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USMLE Step 1. > Immunology > Flashcards

Flashcards in Immunology Deck (108):
1

Cervical node drainage

Head and neck

2

Hilar node drainage

Lungs

3

Mediastinal node drainage

Trachea and esophagus

4

Axillary node drainage

Upper limb, breast, skin above belly button

5

Celiac node drainage

Liver, stomach, spleen, pancreas, upper duodenum

6

Superior mesenteric node drainage

Lower duodenum, jejunum, ileum, colon to splenic flexure

7

Inferior mesenteric node drainage

colon from splenic flexure to upper rectum

8

Internal iliac node drainage

Lower rectum to anal canal (above pectinate line), bladder, vagina (middle third), prostate

9

Para-aortic node drainage

Testes, ovaries, kidneys, uterus

10

Superficial inguinal node drainage

Anal canal (below pectinate line), skin below belly button (not popliteal territory), scrotum

11

Popliteal node drainage

Dorsolateral foot, posterior calf.

12

Right lymphatic duct drainage

Right side of body above diaphragm

13

Thoracic duct drainage

Everything RLD doesn't drain. Goes into subclavian and Internal jugular veins

14

Encapsulated organisms to look out for

1) Strep Pneumo
2) H. flu
3) N. meningitidis
4) E. Coli
5) Salmonella
6) Klebsiella
7) Group B Strep

15

Part of lymph node underdeveloped in DiGeorge Syndrome

paracortex - houses T cells and provides a route for T and B cells to enter blood.

16

MHC 1

HLA- A, B, C

Binds to TCR and CD8

Expressed on all nucleated cells. Not on RBCs

Present endogenously made antigens (viral or cytosolic proteins) to CD8+ cytotoxic T cells.

Antigen peptides loaded onto MHC1 in RER after delivery via TAP (a transporter associated with antigen processing)

Associated with B2-microglobulin

17

MHC 2

HLA- DR, DP, DQ

Binds to TCR and CD4

Expressed on APCs

Presents exogenously made antigens (bacterial proteins) to CD4+ helper T cells.

Antigen loaded following release of invariant chain in an acidified endosome

Associated with Invariant chain (a protein).

18

HLA A3

Hemochromatosis

19

HLA B27

Psoriatic Arthritis, Ankylosing spondylitis, IBD, Reactive arthritis (Reiter Syndrome). PAIR.

20

HLA DQ2/DQ8

Celiac disease

21

HLA DR2

MS, hay fever, SLE, Goodpasture

22

HLA DR3

Diabetes mellitus type 1, SLE, Graves, Hashimoto thyroiditis

23

HLA DR4

Rheumatoid arthritis, diabetes mellitus type 1

24

HLA DR5

Pernicious anemia leading to vitamin B12 deficiency Hashimoto thyroiditis

25

Enhances NK cell activity

IL-2, IL-12, IFN alpha, IFN beta

26

Th1 cells

Secrete IFN-gamma

Activated by IFN-gamma and IL-12 (from Macrophage)

Inhibited by IL-4, IL- 10 (from Th2)

27

Th2 cells

Secrete IL4, IL-5, IL-10, IL-13

Activated by IL-4

Inhibited by IFN-gamma (from Th1)

28

Acute phase reactants

released by liver. Their concentrations change in response to inflammation. Chronic made by liver too. Induced by IL-6

CRP, Ferritin, Fibrinogen, Hepcidin, Serum amyloid A, Albumin, Transferrin

29

C-reactive protein

(Positive) upregulated in immune response.

Opsonin - fixes complement and facilitates phago. Measured clinically as a sign of ongoing inflammation.

30

Ferritin

(Positive) Upregulated in IR.

Binds and sequesters iron to inhibit microbial iron scavenging

31

Fibrinogen

(Positive) Upregulated in IR.

Coagulation factor that promotes endothelial repair - correlates with ESR.

32

Hepcidin

(Positive) Upregulated in IR.

Prevents release of Iron bound by ferritin (anemia of chronic disease)

33

Serum Amyloid A

(Positive) Upregulated in IR.

Prolonged elevationcan lead to amyloidosis

34

Albumin

(Negative) Downregulated in IR

Reduction conserves amino acids for positive reactants

35

Transferrin

(Negative) Downregulated in IR

Internalized by macrophages to sequester iron.

