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USMLE Step 1 > Immunology - First Aid > Flashcards

Immunology - First Aid Flashcards

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1
Q

1° Immune System Organs

A
  • Bone Marrow
  • Thymus
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2
Q

2° Immune System Organs

A
  • Spleen
  • Lymph Nodes
  • Tonsils
  • Peyer Patches
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3
Q

Immune System Organs:

  • immune cell production
  • B cell maturation
A

Bone Marrow

Bone Marrow = B Cell

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4
Q

Immune System Organs:

T cell maturation

A

Thymus

Thymus = T Cell

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5
Q

Immune System Organs:

allow immune cells to interact with antigen

A

2° organs:

  • Spleen
  • Lymph Nodes
  • Tonsils
  • Peyer Patches
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6
Q

Immune System Organs:

  • 2° lymphoid organ that has many afferents, 1 or more efferents
  • encapsulated, with trabeculae
  • functions are nonspecific filtration by macrophages, storage of B and T cells, and immune response activation
A

Lymph Node

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7
Q

Lymph Node

A
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8
Q

Lymph Node:

  • site of B-cell localization and proliferation
  • outer cortex
A

Follicle

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9
Q

Lymph Node:

  • dense
  • dormant
A

1° follicles

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10
Q

Lymph Node:

  • have pale central germinal centers
  • active
A

2° follicles

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11
Q

Lymph Node:

  • consists of cords (closely packed lymphocytes and plasma cells) and sinuses
  • sinuses communicate with efferent lymphatics and contain reticular cells and macrophages
A

Medulla

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12
Q

Lymph Node:

  • houses T cells.
  • region of cortex between follicles and medulla
  • contains high endothelial venules through which T and B cells enter from blood
  • not well developed in patients with DiGeorge syndrome
  • enlarges in an extreme cellular immune response (eg. viral infection)
A

Paracortex

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13
Q

Lymphatic Drainage Associations

A
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14
Q

Lymphatic Drainage Associations:

drains head and neck

A

Cervical

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15
Q

Lymphatic Drainage Associations:

  • URTI
  • Infectious Mononucleosis
  • Kawasaki disease
A

Cervical

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16
Q

Lymphatic Drainage Associations:

drains trachea and esophagus

A

Mediastinal

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17
Q

Lymphatic Drainage Associations:

  • 1° Lung Cancer
  • Granulomatous disease
A

Mediastinal

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18
Q

Lymphatic Drainage Associations:

drains lungs

A

Hilar

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19
Q

Lymphatic Drainage Associations:

Granulomatous disease

A

Hilar

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20
Q

Lymphatic Drainage Associations:

drains upper limbs, breast, and skin above umbilicus

A

Axillary

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21
Q

Lymphatic Drainage Associations:

  • Mastitis
  • Metastasis (especially breast cancer)
A

Axillary

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22
Q

Lymphatic Drainage Associations:

drains liver, stomach, spleen, pancreas, and upper duodenum

A

Celiac

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23
Q

Lymphatic Drainage Associations:

drains lower duodenum, jejunum, ileum, and colon to splenic flexure

A

Superior Mesenteric

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24
Q

Lymphatic Drainage Associations:

