Test your basic knowledge |

USMLE Step 1 Immunology

Subjects : health-sciences, usmle-step-1

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

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. in which immunodef order do you see a lot of pus? no pus?
CGD; Jobs syndrome (defect in Neutrophil chemotactic response)
Type III hypersensitivity where an exogenous antigen results in a systemic antigen antibody complex disease (takes around 5 days after exposure for the Abs to develop); immune complexes then fix in tissue and activate complement resulting in tissue d
High endothelial venules are post capillary cuboidal endothelial cells that contain specific adhesion molecules for lymphocytes with specific binders that allows for lymphocytes to drain out of the vasculature into the lymph node structure (this is h
Antiviral by inducing ribonuclease which degrades only viral mRNA (prevents protein synthesis) and activates NK cells to kill virus infected cells

2. What is the late phase reaction of anaphylaxis allergy? what mediates it?
Receiving preformed Antibodies
Superficial inguinal
Hours later (instead of minutes); instead of release of preformed mediators - mast cells synthesize PGs and LTs that mediate the late phase reaction (edema - inflammation - decreased airflow)
MHC I/CD8 and IL2/IL 2 Receptor (IL 2 is from Th1!); cytoxicity!

3. Which disease is associated with B8?
Anti smooth muscle
MHC I/CD8 and IL2/IL 2 Receptor (IL 2 is from Th1!); cytoxicity!
Intracellular pathogens (acute and chronic viruses and virally induced cancers)
Graves

4. other than C3a - what other complement acts as an anaphyloxin?
S. aureus - E. Coli - aspergillus
T cell precursor
Kill them because they have CD16 on them that recognize the FcG portion
C5a

5. Which HLA's are included in MHC I? MHC II?

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

6. What are the autoantibodies for polymyositis and dermatomyositis?
Anti Jo -1
Cross link
Anti smooth muscle
Steroid responsive nephrotic syndrome

7. How do you test for type III hypersensitivity?
Its main effect is a defect in Ab opsonization for killing
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
Immunoflourescent staining of tissue biopsies
Anemias (esp due to renal failure)

8. The pathogenesis of contact dermatitis is ________ hypersensitivity
type four
Severe pyogenic infections early in life
pathogenesis
Suppresses immune response (also specifically Th1 cells) and activates Th2; regulatory T cells

9. Which diseases are associated with DR5?
Bind FcG for antibody dependent cellular cytotoxicity
IgAs in mothers breast milk!
Coarse Faces - cold (noninflamed d/t inability to attract neutrophils) staph abscesses - retained primary teeth - high igE - dermatologic problems (eczema)
Pernicious Anemia and Hashimotos

10. What is oprelevkin? and What is it used for?
Th2; Th1
active complement pathway
Recom IL 11; thrombocytopenia
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

11. What is the most common example of passive immunity?
Macrophages - Dendritic cells - B cells
Acts as second signal on B cells to induce class switching to IgA; also stimulates eosinophils
IgAs in mothers breast milk!
Cytokine release syndrome due to initial release from initial binding (fever etc) and hypersensitivity reaction

12. What does granzyme do? who secretes it?
Tetanus - Botulinum - HBV - Rabies
Increases expression of MHC I and MHC II and also activates NK cells
Its a serine protease that activates apoptosis; NK and CD8
Recom IL 11; thrombocytopenia

13. If the alternative pathway is constitively active - how come normal cells don't get attacked with MAC?
Cytokine release syndrome due to initial release from initial binding (fever etc) and hypersensitivity reaction
T cell activation; no with CD 4 or CD 8
DAF and C1 esterase inhibitor on cells prevent complement activation on their surfaces (microbial surfaces lack this)
Normal pro B (CD 19 +) - no mature B cells results in decreased total B cell level - and decreased amount of immunoglobulins in each class

