Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/129

Click to flip

129 Cards in this Set

  • Front
  • Back
Immuno FA

Patient with Mycoplasma pneumoniae exhibits cryagglutination during recovery phase.

What type of immunoglobulina are reacting?
IgM
Immuno FA

Young child presents with tetany and candidiasis. Hypocalcemia and immunosuppression are found:
DiGeorges (Tcell deficient)
Immuno FA

Young child has recurrent lung infections and granulomatous lesions.

What is the defect in neutrophils?
NADPH oxidase (chronic granulomatous disease)
Immuno FA

What are the three functions of a lymphnode?
1. nonspecific filtration by macrophages
2. storage/proliferation of B and T cells
3. antibody production
3.
Immuno FA

What is the function of the follicle of the lymphnode?
Site of b-cell proliferation and localization.

Follicles are located in the outer cortex.

There are primary and secondary follicles: primary = dense and dormant; secondary = active and have pale germinal centers
Immuno FA

What is the function of the medulla of the lymph node?
Medulla: consists of medullary cords that are closely packed with lymphocytes and plasma cells.

There are also medullary sinuses within the medulla. These sinuses communicate with efferent lymphatics and contain reticular cells and macrophages.

MMM: Medually sinuses and cords; Megakaryocyte babies = platelets and lymphos; Macro's and reticular cells
Immuno FA

What is the function of the pancortex of the lymphnode?
Pancortex: home for t-cells

Region of the cortex between follicles and medulla that contains high endothelial venuls through which T and B cells enter from blood.

In extreme cellular immune response, paracortex becomes enlarged. This cortex is not well developed in DiGeorges.
Immuno FA

What are the two ways lymph can drain?
Right lymphatic duct (drains right arm and right half of head)

Thoracic duct: drains everything else.
Immuno FA

Describe the spleen sinusoids:

Explain red pulp vs white pulp.
They are long vascular channels in the red pulp of the spleen with fenestrated "barrel hoop" basement membrane.

Macrophages are found nearby. With T-cells found in the periarterial lymphatic sheath (PALS) and in the red pulp of the spleen. B cellls are found in follicles within the white pulp of the spleen. The white pulp also contains T-cells and functions to fight infections
Immuno FA

What is the derivation of the thymus?
Thymus: from epithelium of 3rd branchial pouches
Immuno FA

Describe the thymus?
Thymus is encapsulated
Thymus is the site of t-cell differention (as is bone to b-cells).
Its cortex is dense with immature T-cells and its medulla is pale with mature T cells and epithelial reticular cells as well as containing Hassall's corpuscles.
Immuno FA

What are Hassels corpuscles
Currently unknown.

Thought to direct the maturation of dendritic cells
Immuno FA

What occurs at the corticomedullary junction in the thymus (2)
1. positive selection (MHC restriction)
2. negative selection (nonreactive to self)
Immuno FA

Describe innate immunity:
Response to pathogens that is fast and nonspecific.
Receptors that recognize pathogens are germline encoded.
Consists of neutrophils, macrophages, dendritic cells, and complement
No memory
Immuno FA

Describe adaptive immunity:
Receptors that recognize pathogens undergo VDJ recombination during lymphocyte development.
Response is slow on first exposure but the memory response is faster.
Consists of T-cells, B-cells, and circulating antibody.
Immuno

What is the function of CD8 Tcells
CD8 Tcells are declared as such in the thymus and are brought to the lymph node --> cytotoxic T-cell.

These cells bind MHC class I and kill virus-infected cells directly.
Immuno

What is the function of helper t-cells?
Th1: makes IL-2 amd IGN-gamma activating cytotoxic T-cells and macrophages.

