Chapter 4

Question 1

Type 1 hypersensitivity is also called allergy or _______ type hypersensitivity. It is Ig _______ mediated. Fast response which occurs in minutes after exposure to an “allergen” antigen to which the person has been previously been sensitized.

Once exposed to a specific allergen that has resulted in the formation of Ig _______, a person is sensitized. Type 1 hypersensitivity reactions feature the formation of Ig _______ antibodies that bind avidly to the Fc-epsilon receptors on mast cells and basophils. Subsequent responses to the allergen induce an immediate release of a cascade of proinflammatory mediators responsible for smooth muscle _______, edema formation, and the recruitment of eosinophils.

Severe type 1 hypersensitivity reactions may include broncho _______, airway _______, and circulatory collapse.

Answer 1

Type 1 hypersensitivity is also called allergy or immediate type hypersensitivity. It is IgE mediated. Fast response which occurs in minutes after exposure to an “allergen” antigen to which the person has been previously been sensitized.

Once exposed to a specific allergen that has resulted in the formation of IgE, a person is sensitized. Type 1 hypersensitivity reactions feature the formation of IgE antibodies that bind avidly to the Fc-epsilon receptors on mast cells and basophils. Subsequent responses to the allergen induce an immediate release of a cascade of proinflammatory mediators responsible for smooth muscle contraction, edema formation, and the recruitment of eosinophils.

Severe type 1 hypersensitivity reactions may include bronchoconstriction, airway obstruction, and circulatory collapse.

Question 2

Type 2 hypersensitivity is also called _______. It is mediated by Ig _______ or Ig _______ or _______.

Antibody binds to antigen on a target cell, which is actually a _______ cell that is perceived by the immune system as foreign, leading to cellular destruction via the MAC.

Testing includes both the direct and indirect _______ test.

An example of this occurs incorrect _______ transfusions where autoimmune hemolytic anemia occurs.

Answer 2

Type 2 hypersensitivity is also called cytotoxic. It is mediated by IgM or IgG or (Complement) MAC–membrane attack complex.

Antibody (IgM or IgG) binds to antigen on a target cell, which is actually a host cell that is perceived by the immune system as foreign, leading to cellular destruction via the MAC.

Testing includes both the direct and indirect Coombs test.

An example of this occurs incorrect blood transfusions where autoimmune hemolytic anemia occurs.

Question 3

Type 3 hypersensitivity is also called immune _______ disease.

It is mediated by Ig _______ or Neutrophils.

Ig _______ binds to soluble antigen, forming a circulating immune complex. This is often _______ in the vessel walls of the joints and kidney, initiating a local _______ reaction.

Answer 3

Type 3 hypersensitivity is also called immune complex disease.

It is mediated by IgG (Complement) or Neutrophils.

Antibody (IgG) binds to soluble antigen, forming a circulating immune complex. This is often deposited in the vessel walls of the joints and kidney, initiating a local inflammatory reaction.

Question 4

Type 4 hypersensitivity is also called _______-type hypersensitivity. It is mediated by _______ cells, which find antigen and activate _______.

The reaction is at highest intensity 1 - 2 days after exposure to the antigen. In the initial phase, foreign protein antigens or chemical ligands interact with acessory cells bearing class _______ HLA molecules. Digested antigens are recognized by CD _______ cells which become activated to synthesize an array of cytokines.

Delayed type hypersensitivity is seen in patients with poison _______ and graft _______.

Answer 4

Type 4 hypersensitivity is also called Delayed-type hypersensitivity. It is mediated by T cells, which find antigen and activate macrophages.

The reaction is at highest intensity 1 - 2 days after exposure to the antigen. In the initial phase, foreign protein antigens or chemical ligands interact with acessory cells bearing class II HLA molecules. Digested antigens are recognized by CD 4 cells which become activated to synthesize an array of cytokines.

Delayed type hypersensitivity is seen in patients with poison ivy and graft rejection.

Question 5

Type 5 hypersensitivity is also called _______ mediated autoimmune disease. It is mediated by Ig _______ or Ig _______ (Complement). Examples include _______’ disease & _______ gravis.

Answer 5

Type 5 hypersensitivity is also called receptor mediated autoimmune disease. It is mediated by IgM or IgG (Complement). Examples include Graves’ disease & Myasthenia gravis.

