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USMLE Step 1 Immunology

Subjects : health-sciences, usmle-step-1

Instructions:

Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. which of the IL2 inhibitors produce nephrotoxicity? thrombocytopenia/leukopenia?
Yes
Negative nitroblue tetrazolium reduction test
IgG
Cyclosporine and tacrolimus; sirolimus (as well as hyperlipidemia)

2. What do multimeric antibodies require for assembly?
A j chain
A recomb cytokine of IL 2; RCC and metastatic melanoma
Histamine (causes vasodilation) - leukotrienes (causes bronchoconstriction) - chemotaxins for eos - and heparin (increased blood flow needs to be anticoagulated!)
Anti IF

3. What type of side chains are found on Fc region of an antibody?
...
The red pulp of the spleen its where the vasculature channels go through and interact with the parenchyma of the spleen (has macrophages) which empty in the sinuses; they are both encapsulated (with trabeculae) secondary lymphoid organs that trap ant
NK cells
Carbohydrate

4. Give three examples of bacteria that use antigenic variation and how.
The place of T cell diff and maturation; ant mediastinum above heart; yes; 2
Mycobacterium Tuberculosis - Mycobacterium Avium Intracellulare; Toxoplasmosis Gondii
An acidified endosome with the antigen fuses with the MHC which causes the release of the invariant chain Which is sitting in spot of antigen and stabilizing the MHC II
Salmonella - 2 flagellar variants; Borrelia (relapsing fever); and Neisseria gonorrhoaea - pilus protein

5. In thymic development - What is the positive selection? negative selections?
A chemotactic factor for neutrophils
When you select for which MHC it will have; take out the lymphs that self react
No because no peptide fragment!
Sinusitis - otitis media - pneumonia

6. Name three things that IL 1 does as a cytokine. other than the liver - who secretes IL 1
Activate macrophages
Induces fever - chemokine secretion to recruit - activates adhesion molecules; macrophages
MHC I; from RER with help of the B2 microglobulin
If there is class switching and plasma cell production (that is when memory cells are produced)

7. what happens in order for class switching to occur (after being activated by IL and cd40 L)?
Anti IF
Its involved in inflammation and results in anaphylaxis and neutrophil chemotaxis.
Recomb cytokine of GCSF (granulocyte macrophage colony stimulating factor; for recovery of bone marrow
Alternative splicing of mRNA

8. What lymph node drains the rectum (above the pectinate line)?
heavy chains
Internal iliac
MS
T cell dysfunction

9. What are the autoantibodies for hashimotos?
C3b; coating of a pathogen with molecules that promotes phagocytosis; IgG and CRP
Type III hypersensitivity where an internal antigen antibody complexes activate classical complement pathway resulting in C3a neutrophilic chemotaxis and neutrophilic lysosomal death. SLE
Antimicrosomal and antithyroglobulin
Anemias (esp due to renal failure)

10. which antibodies prevent antigens from binding mucosal surfaces?
IgA
pale central germinal centers
Opsonization (Brutons agammaglobulinemia) - adhesion (Leukocyte adhesion defect) - phagocytosis (chediak higashi syndrome) - respiratory burst (chronic granulomatous disease)
False! B cell class switching requires a second signal

11. What are the major functions of Antibodies?
Immunosuppression after kidney transplantation
Kill them because they have CD16 on them that recognize the FcG portion
Negative!
Opsonize bacteria (for enhanced phagocytosis) - neutralize viruses (igG) - activate complement (igM and igG) - sensitize mast cells (igE)

12. What is the toxicity of azathioprine?
MHC I/CD8 and IL2/IL 2 Receptor (IL 2 is from Th1!); cytoxicity!
...
Its a serine protease that activates apoptosis; NK and CD8
Hereditary angioedema; PNH

13. when can graft versus host disease? What is the result?
T cell precursor
delayed!
In any situation where immunologically competent cells are transplanted into immunologically crippled recipient; graft rejects all the cells due to foreign proteins resulting in severe organ dysfunction
IL 4 - 5 - 10 - 6

