which immune process and when does it occur?
• Which antibody mediates immunity to parasitic worms?
• Which antibody binds to mast cells?
• What happens if a cell does not express MHC-I?
• Hyperacute graft rejection is best explained by which immunologic mechanism?
• The thymus is the primary lymphoid organ for the development of which cells?
• What is the end product of the complement cascade that forms pores in microbial membranes?
• Which cells respond to bacterial PAMPs via Toll-like receptors and coordinate early innate responses?
• In flow cytometry, which markers identify helper T cells?
• Hereditary angioedema results from deficiency of which regulatory protein?
• What immunologic test detects antibodies against specific proteins by antigen-antibody binding and a colorimetric readout in patient serum?
• Which form of severe combined immunodeficiency is caused by a defective interleukin-2 receptor gamma chain leading to markedly reduced T, B, and natural killer cells?
• Which cytokine is primarily responsible for eosinophil activation and mucosal immunity against parasites?
• Which hypersensitivity type is involved in myasthenia gravis?
• Chronic granulomatous disease is caused by which defect and leads to susceptibility to which organisms?