Th2: produces IL-2, IL-4, and IL-5 to provide help for B-cells to make antibody. (IgE > IgG)
Immuno

What encodes MHC?
Human Leukocyte Antigen (HLA genes)
Immuno

Describe MHC I:
MHC-1: HLA-A, HLA-B, HLA-C
expressed on all nucleated cells
antigen is loaded in RER of mostly intracellular peptides
mediates viral immunity
pairs with beta 2-immunoglobulin
Immuno

Describe MHC II:
MHC II
HLA-DR,-DP,-DQ
expressed only on antigen presenting cells (APCs)
Antigen is loaded in an acidified endosome
Main determinants of organ rejection
Immuno

What are the major functions of B-cells?
To make antibody

For IgG it is used to opsonize bacteria and viruses.
IgE is used in allergic reactions
Also, antibodies cause organ rejection (fast)
Immuno

What are the major functions of T-cells?
CD4+ t-cells help b-cells make antibody and produce gamma-interferon that activates macrophages

The CD8+ T cells that kill virus infected cells directly

Induce allergy of type IV hypersensitivity
Cause slow organ rejection
Immuno

What is the identifying marker of tcells? bcells?
T-cell: CD3 (which forms a complex around TCR), CD4 or CD8, CD 28 (which binds to B7 on APC -- done by Th cells)

B-cells: have CD-19 and CD-20 and have antibodies on their surface to bind to virus particles or antigens
Immuno

What are three APC's?
B-cells
Macrophage
Dendritic cell
Immuno

What two signals are required for Th activation?
Signal 1 and Signal 2

Th activation:
Foreign body is phagocytosed by APC
Foreign antigen is presented on MHC II and recognized by TCR on Th cell (Signal 1)
Costimulatory signal is given by interaction with B7 and CD28 (signal 28)
Immuno

What two signals are required for Tc activation?
Endogenously synthesized (viral or self) proteins are presented on MHC I and recognized by TCR on Tc cell (signal 1)

Il-2 from Th cell activates Tc cell to kill virus-infected cell (signal 2)
Immuno
Antibody structure

What does the variable part of L and H chains do?
They recognize antigens
Immuno
Antibody structure

What does the constant part of the H chain of IgM and IgG do?
It fixes complement
Immuno

What is a Fab fragment?
RR, p.27
Fab fragment: portion of antibody molecule, produced by papain digestion, that contains a single antigen binding site.

All antibodies have two or more Fab regions and thus are bivalent or multivalent.

FA: heavy chains and light chains contribute to the Fab fragments
Immuno

What is a Fc fragment?
FA: p.188
Constant, Carboxyterminal, Complement-binding (IgG+IgM only), Carbohydrate side chain, Complement binding fragment

RR, p.27
Postion of antibody molecule, produced by papain digestion, that fixes complement and binds to Fc receptors; varies among immunoglobulin types.

Has only a heavy chain component
Immuno

What causes antibody diverisity?
1. random "recomination" of VJ (lightchain) and VDJ (heavy chain) genes
2. random combination of heavy chains with light chains
3. somatic hypermutation
4. addition of nucleotides to DNA during "genetic recombination" by terminal deoxynucleotidyl transferase
IMMMUNO-CANCER

Causes & Effects of:

Small cell lung carcinoma?
Causes: ACTH or ACTH-like peptide
Effects: Cushing's syndrome
IMMMUNO-CANCER

Causes & Effects of:

Small cell lung carcinoma and intracranial neoplasms?
Causes: ADH

Effect: SIADH
IMMMUNO-CANCER

Causes & Effects of:

Squamous cell lung carcinoma, renal cell carcinoma, breast carcinoma, multiple myeloma, and bone metastasis (lysed bone)?
Causes: PTH-related peptind, TGF-Beta, TNF-alpha, IL-1

Effects: Hypercalcemia
IMMMUNO-CANCER

Causes & Effects of:

Renal cell carcinoma, hemangioblastoma?
Causes: Erythropoietin

Effects: Polycythemia
IMMMUNO-CANCER

Causes & Effects of:

Thymoma, small cell lung carcinoma?
Causes: Antibodies against presynaptic Ca2+ channels at neuromuscular juntion
Effects: Lambert-Eaton syndrome (muscle weakness)
IMMMUNO-CANCER

Causes & Effects of:

Leukemias and lymphomas?
Causes: Hyperuricemia due to excess nucleic acid turnover (i.e., cytotoxic therapy)
Effects: Gout, urate nephropathy
IMMMUNO-CANCER

