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. What is the presentation of hyperIgM syndrome?
Histamine; post capillary venules - vasodilation
Paracortex; viral infection
Surrounds the red pulp and begins with PALS and then turns into follicles with B cells/follicles
Severe pyogenic infections early in life

2. What are the autoantibodies for scleroderma (CREST)? scleroderma diffuse?
Tetanus - Botulinum - HBV - Rabies
Anticentromere; anti Scl -70 (anti DNA topoisomerase I)
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
Stimulate the liver to release acute phase reactants

3. hat is the presentation of Jobs syndrome or Hyper IgE?
Anti smooth muscle
Vasculitis of graft vessels with dense interstitial lymphocytic infiltrate; yes! with immunosuppressants
The place of T cell diff and maturation; ant mediastinum above heart; yes; 2
Coarse Faces - cold (noninflamed d/t inability to attract neutrophils) staph abscesses - retained primary teeth - high igE - dermatologic problems (eczema)

4. DTH (delayed type hypersensitivity) is the ________ of a PPD reaction
Aut. Dominant; C1 esterase inhibitor deficiency resulting in continued C1 which results in increased C2 and C4 cleavage products which have anaphyltoxic activity and result in swelling of face and oropharynx
Induce differentiation of T cells into Th1 helper cells and activates NK cells also; B cells
pathogenesis
IgA

5. If an antigen lacks a peptide component How does the adaptive immunity attack it? What type of response is this called. give an example of bugs that do this. what implications does this have on splenectomy?
Fibrosis of blood vessels and graft tissue from ischemia; obliterative vascular fibrosis with intimal thickening
Mycobacterium Tuberculosis - Mycobacterium Avium Intracellulare; Toxoplasmosis Gondii
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
HBV - HBC - Kaposis - leukemias - malignant melanoma - hairy cell leukemia and condyluma accuminata

6. can igG cross the placenta?
Septicemia with neisseria; because at least you have C3 to act like a neutrophilic chemotactic and an acute phase reactant
Yes
Viral neutralization of igM and IgG!
Ischemia and necrosis of graft due to occlusion of vessels and fibrinoid necrosis and thrombosis within the vessels

7. What are target cells?
By transcytosis
Cells that stil have weird parts of their membrane that macrophages usually bite off
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
Anti U1 RNP (ribonucleoprotein)

8. What is wiskott aldrich syndrome? What is its mode of inheritance? What is the pathogenesis of disease? What is its triad of presentation? what labs does it present with?
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
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
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
acute phase reactants

9. what ensure that a memory response is generated?
Cyclosporine - OKT3
If there is class switching and plasma cell production (that is when memory cells are produced)
Fc
Some microbial surfaces (only) have mannan binding lectin which activates a protease that cleaves C2 and C4 which combine to make C3. the rest follows the alternative pathway

10. How do you test for chronic granulomatous disease?
Immunoflourescent staining of tissue biopsies
TNF alpha and IL1
Complement activation (active in both)
Negative nitroblue tetrazolium reduction test

11. What are the autoantibodies for autoimmune hepatitis?
Adenosine deaminase deficiency (AR) - defective IL 2 receptor (X linked) - and failure to synthesize MHC II; both humoral and cell mediated deficiency
Anti smooth muscle
Interferon gamma and IL 2
Barrel hoop basement membrane fenestrations

12. What bugs can actually infect the lymph node itself?
Anti SS- A (anti RO) and Anti SS- B
The place of T cell diff and maturation; ant mediastinum above heart; yes; 2
Anti IF
Mycobacterium Tuberculosis - Mycobacterium Avium Intracellulare; Toxoplasmosis Gondii

13. what mediates the type II hypersensitivity? What are the two different methods?
carboxy terminal
Lack of response from lymphocytes when activated; because they are self reactive - this is a form of tolerance
Antibody mediated cytotoxicity; either complement dependent or complement independent
Vasculitis of graft vessels with dense interstitial lymphocytic infiltrate; yes! with immunosuppressants

14. What are the autoantibodies for pemphigus bulgaris?
Nuclear remnants that are usually taken out of RBC before complete maturation by Macrophages
Lymphocytes
Antidesmoglein
2 heavy chains and two light chains

15. Name three things that IL 1 does as a cytokine. other than the liver - who secretes IL 1
Induces fever - chemokine secretion to recruit - activates adhesion molecules; macrophages
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
Vasculitis of graft vessels with dense interstitial lymphocytic infiltrate; yes! with immunosuppressants
Some microbial surfaces (only) have mannan binding lectin which activates a protease that cleaves C2 and C4 which combine to make C3. the rest follows the alternative pathway

16. What lymph node drains the sigmoid colon?
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
Inferior mesenteric
Humoral
...