14. What is the most common example of passive immunity?
Activates Th1 helper cells; Macrophages
T cell dysfunction
IgAs in mothers breast milk!
Fibrosis of blood vessels and graft tissue from ischemia; obliterative vascular fibrosis with intimal thickening

15. What is thrombopoietin used for?
Defect in CD40L results in inability to class switch; a lot of IgM and no IgG - A - E
Type II hypersensitivity - complement dependent resulting in phagocytosis of RBCs coated with C3b by fixed macrophages in the spleen; Group O mother has anti A - B - IgG Abs that cross placenta and attach to fetal blood group A or B RBCs
Cytokine IL 10 secreted by Th2
Thrombocytopenia

16. What are the autoantibodies for myasthenia gravis?
Acts as second signal on B cells to induce class switching to IgA; also stimulates eosinophils
Leukocyte adhesion defect; ataxia telangietasia; ataxia telangiectasia; chediak higashi syndrome; IgA def; Digeorge syndrome; Jobs; Chediak Higashi
Anti Ach receptor
Bind FcG for antibody dependent cellular cytotoxicity

17. where are complements produced?
Coarse Faces - cold (noninflamed d/t inability to attract neutrophils) staph abscesses - retained primary teeth - high igE - dermatologic problems (eczema)
Liver! (they are proteins circulating in the blood)
Immunosuppression after kidney transplantation in combination with cyclosporine and corticosteroids
T cell activation; no with CD 4 or CD 8

18. The Fc region is found on the...
carboxy terminal
Proteins; IgG - IgM - endotoxin (microbial surfaces in general - nonspecific ones also) - mannose binding Lectin; classic - alternative - MB pathway (resp)
...
The place of T cell diff and maturation; ant mediastinum above heart; yes; 2

19. Describe the interstitial tissue of a spleen including the sinuses. What type of cells are found in the four structures (cortex - paracortex - medulla and sinuses)?
Immunosuppression after kidney transplantation in combination with cyclosporine and corticosteroids
Periarteriolar lymphatic sheath in the white pulp that surround that dead end of the capillaries in the red pulp - contain T cells
The interstitial tissue of a lymph node is structured into the cortex on the outside Which is densely cellular which transitions into the paracortex Which is less dense and then the medulla Which is least dense. The cells that inhabit these tissues a
Cell mediated due to T cell cytotoxicity reacting to foreign MHCs; few weeks after

20. The ______ in the BM are DN - the DP are in the cortex of thymus
Superficial inguinal
No because no peptide fragment!
acute phase reactants
T cell precursor

21. Which disease is associated with DR7?
Fibrosis of blood vessels and graft tissue from ischemia; obliterative vascular fibrosis with intimal thickening
TNF alpha and IL1
MAC (membrane attack complex) Which is activated by C5b - C9 and results in lysis and cytoxicity by creating pores in the target membrane; encapsulated organisms (S. pnuemonia - H.influenzae - B perfussis for example) and other organisms with non pep
Steroid responsive nephrotic syndrome

22. What does IL 5 do?
The patient could become cyanotic in the OR!
Bind FcG for antibody dependent cellular cytotoxicity
Superior mesenteric
Acts as second signal on B cells to induce class switching to IgA; also stimulates eosinophils

23. which type of immunity is slow but long lasting? as opposed to...
Active; passive - fast but short half life (3 weeks!)
heavy chains
Binds to Mtor which (like tacrolimus and cyclosporine just in a different pathway) inhibits IL 2 production and thus t cell proliferation in response to IL 2 producton
In the germinal center of secondary follicles (In the paler center)

24. In order to produce Antibodies - does the antigen have to be phagocytosed? give an example with a bug and an autoimmune (type II hypersensitivity for example).
Interferon gamma and IL 2
Recurrent sinopulmonary bacterial infections after 6 months (d/t mothers igGs transplacental) due to opsonization defect
No! That is why they are different from T cells - they can recognize antigens in free solution; if a bug has a peptide fragment that a mature naive B cell recognizes it will bind to it and cause activation - it then gets activated into a plasma cell!
Anti Ach receptor

