Immunology USMLE

Secretes interleukin (IL-1) to promote T cell activity

Expresses high levels of major histocompatibility complex (MHC) class 2 on its cell membrane

Macrophage precursor

Total levels and concentration of this antibody can be estimated using radioimmunoabsorbent test (RIST) and radioallergosorbent test (RAST)

What term is used to describe the portion of a molecule that serves as an antigen determinant?

Type 1 reactions involve both primary and secondary mediators. Explain the difference between the two

Histamine and proteases/hydrolases are primary mediators. What are their functions?

Leukotrienes B4, C4, D4, and E4 and cytokines are secondary mediators. What are their functions?

What are the two phases of type I hypersensitivity reactions?

What are the symptoms of the immediate phase of type 1 reactions?

What are the symptoms of the late phase of type I reactions?

What are the common clinical manifestations of type I hypersensitivity reactions?

What are the consequences of IgE mediated responses in the gastrointestinal (GI) tract, airways and blood vessels?

What is the most severe form of type I hypersensitivity reactions?

What are some common cause of anaphylaxis

What drugs are commonly given to prevent anaphylactic reactions?

How does cromolyn sodium work on mast cells?

What do patients with atopic disorders (asthma, eczema and urticarcia) have elevated levels of?

Drugs commonly cause hypersensitivity reactions by acting as haptens. What is a hapten and how does this induce hypersensitivity reactions?

What are type 2 hypersensitivity reactions also known as?

What reaction occurs in type 2 hypersensitivity?

For each disease associated with type 2 hypersensitivity, name the target:

Warm/cold autoimmune hemolytic anemia

Erythroblastosis fetalis

Pernicious anemia

Antineutrophil cytoplasmic antibodies (ANCA) vasculitis

C-Anca

P-ANCA

Goodpasture syndrome

Rheumatic fever

Graves disease

Myasthenia gravis

Lambert-Eaton myasthenic syndrome

Pemphigus vulgaris

Bullous pemphigpoid

What drugs are associated with warm autoimmune hemolytic anemia? Of these, which drug (s) are associated with haptens? Which drug (s) generate autoantibodies?

What test is positive in warm autoantibody disease?

Cold autoimmune hemolytic disease has an acute and chronic form. What infections are associated with the acute form? What type of neoplasm is associated with the chronic form?

How is autoantibody is Grave disease different from other autoantibodies?

What type 2 disease is mediated by an autoantibody that shares the same target as exfoliatin (Staphylococcus toxin in scaled skin syndrome) ?

What region of the autoantibodies attaches to the antigen in type 2 reactions? What region binds the complement?

What are type 3 hypersensitivity reactions also known as?

In type 3 reaction, formation of large antigen-antibody immune complexes deposit into tissues and fix complement. How does activation of complement result in tissue damage? How does this differ from type 2 hypersensitivity?

One important factor that determines if antigen-antibody complexes deposit into tissue is the relative amount of antigen versus antibody. Why do antigen-predominant complexes typically form pathogenic deposits?

What is a pathology term used to describe type 3 inflammation in vessels?

What are the two typical type 3 hypersensitivity reactions?

Describe how an Arthus reaction is evoked:

Hypersensitivity pneumonitis (farmer lung) is an Arthus reaction caused by inhalation of what bacteria?

What is the typical clinical presentation of serum sickness?

What drug is associated with serum sickness?

What re well-known disease that are resulted from type 3 immune complex deposition?

What are type IV hypersensitivity reactions also known as?

What are the two types of type IV hypersensitivity?

In the first step of classic dth, macrophages present antigens to CD4+ helper cells and induce CD4+ cells to become what specific subtype? What cytokine secreted by macrophages drives this process?

These Th1 cells often remains in the circulatory system as memory cells. When the body is exposed to the antigen for a subsequent time, what cells do these Th1 cells activate? What cytokine secreted by the Th1 cells drives this process?

What functions are enhanced when a macrophage is activated?

What is seen histopathologically in classic DTH?

What pathogens trigger classic DTH?

A positive tuberculin skin test is a classic DTH. Describe how a positive test presents

How does contact dermatitis differ from classic DTH?

What are common contact allergens?

What are the common symptoms of contact dermatitis?

What is the role of MHC class 2 proteins on donor cells in graft rejection?

What are the immunological contraindications to organ transplantation?

What does a lymphocyte cross-match do?

What are the typical mechanisms by which transplant recipients are presensitized to donor antigens

The two types of immunity are innate and adaptive immunity. What cells mediate innate immunity?

Adaptive immunity is composed of two responses. What cells mediate each response?

B and T cell proliferation in early lymphocyte maturation is stimulated by which cytokine?

What interacts with the T-cell receptor (TCR) of an immature, double-positive T cell (CD4+/CD8+) to signal differentiation into a single positive cell? In what organ does this occur?

What two processes eliminate immature T cells lacking proper antigen receptor specificities?

What mechanism drives cell elimination in positive selection?

Apoptosis of T helper cells (CD4+, Th) or cytotoxic T cells (CD8+, Tc) bearing TCRs for self-proteins is the result of what process?

What cytokine released by activated Th further stimulates Th-cell survival/proliferation?

Name the two signals that are needed to activate T cells

What is the result of an interaction between a T cell and an APC in the absence of costimulation?

What T cell protein displaces CD28 from B7, inhibiting T cell activation and ensuring T cell homeostasis?

What is a consequence to T cells that lack CTLA-4?

Which MHC class molecule presents processed antigens from organisms that have been phagocytosed? What cells possess this MHC class?

What cells function as professional APCs?

What is the source of antigen presented by MHC-1 molecules? What cells possess this class?

What is the cluster of polypeptides present in all T cells that is important in signal transduction by the TCR?

Induction of which of the T-cell helper lines (Th1 or Th2) elicits a more effective response against intracellular pathogens such as Mycobacterium tuberculosis?

Which cytokine released by Th1 cells is involved in macrophage activation?

What other signaling pathway results in macrophage activation?

What transcription factor is involved in both y-interferon and CD40/CD40L signaling?

How do macrophages respond to y-interferon and CD40/CD40L signalling?

Once activated, what are the major cytokines released by macrophages?

What are the microbicidal substances produced by activated macrophages?

Total levels and concentration of this antibody can be estimated using radioimmunosorbent test (RIST) and radioallergosorbent test (RAST)

What term is used to describe the portion of a molecule that serve as an antigenic determinant?

What term is used to describe a small molecule that can serve as an antigenic determinant only if it is attached to a large carrier molecule?