17. What are the cell surface proteins on NK cells?
Hemochromatosis
S. aureus - E. Coli - aspergillus
MHC I - CD16 - CD56
MHC class molecules bind to KIRS or CD94 to prevent killing

18. What is the main function of interferons?
IgG
Antiviral for uninfected cells (for future protection) and kills virally infected cells (NK activation)
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
Chronic granulomatous disease

19. What is recomb beta interferon used for?
Influenza; antigenic shift; antigenic drift
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
MS
Yes

20. What is the main function of IL 12? other than macrophages who else can release IL 12?
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
C - ANCA (antiproteinase); in neutrophil; c= cytoplasmic
Lack of response from lymphocytes when activated; because they are self reactive - this is a form of tolerance
Induce differentiation of T cells into Th1 helper cells and activates NK cells also; B cells

21. What lymph node drains the stomach?
neutrophilia!
A - B - C; all the D's
Celiac
Recurrent sinopulmonary bacterial infections after 6 months (d/t mothers igGs transplacental) due to opsonization defect

22. What is the defect in hyper IgM syndrome? What are the lab results?
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
Anti SS- A (anti RO) and Anti SS- B
carboxy terminal
Defect in CD40L results in inability to class switch; a lot of IgM and no IgG - A - E

23. How is the antigen loaded onto a MHC II?
N. meningitidis - H. influenzae - S. pneumonia - Salmonella d/t lack of C3b opsonization for MAC d/t lack of complement activation d/t lack of IgM; MAC is needed by encapsulated avoid by humoral and cell mediated through their capsule
Defect in BTK a tyrosine kinase gene; failed maturation of B cells; X linked recessive
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
Cells that stil have weird parts of their membrane that macrophages usually bite off

24. What is the main function of TNF alpha? How does it do this?
Coarse Faces - cold (noninflamed d/t inability to attract neutrophils) staph abscesses - retained primary teeth - high igE - dermatologic problems (eczema)
pale central germinal centers
Mediates septic shock; activates the endothelium for adhesion and dilation and leukocyte recruitment results in vascular leak
MHC I; from RER with help of the B2 microglobulin

25. What lymph node drains the anal canal (below the pectinate line)?
opsonizes
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
Negative nitroblue tetrazolium reduction test
Superficial inguinal

26. What are the autoantibodies for polymyositis and dermatomyositis?
MHC II/CD4 and B7 (on APC) and CD28 (on Th cell); releases cytokines to kill those extracellular buggers!
Th1; interferon gamma; IL 2 for cytotoxic T cell activation
Ischemia and necrosis of graft due to occlusion of vessels and fibrinoid necrosis and thrombosis within the vessels
Anti Jo -1

27. What is colostrum?
The igA found in breast milk
A recomb cytokine of IL 2; RCC and metastatic melanoma
Cells that stil have weird parts of their membrane that macrophages usually bite off
Opsonization (Brutons agammaglobulinemia) - adhesion (Leukocyte adhesion defect) - phagocytosis (chediak higashi syndrome) - respiratory burst (chronic granulomatous disease)

28. What amine is the main chemical mediator released by mast cells? Where does it act What does it result in?
IgA
Graves
DAF and C1 esterase inhibitor on cells prevent complement activation on their surfaces (microbial surfaces lack this)
Histamine; post capillary venules - vasodilation

29. Describe the capsular structure of a lymph node; What are the functions of the LN?
IgG and IgM bind to pathogens activating C1 convertase and leads to C2 and C4 and then C3 convertase activated
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
pale central germinal centers
Capsule of lymph node is made up of type III collagen (made by reticulin fibers!) - extension of this collagen extends into the splenic tissue as trabeculae; nonspecific filtration of lymph by Macrophages - Antibody production (via activation) - stor

30. What are some sinopulmonary infections?
Antimicrobial also secreted by CD8 and NK cells that induces apoptsosis
IgM and IgG
Opsonize bacteria (for enhanced phagocytosis) - neutralize viruses (igG) - activate complement (igM and igG) - sensitize mast cells (igE)
Sinusitis - otitis media - pneumonia

31. What are the autoantibodies for wegeners granulomatosis?
Both decrease cd8 tcell prolif but one through mtor and the other through calcineurin (resp)
C - ANCA (antiproteinase); in neutrophil; c= cytoplasmic
Fab portion
Activate macrophages

32. what will NK cells do to cells covered in IgG Ab? why?
Activate B cells - activate Macrophages - kill viruses directly - delayed cell mediated hypersensitivity - acute and chronic rejection
MS
Kill them because they have CD16 on them that recognize the FcG portion
Normal pro B (CD 19 +) - no mature B cells results in decreased total B cell level - and decreased amount of immunoglobulins in each class