36

C1 esterase inhibitor deficiency

Causes hereditary angioedema. ACE inhibitors are contraindicated.

37

C3 deficiency

Increases risk of severe, recurrent pyogenic sinus and respiratory infections. Higher susceptibility to type 3 hypersensitivity rxns

38

C5-C9 deficiencies

Terminal complement deficiency increases risk to recurrent Neisseria bacteremia

39

DAF (GPI-anchored enxyme) deficiency

causes complement-mediated lysis of RBCs and paroxysmal nocturnal hemoglobinuria

40

cytokines released by macrophages

IL-1, IL-6, IL-8, IL-12, TNF-alpha

41

cytokines released by ALL T cells

IL-2, IL-3

42

cytokines released by Th1 cells

IFN-gamma

43

cytokines released by Th2 cells

IL-4, IL-5, IL-10

44

IL-1

"osteoclast-activating factor"

causes fever, acute inflammation. Activates endothelium to express adhesion molecules. Induces chemokine secretion to recruit WBCs

45

IL-6

Causes fever and stimulates production of acute-phase proteins

46

IL-8

Major chemotactic factor for neutrophils

47

IL-12

Induces differentiation of T cells into Th1 cells. Activates NK cells.

48

TNF-alpha

Mediates septic shock. Activates endothelium. Causes WBC recruitment, vascular leak.

49

IL-2

Stimulates growth of helper, cytotoxic, and regulatory T cells. Also NK cells.

50

IL-3

Supports growth and differentiation of bone marrow stem cells. Functions like GM-CSF

51

IFN-gamma

secreted by NK cells in response to IL-12 from macrophages. Stimulates macrophages to kill phagocytosed pathogens.

Also activates NK cells to kill virus-infected cells. Increases MHC expression and antigen presentation by all cells.

52

IL-4

Induces differentiation into Th2 cells. Promotes growth of B cells. Enhances class switching to IgE and IgG

53

IL-5

Promotes differentiation of B cells. Enhances class switching to IgA. Stimulates growth and differentiation of eosinophils.

54

IL-10

Modulates inflammatory response. Lowers expression of MHC class II and Th1 cytokines. Inhibits activated macrophages and dendritic cells. Also secreted by Treg.

TGF-Beta and IL-10 aTENuate the immune response.

55

Chronic granulomatous disease

Patients cannot make superoxide radical and therefore can't generate ROS.

Can still utilize H2O2 generated by invading organisms to make ROS. However, Cat (+) organisms can neutralize their own H2O2... higher risk of infection from these organisms.

56

Cell surface proteins on all nucleated cells

MHC1. Not on RBCs (no nucleus)

57

Cell surface proteins on T cells

TCR (binds antigen-MHC complex)

CD3 (associated with TCR for signal transduction)

CD28 (binds B7 on APC)

58

Cell surface proteins on Th cells

CD4, CD40L

59

Cell surface proteins on Tcytotox

CD8

60

Cell surface proteins on Treg

CD4, CD25

61

Cell surface proteins on B cells

Ig (binds antigen)

CD19, CD20, CD21 (receptor for EBV), CD40

MHC2, B7

62

Cell surface proteins on Macrophages

CD14, CD40

MHC2, B7

Fc and C3b receptors (enhanced phagocytosis)

63

Cell surface proteins on NK cells

CD16 (binds Fc of IgG), CD56 (unique marker for NK)

64

Cell surface proteins on Hematopoietic stem cells

CD34

65

Chronic granulomatous disease

Patients cannot make superoxide radical and therefore can't generate ROS. Deficiency in NADPH oxidase.

Can still utilize H2O2 generated by invading organisms to make ROS. However, Cat (+) organisms can neutralize their own H2O2... higher risk of infection from these organisms.

66

X-Linked (Bruton) agammaglobulinemia

Defect in BTK (tyrosine kinase gene) leading to no B cell maturation. X-linked recessive and higher in boys.

Presents w/ recurrent bacterial and enteroviral infections after age 6 months (lower maternal IgG at this time)

You'll find absent B cells in peripheral blood, lower Ig of all classes, and absent/scanty lymph nodes and tonsils.

67

Selective IgA deficiency

Unknown cause, but most common primary immunodeficiency

P/w: Majority asymptomatic. You can see airway and GI infections, autoimmune disease, atopy, anaphylaxis to IgA containing products.