Question 6

Seasonal congunctivitis is caused by allergies to _______ in a particular time of the year. Allergic rhinitis or hay fever is the most common type _______ hypersensitivity in adults. It may be caused by pollen, house dust, animal dandruff, and many other allergens.

Antigens inhaled interact with Ig _______ attached to basophils in the nasal mucosa, which causes the release of _______. _______, the main mediator released from mast cells, increases the permeability of the mucosal vessels which leads to sneezing and edema.

Answer 6

Seasonal congunctivitis is caused by allergies to pollen in a particular time of the year. Allergic rhinitis or hay fever is the most common type 1 hypersensitivity in adults. It may be caused by pollen, house dust, animal dandruff, and many other allergens.

Antigens inhaled interact with IgE attached to basophils in the nasal mucosa, which causes the release of histamine. Histamine, the main mediator released from mast cells, increases the permeability of the mucosal vessels which leads to sneezing and edema.

Question 7

Postinfectious glomerulonephritis is a type _______ hypersensitivity rxn.

Answer 7

Postinfectious glomerulonephritis is a type 3 hypersensitivity rxn.

Question 8

Diseases that are attributable to deposition of immune complexes in type _______ hypersensitivity include Lupus, rheumatoid arthritis, and glomerulonephritis.

In some cases streptococcal infection can deposit immune complexes in glomerular basement membranes which can give an acute _______ syndrome (e.g., hematuria, oligouria, and hypertension).

Answer 8

Diseases that are attributable to deposition of immune complexes in type 3 hypersensitivity include Lupus, rheumatoid arthritis, and glomerulonephritis.

In some cases streptococcal infection can deposit immune complexes in glomerular basement membranes which can give an acute nephritic syndrome (e.g., hematuria, oligouria, and hypertension).

Question 9

Systemic lupus erythematous is an autoimmune, inflammatory disease that can affect any organ, but typically affects the kidneys, joints, serous membranes, and skin.

Autoantibodies are formed against _______ antigens, particularly to _______ standed DNA and to a soluble nuclear antigen _______ that is part of the spliceosome and is termed _______ antigen.

High titters of _______ antigen and autoantibodies to _______ stranded DNA are pathognomonic for SLE.

Answer 9

Systemic lupus erythematous is an autoimmune, inflammatory disease that can affect any organ, but typically affects the kidneys, joints, serous membranes, and skin.

Autoantibodies are formed against nuclear antigens, particularly to double standed DNA and to a soluble nuclear antigen complex that is part of the spliceosome and is termed Sm (smith) antigen.

High titters of Smith antigen and autoantibodies to dsDNA are pathognomonic for SLE.

Question 10

Antibodies to _______ factor are seen in patients with rheumatoid arthritis.

Answer 10

Antibodies to rheumatoid factor are seen in patients with rheumatoid arthritis.

Question 11

Antineutrophil cytoplasmic antibodies are seen in patients with _______ vessel vasculitis–_______ granulomatosis.

Answer 11

Antineutrophil cytoplasmic antibodies are seen in patients with small vessel vasculitis–Wegener granulomatosis.

Question 12

Acquired deficiencies of _______ complement components occur in patients with autoimmune diseases. Especially those associated with circulating immune complexes like in Lupus.

Antigen-antibody complexes formed in the circulation during the active stage of these diseases lead to a marked _______ in circulating complement proteins.

Answer 12

Acquired deficiencies of early complement components occur in patients with autoimmune diseases. Especially those associated with circulating immune complexes like in Lupus.

Antigen-antibody complexes formed in the circulation during the active stage of these diseases lead to a marked reduction in circulating complement proteins.

Question 13

_______ is an autoimmune disease of connective tissue. Circulating male _______ cells have been demonstrated in blood and blood vessel walls of many women with _______ who bore _______ children years before the disease began.

_______ is simmilar to graft-vs-host disease. Antinuclear antibodies are _______, but at a lower titer than patients with SLE.

Antibodies specific for scleroderma include:

• _______ autoantibodies vs RNA polymerase
• antibodies to _______ (anti-topoisomerase _______)* = most common
• _______ antibodies, which are associated with the CREST variant.

Answer 13

Scleroderma is an autoimmune disease of connective tissue. Circulating male fetal cells have been demonstrated in blood and blood vessel walls of many women with scleroderma who bore male children years before the disease began.

