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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.
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 lymph node drains the lateral side of the dorsum of the foot?
IgG
Since cant cross placenta most likely means that child was forced early to produce due to an infection (most likely CMV)
Popliteal
A B and T cell disorder; defect in DNA repair enzymes; ataxia - telangactasia and IgA def; igA def. and increased AFP

2. Type IV hypersensitivity is i...
RNA segment reassortment
Both decrease cd8 tcell prolif but one through mtor and the other through calcineurin (resp)
not Ab mediated
Isotype switching (activated by Th2 cell signals and cytokines) - somatic hypermutation

3. What are the sinusoids of the spleen? What is the difference between a spleen and a lymph node?
T cell activation; no with CD 4 or CD 8
Anti mitochondrial
Periarteriolar lymphatic sheath in the white pulp that surround that dead end of the capillaries in the red pulp - contain T cells
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

4. what mediates the type II hypersensitivity? What are the two different methods?
SP infections
Immunoflourescent staining of tissue biopsies
CD56
Antibody mediated cytotoxicity; either complement dependent or complement independent

5. What is Aldesleukin? What is it used for
Antiviral for uninfected cells (for future protection) and kills virally infected cells (NK activation)
MHC II - B7
IgG
A recomb cytokine of IL 2; RCC and metastatic melanoma

6. which interleukin receptor is required for NK development? activation?
IL 15; IL 12 - interferon Beta and interferon alpha
Local infection/inflammation; infection of the ln itself; metastasis
mesenchymal
Hereditary angioedema; PNH

7. What are four results of a splenectomy?
secondary
isotype
1) susceptibility to encapsulated organisms 2) Howell Jolly Bodies 3) Target cells 4) Thrombocytosis
IgAs in mothers breast milk!

8. Leukocyte adhesion defect presents with...
neutrophilia!
Negative selection
IgM and IgA
IL 1 - IL 6 - IL 12 - TNF alpha; IL 6- Th2 cells; IL 12- B cells

9. What is the cause of thymic aplasia? What is its presentation? What are the labs?
Celiac
secondary
Daclizumab; prevent ACUTE rejection of renal transplant
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

10. What are the mediators that mast cells release?
Histamine (causes vasodilation) - leukotrienes (causes bronchoconstriction) - chemotaxins for eos - and heparin (increased blood flow needs to be anticoagulated!)
Hereditary angioedema; PNH
IL 3; supports growth and differentiation of bone marrow stem cells
Anemias (esp due to renal failure)

11. What portion of the lymph node is not well developed in DiGeorge Syndrome?
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
Paracortex
Axillary
IgG

12. What are the autoantibodies for polymyositis and dermatomyositis?
Paracortex; viral infection
Anti Jo -1
IgM
Antibody mediated cytotoxicity; either complement dependent or complement independent

13. What type of fenestrations are found in the red pulp of the spleen?
Cyclosporine and tacrolimus; sirolimus (as well as hyperlipidemia)
Secretory component
Barrel hoop basement membrane fenestrations
Superficial inguinal

14. Describe the capsular structure of a lymph node; What are the functions of the LN?
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
Fibrosis of blood vessels and graft tissue from ischemia; obliterative vascular fibrosis with intimal thickening
B - T - and NK cells
Cyclosporine and tacrolimus; sirolimus (as well as hyperlipidemia)

15. What lymph node drains the rectum (above the pectinate line)?
IgM and IgA
Internal iliac
Normal pro B (CD 19 +) - no mature B cells results in decreased total B cell level - and decreased amount of immunoglobulins in each class
Antihistone

16. What is thrombopoietin used for?
Anticentromere; anti Scl -70 (anti DNA topoisomerase I)
A recomb cytokine of IL 2; RCC and metastatic melanoma
TCR - CD4/8 - CD28 (binds B7) - CD3 (for intracellular transduction) - CD40L
Thrombocytopenia

17. The MALT/GALT are not...
CRP - C3b - IgM
Antiviral for uninfected cells (for future protection) and kills virally infected cells (NK activation)
encapsulated
Activate macrophages

18. What does IL 2 do?
Activates cytotoxic CD 8 T cells as second signal
Glycoproteins; HLA
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
Carbohydrate

19. What is the common variable immunodeficiency ? How is it different from Brutons?
When you select for which MHC it will have; take out the lymphs that self react
Defect in B cell maturation; idiopathic - presents at older age and normal number of B cells and hyperplastic germinal centers because B cells can be activated but can not produce Abs
Recurrent infections to every type of antigen; bone marrow transplant (be weary of GVH disease!)
T cell dysfunction