14. What are the symptoms of serum sickness?
CD21 on B cells (although there is T cell lymphocytosis in EBV)
Coarse Faces - cold (noninflamed d/t inability to attract neutrophils) staph abscesses - retained primary teeth - high igE - dermatologic problems (eczema)
Fever - urticaria - arthralgias - proteinuria - lymphadenopathy
Activates Macrophages and Th1 cells; suppresses Th2 cells; antiviral and antitumor

15. which of the IL2 inhibitors produce nephrotoxicity? thrombocytopenia/leukopenia?
Glycoproteins; HLA
Recom IL 11; thrombocytopenia
Cyclosporine and tacrolimus; sirolimus (as well as hyperlipidemia)
Cytokine IL 10 secreted by Th2

16. What does IgE do on the surface of the mast cell to induce inflammatory mediator release?
Coarse Faces - cold (noninflamed d/t inability to attract neutrophils) staph abscesses - retained primary teeth - high igE - dermatologic problems (eczema)
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
Cross link
pale central germinal centers

17. what prevents NK cells from killing normal cells if their default is to kill?
Anti mitochondrial
MHC class molecules bind to KIRS or CD94 to prevent killing
TLR ad nuclear receptors
Chronic granulomatous disease

18. when can graft versus host disease? What is the result?
TLR ad nuclear receptors
Antimicrobial also secreted by CD8 and NK cells that induces apoptsosis
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
Superficial inguinal

19. describe the pathogenesis of delayed type IV hypersensitivity
T cells react to the angtigen and activate leukocyted (macrophage acitivation)
Superior mesenteric
TGF beta and IL 10
Delayed type hypersensitivity

20. Only the _______ contribute to the Fc region
heavy chains
Steroid responsive nephrotic syndrome
Adaptive uses classic pathway to kill; innate uses alternative pathway to kill
Intracellular pathogens (acute and chronic viruses and virally induced cancers)

21. What does interferon gamma do to be antiviral?
Activates Th1 helper cells; Macrophages
Increases expression of MHC I and MHC II and also activates NK cells
Antimicrosomal and antithyroglobulin
IL 4 -5 -6 for B cell class switching - IL 10 to inhibit TH1

22. The two heavy chains of an antibody contribute to the...
Secretory component
Legionella - N. gonorrhea - L. monocytogenes - viruses - protozoa (leismaniasis)
Hemochromatosis
Fab portion

23. What is the pathology seen in chronic transplant rejection?
An anaphylactic immediate reaction; atopy refers to the inherited propensity to develop asthmatic or allergic reactions
Fibrosis of blood vessels and graft tissue from ischemia; obliterative vascular fibrosis with intimal thickening
Barrel hoop basement membrane fenestrations
Celiac

24. How is the thymus organized? what happens in each section?
Closed circuit where go directly to veins and open where squeeze out of capillary sinusoids and interact with either PALS or with macrophages in the cords of Billroth (for antigen immune function or for blood cleaning or for both) and squeeze back in
Into cortex and medulla; cortex is where immature T lymphocytes enter - at the corticomedullar junction is where positive and negative selection occur; and at the medulla is where the mature T lymphs - reticulin cells and hassalls corpuscles are (dea
Ischemia and necrosis of graft due to occlusion of vessels and fibrinoid necrosis and thrombosis within the vessels
SP infections

25. What is recomb alpha interferon used for?
HBV - HBC - Kaposis - leukemias - malignant melanoma - hairy cell leukemia and condyluma accuminata
Antibody mediated cytotoxicity; either complement dependent or complement independent
Anti TSh receptor
Yes

26. What is the defect in Leukocyte adhesion defect? What is the presentation? What are the labs?
In the germinal center of secondary follicles (In the paler center)
Cyclosporine - OKT3
Defect in LFA 1 integrin (CD 18) protein on phagocytes (neutrophils!); recurrent bacterial infections - severe gingivitis - poor wound healing - absent pus formation - and delayed separation of the umbilicus; neutrophilia
delayed!