Scleroderma is simmilar to graft-vs-host disease. Antinuclear antibodies are present, but at a lower titer than patients with SLE.

Antibodies specific for scleroderma include:

• nucleolar autoantibodies vs RNA polymerase
• antibodies to Scl-70 (anti-topoisomerase I)* = most common
• anticentromere antibodies, which are associated with the CREST variant.

Question 14

Scleroderma is characterized by vasculopathy and excessive _______ deposition in the skin and internal organs like the lung, GI tract, heart, and kidney. The disease occurs 4x more in _______ than men.

Progressive systemic sclerosis is characterized by widespread and excessive collagen deposition (perhaps type _______ collagen). Autoantibodies to centromere proteins are seen in the _______ variant of progressive systemic sclerosis.

Answer 14

Scleroderma is characterized by vasculopathy and excessive collagen deposition in the skin and internal organs like the lung, GI tract, heart, and kidney. The disease occurs 4x more in women than men.

Progressive systemic sclerosis is characterized by widespread and excessive collagen deposition (perhaps type 3 collagen). Autoantibodies to centromere proteins are seen in the CREST variant of progressive systemic sclerosis.

Question 15

Antibody dependent cell mediated _______ involves cytolytic leukocytes that attack _______ coated target cells. ADCC may be involved in the pathogenisis of some autoimmune diseases like autoimmune _______.

Answer 15

Antibody dependent cell mediated toxicity involves cytolytic leukocytes that attack antibody coated target cells. ADCC may be involved in the pathogenisis of some autoimmune diseases like autoimmune thyroiditis.

Question 16

In a patient that is a chronic hepatitis B virus carrier with active hepatitis, humoral immune responses to viral antigens in the patient involve the activation and differentiation of B lymphocytes into antibody secreting _______ cells.

B cells & T cells express an _______ binding receptor called mlg. This immunoglobulin bears the same antigen specificity as the soluble _______ that is ultimaltey secreted by B cells.

Answer 16

In a patient that is a chronic hepatitis B virus carrier with active hepatitis, humoral immune responses to viral antigens in the patient involve the activation and differentiation of B lymphocytes into antibody secreting plasma cells.

B cells & T cells express an antigen binding receptor called mlg. This immunoglobulin bears the same antigen specificity as the soluble immunoglobulin that is ultimaltey secreted by B cells.

Question 17

Class _______ HLA provide targets for cytotoxic CD8 for killing virus infected cells or killing cells of graft rejection. Class _______ HLA are found on nearly every nucleated cell of the body.

All tissues express HLA class _______, whereas HLA class _______ are on macrophages and B cells.

Class _______ HLA molecules are recognized by CD4 T cells which become activated to synthesize an array of cytokines.

Answer 17

Class 1 HLA provide targets for cytotoxic CD8 for killing virus infected cells or killing cells of graft rejection. Class 1 HLA are found on nearly every nucleated cell of the body.

All tissues express HLA class 1, whereas HLA class 2 are on macrophages and B cells.

Class 2 HLA molecules are recognized by CD4 T cells which become activated to synthesize an array of cytokines.

Question 18

GlyCAM-1 facilitates lymphocyte _______ by providing a receptor for leukocyte attachment to _______ endothelial venules.

Answer 18

GlyCAM-1 facilitates lymphocyte recirculation by providing a receptor for leukocyte attachment to high endothelial venules.

Question 19

_______ syndrome is an autoimmune sidorder characterized by a keratoconjuntivitis sicca (dry eye) and xerostomia (dry mouth) in the absence of other connective tissue disease.

The production of autoantibodies, particularrly _______ antibodies directed against _______ or nonhistone proteins occurs in patients with _______.

Autoantibodies to soluble nuclear nonhistone proteins, especially the antigens _______ & _______, are found in half of patients with primary SS and are associated with more sever glandular and extraglandular manifestations. Autoantibodies to DNA or histones are rare. Organ specific autoantibodies like those directed against salivary gland antigens are distincly uncommon.

Answer 19

Sjogren syndrome is an autoimmune sidorder characterized by a keratoconjuntivitis sicca (dry eye) and xerostomia (dry mouth) in the absence of other connective tissue disease.

The production of autoantibodies, particularrly antinuclear antibodies directed against DNA or nonhistone proteins occurs in patients with SS.