drains colon from splenic flexure to upper rectum

A

Inferior Mesenteric

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Lymphatic Drainage Associations: * Mesenteric Lymphadenitis * Typhoid Fever * Ulcerative Colitis * Celiac disease
* Celiac * Superior Mesenteric * Inferior Mesenteric
26
Lymphatic Drainage Associations: drains testes, ovaries, kidneys, and uterus
Para-aortic
27
Lymphatic Drainage Associations: Metastasis
Para-aortic
28
Lymphatic Drainage Associations: drains lower rectum to anal canal (above pectinate line), bladder, vagina (middle third), cervix, and prostate
Internal Iliac
29
Lymphatic Drainage Associations: drains anal canal (below pectinate line), skin below umbilicus (except popliteal area), scrotum, and vulva
Superficial Inguinal
30
Lymphatic Drainage Associations: Sexually Transmitted Infections
* Internal Iliac * Superficial Inguinal
31
Lymphatic Drainage Associations: drains dorsolateral foot and posterior calf
Popliteal
32
Lymphatic Drainage Associations: Foot/Leg Cellulitis
Popliteal
33
The right lymphatic duct drains the right side of body above diaphragm into the \_\_\_\_\_.
junction of the right subclavian and internal jugular vein
34
The _____ drains everything into the junction of left subclavian and internal jugular veins. Rupture can cause chylothorax.
Thoracic Duct
35
The spleen is located in the _____ and is protected by \_\_\_\_\_.
LUQ of abdomen, anterior to left kidney ribs 9-11
36
Spleen
37
Spleen: long, vascular channels in red pulp with fenestrated “barrel hoop” basement membrane
Sinusoids
38
Spleen: T cells are found in the _____ within the white pulp.
Periarteriolar Lymphatic Sheath (PALS)
39
Spleen: B cells are found in _____ within the white pulp.
follicles
40
Spleen: * in between the red pulp and white pulp * contains macrophages and specialized B cells * where antigen-presenting cells (APCs) capture blood-borne antigens for recognition by lymphocytes
Marginal Zone
41
Splenic macrophages remove _____ bacteria.
encapsulated
42
Splenic Dysfunction
↓ IgM → ↓ complement activation → ↓ C3b opsonization → ↑ susceptibility to encapsulated organisms
43
Postsplenectomy Blood Findings
* Howell-Jolly bodies (nuclear remnants) * Target cells * Thrombocytosis (loss of sequestration and removal) * Lymphocytosis (loss of sequestration)
44
You should vaccinate patients undergoing splenectomy against \_\_\_\_\_.
encapsulated organisms * pneumococcal * Hib * meningococcal
45
The thymus is located in the \_\_\_\_\_.
anterosuperior mediastinum
46
The _____ is an encapsulated organ where T-cells differentiate and mature.
Thymus
47
The thymus is derived from the \_\_\_\_\_.
3rd pharyngeal pouch **Th**ymus = **Th**ird pharyngeal pouch
48
The thymus contains lymphocytes of _____ origin.
mesenchymal
49
Thymus: dense with immature T cells
Cortex
50
Thymus: * pale * mature T cells * Hassall corpuscles containing epithelial reticular cells
Medulla
51
The normal neonatal thymus is _____ on CXR, involutes with age.
“sail-shaped”
52
The thymus is hypoplastic in \_\_\_\_\_.
* DiGeorge Syndrome * Severe Combined Immunodeficiency (SCID)
53
\_\_\_\_\_ is a neoplasm of thymus. It is associated with myasthenia gravis and superior vena cava syndrome.
Thymoma
54
Innate Immunity: Components
* neutrophils * macrophages * monocytes * dendritic cell * natural killer (NK) cells (lymphoid origin), * complement * physical epithelial barriers * secreted enzymes
55
Innate Immunity: Mechanism
germline encoded
56
Innate Immunity: Resistance
* resistance persists through generations * does not change within an organism’s lifetime
57
Innate Immunity: Response to Pathogens
* nonspecific * occurs rapidly (minutes to hours) * no memory response
58
Innate Immunity: Secreted Proteins
* lysozyme * complement * C-reactive protein (CRP) * defensins
59
Innate Immunity: Pathogen Recognition
* Toll-like receptors (TLRs): pattern recognition receptors that recognize pathogen-associated molecular patterns (PAMPs) and lead to activation of NF-κB * Examples of PAMPs include LPS (gram ⊝ bacteria), flagellin (bacteria), nucleic acids (viruses).
60
Adaptive Immunity: Components
* T cells * B cells * circulating antibodies
61
Adaptive Immunity: Mechanism
variation through V(D)J recombination during lymphocyte development
62
Adaptive Immunity: Resistance
microbial resistance not heritable
63
Adaptive Immunity: Response to Pathogens
* highly specific * refined over time * develops over long periods * memory response is faster and more robust
64
Adaptive Immunity: Secreted Proteins
immunoglobulins
65
Adaptive Immunity: Pathogen Recognition
* Memory cells: activated B and T cells * Subsequent exposure to a previously encountered antigen → stronger, quicker immune response.
66
Major histocompatibility complex I and II are encoded by \_\_\_\_\_.
HLA genes
67
\_\_\_\_\_ present antigen fragments to T cells and bind T-cell receptors (TCRs).
Major Histocompatibility Complex I and II
68
MHC I: Loci
* HLA-**A** * HLA-**B** * HLA-**C** MHC **I** loci have **1** letter
69
MHC I: Binding
* TCR * CD8
70
MHC I: Structure
1 long chain, 1 short chain
71
MHC I: Expression
* all nucleated cells, APCs, platelets * not on RBCs
72
MHC I: Function
present endogenously synthesized antigens (eg. viral or cytosolic proteins) to CD8+ cytotoxic T cells
73
MHC I: Antigen Loading
antigen peptides loaded onto MHC I in RER after delivery via TAP (transporter associated with antigen processing)
74
MHC I: Associated Protein
β2-microglobulin
75
MHC II: Loci
* HLA-**DP** * HLA-**DQ** * HLA-**DR** MHC **II** loci have **2** letters
76
MHC II: Binding
* TCR * CD4
77
MHC II: Structure
2 equal-length chains (2 α, 2 β)
78
MHC II: Expression
APCs
79
MHC II: Function
present exogenously synthesized antigens (eg. bacterial proteins) to CD4+ helper T cells
80
MHC II: Antigen Loading
antigen loaded following release of invariant chain in an acidified endosome
81
MHC II: Associated Protein
invariant chain
82
HLA Subtypes: Hemochromatosis
A3
83
HLA Subtypes: * Addison disease * Myasthenia Gravis * Graves disease
B8 Don’t **B**e late(**8**), Dr. **Addison**, or else you’ll send **my** patient to the **grave**.
84
HLA Subtypes: * Psoriatic Arthritis * Ankylosing Spondylitis, * IBD-associated Arthritis * Reactive Arthritis
B27 **PAIR** \*also known as seronegative arthropathies
85
HLA Subtypes: Celiac disease
DQ2/DQ8 I ate (**8**) too (**2**) much gluten at **D**airy **Q**ueen.
86
HLA Subtypes: * Multiple Sclerosis * Hay Fever * SLE * Goodpasture Syndrome
DR2 **Multiple hay pasture**s have **dirt**.
87
HLA Subtypes: * Diabetes Mellitus Type 1 * SLE * Graves disease, * Hashimoto Thyroiditis * Addison disease
DR3 **2**-**3**, **S**-**L**-**E**
88
HLA Subtypes: * Rheumatoid Arthritis * Diabetes Mellitus Type 1 * Addison disease
DR4 There are **4** walls in a “**rheum**” (room).
89
HLA Subtypes: Hashimoto Thyroiditis
DR5 **Hashimoto** is an **odd** **d**octo**r** (**DR3**, **DR5**).
90
Natural killer cells are lymphocyte members of the \_\_\_\_\_.
innate immune system
91
Natural killer cells use _____ to induce apoptosis of virally infected cells and tumor cells.
* perforin * granzymes
92
Natural killer cells' activity is enhanced by \_\_\_\_\_.
* IL-2 * IL-12 * IFN-α * IFN-β
93
\_\_\_\_\_ are induced to kill when exposed to a nonspecific activation signal on target cell and/or to an absence of MHC I on target cell surface.
Natural Killer Cells
94
Natural killer cells kill via _____ (CD16 binds Fc region of bound Ig, activating the NK cell).
antibody-dependent cell-mediated cytotoxicity
95
Immune Cells: * humoral immunity * recognize antigen—undergo somatic hypermutation to optimize antigen specificity * produce antibody—differentiate into plasma cells to secrete specific immunoglobulins. * maintain immunologic memory—memory _____ persist and accelerate future response to antigen.