27. What is anergy? why does this occur?
Type III hypersensitivity where an internal antigen antibody complexes activate classical complement pathway resulting in C3a neutrophilic chemotaxis and neutrophilic lysosomal death. SLE
Lack of response from lymphocytes when activated; because they are self reactive - this is a form of tolerance
Previous transfusion; pregnant woman whose fetus had paternal antigens
Anti IF

28. A lymph node is a ________ lymphoid organ.
secondary
Adenosine deaminase deficiency (AR) - defective IL 2 receptor (X linked) - and failure to synthesize MHC II; both humoral and cell mediated deficiency
carboxy terminal
Defect in CD40L results in inability to class switch; a lot of IgM and no IgG - A - E

29. Type IV hypersensitivity is i...
Paracortex; viral infection
Activate B cells - activate Macrophages - kill viruses directly - delayed cell mediated hypersensitivity - acute and chronic rejection
IgM and IgD
not Ab mediated

30. explain the process from beginning (ie phagocytosis of the peptide) to end of how Abs are formed in Goodpasteurs.
Cytokine IL 10 secreted by Th2
CROSS LINK Beta region on TCR of CD4 cells to the MHC class II on APCs this results in uncoordinated release of Interferon gamma from CD4 Th1 cells and subsequent release of IL1 - IL6 and TNF alpha from Macrophages --> toxic shock syndrome; s. pyogen
For some reason a mature naive B lymphocyte got away from tolerance and the result was a production an Ab on its surface with an Fab region that recognized the alpha 3 collagen subunit on the BM as non self. It then gets activated by a Th2 cell (enti
IL 3; supports growth and differentiation of bone marrow stem cells

31. Which antibody mediates immunity to worms? how?
Adaptive uses classic pathway to kill; innate uses alternative pathway to kill
When you select for which MHC it will have; take out the lymphs that self react
IgE; by activating eosinophils
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

32. what mediates the type II hypersensitivity? What are the two different methods?
Lack of response from lymphocytes when activated; because they are self reactive - this is a form of tolerance
Alternative splicing of mRNA
Antibody mediated cytotoxicity; either complement dependent or complement independent
A recomb cytokine of IL 2; RCC and metastatic melanoma

33. How do endotoxin/LPS of gram negative bacteria stimulate the immune system if they do not have a peptide fragment?
IgAs in mothers breast milk!
They directly stimulate Macrophages by binding CD14; also the alternative complement pathway binds to these host surfaces and induces MAC complex; also TLRs exist for endotoxins; also IgM though not an opsonin can act as a pentamer and trap the antig
Anti topoisomerase
Type IV

34. Which TCR MHC system is important for viral immunity? neoplastic? donor graft cells?
MS
All MHC 1/CD8
MHC I/CD8 and IL2/IL 2 Receptor (IL 2 is from Th1!); cytoxicity!
Local infection/inflammation; infection of the ln itself; metastasis

35. which antibody activate mast cells - basophils - and eosinophils?
IgE
type four
Antiviral for uninfected cells (for future protection) and kills virally infected cells (NK activation)
carboxy terminal

36. What is muromonab - CD3 (OKT3)
Monoclonal Ab to CD3- blocks cellular transduction and signaling of T cells
Both decrease cd8 tcell prolif but one through mtor and the other through calcineurin (resp)
Induce differentiation of T cells into Th1 helper cells and activates NK cells also; B cells
TCR - CD4/8 - CD28 (binds B7) - CD3 (for intracellular transduction) - CD40L

37. What is epo used for?
Both decrease cd8 tcell prolif but one through mtor and the other through calcineurin (resp)
Activate macrophages
Anemias (esp due to renal failure)
Th2; Th1

38. What is MHC I made out of? Where is it found? What does it bind to? What type of antigens does it present?
MS
An alpha chain and a B2 microglobulin; on all nucleated cells; TCR and CD8; intracellular antigens
Antidote for digoxin intoxication
Steroid responsive nephrotic syndrome