Autoantibodies to soluble nuclear nonhistone proteins, especially the antigens SS-A & SS-B, are found in half of patients with primary SS and are associated with more sever glandular and extraglandular manifestations. Autoantibodies to DNA or histones are rare. Organ specific autoantibodies like those directed against salivary gland antigens are distincly uncommon.

Question 20

The congenital disorder Bruton X-linked agammaglobulinemia appears in _______ infants at 5 - 8 months of age, the period during which maternal antibody levels begin to decline. The infant suffers from recurrent _______ infections and severe hypogammaglobulinemia.

There is an absence of both mature _______ cells in peripheral blood and plasma levels in lymphoid tissues. The genetic defect, located on the long arm of the X chromosome, is an inactivaing mutation of the gene for B-cell _______ kinase, an enzyme critical to B-lymphocyte _______.

Answer 20

The congenital disorder Bruton X-linked agammaglobulinemia appears in male infants at 5 - 8 months of age, the period during which maternal antibody levels begin to decline. The infant suffers from recurrent pyogenic infections and severe hypogammaglobulinemia.

There is an absence of both mature B cells in peripheral blood and plasma levels in lymphoid tissues. The genetic defect, located on the long arm of the X chromosome, is an inactivaing mutation of the gene for B-cell tyrosine kinase, an enzyme critical to B-lymphocyte maturation.

Question 21

Wiskott-Aldrich syndrome is an X-linked recessive genetic disease where there is a defect in both _______ cell and _______ cell funtions.

This syndrome is charictarized by recurrent _______, hemorrhages secondary to thrombocyto _______, and _______. It typically manifests in boys within the first few months of life as _______ and recurrent infections (e.g., diarrhea).

It is caused by numerous distinct mutations on the X chromosome that encodes a protein called _______, which is expressed at high levels in lymphocytes and megakaryocytes.

_______ binds to the Rho family of GTPases. _______ controlls the assembly of actin filaments that are required to form microvesicles.

Answer 21

Wiskott-Aldrich syndrome is an X-linked recessive genetic disease where there is a defect in both B cell and T cell funtions (humoral and cellular immunity).

This syndrome is charictarized by recurrent infections, hemorrhages secondary to thrombocytopenia, and eczema. It typically manifests in boys within the first few months of life as petechia and recurrent infections (e.g., diarrhea).

It is caused by numerous distinct mutations on the X chromosome that encodes a protein called WASP (Wiskott-Aldrich syndrome protein), which is expressed at high levels in lymphocytes and megakaryocytes.

WASP binds to the Rho family of GTPases. WASP controlls the assembly of actin filaments that are required to form microvesicles.

Question 22

DiGeorge syndrome is a a developmental disorder charactarized by thymic and parathyroid _______ plasia.

_______ q11.2 deletion of DiGeorge is a chromosomal defect that results in the developmental anomalies of the third and fourth branchial pouches (pharyngeal pouches) and organs that develop from these embryonic structures like the thymus, parathyroids, and aortic arch.

These children present with tetany (seizure) caused by _______ parathyroidism and deficiency of cellular immunity. They also havecharecteristic facial features (“angry look”). In the absence of a thymus, T-cell maturation is interrupted at the pre-T stage.

Treatment involves transplanting thymic tissue.

Answer 22

DiGeorge syndrome is a a developmental disorder charactarized by thymic and parathyroid aplasia.

22q11.2 deletion of DiGeorge is a chromosomal defect that results in the developmental anomalies of the third and fourth branchial pouches (pharyngeal pouches) and organs that develop from these embryonic structures like the thymus, parathyroids, and aortic arch.

These children present with tetany (seizure) caused by hypoparathyroidism and deficiency of cellular immunity. They also havecharecteristic facial features (“angry look”). In the absence of a thymus, T-cell maturation is interrupted at the pre-T stage.

Treatment involves transplanting thymic tissue.

Question 23

Hyperacute renal transplant rejection is manifested as a _______ of urine output, along with pain and fever in the area of the graft site.

This immediate rejection is mediated by _______ antibodies and complement activation products.

Answer 23

Hyperacute renal transplant rejection is manifested as a cessation of urine output, along with pain and fever in the area of the graft site.

This immediate rejection is mediated by preformed antibodies and complement activation products.

Question 24

Note that lymphocytes and macrophages are associated with acute and chronic transplant _______ rejection.