33. 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

34. From where do cytokines come from?
Fc
type four
Lymphocytes
Its a serine protease that activates apoptosis; NK and CD8

35. What can cause a lymph node enlargement?
1) susceptibility to encapsulated organisms 2) Howell Jolly Bodies 3) Target cells 4) Thrombocytosis
An alpha and beta chain; only on APCs; TCR and CD4; extracellular (phagocytosed by APCs)
Local infection/inflammation; infection of the ln itself; metastasis
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

36. Other than stimulating fever - what else does IL 6 do?
Hereditary angioedema; PNH
Stimulate the liver to release acute phase reactants
...
Type IV

37. So antibodies are the effectors for the humoral response. List some of their functions.
TGF beta and IL 10
Cross link antigens which increases their phagocytability; activate complement for MAC attack; opsonization; neutralization
An alpha and beta chain; only on APCs; TCR and CD4; extracellular (phagocytosed by APCs)
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

38. is IgM an opsonizer?
pale central germinal centers
except hyperacute
Negative!
MHC I - CD16 - CD56

39. What is the symptoms involved in graft versus host disease? it What transplant cases does it usually occur? give an example
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
Anemias (esp due to renal failure)
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
Recurrent infections to every type of antigen; bone marrow transplant (be weary of GVH disease!)

40. How does the alternative pathway lead to MAC activation?
Paracortex; viral infection
Soluble C3 spontaneously hydrolyzes spontaneously to C3b and opsonizes microbial and host cell surfaces and accumulates on surfaces; C3b activates C5 convertase which leads to MAC activation
Antimicrosomal and antithyroglobulin
Recurrent infections to every type of antigen; bone marrow transplant (be weary of GVH disease!)

41. where do somatic hypermutation and class switching occur?
lowest concentration
Ig - CD19 - CD20 - CD21 - CD40 - MHC II - B7
In the germinal center of secondary follicles (In the paler center)
MHC II - B7

42. Which disease is associated with B8?
C - ANCA (antiproteinase); in neutrophil; c= cytoplasmic
Graves
Interferon gamma and IL 2
isotype

43. What part of the complement system also acts as an opsonin? What is opsonization? can you Name two other opsonins?
C3b; coating of a pathogen with molecules that promotes phagocytosis; IgG and CRP
Antidote for digoxin intoxication
IgA
In the germinal center of secondary follicles (In the paler center)

44. What are the autoantibodies for sjorgens syndrome?
Anti SS- A (anti RO) and Anti SS- B
Inferior mesenteric
Th2; Th1
Tetanus - Botulinum - HBV - Rabies

45. What does it mean if there are igM in the serum at birth?
Mediates septic shock; activates the endothelium for adhesion and dilation and leukocyte recruitment results in vascular leak
Since cant cross placenta most likely means that child was forced early to produce due to an infection (most likely CMV)
Sinusitis - otitis media - pneumonia
Kill them because they have CD16 on them that recognize the FcG portion

46. The two heavy chains of an antibody contribute to the...
Fab portion
Antimicrobial also secreted by CD8 and NK cells that induces apoptsosis
Sinusitis - otitis media - pneumonia
Digeorge syndrome - 22q11 deletion resulting in failure to develop 3rd and 4th pharyngeal pouches; cardiac and great vessel congenital defects - tetany from hypocalcemia - recurrent viral/fungal infections from T cell deficiency; hypoPTH - hypoCa - a

47. Leukocyte adhesion defect presents with...
Basophils! THey want IG E class switch!
Adenosine deaminase deficiency (AR) - defective IL 2 receptor (X linked) - and failure to synthesize MHC II; both humoral and cell mediated deficiency
Found in the red pulp; contains the cords of billroth or the splenic parenchyma that have APCs/Macrophages that closely interact with the basement membrane of the vasculature and where RBCs squeeze through into the parenchyma and interact with Macrop
neutrophilia!

48. What links the adaptive and innate immunity?
Complement activation (active in both)
encapsulated
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
An anaphylactic immediate reaction; atopy refers to the inherited propensity to develop asthmatic or allergic reactions

49. What do mature naive B lymphocytes express?
Cytokine release syndrome due to initial release from initial binding (fever etc) and hypersensitivity reaction
IgM and IgD
...
Leukocyte adhesion defect; ataxia telangietasia; ataxia telangiectasia; chediak higashi syndrome; IgA def; Digeorge syndrome; Jobs; Chediak Higashi

50. What do macrophages secrete that activate Th1 cells to secrete interferon gamma?
Anti nuclear Antibodies (ANA); Anti dsDNA - anti Smith
TNF alpha and IL1
Proteins; IgG - IgM - endotoxin (microbial surfaces in general - nonspecific ones also) - mannose binding Lectin; classic - alternative - MB pathway (resp)
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