20. Which antibodies can be multimeric?
Antigliadin - antiendomysial (both are IgAs - anti tissue transgluataminase igA)
Recomb cytokine of GCSF (granulocyte macrophage colony stimulating factor; for recovery of bone marrow
IgM and IgA
AR; defect in MT function results in decreased transport and phagocytosis; recurrent pyogenic infections by staphylococci and streptococci - partial albinism - and peripheral neuropathy

21. Which MHC presents intracellular peptides? how so?
Salmonella - 2 flagellar variants; Borrelia (relapsing fever); and Neisseria gonorrhoaea - pilus protein
MHC I; from RER with help of the B2 microglobulin
Active; passive - fast but short half life (3 weeks!)
carboxy terminal

22. which cells have more complete tolerance - B or T cells?
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
Interferon gamma; Th1
T
Antimicrosomal and antithyroglobulin

23. What does interferon gamma do? What two type of cells does it attack mostly?
Hereditary angioedema; PNH
IL 5
Activates Macrophages and Th1 cells; suppresses Th2 cells; antiviral and antitumor
secondary

24. What are the PALS?
T cells react to the angtigen and activate leukocyted (macrophage acitivation)
Daclizumab; prevent ACUTE rejection of renal transplant
...
Periarteriolar lymphatic sheath in the white pulp that surround that dead end of the capillaries in the red pulp - contain T cells

25. For which toxins are preformed antibodies (passive) given?
Tetanus - Botulinum - HBV - Rabies
Recurrent infections to every type of antigen; bone marrow transplant (be weary of GVH disease!)
except hyperacute
Remove encapsulated bacateria

26. What is MHC II made out of? Where is it found? What does it bind to? What type of antigens does it present?
Proteins; IgG - IgM - endotoxin (microbial surfaces in general - nonspecific ones also) - mannose binding Lectin; classic - alternative - MB pathway (resp)
An alpha and beta chain; only on APCs; TCR and CD4; extracellular (phagocytosed by APCs)
T
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

27. What is an autograft? syngeneic graft? allograft? xenograft? What is an ex of an allograft? xenograft?
IL 3; supports growth and differentiation of bone marrow stem cells
Opsonization (Brutons agammaglobulinemia) - adhesion (Leukocyte adhesion defect) - phagocytosis (chediak higashi syndrome) - respiratory burst (chronic granulomatous disease)
IL 15; IL 12 - interferon Beta and interferon alpha
From self; from identical twin or clone; from nonidentical individual of same species; from different species; fetus; pig valve

28. What is the main function of IL 12? other than macrophages who else can release IL 12?
Induce differentiation of T cells into Th1 helper cells and activates NK cells also; B cells
Superficial inguinal
DM type I
Adenosine deaminase deficiency (AR) - defective IL 2 receptor (X linked) - and failure to synthesize MHC II; both humoral and cell mediated deficiency

29. What is recomb gamma interferon used for?
Isotype switching (activated by Th2 cell signals and cytokines) - somatic hypermutation
Chronic granulomatous disease
Adenosine deaminase deficiency (AR) - defective IL 2 receptor (X linked) - and failure to synthesize MHC II; both humoral and cell mediated deficiency
Nuclear remnants that are usually taken out of RBC before complete maturation by Macrophages

30. The two heavy chains of an antibody contribute to the...
Paracortex
Fab portion
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
Trypanosomes with programmed rearrangement (results in recurring fever -- sleeping sickness!)

31. What cytokines to Th2 secrete?
C5a
Increases expression of MHC I and MHC II and also activates NK cells
Cyclosporine and tacrolimus; sirolimus (as well as hyperlipidemia)
IL 4 - 5 - 10 - 6

32. give an example of a virus that uses antigenic variation. What does a major variation result in? minor?
Influenza; antigenic shift; antigenic drift
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
Normal pro B (CD 19 +) - no mature B cells results in decreased total B cell level - and decreased amount of immunoglobulins in each class
AR; defect in MT function results in decreased transport and phagocytosis; recurrent pyogenic infections by staphylococci and streptococci - partial albinism - and peripheral neuropathy

33. What are the autoantibodies for hashimotos?
Antimicrosomal and antithyroglobulin
Hyperacute; presence of preformed antibodies in the recipient ( to blood groups or HLA )
Fab portion
IgM

34. What happens in a deficiency of C3?
Immune complex - Arthus reaction and Serum sickness; they are all a result of antibody- antigen complex deposition resulting in complement activation
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
Severe recurrent pyogenic sinus and resp tract And increased susceptibility to type III hypersensitivity like SLE
Ischemia and necrosis of graft due to occlusion of vessels and fibrinoid necrosis and thrombosis within the vessels