Answer 24

Note that lymphocytes and macrophages are associated with acute and chronic transplant graft rejection.

Question 25

Myasthenia gravis is a type _______ hypersensitivity disorder caused by antibodies that bind to the _______ receptor. These antibodies interfere with the transmission of neural impulses at the neuromuscular junction, causing muscle _______ and easy _______.

External ocular and eyelid muscles are _______ often affected, but the disease is often progressive and may cause death by respiratory muscle paralysis.

Answer 25

Myasthenia gravis is a type 2 hypersensitivity disorder caused by antibodies that bind to the Ach receptor. These antibodies interfere with the transmission of neural impulses at the neuromuscular junction, causing muscle weakness and easy fatigability.

External ocular and eyelid muscles are most often affected, but the disease is often progressive and may cause death by respiratory muscle paralysis.

Question 26

Autoantibodies to demoglein-3 are found in patients with pemphigus _______, an autoimmine blistering skin disorder.

Answer 26

Autoantibodies to demoglein-3 are found in patients with pemphigus vulgaris, an autoimmine blistering skin disorder.

Question 27

Graves Hyperthyroidism is a type _______ hypersensitivity disorder caused by antibodies to the _______ receptor on follicular cells of the thyroid.

Antibody binding to the _______ receptor stimulates the release of tetraiodothyronine T4 and Triiodothyronine T3 from the thyroid into the circulation.

Circulating T3 & T4 supress _______ production in the pituitary. Exopthalmos, sweating, weight loss, and tachycardia are evidence of hypermetabolism .

Answer 27

Graves Hyperthyroidism is a type 2 hypersensitivity disorder caused by antibodies to the TSH receptor on follicular cells of the thyroid.

Antibody binding to the TSH receptor stimulates the release of tetraiodothyronine T4 and Triiodothyronine T3 from the thyroid into the circulation.

Circulating T3 & T4 supress TSH production in the pituitary. Exopthalmos, sweating, weight loss, and tachycardia are evidence of hypermetabolism .

Question 28

Antibodies to _______ channels are found in patients with Eaton-Lambert syndrome. This paraneoplastic syndrome also manifests as muscle weakness but is usually associated with _______ cell carcinoma of the lung.

Answer 28

Antibodies to calcium channels are found in patients with Eaton-Lambert syndrome. This paraneoplastic syndrome also manifests as muscle weakness but is usually associated with small cell carcinoma of the lung.

Question 29

Reumatoid factor represents multiple _______ directed against the Fc portion of Ig _______ and is seen in patients with rheumatoid arthritis and many other collagen vascular diseases. This is an example of type _______ hypersensitivity.

Answer 29

Reumatoid factor represents multiple antibodies directed against the Fc portion of IgG and is seen in patients with rheumatoid arthritis and many other collagen vascular diseases. This is an example of type 3 hypersensitivity.

Rheumatoid factor (RF) is the autoantibody (antibody directed against an organism’s own tissues) that was first found in rheumatoid arthritis. It is defined as an antibody against the Fc portion of IgG (an antibody against an antibody). RF and IgG join to form immune complexes that contribute to the disease process = type 3 hypersensitivity.

Question 30

HIV does infect monocytes/macrophages, but infected cells exhibit little if any _______ toxicity. NK cell activity is also _______ in AIDS, which may lead to the appearance of malignant tumors and the viral infections that plague these patients.

Suppresion of NK cell activity is related to a decrease in the number of NK cells and to a reduction in IL-_______ levels due to the loss of CD4 helper cells.

Answer 30

HIV does infect monocytes/macrophages, but infected cells exhibit little if any cytotoxicity. NK cell activity is also decreased in AIDS, which may lead to the appearance of malignant tumors and the viral infections that plague these patients.

Suppresion of NK cell activity is related to a decrease in the number of NK cells and to a reduction in IL-2 levels due to the loss of CD4 helper cells.

Question 31

HIV is an RNA retrovirus that contains _______ transcriptase. After it enters into the cytoplasm of a T lymphocyte, the virus is uncoated, and its RNA is copied into dsDNA by retroviral _______ transcriptase.

The DNA derived from the virus is integrated into the host genome by the viral _______ protein, thereby producing the latent proviral form of HIV. Viral genes are replicated along with host chromosomes and therefore persist for the life of the cell.