B Cells
96
Immune Cells: * cell-mediated immunity * CD4+ _____ help B cells make antibodies and produce cytokines to recruit phagocytes and activate other leukocytes * CD8+ _____ directly kill virus-infected cells * delayed cell-mediated hypersensitivity (type IV) * acute and chronic cellular organ rejection
T Cells **Rule of 8**: * MHC **II** × CD**4** = **8** * MHC **I** × CD**8** = **8**
97
Differentiation of T Cells
98
Differentiation of T Cells: * thymic cortex * T cells expressing TCRs capable of binding self-MHC on cortical epithelial cells survive
Positive Selection
99
Differentiation of T Cells: * thymic medulla * T cells expressing TCRs with high affinity for self antigens undergo apoptosis or become regulatory T cells * tissue-restricted self-antigens are expressed in the thymus due to the action of autoimmune regulator (AIRE)—deficiency leads to autoimmune polyendocrine syndrome-1
Negative Selection
100
Th1 cells secrete \_\_\_\_\_.
IFN-γ
101
\_\_\_\_\_ activate macrophages and cytotoxic T cells to kill phagocytosed microbes.
Th1 Cells
102
Th1 cells are induced by \_\_\_\_\_.
* IFN-γ * IL-12
103
Th1 cells are inhibited by \_\_\_\_\_.
* IL-4 * IL-10 \*from Th2 cell
104
Th1 Cells: Immunodeficiency
Mendelian Susceptibility to Mycobacterial Disease (MSMD)
105
Th2 cells secrete \_\_\_\_\_.
* IL-4 * IL-5 * IL-6 * IL-10 * IL-13
106
\_\_\_\_\_ activate eosinophils and promote production of IgE for parasite defense.
Th2 Cells
107
Th2 cells are induced by \_\_\_\_\_.
* IL-2 * IL-4
108
Th2 cells are inhibited by \_\_\_\_\_.
IFN-γ \*from Th1 cell
109
Th17 cells secrete \_\_\_\_\_.
* IL-17 * IL-21 * IL-22
110
\_\_\_\_\_ provide immunity against extracellular microbes, through induction of neutrophilic inflammation.
Th17 Cells
111
Th17 cells are induced by \_\_\_\_\_.
* TGF-β * IL-1 * IL-6
112
Th17 cells are inhibited by \_\_\_\_\_.
* IFN-γ * IL-4
113
Th17 Cells: Immunodeficiency
Hyper-IgE Syndrome
114
Treg cells secrete \_\_\_\_\_.
* TGF-β * IL-10 * IL-35
115
\_\_\_\_\_ prevent autoimmunity by maintaining tolerance to self-antigens.
Treg Cells
116
Treg cells are induced by \_\_\_\_\_.
* TGF-β * IL-2
117
Treg cells are inhibited by \_\_\_\_\_.
IL-6
118
Treg Cells: Immunodeficiency
IPEX (Immune dysregulation, Polyendocrinopathy, Enteropathy, X-linked) Syndrome
119
Immunity: * Th1 cells secrete IFN-γ, which enhances the ability of monocytes and macrophages to kill microbes they ingest. * This function is also enhanced by interaction of T cell CD40L with CD40 on macrophages.
Macrophage-Lymphocyte Interaction
120
Immunity: * kill virus-infected, neoplastic, and donor graft cells by inducing apoptosis * release cytotoxic granules containing preformed proteins (eg. perforin, granzyme B) * have CD8, which binds to MHC I on virus-infected cells
Cytotoxic T Cells
121
Immunity: * help maintain specific immune tolerance by suppressing CD4 and CD8 T-cell effector functions * identified by expression of CD3, CD4, CD25, and FOXP3 * once activated, they produce anti-inflammatory cytokines (eg. IL-10, TGF-β)
Regulatory T Cells (Tregs)
122
\_\_\_\_\_ is caused by the genetic deficiency of FOXP3 → autoimmunity. Characterized by enteropathy, endocrinopathy, nail dystrophy, dermatitis, and/or other autoimmune dermatologic conditions. Associated with diabetes in male infants.
IPEX (Immune dysregulation, Polyendocrinopathy, Enteropathy, X-linked) Syndrome
123
Antigen-Presenting Cells
* B Cells * Dendritic Cells * Langerhans Cells * Macrophages
124
T Cell Activation
1. Dendritic cell (specialized APC) samples antigen, processes antigen, and migrates to the draining lymph node. 2. T-cell activation (signal 1): antigen ispresented on MHC II and recognized by TCR on Th (CD4+) cell. Endogenous or cross-presented antigen is presented on MHC I to Tc (CD8+) cell. 3. Proliferation and survival (signal 2): costimulatory signal via interaction of B7 protein (CD80/86) on dendritic cell and CD28 on naïve T cell. 4. Th cell activates and produces cytokines. Tc cell activates and is able to recognize and kill virus-infected cell.
125
B Cell Activation
1. Th-cell activation as above. 2. B-cell receptor–mediated endocytosis; foreign antigen is presented on MHC II and recognized by TCR on Th cell. 3. CD40 receptor on B cell binds CD40 ligand (CD40L) on Th cell. 4. Th cell secretes cytokines that determine Ig class switching of B cell. B cell activates and undergoes class switching, affinity maturation, and antibody production.
126
Antibody Structure
127
Antibody Function
128
Antibodies: \_\_\_\_\_ (containing the variable/hypervariable regions) consisting of light (L) and heavy (H) chains recognizes antigens.
Fab
129
Antibodies: \_\_\_\_\_ of IgM and IgG fixes complement.
Fc region
130
Antibodies: \_\_\_\_\_ contributes to Fc and Fab regions.
Heavy Chain
131
Antibodies: \_\_\_\_\_ contributes only to Fab region.
Light Chain
132
Antibodies: * fragment, antigen binding * determines idiotype: unique antigen-binding pocket; only 1 antigenic specificity expressed per B cell
Fab **F**ragment, **a**ntigen **b**inding
133
Antibodies: * constant * carboxy terminal * complement binding * carbohydrate side chains * determines isotype (IgM, IgD, etc)
Fc * **c**onstant * **c**arboxy terminal * **c**omplement binding * **c**arbohydrate side chains
134
Generation of Antibody Diversity (antigen independent)
1. random recombination of VJ (light-chain) or V(D)J (heavy-chain) genes 2. random addition of nucleotides to DNA during recombination by terminal deoxynucleotidyl transferase (TdT) 3. random combination of heavy chains with light chains
135
Generation of Antibody Specificity (antigen dependent)
1. somatic hypermutation and affinity maturation (variable region) 2. isotype switching (constant region)
136
All immunoglobulin isotypes can exist as \_\_\_\_\_.
monomers
137
Mature, naive B cells prior to activation express _____ on their surfaces.
* IgM * IgD
138
Mature, naive B cells may differentiate in germinal centers of lymph nodes by isotype switching (gene rearrangement; induced by cytokines and CD40L) into plasma cells that secrete \_\_\_\_\_.
* IgA * IgE * IgG
139
Immunoglobulin Isotypes: * main antibody in 2° response to an antigen * most abundant isotype in serum * fixes complement, opsonizes bacteria, neutralizes bacterial toxins an viruses * only isotype that crosses the placenta (provides infants with passive immunity)
IgG
140
Immunoglobulin Isotypes: * prevents attachment of bacteria and viruses to mucous membranes; does not fix complement * monomer (in circulation) or dimer (with J chain when secreted) * crosses epithelial cells by transcytosis * produced in GI tract (eg. by Peyer patches) and protects against gut infections (eg. Giardia) * most produced antibody overall, but has lower serum concentrations * released into secretions (tears, saliva, mucus) and breast milk * picks up secretory component from epithelial cells, which protects the Fc portion from luminal proteases
IgA
141
Immunoglobulin Isotypes: * produced in the 1° (immediate) response to an antigen * fixes complement * cannot cross the placenta * antigen receptor on the surface of B cells * monomer on B cell, pentamer with J chain when secreted * pentamer enables avid binding to antigen while humoral response evolves
IgM
142
Immunoglobulin Isotypes: * unclear function * found on surface of many B cells and in serum
IgD
143
Immunoglobulin Isotypes: * binds mast cells and basophils; cross-links when exposed to allergen, mediating immediate (type I) hypersensitivity through release of inflammatory mediators such as histamine * contributes to immunity to parasites by activating eosinophils * lowest concentration in serum