25. What is the main function of IL 12? other than macrophages who else can release IL 12?
IgG
MHC I/CD8 and IL2/IL 2 Receptor (IL 2 is from Th1!); cytoxicity!
Remove encapsulated bacateria
Induce differentiation of T cells into Th1 helper cells and activates NK cells also; B cells

26. What is the monoclonal antibody to IL2 on activated T cells? What is it used for?
Type IV
Daclizumab; prevent ACUTE rejection of renal transplant
Psoriasis - Ankylosis Spondylitis - IBD - Reiters; all seronegative spondylopathies
When you select for which MHC it will have; take out the lymphs that self react

27. What lymph node drains the upper limb?
Axillary
Antibody mediated cytotoxicity; either complement dependent or complement independent
P - ANCA (antimyeloperoxidase); in neutrophil; p= perinuclear
IgE; by activating eosinophils

28. which of the hypersensitivity reactions is not Ab mediated?
Type IV
Histamine (causes vasodilation) - leukotrienes (causes bronchoconstriction) - chemotaxins for eos - and heparin (increased blood flow needs to be anticoagulated!)
A B and T cell disorder; X linked recessive; progressive deletion of B and T cells; thrombocytopenic purpura - infections - eczema; high IgE and IgA but low IgM
pentamer

29. Which Thelper cell activated Macrophages? by secreting what? what else does Th1 secrete? For what?
Activate B cells - activate Macrophages - kill viruses directly - delayed cell mediated hypersensitivity - acute and chronic rejection
C3b; coating of a pathogen with molecules that promotes phagocytosis; IgG and CRP
Popliteal
Th1; interferon gamma; IL 2 for cytotoxic T cell activation

30. What lymph node drains the stomach?
The place of T cell diff and maturation; ant mediastinum above heart; yes; 2
Celiac
Tumor cells and virally infected cells; perforin pore to secrete granzymes through it; apoptosis
Remove encapsulated bacateria

31. Type Iv hypersensitivity is...
secondary
Induce differentiation of T cells into Th1 helper cells and activates NK cells also; B cells
delayed!
cannot cross placenta

32. What does Interferon alpha and beta do? how?
It is a localized type III hypersensitivity reaction to an external antigen; localized instead of systemic; ?; intradermal injection of the antigen results in antibody production and antigen antibody complexes deposit in the skin
Antiviral by inducing ribonuclease which degrades only viral mRNA (prevents protein synthesis) and activates NK cells to kill virus infected cells
1) susceptibility to encapsulated organisms 2) Howell Jolly Bodies 3) Target cells 4) Thrombocytosis
MHC II - B7 - CD40 and CD14; CD40 and D14 for FcG and C3b resp

33. What is the pathogenesis of chronic transplant rejection? When does it occur? is it reversible?
Defect in BTK a tyrosine kinase gene; failed maturation of B cells; X linked recessive
...
T cell and antibody mediated vascular damage due to MHC non self being recognized as self by self lymphocytes and resulting in attack of the foreign antigens it presents (all of them); months to years after; no :(
IL 1 and IL 6

34. What does IgA pick up from epithelial cells before being secreted?
Th cells fail to produce interferon gamma; a lot of IgE
Secretory component
Its a serine protease that activates apoptosis; NK and CD8
Humoral

35. What are the function of B cells?
Anti Jo -1
Activate B cells - activate Macrophages - kill viruses directly - delayed cell mediated hypersensitivity - acute and chronic rejection
encapsulated
Make antibody - allergy type 1 (igE) - Cytotoxic and immunecomplex hypersensitivity type II and III (igG); hyperacute organ rejection is Ab mediated

36. What type of cells do NK cells attack? with What tools? by necrosis or apoptosis?
A recomb cytokine of IL 2; RCC and metastatic melanoma
CRP - C3b - IgM
Tumor cells and virally infected cells; perforin pore to secrete granzymes through it; apoptosis
Antiviral by inducing ribonuclease which degrades only viral mRNA (prevents protein synthesis) and activates NK cells to kill virus infected cells

37. How do you test for type III hypersensitivity?
Antidote for digoxin intoxication
Type IV
Anti glutamate carboxylase and anti insulin
Immunoflourescent staining of tissue biopsies