You'll find lower IgA with normal IgG, IgM levels

68

Common variable immunodeficiency

Defect in B-cell differentiation from many causes.

p/w: can be acquired in 20s-30s; higher risk of autoimmune diseases, bronchiectasis, lymphoma, sinopulmonary infections.

You'll find lower plasma cells, lower immunoglobulins.

69

Thymic aplasia (DiGeorge Syndrome)

22q11 deletion; failure to develop 3rd and 4th pharyngeal pouches leadings to absent thymus and parathyroids

P/w: tetany (hypocalcemia), recurrent viral/fungal infections (T Cell deficiency), conotruncal abnormalities (e.g. tetralogy of fallot, truncus arteriosus)

Findings: low T cells, low PTH, low Ca

Absent thymic shadow on CXR. 22q11 deletion detected by FISH

70

IL-12 receptor deficiency

lower Th1 response. Autosomal recessive

Disseminated mycobacterial and fungal infections; may present after administration of BCG vaccine

Findings: low IFN-gamma

71

Autosomal dominant hyper-IgE Syndrome (Job Syndrome)

deficiency of Th17 cells due to STAT3 mutation leads to impaired recruitment of neutrophils to sites of infection.

p/w: FATED - coarse Facies, cold (noninflamed) staphlococcal Abscesses, retained primary Teeth, higher IgEEEE, Derm problems (eczema)

Findings: high IgE, Low IFN-gamma

72

Chronic mucocutaneous candidiasis

T cell dysfunction from many causes.

p/w: noninvasive candida albicans infections of skin and mucous membranes

73

Severe Combined Immunodeficiency

Dif types: Defective IL-2R gamma chain (most common, X-linked). Adenosine deaminase deficiency also possible (Auto recess)

p/w: Failure to thrive, chronic diarrhea, thrush, recurrent viral, bacterial, fungal and protozoal infections. Tx = bone marrow transplant (no rejection concern)

Findings: Low T cell receptor excision circles (TRECS). No Thymic shadow on CXR. No germinal centers (lymph node biopsy), No T cells (flow cytometry)

74

Ataxia-Telangiectasia

Defects in ATM gene leads to failure to repair DNA ds breaks leading to cell cycle arrest.

Triad: cerebellar defects (ataxia), spider angiomas (telangiectasia), IgA deficiency

Findings: Higher AFP (alpha fetoprotein), Lower IgA, Low IgG, Low IgE

Lymphopenia, cerebellar atrophy

75

Hyper-IgM Syndrome

Defective CD40L on Th cells leads to class switching defect. X recessive.

p/w: Severe pyogenic infections early in life; opportunistic infection with Pneumocystis, Crypto, CMV

Findings: High IgM. Very low IgG, IgA, IgE

76

Wiskott-Aldrich Syndrome

Mutation in WAS gene (X recess); T cells unable to reorganize actin cytoskeleton

p/w: Thrombocytopenic purpura, eczema, recurrent infections. Higher risk of autoimmune diseases and malignancy

Findings: Low to normal IgG, IgM. High IgE, IgA, Fewer and smaller platelets

77

Chronic granulomatous disease

Patients cannot make superoxide radical and therefore can't generate ROS. Deficiency in NADPH oxidase.

Can still utilize H2O2 generated by invading organisms to make ROS. However, Cat (+) organisms can neutralize their own H2O2... higher risk of infection from these organisms.

Nocardia, Pseudomonas, Listeria, Aspergillis, Candida, E Coli, S aureus, Serratia

Findings: Abnormal dihyrdorhodamine (flow cytometry) test. Nitroblue tetrazolium dye reduction test is negative

78

Leukocyte adhesion deficiency (type 1)

Defect in LFA-1 integrin (CD18) protein on phagoctyes leads to impaired migration and chemotaxis. Auto recess.

Recurrent bacterial skin and mucosal infection, absent pus formation, impaired wound healing, delayed separation of umbilical cord (>30 days).

Findings: High neutrophils. Absence of neutrophils at infection sites.

79

Chediak-Higashi Syndrome

Defect in lysosomal trafficking regulator gene (LYST). Microtubule dysfunction in phagosome-lysosome fusion; auto recess

Recurrent pyogenic infections by staph and strep, partial albinism, peripheral neuropathy, progressive neurodegeneration, infiltrative lymphohistiocytosis

Findings: Giant granules in granulocytes and platelets. Pancytopenia. Mild coagulation defects.