39. What is the presentation of common variable immunodef? and What are the labs?
Can be acquired in 20s -30s; increased risk of autoimmune disease - lymphoma - Sp infections; normal number of B cells and no plasma cells and immunoglobulin
IL 1 and IL 6
False! B cell class switching requires a second signal
Adenosine deaminase deficiency (AR) - defective IL 2 receptor (X linked) - and failure to synthesize MHC II; both humoral and cell mediated deficiency

40. What lymph node drains the stomach?
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
Active; passive - fast but short half life (3 weeks!)
In the germinal center of secondary follicles (In the paler center)
Celiac

41. what cell surface marker is used for NK cells as it is unique to them?
C5a
CD56
This means that MHC can not recognize it and thus will not be phagocytosed. The humoral response rescues - IgM is the primary response attack. Since there is no class switching (without MHC activation no CD40 L and interleukins to activate!) then the
Para aortic

42. What are the function of B cells?
Superficial inguinal
Make antibody - allergy type 1 (igE) - Cytotoxic and immunecomplex hypersensitivity type II and III (igG); hyperacute organ rejection is Ab mediated
Activate B cells - activate Macrophages - kill viruses directly - delayed cell mediated hypersensitivity - acute and chronic rejection
CROSS LINK Beta region on TCR of CD4 cells to the MHC class II on APCs this results in uncoordinated release of Interferon gamma from CD4 Th1 cells and subsequent release of IL1 - IL6 and TNF alpha from Macrophages --> toxic shock syndrome; s. pyogen

43. What are C1 - C2 - C3 - C4 important for?
Viral neutralization of igM and IgG!
Local infection/inflammation; infection of the ln itself; metastasis
Interferon gamma; Th1
Proteins; IgG - IgM - endotoxin (microbial surfaces in general - nonspecific ones also) - mannose binding Lectin; classic - alternative - MB pathway (resp)

44. What is the symptoms involved in graft versus host disease? it What transplant cases does it usually occur? give an example
MHC II - B7
Maculopapular rash (palm - soles - back - neck) - jaundice with bile duct necrosis - hepatosplenomegaly - diarrhea; bone marrow and liver transplants (rich with lymphocytes); SCID patient receiving whole blood transfusion
Th2; Th1
Cytokine release syndrome due to initial release from initial binding (fever etc) and hypersensitivity reaction

45. All transplant rejections - _____________ are mediated by Type IV hypersensitivity
Macrophages - Dendritic cells - B cells
Cells that stil have weird parts of their membrane that macrophages usually bite off
except hyperacute
Isotype switching (activated by Th2 cell signals and cytokines) - somatic hypermutation

46. Which diseases are associated with DR4?
Trypanosomes with programmed rearrangement (results in recurring fever -- sleeping sickness!)
DM type I and RA
Suppresses immune response (also specifically Th1 cells) and activates Th2; regulatory T cells
...

47. other than eat and bite RBCs what else do Macrophages of spleen do>
Negative!
They directly stimulate Macrophages by binding CD14; also the alternative complement pathway binds to these host surfaces and induces MAC complex; also TLRs exist for endotoxins; also IgM though not an opsonin can act as a pentamer and trap the antig
Remove encapsulated bacateria
Anti Jo -1

48. What is the main function of IL 12? other than macrophages who else can release IL 12?
A recomb cytokine of IL 2; RCC and metastatic melanoma
Hemochromatosis
Induce differentiation of T cells into Th1 helper cells and activates NK cells also; B cells
Vasculitis of graft vessels with dense interstitial lymphocytic infiltrate; yes! with immunosuppressants

49. ________ regulate the cell mediated response.
Graves
Trypanosomes with programmed rearrangement (results in recurring fever -- sleeping sickness!)
Humoral
Since cant cross placenta most likely means that child was forced early to produce due to an infection (most likely CMV)

50. What cytokines to Th2 secrete?
IgG and IgM bind to pathogens activating C1 convertase and leads to C2 and C4 and then C3 convertase activated
No because no peptide fragment!
IL 4 - 5 - 10 - 6
Receiving preformed Antibodies