35. What lymph node drains the stomach?
S. aureus - E. Coli - aspergillus
Antidesmoglein
Adenosine deaminase deficiency (AR) - defective IL 2 receptor (X linked) - and failure to synthesize MHC II; both humoral and cell mediated deficiency
Celiac

36. What is the white pulp of the spleen?
pale central germinal centers
Previous transfusion; pregnant woman whose fetus had paternal antigens
except hyperacute
Surrounds the red pulp and begins with PALS and then turns into follicles with B cells/follicles

37. 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)?
P - ANCA (antimyeloperoxidase); in neutrophil; p= perinuclear
Anti alpha subunit 3 of collagen on type IV bm
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
NK cells

38. What is recomb alpha interferon used for?
HBV - HBC - Kaposis - leukemias - malignant melanoma - hairy cell leukemia and condyluma accuminata
Histamine (causes vasodilation) - leukotrienes (causes bronchoconstriction) - chemotaxins for eos - and heparin (increased blood flow needs to be anticoagulated!)
Increases expression of MHC I and MHC II and also activates NK cells
Opsonization (Brutons agammaglobulinemia) - adhesion (Leukocyte adhesion defect) - phagocytosis (chediak higashi syndrome) - respiratory burst (chronic granulomatous disease)

39. How is sirolimus different from tacrolimus?
Periarteriolar lymphatic sheath in the white pulp that surround that dead end of the capillaries in the red pulp - contain T cells
The igA found in breast milk
IL 4 -5 -6 for B cell class switching - IL 10 to inhibit TH1
Both decrease cd8 tcell prolif but one through mtor and the other through calcineurin (resp)

40. What is the pathogenesis of chronic granulomatous disease; What is the presentation? What is the labs?
Lack of NADPH oxidase results in a lack of respiratory burst in neutrophils; susceptibility to catalase positive organisms (S. aureus - E. Coli - Aspergillus)
Yes
Lack of MHC class I constant region which it binds or a nonspecific activation signal (TLR)
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

41. What are the main Cell surface proteins on T cells?
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
Antidesmoglein
TCR - CD4/8 - CD28 (binds B7) - CD3 (for intracellular transduction) - CD40L
Anti nuclear Antibodies (ANA); Anti dsDNA - anti Smith

42. What are the autoantibodies for pernicious anemia?
Severe recurrent pyogenic sinus and resp tract And increased susceptibility to type III hypersensitivity like SLE
Decreased Th1 response; disseminated mycobacterial infections; decreased interferon gamma
Anti IF
1) susceptibility to encapsulated organisms 2) Howell Jolly Bodies 3) Target cells 4) Thrombocytosis

43. what else does interferon gamma do other than inducing ribonuclease production - activating NK cells - inducing increased MHC expression?
Activate macrophages
IgG and IgM bind to pathogens activating C1 convertase and leads to C2 and C4 and then C3 convertase activated
Cytokine release syndrome due to initial release from initial binding (fever etc) and hypersensitivity reaction
S. aureus - E. Coli - aspergillus

44. What is the toxicity of muromonab?
Anti SS- A (anti RO) and Anti SS- B
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
T cells react to the angtigen and activate leukocyted (macrophage acitivation)
Cytokine release syndrome due to initial release from initial binding (fever etc) and hypersensitivity reaction

45. What is the result of an IL 12 deficiency? What is the presentation? What are the labs?
Th2; Th1
Decreased Th1 response; disseminated mycobacterial infections; decreased interferon gamma
Interferon gamma; Th1
When you select for which MHC it will have; take out the lymphs that self react

46. What lymph node drains the sigmoid colon?
acute phase reactants
Brain - eyes - placenta/fetus - testicles; because they can have an antigen in there and not get attacked by immune system because dont have contact with immune system via blood and lymph; if an infection occurs such that trauma results in exposure t
Inferior mesenteric
Superficial inguinal

47. which B and T cell disorder presents with specifically low IgM?
Wiskott Aldrich syndrome
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
Antibody mediated cytotoxicity; either complement dependent or complement independent
Since cant cross placenta most likely means that child was forced early to produce due to an infection (most likely CMV)

48. what characterizes an arthus reaction?
Edema and necrosis in that region
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
Local infection/inflammation; infection of the ln itself; metastasis
Antidesmoglein

49. What kinds of receptors activate innate immunity?
TLR ad nuclear receptors
Cyclosporine - OKT3
Ig - CD19 - CD20 - CD21 - CD40 - MHC II - B7
S. aureus - E. Coli - aspergillus

50. Which disease is associated with DR7?
Steroid responsive nephrotic syndrome
TGF beta and IL 10
active complement pathway
Lack of NADPH oxidase results in a lack of respiratory burst in neutrophils; susceptibility to catalase positive organisms (S. aureus - E. Coli - Aspergillus)