IgE
144
Antigen Type and Memory: * antigens lacking a peptide component (eg. lipopolysaccharides from gram ⊝ bacteria) * cannot be presented by MHC to T cells * weakly immunogenic * vaccines often require boosters and adjuvants (eg. pneumococcal polysaccharide vaccine)
Thymus-Independent Antigens
145
Antigen Type and Memory: * antigens containing a protein component (eg. diphtheria vaccine) * class switching and immunologic memory occur as a result of direct contact of B cells with Th cells
Thymus-Dependent Antigens
146
\_\_\_\_\_ is a system of hepatically synthesized plasma proteins that play a role in innate immunity and inflammation.
Complement
147
Membrane Attack Complex (MAC) defends against \_\_\_\_\_.
gram ⊝ bacteria
148
Complement Activation Pathways: IgG or IgM mediated
Classic **GM** makes **classic** cars.
149
Complement Activation Pathways: microbe surface molecules
Alternative
150
Complement Activation Pathways: mannose or other sugars on microbe surface
Lectin
151
Complement Activation Pathways
152
Complement Functions: opsonization
C3b C3**b** **b**inds **b**acteria.
153
Complement Functions: anaphylaxis
* C3a * C4a * C5a C3**a**, C4**a**, C5**a** = **a**naphylaxis
154
Complement Functions: neutrophil chemotaxis
C5a
155
Complement Functions: cytolysis by MAC
C5b-9
156
C3b and IgG are the two 1° _____ in bacterial defense; enhance phagocytosis. C3b also helps clear immune complexes.
Opsonins
157
\_\_\_\_\_ like decay-accelerating factor (DAF, aka CD55) and C1 esterase inhibitor help prevent complement activation on self cells (eg. RBCs).
Inhibitors
158
Complement Protein Peficiencies
* Early Complement Deficiencies (C1-C4) * Terminal Complement Deficiencies (C5–C9)
159
Complement Disorders: * increased risk of severe, recurrent pyogenic sinus and respiratory tract infections * increased risk of SLE
Early Complement Deficiencies (C1-C4)
160
Complement Disorders: increased susceptibility to recurrent Neisseria bacteremia
Terminal Complement Deficiencies (C5–C9)
161
Complement Regulatory Protein Deficiencies
* C1 Esterase Inhibitor Deficiency * Paroxysmal Nocturnal Hemoglobinuria
162
Complement Disorders: * causes hereditary angioedema due to unregulated activation of kallikrein → ↑ bradykinin * characterized by ↓ C4 levels * ACE inhibitors are contraindicated
C1 Esterase Inhibitor Deficiency
163
Complement Disorders: * a defect in the PIGA gene preventing the formation of anchors for complement inhibitors, such as decay-acclerating factor (DAF/CD55) and membrane inhibitor of reactive lysis (MIRL/CD59) * causes complement-mediated lysis of RBCs
Paroxysmal Nocturnal Hemoglobinuria
164
Interleukins
“**Hot T-bone** st**EAK**”: * IL-1: fever (**hot**) * IL-2: stimulates **T** cells * IL-3: stimulates **bone** marrow * IL-4: stimulates Ig**E** production * IL-5: stimulates Ig**A** production * IL-6: stimulates a**K**ute-phase protein production
165
Cytokines Secreted by Macrophages
* Interleukin-1 * Interleukin-6 * Interleukin-8 * Interleukin-12 * Tumor Necrosis Factor-α
166
Cytokines Secreted by Macrophages: * causes fever, acute inflammation * activates endothelium to express adhesion molecules * induces chemokine secretion to recruit WBCs * also known as osteoclast-activating factor
Interleukin-1
167
Cytokines Secreted by Macrophages: * causes fever * stimulates production of acutephase proteins
Interleukin-6
168
Cytokines Secreted by Macrophages: major chemotactic factor for neutrophils
Interleukin-8 “**Clean up** on **aisle 8**.” Neutrophils are recruite by **IL-8** to **clear** infections.
169
Cytokines Secreted by Macrophages: * induces differentiation of T cells into Th1 cells * activates NK cells
Interleukin-12
170
Cytokines Secreted by Macrophages: * activates endothelium * causes WBC recruitment, vascular leak * causes cachexia in malignancy * maintains granulomas in TB
Tumor Necrosis Factor-α
171
\_\_\_\_\_ are cytokines that can mediate fever and sepsis.
* IL-1 * IL-6 * TNF-α
172
Cytokines Secreted by All T Cells
* Interleukin-2 * Interleukin-3
173
Cytokines Secreted by All T Cells: stimulates growth of helper, cytotoxic, and regulatory T cells, and NK cells
Interleukin-2
174
Cytokines Secreted by All T Cells: * supports growth and differentiation of bone marrow stem cells * functions like GM-CSF
Interleukin-3
175
Cytokines from Th1 Cells
Interferon-γ
176
Cytokines from Th1 Cells: * secreted by NK cells and T cells in response to antigen or IL-12 from macrophages * stimulates macrophages to kill phagocytosed pathogens * inhibits differentiation of Th2 cells * activates NK cells to kill virus-infected cells * increases MHC expression and antigen presentation by all cells
Interferon-γ
177
Cytokines from Th2 Cells
* Interleukin-4 * Interleukin-5 * Interleukin-10
178
Cytokines from Th2 Cells: * induces differentiation of T cells into Th (helper) 2 cells * promotes growth of B cells * enhances class switching to IgE and IgG
Interleukin-4 Ain’t too proud **2 BEG 4 help**.
179
Cytokines from Th2 Cells: * promotes growth and differentiation of B cells * enhances class switching to IgA * stimulates growth and differentiation of eosinophils
Interleukin-5
180
Cytokines from Th2 Cells: * attenuates inflammatory response * decreases expression of MHC class II and Th1 cytokines * inhibits activated macrophages and dendritic cells * also secreted by regulatory T cells
Interleukin-10 TGF-**β** and IL-**10** both at**ten**uate the immune response.
181
Immunity: * involves the activation of the phagocyte NADPH oxidase complex (eg. in neutrophils, monocytes), which utilizes O2 as a substrate * plays an important role in the immune response → rapid release of reactive oxygen species (ROS) * NADPH plays a role in both the creation and neutralization
Respiratory Burst | (Oxidative Burst)
182
\_\_\_\_\_ contains a blue-green heme-containing pigment that gives sputum its color.
Myeloperoxidase
183
Respiratory Burst | (Oxidative Burst)
184
Phagocytes of patients with _____ can utilize H2O2 generated by invading organisms and convert it to ROS. Patients are at ↑ risk for infection by catalase ⊕ species (eg. *S. aureus, Aspergillus*) capable of neutralizing their own H2O2, leaving phagocytes without ROS for fighting infections.
Chronic Granulomatous Disease
185
\_\_\_\_\_ of *P. aeruginosa* generates ROS to kill competing pathogens.
Pyocyanin
186
Oxidative burst leads to \_\_\_\_\_, which releases lysosomal enzymes from proteoglycans.
K+ influx
187
\_\_\_\_\_ is a protein found in secretory fluids and neutrophils that inhibits microbial growth via iron chelation.
Lactoferrin
188
Immunity: * part of innate host defense against both RNA and DNA viruses * glycoproteins synthesized by virus-infected cells that act on local cells, “priming them” for viral defense by downregulating protein synthesis to resist potential viral replication and upregulating MHC expression to facilitate recognition of infected cells
Interferon-α and -β **Interfer**e with **virus**es.
189
Cell Surface Proteins: T Cells
* TCR (binds antigen-MHC complex) * CD3 (associated with TCR for signal transduction) * CD28 (binds B7 on APC)
190
Cell Surface Proteins: Helper T Cells
* CD4 * CD40L * CXCR4/CCR5 (co-receptor for HIV)
191
Cell Surface Proteins: Cytotoxic T Cells
CD8
192
Cell Surface Proteins: Regulatory T Cells
* CD4 * CD25
193
Cell Surface Proteins: B Cells
* Ig (binds antigen) * CD19 * CD20 * CD21 (receptor for EBV) * CD40 * MHC II * B7 You can drink **B**eer at the **B**ar when you’re **21**: **B** cells, Epstein-**B**arr virus, CD**21**.
194
Cell Surface Proteins: Macrophages
* CD14 (receptor for PAMPs, eg. LPS) * CD40 * CCR5 * MHC II * B7 (CD80/86) * Fc and C3b receptors (enhanced phagocytosis)
195
Cell Surface Proteins: NK Cells