What is 1 degree tumors that metastasize to brain?
Lung, Breast, Skin (melanoma), Kidney (renal cell carcinoma), GI. Overall, approx 50% of brain tumors are from metastases.
Lots of Bad Stuff Kills Glia. Typically multiple well-circumscribed tumors at gray-white border.
IMMMUNO-CANCER

What are the most common sites of metastasis after the regional lymph nodes:
The liver and lung.
IMMMUNO-CANCER

1 degree tumors that metastasize to the liver?
Colon > Stomach > Pancreas > Breast > Lung.
Metastases >> 1 degree liver tumors.
Cancer Sometimes Penetrates Benign Liver.
IMMMUNO-CANCER

What 1 degree tumors metastasize to bone?
Prostate, Thyroid, Testes, Breast, Lung, Kidney.
Metastases from breast and prostate are most common.
Metastatic bone tumors are far more common than 1 degree bone tumors.
P.T. Barnum Loves Kids.
Lung = Lytic.
Prostate = blastic.
Breast = Both lytic and blastic
IMMMUNO-CANCER

What is the cancer incidence in males?
Prostate (32%)
Lung (16%)
Colon and rectum (12%)
IMMMUNO-CANCER

What is the cancer incidence in females?
Breast (32%)
Lung (13%)
Colon and rectum (13%)
IMMMUNO-CANCER

What is the cancer mortality in males?
Lung (33%)
Prostate (13%)
IMMMUNO-CANCER

What is the cancer mortality rate in females?
Lung (23%)
Breast (18%)
Immunodeficiency

Decreased production of B cells causes:
Bruton's agammaglobulinemia:
X-linked recessive defect in a tyrosine kinase gene assoc with low levels of all classes of immunoglobulins. Assoc with recurrent Bacterial infections after 6 months of age, when lefels of maternal IgG antibody decline. Occurs in Boys (X-linked).
Immunodeficiency

What immunodeficiency decreases production of T-cells?
Thymic aplasia (DiGeorge syndrome)
Thymus & parathyroids fail to develop owing to failure of development of the 3rd and 4th pharyngeal pouches. Presents with Tetany owing to hypocalcemia. Recurrent viral and fungal infections due to T-cell deficiency. Congenital defects of heart and great vessels. 22q11 deletion.
Immunodeficiency

What immunodeficiency decreases production of B and T-cells?
Severe combined immunodeficiency (SCID)
Defect in early stem-cell differentiation. Presents with recurrent viral, bacterial, fungal, and protozoal infections. May have multiple causes (e.g., failure to synthesize MHC II antigens, defective IL-2 receptors, or adenosine deaminase deficiency).
Immunodeficiency

What immunodeficiency decreases activation of T cells?
Il-12 receptor deficiency

Presents with disseminated mycobacterial infections.
Immunodeficiency

What immunodeficiency decreases activation of B cells and causes IgM syndrome? Describe.
Defect in CD40 ligand on CD4 T helper cells leads to inability to class switch. Presents early in life with severe pyogenic infections. High levels of IgM; very low levels of IgG, IgA, and IgE.
Immunodeficiency

What immunodeficiency deacreases activation of B cells and causes Wiskott-Aldrich syndrome? Describe.
X-linked defect in the ability to mount an IgM response to capsular polysaccharides of bacteria. Associated with elevated IgA levels, normal IgE levels, and low IgM levels. Triad of symptoms includes recurrent pyogenic Infections, thrombocytopenic Purpura, Eczema (WIPE).
Immunodeficiency

What immunodeficiency deacreases activation of Macrophages?
Job's syndrome.
Failure of gamma-interferon production by helper T cells. Neutrophils fail to respond to chemotactic stimuli. Presents with recurrent "cold" (noninflamed) staphylococcal absceses,eczema, coarse facies, retained primary teeth, and high levels of IgE.
Immunodeficiency

Phagocytic cell deficiency causes Leukocyte adhesion deficiency syndrome. Describe?
Defect in LFA-1 adhesion proteins on phagocytes. Presents early with eevere pyogenic and fungal infections and delayed separation of umbilicus.
Immunodeficiency