Answer 31

HIV is an RNA retrovirus that contains reverse transcriptase. After it enters into the cytoplasm of a T lymphocyte, the virus is uncoated, and its RNA is copied into dsDNA by retroviral reverse transcriptase.

The DNA derived from the virus is integrated into the host genome by the viral integrase protein, thereby producing the latent proviral form of HIV. Viral genes are replicated along with host chromosomes and therefore persist for the life of the cell.

Question 32

The advent of transplantation of bone marrow into immunodeficient patients has resulted in graft-vs-host disease. GVHD occurs when lymphocytes in the _______ tissue recognize and react to the _______. GVHD can also occur when an immunodeficient patient is transfused with blood containing HLA-incompatible _______.

Major organs affected in GVHD are skin, GI tract, and liver. Hence, clinical presentation includes rash, diarrhea, abdominal cramps, anemia and liver dysfunction.

Answer 32

The advent of transplantation of bone marrow into immunodeficient patients has resulted in graft-vs-host disease. GVHD occurs when lymphocytes in the grafted tissue recognize and react to the recipient. GVHD can also occur when an immunodeficient patient is transfused with blood containing HLA-incompatible lymphocytes.

Major organs affected in GVHD are skin, GI tract, and liver. Hence, clinical presentation includes rash, diarrhea, abdominal cramps, anemia and liver dysfunction.

Question 33

Poison ivy is a type _______ hypersensitivity reaction to plants of the Rhus genus. This _______ lymphocyte mediated allergic contact dermatitis presents as urticaria (hives) and bullous eruption. Blisters rupture and heal with crusts, usually without scarring.

IgE mast cell degranulation is part of the response to poison ivy (hypersensitivty reactions overlap), but this immediate response does not explain the pathogenisis of delayed hypersensitivity.

Answer 33

Poison ivy is a type 4 hypersensitivity reaction to plants of the Rhus genus. This T lymphocyte mediated allergic contact dermatitis presents as urticaria (hives) and bullous eruption. Blisters rupture and heal with crusts, usually without scarring.

IgE mast cell degranulation is part of the response to poison ivy (hypersensitivty reactions overlap), but this immediate response does not explain the pathogenisis of delayed hypersensitivity.

Question 34

Deposition of antigluten antibodies occurs in patients with _______ herpetiformis.

Answer 34

Deposition of antigluten antibodies occurs in patients with dermatitis herpetiformis.

Question 35

Severe combined immunodeficiency is a group of disorders of _______ and _______ lymphocytes that are characterized by recurrent viral, bercterial, fungal, and protozoal infections. Many infants with SCID have reduced volumes of lymphoid _______ and an immature thymus that lacks lymphocytes.

50% of these SCID infants lack adenosine _______. _______ deficiency causes the accumulation of intermediate products that are toxic to lymphocytes. These children cannot survive beyond early infancy unless they are raised in a sterile enviornment “bubble boy”.

Answer 35

Severe combined immunodeficiency is a group of disorders of T and B lymphocytes that are characterized by recurrent viral, bercterial, fungal, and protozoal infections. Many infants with SCID have reduced volumes of lymphoid tissue and an immature thymus that lacks lymphocytes.

50% of these SCID infants lack adenosine deaminase. ADA deficiency causes the accumulation of intermediate products that are toxic to lymphocytes. These children cannot survive beyond early infancy unless they are raised in a sterile enviornment “bubble boy”.

Question 36

Vasculitis is caused by immune complex type _______ hypersensitivity reactions. Antigen-antibody complexes are either formed in the circulation and deposited in the _______ or formed in situ.

Immune complexes induce a localized inflammatory response by fixing _______, which leads to the recruitment of neutrophils and monocytes.

The vasculitis in patients with polyarteritis nodosa involves small to medium sized muscular _______. Diagnosis is made on biopsy of the skin, muscle, peripheral nerves, or the most caffected internal organ (e.g., kidney).

The most common morphologic feature of the affected artery in vasculitis is an area of fibrinoid _______.

Answer 36

Vasculitis is caused by immune complex type 3 hypersensitivity reactions. Antigen-antibody complexes are either formed in the circulation and deposited in the tissues or formed in situ.

Immune complexes induce a localized inflammatory response by fixing complement, which leads to the recruitment of neutrophils and monocytes.