* CD16 * CD56 (suggestive marker for NK)
196
Cell Surface Proteins: Hematopoietic Stem Cells
CD34
197
\_\_\_\_\_ is the state during which a cell cannot become activated by exposure to its antigen. This seen in T and B cells when exposed to their antigen without costimulatory signal (signal 2). Another mechanism of self-tolerance.
Anergy
198
Immunity: * receiving preformed antibodies * rapid onset * short span of antibodies (half-life = 3 weeks)
Passive
199
Immunity: * IgA in breast milk * maternal IgG crossing placenta * antitoxin * humanized monoclonal antibody
Passive
200
Immunity: * exposure to foreign antigens * slow onset * long-lasting protection (memory)
Active
201
Immunity: * natural infection * vaccines * toxoid
Active
202
After exposure to \_\_\_\_\_, unvaccinated patients are given preformed antibodies (passive).
“**D**iseases **T**o **B**e **H**ealed **V**ery **R**apidly” * **D**iphtheria toxin * **T**etanus toxin * **B**otulinum toxin * **H**BV * **V**aricella * **R**abies virus
203
Combined passive and active immunizations can be given for _____ exposure.
* Hepatitis B * Rabies
204
Vaccines: * microorganism loses its pathogenicity but retains capacity for transient growth within inoculated host * induces cellular and humoral responses
Live Attenuated Vaccine
205
\_\_\_\_\_ vaccines can be given to HIV ⊕ patients without evidence of immunity if CD4 cell count ≥ 200 cells/mm3.
* MMR * Varicella
206
Vaccines: Pros of Live Attenuated Vaccine
induces strong, often lifelong immunity
207
Vaccines: Cons of Live Attenuated Vaccine
* may revert to virulent form * often contraindicated in pregnancy and immunodeficiency
208
Live Attenuated Vaccines
“**A**ttention! **P**lease **V**accinate **S**mall, **B**eautiful **Y**oung **I**nfants with **MMR** **R**egularly!” * **A**denovirus (nonattenuated, given to military recruits) * **P**olio (Sabin) * **V**aricella (chickenpox) * **S**mallpox * **B**CG * **Y**ellow fever * **I**nfluenza (intranasal) * **MMR** * **R**otavirus
209
Vaccines: * pathogen is inactivated by heat or chemicals * maintaining epitope structure on surface antigens is important for immune response * mainly induces a humoral response
Killed or Inactivated Vaccine
210
Vaccines: Pros of Killed or Inactivated Vaccine
safer than live vaccines
211
Vaccines: Cons of Killed or Inactivated Vaccine
* weaker immune response * booster shots usually required
212
Killed or Inactivated Vaccines
**RIP A**lways * **R**abies * **I**nfluenza (injection) * **P**olio (Salk)—Sal**K** = **K**illed * Hepatitis **A**
213
Vaccines: includes only the antigens that best stimulate the immune system
Subunit Vaccine
214
Vaccines: Pros of Subunit Vaccine
lower chance of adverse reactions
215
Vaccines: Cons of Subunit Vaccine
* expensive * weaker immune response
216
Subunit Vaccines
* HBV (antigen = HBsAg) * HPV (types 6, 11, 16, and 18) * acellular Pertussis (aP) * *Neisseria meningitidis* (various strains) * *Streptococcus pneumoniae* * *Haemophilus influenzae* type b
217
Vaccines: * denatured bacterial toxin with an intact receptor binding site * stimulates the immune system to make antibodies without potential for causing disease
Toxoid
218
Vaccines: Pros of Toxoid
protects against the bacterial toxins
219
Vaccines: Cons of Toxoid
* antitoxin levels decrease with time * may require a booster
220
Toxoids
* *Clostridium tetani* * *Corynebacterium diphtheriae*
221
Hypersensitivity Types
**ABCD** * **A**naphylactic and **A**topic (type I) * Anti**B**ody-mediated (type II) * Immune **C**omplex (type III) * **D**elayed (cell-mediated, type IV) \*Types I, II, and III are all antibody-mediated.
222
Type I Hypersensitivity Anaphylactic and Atopic
* **Immediate** (minutes): antigen crosslinks preformed IgE on presensitized mast cells → immediate degranulation → release of histamine (a vasoactive amine) and tryptase (a marker of mast cell activation). * **Late** (hours): chemokines (attract inflammatory cells, eg. eosinophils) and cytokines (eg. leukotrienes) from mast cells → inflammation and tissue damage. **First** (type) and **Fast** (anaphylaxis).
223
Tests for Type I Hypersensitivity
skin test or blood test (ELISA) for allergen-specific IgE
224
Type II Hypersensitivity Antibody-Mediated
* Antibodies bind to cell-surface antigens → cellular destruction, inflammation, and cellular dysfunction. * **Cellular Destruction**—cell is opsonized (coated) by antibodies, leading to either: * Phagocytosis and/or activation of complement system. * NK cell killing (antibody-dependent cellular cytotoxicity). * **Inflammation**—binding of antibodies to cell surfaces → activation of complement system and Fc receptor-mediated inflammation. * **Cellular Dysfunction**—antibodies bind to cell surface receptors → abnormal blockade or activation of downstream process.
225
Tests for Type II Hypersensitivity
* Direct Coombs test—detects antibodies attached directly to the RBC surface. * Indirect Coombs test—detects presence of unbound antibodies in the serum
226
Examples of Type II Hypersensitivity
* Autoimmune Hemolytic Anemia * Immune Thrombocytopenia * Transfusion Reactions * Hemolytic Disease of the Newborn * Goodpasture Syndrome * Rheumatic Fever * Hyperacute Transplant Rejection * Myasthenia Gravis * Graves Disease * Pemphigus Vulgaris
227
Type III Hypersensitivity Immune Complex
* Immune complex—antigen-antibody (mostly IgG) complexes activate complement, which attracts neutrophils; neutrophils release lysosomal enzymes. * Can be associated with vasculitis and systemic manifestations. In type **III** reaction, imagine an immune complex as **3** things stuck together: antigen-antibody-complement.
228
Hypersensitivity Reactions: * the prototype immune complex disease * antibodies to foreign proteins are produced and 1–2 weeks later, antibody-antigen complexes form and deposit in tissues → complement activation → inflammation and tissue damage * fever, urticaria, arthralgia, proteinuria, lymphadenopathy occur 1–2 weeks after antigen exposure
Serum Sickness (Type III Hypersensitivity)
229
Hypersensitivity Reactions: * a local subacute immune complex-mediated hypersensitivity reaction * intradermal injection of antigen into a presensitized (has circulating IgG) individual leads to immune complex formation in the skin * characterized by edema, necrosis, and activation of complement
Arthus Reaction (Type III Hypersensitivity)
230
Examples of Type III Hypersensitivity
* SLE * Polyarteritis nodosa * Poststreptococcal glomerulonephritis
231
Type IV Hypersensitivity Delayed
* **Direct Cell Cytotoxicity**: CD8+ cytotoxic T cells kill targeted cells. * **Inflammatory Reaction**: effector CD4+ T cell recognize antigen and release inflammation inducing cytokines (shown in illustration). **4T’s**: **T** cells, **T**ransplant rejections, **T**B skin tests, **T**ouching (contact dermatitis). **Fourth** (type) and **last** (delayed).
232
Tests for Type IV Hypersensitivity
* PPD (tuberculosis infection) * patch test (cause of contact dermatitis) * *Candida* extract (T cell immune function)
233
Examples of Type IV Hypersensitivity
* contact dermatitis (eg. poison ivy, nickel allergy) * graft-versus-host disease
234
Blood Transfusion Reactions
* Allergic/Anaphylactic Reaction * Febrile Nonhemolytic Transfusion Reaction * Acute Hemolytic Transfusion Reaction * Transfusion-Related Acute Lung Injury
235
Blood Transfusion Reactions: * type I hypersensitivity reaction against plasma proteins in transfused blood * IgA deficient individuals must receive blood products without IgA
Allergic/Anaphylactic Reaction
236
Blood Transfusion Reactions: * urticaria * pruritus * fever * wheezing * hypotension * respiratory arrest * shock
Allergic/Anaphylactic Reaction
237