Phagocytic cell deficiency causes Chediak-Higashi disease. Describe?
Autosomal recessive. Defect in microtubular function and lysosomal emptying of phagocytic cells. Present swith recurrent pyogenic infections by staphylococci and streptococci, partial albinism, and peripheral neuropathy.
Immunodeficiency

Phagocytic cell deficiency causes Chronic granulomatous disease. Describe?
Defect in phagocytosis of neutrophils owing to lack of NADPH oxidase activity or similar enzymes. Presents with marked susceptibility to opportunistic infections with bacteria, especially S. aureaus, E., coli, and Aspergillus. Diagnosis confirmed with negative nitroblue tetrazolium dye reduction test.
Immunodeficiency

Idiopathic dysfunction causes chronic nucocutaneous candidiases in T cells. Describe?
T-cell dysfunction specifically against Candida albicans. Presents with skin and mucouse membraine Candida infections.
Immunodeficiency

Idiopathic dysfunction causes selective immunoglobulin deficiency in B cells. Describe?
Deficiency in a specific class of immunoglobulins - possibly due to a defect in isotype switching. Selective IgA deficiency is the most common selective immunoglobulin deficiency. Presents with sinus and lung infections; milk allergies and diarrhea are common.
Immunodeficiency
Idiopathic dysfunction causes ataxia-telangiectasia in B cells. Describe?
Defect in DNA repair enzymes with associated IgA deficiency. Presents with cerebellar problems (ataxia) and spider angiomas (telangiectasia).
Immunodeficiency

Idiopathic dysfunction causes common variable immunodeficiency in B cells. Describe?
Normal numbers of circulating B cells, decreased plasma cells, decreased Ig, can be acquired in 10's-30's
IMMUNO

What disorder is assoc'd with:

Antinuclear antibodies (ANA)?
SLE
IMMUNO

What disorder is assoc'd with:
Anti-dsDNA, anti-Smith
Specific for SLE
IMMUNO

What disorder is assoc'd with:
Antihistone?
Drug-induced lupus
IMMUNO

What disorder is assoc'd with: Anti-IgG (rheumatoid factor)?
Rheumatoid arthritis
IMMUNO

What disorder is assoc'd with: Antineutrophil (C-ANCA, P-ANCA)?
Vasculitis
IMMUNO

What disorder is assoc'd with: Anticentromere?
Seleroderma (CREST)
IMMUNO

What disorder is assoc'd with: Anti-Sel-70?
Seleroderma (diffuse)
IMMUNO

What disorder is assoc'd with: Antimitochondrial?
1 degree biliary cirrhosis
IMMUNO

What disorder is assoc'd with: Antigliadin?
Celiac disease
IMMUNO

What disorder is assoc'd with: Anti-basement membrane?
Goodpasture's syndrome
IMMUNO

What disorder is assoc'd with: Anti-epithelial cell?
Pemphigus vulgaris
IMMUNO

What disorder is assoc'd with: Antimicrosomal?
Hashimoto's thyroiditis
IMMUNO

What disorder is assoc'd with: Anti-Jo-1
Polymyositis, dermatomyositis
IMMUNO

HLA subtypes: B27
Psoriasis, Ankylosing spondylitis, Inflammatory bowel disease, Reiter's syndrome.
PAIR
IMMUNO

HLA subtypes: B8
Graves' disease, celiac spruc
IMMUNO

HLA subtypes: DR2
Multiple selerosis, hay fever, SLE, Goodpasture's.
IMMUNO

HLA subtypes: DR3
Diabetes mellitus type 1,.
IMMUNO

HLA subtypes: DR4 ?
Rheumatoid arthritis, diabetes mellitus type 1
IMMUNO

HLA subtypes: DR5 ?
Pernicious anemia --> B12 deficiency, Hashimoto's thyroiditis.
IMMUNO

HLA subtypes: DR7 ?
Steroid-responsive nephrotic syndrome.
IMMUNO

Transplant rejection:

Hyperacute rejection. Describe?
Antibody mediated due to the presence of preformed antidonor antibodies in the transplant recipient. Occurs within minutes after transplantation.
IMMUNO

Transplant rejection:

Acute rejection. Describe?
Cell mediated due to cytotoxic T lymphocytes reacting against foreign MHCs. Occurs weeks after transplantation. Reversible with immunosuppressants such as cyclosporin and OKT3.
IMMUNO

Transplant rejection:

Chronic rejection. Describe?
Antibody-mediated vascular damage (fibrinoid necrosis); occurs months to years after transplantation. Irreversible.
IMMUNO

Transplant rejection:

Graft-versus-host disease. Describe?
Grafted immunocompetent T cells proliferate in the irradiated immunocompromised host and reject cells with "foreign" proteins, resulting in severe organ dysfunction. Major symptoms include a maculopapular rash, jaundice, hepatosplenomegaly, and diarrhea.
Immuno

IL-1
Secreted by macrophages.
Stimulates T and B cells, neutrophils, fibroblasts, and epithelial cells to grow, differentiate, or synthesis specific products
(an endogenous pyrogen)
Immuno

IL-2
Secreted by Th cells.
Stimulates growth of helper and cytotoxic t-cells
Immuno

IL-3
Secreted by activated T cells
Supports growth of B cells
Enhances class switching of IgE and IgG
Immuno

IL-4 vs IL-5
IL-4 and 5
Both are secreted by Th2 cells.

IL-4: promotes growth of B cells and enhances class switching of IgE and IgG

IL-5: promotes differentiation of B cells. Enhances class switching of IgA.
Stimulates production and activation of eosinophils
Immuno

IL-6
Secreted by Th cells and macrophages.
Stimulates production of acute-phase reactants and immunoglobulins
Immuno

IL-8
major chemotactic factor for neutrophils.
Immuno

IL-10
Secreted by Th2 cells while inhibiting Th1
Immuno

IL-12
Secreted by B cells and macrophages
Activates NK and Th1 cells
Immuno

gamma interferon
Secreted by Th1 cells.
Stimulates macrophages
Immuno

TNF-alpha
Secreted by macrophages.
Increase IL-2 receptor synthesis by Th cells
Increase B-cell proliferation
Attracts and activates neutrophils
Stimulates dendritic cell migration to lymph nodes
Immuno

Cell surface proteins for:
Helper T cells
Cytotoxic T cells
B cells
Macrophages
NK cells
All cells except mature RBCs
Helper T
CD4, TCR, CD3, 28, 40L
Cytotoxic
CD8, TCR, CD3
B cells
IgM, B7, CD 19,20,40, MHC II
Macophages
MHC II, CD 14, receptors for Fc and C3b
NK cells
receptors for MHC I, CD16, CD56
All cells except mature RBC's: MHCI
Immuno

What is the mechanism of interferons?
Interferons are proteins that place uninfected cells in an antiviral state.

Interferons induce a production of a 2nd protein that inhibits viral protein synthesis by degrading viral mRNA (but not host mRNA)
Immuno

What are the functions of alpha, beta, and gamma interferon?
INTERFERes with viruses:

alpha and beta:
inhibit viral protein synthesis

gamma interferons increase MHCI and II expression and antigen presentation in all cells

They all activate NK cells to kill virus-infected cells.
Immuno
Complement:

Function of C1, C2, C3, C4?
All are for viral neutralization
Immuno
Complement:

Function of C3b
Opsonization
Immuno
Complement

Function of C3a and C5a
Anaphylaxis (stimulate mast cells to release histamine)

and C5a also is a neutrophil chemotaxant
Immuno
Complement

Function of C5b,6,7,8,9
cytolysis by membrane attack complex (MAC)
Immuno
Complement

Deficiency of C1 esterase?
C1 esterase inhibitor leads to hereditary angioedema (overactive complement)
Immuno
Complement

Deficiency of C3?
Leads to severe, recurrent pyogenic sinus and respiratory tract infections
Immuno
Complement

Deficiency of C6-8
Leads to Neisseria bacteremia
Immmuno
Complement

Deficiency of decay accelerating factor (DAF)
DAF increases degradation of C3 and C5 convertase protecting against MAC.
This deficiency would cause paroxysmal nocturnal hemoglobinuria
Complement:

C2 deficiency?
Increase incidence of autoimmune dz like SLE

(MC hereditary complement deficiency)
Immuno

Does IgA fix complement?
No
Immuno

Characteristics of IgM
Produced in the primary response to an antigen.
Fixes complement but does not cross the placenta.
Antigen receptor on the surface of B cells.
Monomer or polymer
Involved in cold-agglutin
Immuno

Compare Ig isotype to idiotype
Isotype: the Ig epitope common to a single class of Ig (5 classes, determined by heavy chain)

Idiotype (specific for a specific antigen): determined by antigen-binding site thus the hypervariable region since it is unique
Immuno

The Fab fragment of an antibody is composed of light and heavy chains and the heavy chain in the Fab fragment is the hypervariable region (constant part of the H chain of IgM and IgG fixes complement)

What characteristics does the Fc fragment have?
Fc: (4C's)
Constant
Carboxyl terminal
Complement-binding (IgG and IgM only)
Carbohydrate side chains
Immuno

Four causes of antibody diversity:
1. random "recombination" of VJ (light-chain) or VDJ (heavy chain) genes
2. random combination of heavy chains with light chains
3. somatic hypermutation
4. addition of nucleotides to DNA during "genetic recombination" by terminal deoxynucleotidyl transferase
Immuno

Major function of B and T cells:
Bcells:
make Ab
IgG antibodies then opsonize bacteria and viruses
IgE cause type I hypersensitivity
These antibodies also cause organ rejection (fast)

T-cells
CD4+ tcells help B cells make antibody and produce gamma interferon that activates macrophages
Kills virus-infected cells directly (CD8+ T cells)
Allergy inducers via Type IV hypersensitivity
Organ rejection (slow)
Immuno

What MHC do APC's present? Who do they present to?
APC's present on MHC II (only on APC's) and they present to CD4 t-cells which are Th cells.
Immuno

What two signal are required for T-cell activation in the Th cell?
Th cell activation:
1. foreign body is phagocytosed by APC
2. Foreign antigen is presented on MHC II and recognized by TCR on Th cell (signal 1)
3. "Costimulatory signal" is given by interaction of B7 and CD28
4. Th cell activated to produce cytokines
Immuno

What two signal are required for T-cell activation in the Th cell?
Tc activation:
1. Endogenously synthesized (viral or self) proteins are presented on MHC I and recognized by TCR on Tc cell (signal 1)
2. IL-2 from Th cell activates Tc cell to kill virus-infected cell (signal 2)
Immuno

What MHC mediates viral immunity?
MHC I
Immuno

What are the characteristics of MHC I:
MHC I: HLA-A,-B,-C
Expressed on almost all nucleated cells
Antigen is loaded in RER of mostly intracellular peptides
Mediates viral immunity
Pairs with beta2-immunoglobulin
Immuno:

What are the characteristics of MHC II:
MHC II: HLA-DR, HLA-DP, HLA-DQ

Expressed only on antigen presenting cells
Antigen is loaded in an acidified endosome
Main determinants of organ rejection
Immuno:

Anergy
Self-reactive Tcells become nonreactive without costimulatory molecule. B cells also become anergic, but tolerance is less complete than in T-cells.
Immuno:

Describe a Type I hypersensitivity rxn:
Anaphylactic and atopic:
IgE dependant that causes an allergic response and is great for parasites and toxin neutralization

Initiation: cross-linkage by antigen (allergen) of IgE bound to Fc receptors on the mast cells and basophils following reexposure of sensitized host to allergen

2. Effector mechanism: degranulation of mast cells and basophils releasing vasoactive mediators such as histamine and SRS-A (slow-reacting substance anaphylaxis)
3. Clinical manifestations: either acute genealized anaphylaxis (shock, vascular collapse, resp collapse) or chronic recurrent localized reactions: asthma, allergic rhinitis (hay fever), wheal and flare (hives)

Rx: desensitization therapy - repeated injections of increasing doses of allergen induce production of IgG which binds to allergen and prevents its binding to IgE on sensitized cells.
Immuno:

Describe a Type II hypersensitivity rxn:
Type II hypersensitivity:
1. initiation: binding of antibody to cell surface antigens
2. effector mechanisms involve complement activated by cell surface antigen-antibody complex.
Antibody-dependant cellular cytoxicity triggered by binding of antibody to Fc receptors on macrophages and NK cells --> cell destruction.