The vasculitis in patients with polyarteritis nodosa involves small to medium sized muscular arteries. Diagnosis is made on biopsy of the skin, muscle, peripheral nerves, or the most caffected internal organ (e.g., kidney).

The most common morphologic feature of the affected artery in vasculitis is an area of fibrinoid necrosis.

Question 37

Hneoch-Schonlein purpura (vascular IgA deposits) and vasculitis associated with hepatitis _______ infection are examples of type _______ immune complex hypersensitivy reactions.

Answer 37

Hneoch-Schonlein purpura (vascular IgA deposits) and vasculitis associated with hepatitis C infection are examples of type 3 immune complex hypersensitivy reactions.

Question 38

_______ connective tissue disease has features of other common autoimmune diseases but appears to be distinct. Patients typically have autoantibodies to _______ nucleoproteins, but unlike SLE, they do not have antibodies to Sm antigen or dsDNA.

Some patients with MCTD develop symptoms of scleoderma or rheumatoid arthritis, suggesting that MCTD may be an _______ stage in a genetically determined progression. Whether MCTD represents a distinct entity or simply an overlap of symptoms in patients with other types of collagen vascular diseases remains an open question.

Intermittent episodes of ischemia of the fingers, marked by pallor, paresthesais , and pain are referred to as _______ phenomenon.

Answer 38

Mixed connective tissue disease has features of other common autoimmune diseases but appears to be distinct. Patients typically have autoantibodies to ribonucleoproteins, but unlike SLE, they do not have antibodies to Sm antigen or dsDNA.

Some patients with MCTD develop symptoms of scleoderma or rheumatoid arthritis, suggesting that MCTD may be an intermadiate stage in a genetically determined progression. Whether MCTD represents a distinct entity or simply an overlap of symptoms in patients with other types of collagen vascular diseases remains an open question.

Intermittent episodes of ischemia of the fingers, marked by pallor, paresthesais , and pain are referred to as Raynaud phenomenon.

Question 39

One third of patients with systemic lupus erythematosus posess elevated concentrations of anti _______ antibodies. This phenomenon predisposes these patients to thrombo _______ complications, including stroke, pulmonary embolism, deep venous thrombosis, and portal vein thrombosis.

The clinical course of SLE is highly variable and typically exhibits exacerbations and remissions. With the recognition of mild forms of the disease, improved _______ hypertensive medications, and the use of immunosuppressive agents, the overal 10-year survival rate approaches 90%.

Answer 39

One third of patients with systemic lupus erythematosus posess elevated concentrations of antiphospholipid antibodies. This phenomenon predisposes these patients to thromboembilic complications, including stroke, pulmonary embolism, deep venous thrombosis, and portal vein thrombosis.

The clinical course of SLE is highly variable and typically exhibits exacerbations and remissions. With the recognition of mild forms of the disease, improved antihypertensive medications, and the use of immunosuppressive agents, the overal 10-year survival rate approaches 90%.

Question 40

Selective Ig _______ deficiency is the most common primary immunodeficiency syndrome with a high incidence in europeans. Although patients are often asymptomatic, they ocasionally present with respiratory or _______ infections of varying severity. They also display a strong predilection for allergies and collagen vascular diseases.

Patients with Ig _______ deficiency have normal numbers of Ig _______-bearing B cells, and their varied defects result in an inability to _______ and secrete Ig _______ subclasses.

Answer 40

Selective IgA deficiency is the most common primary immunodeficiency syndrome with a high incidence in europeans. Although patients are often asymptomatic, they ocasionally present with respiratory or GI infections of varying severity. They also display a strong predilection for allergies and collagen vascular diseases.

Patients with IgA deficiency have normal numbers of IgA-bearing B cells, and their varied defects result in an inability to synthesize and secrete IgA subclasses.

Question 41

Patients with chronic mucocutaneous candidiasis show an increased susceptibility to _______ infections and may also exhibit endocrine like addison disease and hypoparathyroidism.

Answer 41

Patients with chronic mucocutaneous candidiasis show an increased susceptibility to Candida infections and may also exhibit endocrine like addison disease and hypoparathyroidism.

Question 42

Transplant rejection reactions have been traditionally categorized into hyperacute, acute, and chronic rejection based on the clinical tempo of the response and on the mechanisms involved.

_______ rejection is characterized by an abrupt onset of azotemia (high levels of nitrogen-containing compounds) and oliguria, which may be associated with fever and grat tenderness.