38. What lymph node drains the sigmoid colon?
An alpha and beta chain; only on APCs; TCR and CD4; extracellular (phagocytosed by APCs)
Inferior mesenteric
A j chain
IgE

39. The alternative pathway is the only constutively...
Defect in CD40L results in inability to class switch; a lot of IgM and no IgG - A - E
active complement pathway
Type IV
Fab portion

40. Which is the most abundant antibody in blood?
T cells react to the angtigen and activate leukocyted (macrophage acitivation)
C - ANCA (antiproteinase); in neutrophil; c= cytoplasmic
IgG
Tumor cells and virally infected cells; perforin pore to secrete granzymes through it; apoptosis

41. What are the autoantibodies for Mixed connective tissue disease?
A recomb cytokine of IL 2; RCC and metastatic melanoma
MHC I - CD16 - CD56
Anti U1 RNP (ribonucleoprotein)
Anti smooth muscle

42. What cytokines to Th2 secrete?
type four
Defect in CD40L results in inability to class switch; a lot of IgM and no IgG - A - E
Secretory component
IL 4 - 5 - 10 - 6

43. What is the general structure of an Ab?
Th1; interferon gamma; IL 2 for cytotoxic T cell activation
Give a vaccine with a peptide comp from it that the cell mediated immunity otherwise cant get to! like h.influenzae vaccine. then class switching and memory response can occur
Cyclosporine and tacrolimus; sirolimus (as well as hyperlipidemia)
2 heavy chains and two light chains

44. where do somatic hypermutation and class switching occur?
First a B cell gets sensitized to an allergen - after sensitization - it gets induce by Th2 secreting IL4 to class switch from IgM to IgE - next time blood stream is exposed to allergen these antigens cross like IgEs on mast cells and result in chemi
Intracellular pathogens (acute and chronic viruses and virally induced cancers)
In the germinal center of secondary follicles (In the paler center)
Antigliadin - antiendomysial (both are IgAs - anti tissue transgluataminase igA)

45. The lymphocytes are ________ origin
Severe pyogenic infections early in life
mesenchymal
Opsonization (Brutons agammaglobulinemia) - adhesion (Leukocyte adhesion defect) - phagocytosis (chediak higashi syndrome) - respiratory burst (chronic granulomatous disease)
Receiving preformed Antibodies

46. What does IgE do on the surface of the mast cell to induce inflammatory mediator release?
Recomb cytokine of GCSF (granulocyte macrophage colony stimulating factor; for recovery of bone marrow
Celiac
Cross link
Wiskott Aldrich syndrome

47. What is the autoantibody for SLE that is nonspecific? Specific?
IgM and IgA
Anti nuclear Antibodies (ANA); Anti dsDNA - anti Smith
Septicemia with neisseria; because at least you have C3 to act like a neutrophilic chemotactic and an acute phase reactant
The place of T cell diff and maturation; ant mediastinum above heart; yes; 2

48. What is oprelevkin? and What is it used for?
Recom IL 11; thrombocytopenia
IgE
Graves
Anti alpha subunit 3 of collagen on type IV bm

49. What is the pathogenesis of IgG AIHA ABO hemolytic disease of a newborn? describe what happens.
Type II hypersensitivity - complement dependent resulting in phagocytosis of RBCs coated with C3b by fixed macrophages in the spleen; Group O mother has anti A - B - IgG Abs that cross placenta and attach to fetal blood group A or B RBCs
Liver! (they are proteins circulating in the blood)
Induces fever - chemokine secretion to recruit - activates adhesion molecules; macrophages
DM type I

50. What is the difference of IgE AIHA and IgG AIHA if they are both complement dependent type II hypersensitivities?
Antiviral by inducing ribonuclease which degrades only viral mRNA (prevents protein synthesis) and activates NK cells to kill virus infected cells
Graves
T cell dysfunction
In IgE AIHA- it results in MAC attack (remember IgE is not an opsonin!) - in IgG AIHA C3b (and IgG) opsonization results in phagocytosis by fixed macrophages in the spleen