Clinical manifestations:
1. hemolytic transfusion reaction - antibodies to RBC antigens
2. drug-induced thrombocytopenia and hemolytic anemia (Abs to drugs absorbed on platelets on RBCs)
3. Hemolytic dz of the newborn (erythroblastosis fetalis) maternal Ab to antigens
4. Autoimmune dz (RR p.43)
Immuno:

Describe a Type III hypersensitivity rxn:
Type III: immune complex-induced tissue-damaging inflammation

1. Initiation: formation of large amts of circulating antigen-antibody (immune) complexes and their deposition in various tissues or on vessel walls.
2. Effector mechanism: activation of the complement cascade (by immune complexes)

Clinical manifestations:
Arthus reaction - local skin rxn (redness and swelling) induced by intradermally injected antigen or insect bite. Can also be intrapulmonary from inhalation of bacterial spores or fungi (farmers)

Serum sickness: generalized reaction developing 1-2wks after administration of foreign serum (in passive immunization). Penicillin and other drugs can cause similar reactions marked by fever, lymphadenopathy, and arthralgia.

There are also vasculitis, nephritis, and arthritis associated with infections and autoimmune disease.
Immuno:

Describe a Type IV hypersensitivity rxn:
Type IV: delayed type
Initiation: antigen stimulated release of cytokines (IL-2, INF gamma, TNF beta) from sensitized (activated) CD4 TH1 cells.

Effector mech:
Primary inflam response: recruitement and activation of macrophages, which kill microbes and release various substances responsible for local inflammation and tissue damage.
Secondary cytotoxic response: activation of CD8 Tc cells and killing of target cells bearing antigen associated with class I MHC molecules

Clinical manifestations and examples:
Contact dermatitis (eczema and many macrophages)
Tuberculin reaction: local induration and swelling, Tcells, and fewer macrophages
Graft rejections
Granuloma formations (nodule composed of epithelioid cells, giant cells, and macrophages, fibrosis, necrosis)
Immuno:

What is sleeping sickness?
Serum sickness: an immune complex disease (type III) in which antibodies to the foreign proteins are produced (takes 5 days). Immune complexes form and are deposited in membranes, where they fix complement (leads to tissue damage).

These are more common than Arthus.

Most serum sickness is now caused by drugs (not serum). Fever, urticaria, arthralgias, proteinuria, lymphadenopathy 5-10d post exposure.
Immuno:

Describe an immune complex:
Three things stuck together:
Antigen, Antibody, Complement
Immuno:

What are the four T's of Type IV hypersensitivity reaction?
T lymphocytes
Transplant rejections
TB skin tests
Touching (contact dermatitis)
Immuno:

Three causes of type I hypersensitivity:
Anaphylaxis
Allergic rhinitis
Pen allergy that responds with rash
Immuno:

9 causes of type II hypersens:
Type II
1. Hemolytic anemia
2. Idiopathic thrombocytopenic purpura
3. Erythroblastosis fetalis
4. Rheumatic fever
5. Goodpastures syndrome
6. Bullous pemphigoid
7. Grave's dz
8. Myasthenia gravis (autoantibody against nictotinic acetylcholine receptors on skel m.)
Immuno

9 causes of Type III hypersensitivity
1. Lupus (mixed II and III)
2. Rheumatoid arth (mixed III and IV)
3. Polyarteritis nodosum (HBsAg + antiHBS IC's)
4. Post-strept glomerulonephritis
5. Serum sickness
6. Arthus reaction
7. Hypersens pneumo (mixed III and IV)
8. Henoch-Scholein purpura (antiIgA)
9. Parvovirus B19
Immuno

9 causes of Type IV hypersensitivity reactions:
1. Type I DM (mixed III and IV)
2. Multiple sclerosis
3. Guillain-Barre syndrome
4. Hashimotos thyroiditis (type II and IV)
5. Graft vs host dz
6. PPD
7. Contact dermatitis (eczema)
8. Acute transplant rejection (II and IV)
9. Pernicious anemia (II and IV)