Blood Transfusion Reactions: within minutes to 2–3 hours
Allergic/Anaphylactic Reaction
238
Blood Transfusion Reactions: * type II hypersensitivity reaction with host antibodies against donor HLA and WBCs * induced by cytokines that are created and accumulate during the storage of blood products
Febrile Nonhemolytic Transfusion Reaction
239
Blood Transfusion Reactions: * fever * headaches * chills * flushing
Febrile Nonhemolytic Transfusion Reaction
240
Blood Transfusion Reactions: within 1–6 hours
Febrile Nonhemolytic Transfusion Reaction
241
Blood Transfusion Reactions: * type II hypersensitivity reaction * intravascular hemolysis (ABO blood group incompatibility) * extravascular hemolysis (host antibody reaction against foreign antigen on donor RBCs)
Acute Hemolytic Transfusion Reaction
242
Blood Transfusion Reactions: * fever * hypotension * tachypnea * tachycardia * flank pain * hemoglobinuria (intravascular hemolysis) * jaundice (extravascular)
Acute Hemolytic Transfusion Reaction
243
Blood Transfusion Reactions: within 1 hour
Acute Hemolytic Transfusion Reaction
244
Blood Transfusion Reactions: donor anti-leukocyte antibodies against recipient neutrophils and pulmonary endothelial cells
Transfusion-Related Acute Lung Injury
245
Blood Transfusion Reactions: * respiratory distress * noncardiogenic pulmonary edema
Transfusion-Related Acute Lung Injury
246
Blood Transfusion Reactions: within 6 hours
Transfusion-Related Acute Lung Injury
247
Autoantibodies: Myasthenia Gravis
Anti-ACh receptor
248
Autoantibodies: Lambert-Eaton Myasthenic Syndrome
Anti-Presynaptic Voltage-Gated Calcium Channel
249
Autoantibodies: Antiphospholipid Syndrome
Anti-β2 Glycoprotein
250
Autoantibodies: * nonspecific screening antibody * often associated with SLE
Antinuclear (ANA)
251
Autoantibodies: * SLE * Antiphospholipid Syndrome
* Anticardiolipin * Lupus Anticoagulant
252
Autoantibodies: SLE
* Anti-dsDNA * Anti-Smith
253
Autoantibodies: Drug-Induced Lupus
Anti-Histone
254
Autoantibodies: Mixed Connective Tissue Disease
Anti-U1 RNP (ribonucleoprotein)
255
Autoantibodies: Rheumatoid Arthritis
* Rheumatoid Factor (IgM antibody against IgG Fc region) * Anti-CCP (more specific)
256
Autoantibodies: Sjögren Syndrome
* Anti-Ro/SSA * Anti-La/SSB
257
Autoantibodies: Scleroderma (diffuse)
Anti-Scl-70 (anti-DNA topoisomerase I)
258
Autoantibodies: Limited Scleroderma (CREST syndrome)
Anticentromere
259
Autoantibodies: * Polymyositis * Dermatomyositis
* Antisynthetase (eg. anti-Jo-1) * Anti-SRP * Anti-Helicase (anti-Mi-2)
260
Autoantibodies: 1° Biliary Cholangitis
Antimitochondrial Antibodies
261
Autoantibodies: Autoimmune Hepatitis Type 1
Anti-Smooth Muscle
262
Autoantibodies: * Microscopic Polyangiitis * Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome) * Ulcerative Colitis
MPO-ANCA/p-ANCA
263
Autoantibodies: Granulomatosis with Polyangiitis (Wegener)
PR3-ANCA/c-ANCA
264
Autoantibodies: 1° Membranous Nephropathy
Anti-Phospholipase A2 Receptor
265
Autoantibodies: Bullous Pemphigoid
Anti-Hemidesmosome
266
Autoantibodies: Pemphigus Vulgaris
Anti-Desmoglein (Anti-Desmosome)
267
Autoantibodies: Hashimoto Thyroiditis
* Antimicrosomal * Antithyroglobulin * Antithyroid Peroxidase
268
Autoantibodies: Graves Disease
Anti-TSH Receptor
269
Autoantibodies: Celiac Disease
* IgA Anti-Endomysial * IgA Anti-Tissue Transglutaminase * IgA and IgG Deamidated Gliadin Peptide
270
Autoantibodies: Type 1 Diabetes Mellitus
* Anti-Glutamic Acid Decarboxylase * Islet Cell Cytoplasmic Antibodies
271
Autoantibodies: Pernicious Anemia
* Antiparietal Cell * Anti-Intrinsic Factor
272
Autoantibodies: Goodpasture Syndrome
Anti-Glomerular Basement Membrane
273
B-Cell Immunodeficiencies
* X-linked (Bruton) Agammaglobulinemia * Selective IgA Deficiency * Common Variable Immunodeficiency
274
B-Cell Immunodeficiencies: * defect in BTK, a tyrosine kinase gene → no B-cell maturation * X-linked recessive (↑ in boys)
X-linked (Bruton) Agammaglobulinemia **B**ruton, **B**TK, **B**-cell, **B**oys
275
B-Cell Immunodeficiencies: recurrent bacterial and enteroviral infections after 6 months (↓ maternal IgG)
X-linked (Bruton) Agammaglobulinemia
276
B-Cell Immunodeficiencies: * absent B cells in peripheral blood * ↓ Ig of all classes * absent/scanty lymph nodes and tonsils * live vaccines contraindicated
X-linked (Bruton) Agammaglobulinemia
277
B-Cell Immunodeficiencies: * unknown defect * most common 1° immunodeficiency
Selective IgA Deficiency
278
B-Cell Immunodeficiencies: * majority are asymptomatic * airway and GI infections * autoimmune disease * atopy * anaphylaxis to IgA-containing products
Selective IgA Deficiency Ig**A**, **A**symptomatic, **A**irway, **A**utoimmune, **A**topy, **A**naphylaxis
279
B-Cell Immunodeficiencies: * ↓ IgA with normal IgG, IgM levels * ↑ susceptibility to giardiasis
Selective IgA Deficiency
280
B-Cell Immunodeficiencies: * defect in B-cell differentiation * cause is unknown in most cases
Common Variable Immunodeficiency
281
B-Cell Immunodeficiencies: * usually presents after age 2 and may be considerably delayed * ↑ risk of autoimmune disease, bronchiectasis, lymphoma, and sinopulmonary infections
Common Variable Immunodeficiency
282
B-Cell Immunodeficiencies: * ↑ plasma cells * ↑ immunoglobulins
Common Variable Immunodeficiency
283
T-Cell Immunodeficiencies
* Thymic Aplasia (DiGeorge Syndrome) * IL-12 Receptor Deficiency * Autosomal Dominant Hyper-IgE Syndrome (Job Syndrome) * Chronic Mucocutaneous Candidiasis
284
T-Cell Immunodeficiencies: * 22q11 deletion * failure of 3rd and 4th pharyngeal pouches to develop → absent thymus and parathyroids
Thymic Aplasia (DiGeorge Syndrome)
285
T-Cell Immunodeficiencies: * tetany (hypocalcemia) * recurrent viral/fungal infections (T-cell deficiency) * conotruncal abnormalities (eg. tetralogy of Fallot, truncus arteriosus)
Thymic Aplasia (DiGeorge Syndrome)
286
T-Cell Immunodeficiencies: * ↓ T cells, ↓ PTH, ↓ Ca2+ * thymic shadow absent on CXR
Thymic Aplasia (DiGeorge Syndrome)
287
T-Cell Immunodeficiencies: * ↓ Th1 response * autosomal recessive
IL-12 Receptor Deficiency
288
T-Cell Immunodeficiencies: * disseminated mycobacterial and fungal infections * may present after administration of BCG vaccine
IL-12 Receptor Deficiency
289
T-Cell Immunodeficiencies: ↓ IFN-γ
IL-12 Receptor Deficiency
290
T-Cell Immunodeficiencies: deficiency of Th17 cells due to STAT3 mutation → impaired recruitment of neutrophils to sites of infection
Autosomal Dominant Hyper-IgE Syndrome (Job Syndrome)
291
T-Cell Immunodeficiencies: * coarse facies * cold noninflamed staphylococcal abscesses * retained primary teeth * ↑ IgE * dermatologic problems (eczema) * bone fractures from minor trauma
Autosomal Dominant Hyper-IgE Syndrome (Job Syndrome) **FATED**: * coarse **F**acies * cold (noninflamed) staphylococcal **A**bscesses * retained primary **T**eeth * ↑ Ig**E** * **D**ermatologic problems (eczema)
292
T-Cell Immunodeficiencies: * ↑ IgE * ↑ eosinophils
Autosomal Dominant Hyper-IgE Syndrome (Job Syndrome)
293
T-Cell Immunodeficiencies: * T-cell dysfunction * can result from congenital genetic defects in IL-17 or IL-17 receptors
Chronic Mucocutaneous Candidiasis
294
T-Cell Immunodeficiencies: noninvasive *Candida albicans* infections of skin and mucous membranes
Chronic Mucocutaneous Candidiasis
295
T-Cell Immunodeficiencies: * absent in vitro T-cell proliferation in response to *Candida* antigens * absent cutaneous reaction to *Candida* antigens
Chronic Mucocutaneous Candidiasis
296
B-cell and T-Cell Immunodeficiencies
* Severe Combined Immunodeficiency * Ataxia-Telangiectasia * Hyper-IgM Syndrome * Wiskott-Aldrich Syndrome
297
B-cell and T-Cell Immunodeficiencies: several types including defective IL-2R gamma chain (most common, X-linked recessive) and adenosine deaminase deficiency (autosomal recessive)