A needle biopsy would be expected to show interstitial infiltrates of _______ and _______, edema, lymphocytic tubulitis, and tubular necrosis.

Answer 42

Transplant rejection reactions have been traditionally categorized into hyperacute, acute, and chronic rejection based on the clinical tempo of the response and on the mechanisms involved.

Acute rejection is characterized by an abrupt onset of azotemia (high levels of nitrogen-containing compounds) and oliguria, which may be associated with fever and grat tenderness.

A needle biopsy would be expected to show interstitial infiltrates of lymphocytes and macrophages, edema, lymphocytic tubulitis, and tubular necrosis.

Question 43

Neutrophilic vasculitis and fibrinoid necrosis are seen in _______ graft rejection.

Answer 43

Neutrophilic vasculitis and fibrinoid necrosis are seen in hyperacute graft rejection.

Question 44

Glomerulosclerosis and tubular atrophy are seen in _______ graft rejection.

Answer 44

Glomerulosclerosis and tubular atrophy are seen in chronic graft rejection.

Question 45

B and T lymphocytes circulate via the vascular system to secondary lymphoid organs and tissues. Included among these tissues are lymph nodes, mucosa-associated lymphoid tissue, and spleen. In the case of lymph nodes, lymphocyte trafficking occurs though specialized postcapillary venules termed high _______ venules.

Answer 45

B and T lymphocytes circulate via the vascular system to secondary lymphoid organs and tissues. Included among these tissues are lymph nodes, mucosa-associated lymphoid tissue, and spleen. In the case of lymph nodes, lymphocyte trafficking occurs though specialized postcapillary venules termed high endothelial venules.

HEVs express an array of specific cell adhesion molecules like CD31 that allow lymphocyte binding and diapedesis. The cuboidal shape of HEV cells reduces flow mediated shear forces and specialized intercellular connections facilitate egress of lymphocytes out of the vascular space.

High endothelial venules (HEV) are specialized post-capillary venous swellings characterized by plump endothelial cells as opposed to the usual thinner endothelial cells found in regular venules. HEVs enable lymphocytes circulating in the blood to directly enter a lymph node (by crossing through the HEV).

Hassals corpuscles are found in the medulla of the thymus. Peyer patches are organized lymphoid tissues in the small intestine.

Question 46

The HIV-1 genome consists of _______ identical strands of RNA enclosed within a core of viral proteins. The core is enveloped by a phospholipid bilayer derived from the host cell membrane, in which are found virally encoded glycoproteins gp _______ & gp _______.

In addition to the gag, pol, and env genes characteristic of all replication competent RNA viruses–HIV 1 contains six other genes that code for proteins involved in replication.

The specific target cells for HIV-1 are _______ lymphocytes and _______ phagocytes, although infection of other cells occurs.

The HIV envelope glycoprotein gp _______ binds CD4 on the surface of helper T cells. The binding of gp _______ to CD4 allows gp _______ to insert into the cell membrane of the lymphocyte, thereby promoting fusion of the viral envelope with the lymphocyte. Entry of HIV-1 into a target cell also requires viral binding to a coreceptor, _______ (B-chemokine receptor 5).

Answer 46

The HIV-1 genome consists of two identical strands of RNA enclosed within a core of viral proteins (so its diploid). The core is enveloped by a phospholipid bilayer derived from the host cell membrane, in which are found virally encoded glycoproteins gp120 & gp41.

In addition to the gag, pol, and env genes characteristic of all replication competent RNA viruses–HIV 1 contains six other genes that code for proteins involved in replication.

The specific target cells for HIV-1 are CD4+ helper T lymphocytes and mononuclear phagocytes, although infection of other cells occurs.

The HIV envelope glycoprotein gp120 binds CD4 on the surface of helper T cells. The binding of gp120 to CD4 allows gp41 to insert into the cell membrane of the lymphocyte, thereby promoting fusion of the viral envelope with the lymphocyte. Entry of HIV-1 into a target cell also requires viral binding to a coreceptor, CCR5 (B-chemokine receptor 5).

Question 47

Picture: Question 18; diagnosis = ?

Answer 47

Picture: Question 18; diagnosis = Graves disease, cytopathic antibodies

Question 48

Picture: Question 23; diagnosis = ?

Answer 48

Picture: Question 23; diagnosis = Polyarteritis nodosa