80

Cyclosporine

Inhibits calcineurin. It binds to cyclophilin to do this. Blocks T cell activation by preventing IL-2 transcription.

Use in transplant rejection prophylaxis, psoriasis, RA.

Toxicity: Nephrotoxicity, HTN, hyperlipidemia, neurotox, gingival hyperplasia, hirsutism

81

Tacrolimus (FK506)

Inhibits calcineurin - binds FK506 binding protein (FKBP). Blocks T cell activation by preventing IL-2 transcription

Use in transplant rejection prophylaxis

Toxicity: Nephro, similar to cyclosporine, increases risk of diabetes and neurotox - no gingival hyperplasia or hirsutism.

82

Sirolimus (Rapamycin)

mTOR inhibitor, binds FKBP. Blocks T cell activation and B cell differentiation by preventing response to IL-2.

Use in Kidney transplant rejection prophylaxis

Toxicity: Anemia, thrombocytopenia, leukopenia, insulin resistance, hyperlipidemia, NOT NEPHROTOX

Kidney SIRvives. Works well with cyclosporine. Also used in drug-eluting stents.

83

Daclizumab, basiliximab

Monoclonal antibodies - block IL-2R

Use in kidney transplant rejection prophylaxis

Toxicity - Edema, HTN, tremor

84

Azathioprine

Antimetabolite precursor of 6-mercaptopurine (6-MP). Inhibits lymphocyte proliferation by blocking nucleotide synthesis.

Use in transplant rejection prophylaxis, RA, Crohn, glomerulonephritis, other autoimmune disorders

Toxic: Leukopenia, anemia, thrombocytopenia

6-MP degraded by XO so toxicity is increased by allopurinol

85

Glucocorticoids

Inhibit NF-kB. Suppress both B and T cell function by lowering transcription of many cytokines.

Use in transplant rejection prophylaxis (immunosuppression), many autoimmune disorders, inflammation.

Toxic: Hyperglycemia, osteoporosis, central obesity, muscle breakdown, psychosis, acne, HTN, cataracts, avascular necrosis

Can cause iatrogenic Cushing syndrome.

86

Anti-ACh receptor antibody

Myasthenia gravis

87

Anti-basement membrane antibody

Goodpasture syndrome

88

Anticardiolipin, lupus anticoagulant antibodies

SLE, antiphospholipid syndrome

89

Anticentromere antibody

Limited scleroderma (CREST Syndrome)

90

Anti-desmosome (anti-desmoglein) antibodies

Pemphigus vulgaris

91

Anti-dsDNA, ant-Smith antibodies

SLE

92

Anti-glutamic acid decarboxylase (GAD-65) antibodies

Type 1 diabetes mellitus

93

Antihemidesmosome antibodies

Bullous pemphigoid

94

Anti-histone antibodies

Drug-induced lupus

95

Anti-Jo-1, anti-SRP, anti-Mi-2 antibodies

Polymyositis, dermatomyositis

96

Antimicrosomal, antithyroglobulin antibodies

Hashimoto thyroiditis

97

Antimitochondrial antibodies

Primary biliary cirrhosis

98

Antinuclear antibodies

SLE, nonspecific

99

Antiparietal cell antibodies

Pernicious anemia

100

Anti-Scl-70 (anti-DNA topoisomerase I) antibodies

Scleroderma (diffuse)

101

Anti-smooth muscle antibodies

Autoimmune hepatitis

102

Anti-SSA, anti-SSB (anti-Ro, anti-La) antibodies

Sjogren Syndrome

103

Anti-TSH receptor antibodies

Graves disease

104

Anti-U1 RNP (ribonucleoprotein) antibodies

Mixed connective tissue disease

105

IgA anti-endomysial, IgA anti-tissue transglutaminase antibodies

Celiac Disease

106

MPO-ANCA/p-ANCA antibodies

Microscopic polyangiitis

Eosinophilic granulomatosis with polyangiitis (Churg-Strauss Syndrome)

107

PR3-ANCA/c-ANCA antibodies

Granulomatosis with polyangiitis (Wegener)

108

Rheumatoid factor (IgM antibody that targets IgG Fc region), anti-CCP (more specific) antibodies

Rheumatoid Arthritis