Severe Combined Immunodeficiency
298
B-cell and T-Cell Immunodeficiencies: * failure to thrive * chronic diarrhea * thrush * recurrent viral, bacterial, fungal, and protozoal infections
Severe Combined Immunodeficiency
299
B-cell and T-Cell Immunodeficiencies: * live vaccines are avoided * given antimicrobial prophylaxis and IVIG * bone marrow transplant is curative (no concern for rejection)
Severe Combined Immunodeficiency
300
B-cell and T-Cell Immunodeficiencies: * ↓ T-cell receptor excision circles (TRECs) * absence of thymic shadow (CXR) * absence of germinal centers (lymph node biopsy) * absence of T cells (flow cytometry)
Severe Combined Immunodeficiency
301
B-cell and T-Cell Immunodeficiencies: * defects in ATM gene → failure to detect DNA damage → failure to halt progression of cell cycle → mutations accumulate * autosomal recessive
Ataxia-Telangiectasia **A**taxia-Telangiectasia, **A**TM gene, **A**taxia, spider **A**ngiomas, Ig**A** deficiency, ↑ **A**FP
302
B-cell and T-Cell Immunodeficiencies: triad of cerebellar defects (ataxia), spider angiomas (telangiectasia) and IgA deficiency
Ataxia-Telangiectasia **A**taxia-Telangiectasia, **A**TM gene, **A**taxia, spider **A**ngiomas, Ig**A** deficiency, ↑ **A**FP
303
B-cell and T-Cell Immunodeficiencies: * ↑ AFP * ↓ IgA, IgG, and IgE * lymphopenia * cerebellar atrophy * ↑ risk of lymphoma and leukemia
Ataxia-Telangiectasia **A**taxia-Telangiectasia, **A**TM gene, **A**taxia, spider **A**ngiomas, Ig**A** deficiency, ↑ **A**FP
304
B-cell and T-Cell Immunodeficiencies: * most commonly due to defective CD40L on Th cells → class switching defect * X-linked recessive
Hyper-IgM Syndrome
305
B-cell and T-Cell Immunodeficiencies: * severe pyogenic infections early in life * opportunistic infection with *Pneumocystis*, *Cryptosporidium*, and CMV
Hyper-IgM Syndrome
306
B-cell and T-Cell Immunodeficiencies: * normal or ↑ IgM * ↓↓ IgG, IgA, IgE * failure to make germinal centers
Hyper-IgM Syndrome
307
B-cell and T-Cell Immunodeficiencies: * mutation in WASp gene * leukocytes and platelets unable to reorganize actin cytoskeleton → defective antigen presentation * X-linked recessive
Wiskott-Aldrich Syndrome
308
B-cell and T-Cell Immunodeficiencies: * thrombocytopenia * eczema * recurrent pyogenic infections * ↑ risk of autoimmune disease and malignancy
Wiskott-Aldrich Syndrome **WATER**: * **W**iskott-**A**ldrich * **T**hrombocytopenia * **E**czema * **R**ecurrent (pyogenic) infections
309
B-cell and T-Cell Immunodeficiencies: * ↓ to normal IgG, IgM * ↑ IgE, IgA * fewer and smaller platelets
Wiskott-Aldrich Syndrome
310
Phagocyte Dysfunction Immunodeficiencies
* Leukocyte Adhesion Deficiency (type 1) * Chédiak-Higashi Syndrome * Chronic Granulomatous Disease
311
Phagocyte Dysfunction Immunodeficiencies: * defect in LFA-1 integrin (CD18) protein on phagocytes * impaired migration and chemotaxis * autosomal recessive
Leukocyte Adhesion Deficiency (type 1)
312
Phagocyte Dysfunction Immunodeficiencies: * recurrent skin and mucosal bacterial infections * absent pus * impaired wound healing * delayed (\> 30 days) separation of umbilical cord
Leukocyte Adhesion Deficiency (type 1)
313
Phagocyte Dysfunction Immunodeficiencies: * ↑ neutrophils in blood * absence of neutrophils at infection sites
Leukocyte Adhesion Deficiency (type 1)
314
Phagocyte Dysfunction Immunodeficiencies: * defect in lysosomal trafficking regulator gene (LYST) * microtubule dysfunction in phagosome-lysosome fusion * autosomal recessive
Chédiak-Higashi Syndrome
315
Phagocyte Dysfunction Immunodeficiencies: * progressive neurodegeneration * lymphohistiocytosis * albinism (partial) * recurrent pyogenic infections by staphylococci and streptococci * peripheral neuropathy
Chédiak-Higashi Syndrome **PLAIN**: * **P**rogressive neurodegeneration * **L**ymphohistiocytosis * **A**lbinism (partial) * recurrent pyogenic **I**nfections by staphylococci and streptococci * peripheral **N**europathy
316
Phagocyte Dysfunction Immunodeficiencies: * giant granules in granulocytes and platelets * pancytopenia * mild coagulation defects
Chédiak-Higashi Syndrome
317
Phagocyte Dysfunction Immunodeficiencies: * defect of NADPH oxidase → ↓ reactive oxygen species (eg, superoxide) and ↓ respiratory burst in neutrophils * X-linked form most common
Chronic Granulomatous Disease
318
Phagocyte Dysfunction Immunodeficiencies: ↑ susceptibility to catalase ⊕ organisms
Chronic Granulomatous Disease
319
Phagocyte Dysfunction Immunodeficiencies: * abnormal Dihydrorhodamine (flow cytometry) Test (↓ green fluorescence) * Nitroblue Tetrazolium Dye Reduction Test (obsolete) fails to turn blue
Chronic Granulomatous Disease
320
Bacterial Infections in Immunodeficiency: ↓ T Cells
Sepsis
321
Bacterial Infections in Immunodeficiency: ↓ B Cells
Encapsulated (**P**lease **SHINE** my **SK**i**S**): * ***P**seudomonas aeruginosa* * ***S**treptococcus pneumoniae* * ***H**aemophilus **I**nfluenzae* type b * ***N**eisseria meningitidis* * ***E**scherichia coli* * ***S**almonella* * ***K**lebsiella pneumoniae* * Group B ***S**treptococcus*
322
Bacterial Infections in Immunodeficiency: ↓ Granulocytes
* *Staphylococcus* * *Burkholderia cepacia* * *Pseudomonas* *aeruginosa* * *Serratia* * *Nocardia*
323
Bacterial Infections in Immunodeficiency: ↓ Complement
* encapsulated species with early complement deficiencies * *Neisseria* with late complement (C5–C9) deficiencies
324
Viral Infections in Immunodeficiency: ↓ T Cells
* CMV * EBV * JC virus * VZV * chronic infection with respiratory/GI viruses
325
Viral Infections in Immunodeficiency: ↓ B Cells
* enteroviral encephalitis * poliovirus (live vaccine contraindicated)
326
Fungal/Parasitic Infections in Immunodeficiency: ↓ T Cells
* *Candida* (local) * PCP * *Cryptococcus*
327
Fungal/Parasitic Infections in Immunodeficiency: ↓ B Cells
GI giardiasis (no IgA)
328
Fungal/Parasitic Infections in Immunodeficiency: ↓ Granulocytes
* *Candida* (systemic) * *Aspergillus* * *Mucor*
329
B-cell deficiencies tend to produce recurrent _____ infections, whereas T-cell deficiencies produce more _____ infections.
B-cell → bacterial T-cell → fungal and viral
330
Grafts: from self
Autograft
331
Grafts: from identical twin or clone
Syngeneic Graft (Isograft)
332
Grafts: from nonidentical individual of same species
Allograft
333
Grafts: Xenograft
from different species
334
Transplant Rejection: onset within minutes
Hyperacute
335
Transplant Rejection: * pre-existing recipient antibodies react to donor antigen (type II hypersensitivity reaction) * activate complement
Hyperacute
336
Transplant Rejection: * widespread thrombosis of graft vessels → ischemia/necrosis * graft must be removed
Hyperacute
337
Transplant Rejection: onset within weeks to months
Acute
338
Transplant Rejection: * Cellular: CD8+ T cells and/or CD4+ T cells activated against donor MHCs (type IV hypersensitivity reaction) * Humoral: similar to hyperacute, except antibodies develop after transplant
Acute
339
Transplant Rejection: * vasculitis of graft vessels with dense interstitial lymphocytic infiltrate * prevent/reverse with immunosuppressants
Acute
340
Transplant Rejection: onset within months to years
Chronic
341
Transplant Rejection: * CD4+ T cells respond to recipient APCs presenting donor peptides, including allogeneic MHC * both cellular and humoral components (type II and IV hypersensitivity reactions)
Chronic
342
Transplant Rejection: * recipient T cells react and secrete cytokines → proliferation of vascular smooth muscle, parenchymal atrophy, interstitial fibrosis * dominated by arteriosclerosis
Chronic
343
Transplant Rejection: * Bronchiolitis Obliterans (lung) * Atherosclerosis (heart) * Chronic Graft Nephropathy (kidney) * Vanishing Bile Duct Syndrome (liver)
