Fill-In-The-Blank: these statements are conceptual; as such there may be other correct answers in addition to the ones provided.
In humans, MHC molecules are called .
MHC molecules come in thousands of different .
Inappropriate immune reactions against foreign antigens are called , whereas reaction against self antigens are called .
Rapid onset allergic reactions against things like cat saliva or ragweed are called type- or . These reactions are caused by the crosslinking of antibodies on the surface of .
Degranulation of mast cells releases leukotrienes, prostaglandins and . On the skin, this degranulation cause , more formally known as .
If these reactions go out of control, they can cause systemic .
In contrast, slow onset allergies against things like poison oak or nickel are called type- or . These reactions are mediated by dendritic and .
Rheumatic heart disease, where a self antigen is mistaken for a foreign antigen, is an example of .
Tissue damage and/or infection can bring on autoimmune disease by uncovering hidden antigens AND providing that stimulate innate immunity.
Soluble immune complexes are found in type- hypersensitivity reactions.
Delayed-Type Hypersensitivity (DTH) reactions are also know as type- hypersensitivity reactions.
Autoantibodies against bound (surface) antigens are found in type- hypersensitivity reactions.
Immediate hypersensitivity due crosslinking of IgE on mast cells is found in type- hypersensitivity reactions.
T-cells that inhibit autoimmune reactions are called T-cells.
Severe Combined Immunodeficiency (SCID) is an example of a immunodeficiency.
Steroids, TB, HIV, advanced cancer, and age can all cause immunodeficiency.
Immunodeficient patients can develop infections.
Transplanting a blood type A organ into a blood type B patient will result in rejection.
Most transplant patients will undergo at least one bout of .
Ultimately the only treatment for chronic rejection is .
Multiple Choice Questions:
1) IgA deficiency is a fairly common and mild immunodeficiency. Many patients don't know they have it, but they may be at increase risk for: Autoimmune Diseases Mucosal Infections Allergies All of the above
Explanation: IgA has both immunoprotective and immunoinhibitory properties. Healthy mucosa is required for the prevention of allergic reactions. People with selective IgA deficiency may be at risk for any of these conditions.
2) Recent studies of the Tsimane, an indigenous people of Bolivia, have shown that the incidence of allergies and asthma are non-existent, but the patients have markedly elevated levels of C-reactive protein (CRP), eosinophils, and serum IgE. The best explanation for these findings is: Their hunter-gatherer existence ensures adequate exercise They live far away from urban centers and have minimal exposure to pollutants They are chronically infected with parasites (helminths) They have a varied diet of fruits and vegetables but limited meat
Explanation: Although all 4 options are true statements, elevated CRP levels indicate an ongoing chronic inflammatory state. Increased eosinophils and IgE indicate exposure to parasites. There is some evidence to suggest that exposure to parasites minimizes the risk of developing allergies and autoimmune disease (the so-called "hygiene hypothesis")..
3) Systemic mastocytosis is a disease where patients have far too many mast cells in their body. Which of the following are symptoms of the disease: Urticaria (hives) Diarrhea Anaphylaxis All of the above
Explanation: Degranulation of mast cells leads to type-I immediate hypersensitivity reactions. Systemically it can lead to anaphylaxis.
4) You see a patient with autoimmune hemolytic anemia, an autoimmune disease characterized by autoantibodies that bind the surface of red blood cells (RBC) causing them to lyse. What type of hypersensitivity reaction is it: type-I type-II type-III type-IV
Explanation: Although RBCs are in the circulation they are not "soluble". Therefore this is a type-II reaction.
5) You see a child who has been diagnosed with atopic dermatitis. You know that this skin condition is the result of: IgE-mediated mast cell degranulation IgA deficiency Delayed-type hypersensitivity A primary immunodeficiency
Explanation: Atopy or atopic refers to the propensity to have inappropriate type-I hypersensitivity reactions (due to IgE-mediated mast cell degranulation).
6) Lupus patients often have immune complexes consisting of antibody and soluble, nuclear proteins in their blood. This is an example of what type of hypersensitivity? Type I Type II Type III Type IV
Explanation: Type III reactions involve soluble antigen and the formation of immune complexes
7) SCID is short for... Self Contained Immune Domain Severe Combined Immune Deficiency Sub Cutaneous Immune Deposit Surface Complement Inhibition Disease
Explanation: SCID is a severe form of primary immunodeficiency
8) Which of the following are NOT typically involved in Type IV hypersensitivity reactions? Dendritic Cells T-Cells Mast Cells B-Cells Both C and D
Explanation: Type IV hypersensitivity reactions are due to the interactions of antigen, DCs, and T-cells.
9) Two drugs that are helpful in treating acute type-I hypersensitivity reactions are: Antihistamines (e.g. Benadryl) Epinephrine (e.g. Epi-pen) Anti IL-6 antibodies Both A & B
Explanation: IgE-mediated degranulation of mast cells releases histamines which can be counteracted with anti-histamines. In severe systemic anaphylactic reactions, epinephrine is useful.
10) Regulatory T cells are responsible for... Bureaucratic red tape Preventing autoimmune disease Promoting type IV hypersensitivity reactions Stimulating innate immune responses
Explanation: When stimulated by a specific peptide antigen, regulatory T-cells inhibit rather than promote immune reactions.
11) Which of the following is true about acute cellular rejection? It can occur within weeks / months after engraftment It can be T-cell or antibody mediated It can be controlled using immunosuppressive therapy It can lead to chronic rejection All of the above
Explanation: All are correct!
12) Patients with group A strep infections (e.g. strep throat) are treated with antibiotics primarily to prevent... Sepsis Lupus Rheumatic heart disease Asthma Goodpasture syndrome
Explanation: Group A strep contains a molecular mimic that cross-reacts with proteins found in the heart muscle & valves.
13) A PPD reaction (T.B. test) is an example of which type of hypersensitivity reaction? Type I Type II Type III Type IV
Explanation: PPDs are a delayed type hypersensitivity reaction