Chronic
344
Transplant Rejection: onset varies
Graft-Versus-Host Disease
345
Transplant Rejection: * grafted immunocompetent T cells proliferate in the immunocompromised host and reject host cells with “foreign” proteins → severe organ dysfunction * type IV hypersensitivity reaction
Graft-Versus-Host Disease
346
Transplant Rejection: * maculopapular rash * jaundice * diarrhea * hepatosplenomegaly * usually in bone marrow and liver transplants (rich in lymphocytes) * potentially beneficial in bone marrow transplant for leukemia (graft-versus-tumor effect)
Graft-Versus-Host Disease
347
\_\_\_\_\_ are agents that block lymphocyte activation and proliferation. Reduce acute transplant rejection by suppressing cellular immunity (used as prophylaxis). Frequently combined to achieve greater efficacy with ↓ toxicity. Chronic suppression ↑ risk of infection and malignancy.
Immunosuppressants
348
Immunosuppressants: * calcineurin inhibitor * binds cyclophilin * blocks T-cell activation by preventing IL-2 transcription
Cyclosporine
349
Immunosuppressants: * Psoriasis * Rheumatoid Arthritis
Cyclosporine
350
Immunosuppressants: * nephrotoxicity * hypertension * hyperlipidemia * neurotoxicity * gingival hyperplasia * hirsutism
Cyclosporine
351
Immunosuppressants: * calcineurin inhibitor * binds FK506 binding protein (FKBP) * blocks T-cell activation by preventing IL-2 transcription
Tacrolimus (FK506)
352
Immunosuppressants: * similar to cyclosporine * ↑ risk of diabetes and neurotoxicity * no gingival hyperplasia or hirsutism
Tacrolimus (FK506)
353
Calcineurin inhibitors are highly \_\_\_\_\_.
nephrotoxic
354
Immunosuppressants: * mTOR inhibitor * binds FKBP * blocks T-cell activation and B-cell differentiation by preventing response to IL-2
Sirolimus (Rapamycin)
355
Immunosuppressants: * pancytopenia * insulin resistance * hyperlipidemia * not nephrotoxic
Sirolimus (Rapamycin)
356
Immunosuppressants: * synergistic with cyclosporine * used in drug-eluting stents
Sirolimus (Rapamycin)
357
Immunosuppressants: * monoclonal antibody * blocks IL-2R
Basiliximab
358
Immunosuppressants: * edema * hypertension * tremor
Basiliximab
359
Immunosuppressants: specifically for kidney transplant rejection prophylaxis .
* Sirolimus (Rapamycin) * Basiliximab
360
Immunosuppressants: * antimetabolite precursor of 6-mercaptopurine * inhibits lymphocyte proliferation by blocking nucleotide synthesis
Azathioprine
361
Immunosuppressants: * Rheumatoid Arthritis * Crohn disease * Glomerulonephritis * other autoimmune conditions
Azathioprine
362
Immunosuppressants: pancytopenia
Azathioprine
363
Immunosuppressants: * 6-MP degraded by xanthine oxidase * toxicity ↑ by allopurinol
Azathioprine
364
Immunosuppressants: reversibly inhibits IMP dehydrogenase preventing purine synthesis of B and T cells
Mycophenolate Mofetil
365
Immunosuppressants: Lupus Nephritis
Mycophenolate Mofetil
366
Immunosuppressants: * GI upset * pancytopenia * hypertension * hyperglycemia * less nephrotoxic and neurotoxic
Mycophenolate Mofetil
367
Immunosuppressants: associated with invasive CMV infection
Mycophenolate Mofetil
368
Immunosuppressants: * inhibit NF-κB * suppress both B- and T-cell function by ↓ transcription of many cytokines * induce T cell apoptosis
Glucocorticoids
369
Immunosuppressants: * many autoimmune and inflammatory disorders * adrenal insufficiency * asthma * CLL * non-Hodgkin lymphoma
Glucocorticoids
370
Immunosuppressants: * Cushing syndrome * osteoporosis * hyperglycemia * diabetes * amenorrhea * adrenocortical atrophy * peptic ulcers * psychosis * cataracts * avascular necrosis (femoral head)
Glucocorticoids
371
Immunosuppressants: * demargination of WBCs causes artificial leukocytosis * adrenal insufficiency may develop if drug is stopped abruptly after chronic use
Glucocorticoids
372
Immunosuppression
373
Recombinant Cytokines for Bone Marrow Stimulation
* Erythropoietin * Colony Stimulating Factors * Thrombopoietin
374
Recombinant Cytokines for Bone Marrow Stimulation: * Epoetin alfa (EPO analog) * used in anemias (especially in renal failure)
Erythropoietin
375
Recombinant Cytokines for Bone Marrow Stimulation: * Filgrastim (G-CSF) and Sargramostim (GM-CSF) * used in leukopenia to recover granulocyte and monocyte counts
Colony Stimulating Factors
376
Recombinant Cytokines for Bone Marrow Stimulation: * Romiplostim (TPO analog) and Eltrombopag (TPO receptor agonist) * used in autoimmune thrombocytopenia
Thrombopoietin
377
Recombinant Cytokines for Immunotherapy
* Interleukin-2 * Interferon
378
Recombinant Cytokines for Immunotherapy: * Aldesleukin * used in renal cell carcinoma and metastatic melanoma
Interleukin-2
379
Recombinant Cytokines for Immunotherapy: Interferons
* IFN-α—Chronic Hepatitis C (not preferred) and B, Renal Cell Carcinoma * IFN-β—Multiple Sclerosis * IFN-γ—Chronic Granulomatous Disease
380
Therapeutic Antibodies for Cancer Therapy
* Alemtuzumab * Bevacizumab * Cetuximab * Rituximab * Trastuzumab
381
Therapeutic Antibodies for Cancer Therapy: * targets CD52 * used in CLL and MS
Alemtuzumab “A**lym**tuzumab”—chronic **lym**phocytic leukemia
382
Therapeutic Antibodies for Cancer Therapy: * targets VEGF * used in colorectal cancer, renal cell carcinoma, and non-small cell lung cancer * also used in neovascular agerelated macular degeneration, proliferative diabetic retinopathy, and macular edema
Bevacizumab
383
Therapeutic Antibodies for Cancer Therapy: * targets EGFR * used in stage IV colorectal cancer, head and neck cancer
Cetuximab
384
Therapeutic Antibodies for Cancer Therapy: * targets CD20 * usedin B-cell non-Hodgkin lymphoma, CLL, rheumatoid arthritis, ITP, and multiple sclerosis
Rituximab
385
Therapeutic Antibodies for Cancer Therapy: * targets HER2 * used in breast cancer and gastric cancer
Trastuzumab HER**2**—“tras**2**zumab”
386
Therapeutic Antibodies for Autoimmune Disease Therapy
* Adalimumab * Certolizumab * Golimumab * Infliximab * Daclizumab * Eculizumab * Natalizumab * Ustekinumab
387
Therapeutic Antibodies for Autoimmune Disease Therapy: * targets soluble TNF-α * used inIBD, rheumatoid arthritis, ankylosing spondylitis, and psoriasis
* Adalimumab * Certolizumab * Golimumab * Infliximab
388
Therapeutic Antibodies for Autoimmune Disease Therapy: * targets CD25 (part of IL-2 receptor) * used in relapsing multiple sclerosis
Daclizumab
389
Therapeutic Antibodies for Autoimmune Disease Therapy: * targets complement protein C5 * used in paroxysmal nocturnal hemoglobinuria
Eculizumab
390
Therapeutic Antibodies for Autoimmune Disease Therapy: * targets α4-integrin—WBC adhesion * used in multiple sclerosis and Crohn disease * risk of PML (progressive multifocal leukoencephalopathy) in patients with JC virus
Natalizumab
391
Therapeutic Antibodies for Autoimmune Disease Therapy: * targets IL-12/IL-23 * used in psoriasis and psoriatic arthritis
Ustekinumab
392
Therapeutic Antibodies: * targets platelet glycoproteins IIb/IIIa * antiplatelet agent for prevention of ischemic complications in patients undergoing percutaneous coronary intervention
Abciximab **II**b x **III**a equals “ab**six**imab”
393
Therapeutic Antibodies: * targets RANKL * used in osteoporosis * inhibits osteoclast maturation (mimics osteoprotegerin)
Denosumab Den**os**umab affects **os**teoclasts
394
Therapeutic Antibodies: * targets digoxin * antidote for digoxin toxicity
Digoxin immune Fab
395
Therapeutic Antibodies: * targets IgE * used in refractory allergic asthma * prevents IgE binding to FcεRI
Omalizumab
396
Therapeutic Antibodies: * targets RSV F protein * used as RSV prophylaxis for high-risk infants
Palivizumab Pali**VI**zumab—**VI**rus

USMLE Step 1 (18 decks)

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