Immunodermatology1)Which of the following statements regarding TH1 and TH2 immune responses is true?

A. TH2 cells secrete TNF and lymphotoxin

B. TH1 cells secrete IL-10, which is the main macrophage-activating cytokine

C. TH2 cytokines include IL-5, which activates B cellsCorrect Choice

D. TH1 and TH2 cytokines both activate macrophages

E. Key TH2 ctyokines include IFN-gamma and IL-4

TH1 and TH2 cells release different, but overlapping sets of cytokines. TH2 cells secrete IL-4 and IL-5, which activate B cells, and IL-10, which inhibits macrophage activation. TH1 cells secrete IFN-gamma, which is the main macrophage-activating cytokine, TNF, and lymphotoxin.

2) Linear IgA disease is most closely associated with which of the following medications?

A. Clarithromycin

B. Vancomycin Correct Choice

C. Azithromycin

D. Streptomycin

E. Erythromycin

Vancomycin is an antibiotic frequently used in subjects allergic to penicillin. It has been reported to produce subepidermal blistering disease with linear IgA deposits.

3)Which monoclonal gammopathy is most commonly associated with erythema elevatum diutinum?

A. IgM

B. IgD

C. IgE

D. IgA Correct Choice

E. IgG

A report of 13 patients indicated IgA is most commonly associated with EED (Yiannias, et al, 1992).

4) Gene rearrangement analysis is usedful for determining all of the following except:

A. Lymphocyte clonality in mycosis fungoides

B. T cell clonality

C. B cell clonality

D. Lymphocyte

E. Natural killer cell clonalityCorrect Choice

Gene rearrangement studies cannot by used to detect clonality in natural killer cells. Natural killer cells are not antigen-specific, and therefore, do not undergo gene rearrangement.

5) Which systemic anti-inflammatory agent specifically blocks the ability of T cells to leave the vasculature and enter the skin?

A. etanercept

B. efalizumabCorrect Choice

C. infliximab

D. alefacept

E. none of the above

Efalizumab is a humanized monoclonal antibody to CD11a that blocks the immunologic synapse between LFA-1 on the T-cell and ICAM-1 on the antigen presenting cell. By targeting LFA-1 efalizumab specifically blocks the ability of T cells to leave the vasculature and enter the skin.

6) Dermatitis herpetiformis is associated with which HLA type(s)?

A. HLA-DQw2

B. HLA-B8

C. HLA-DR3

D. none of the above

E. all of the aboveCorrect Choice

Dermatitis herpetiformis is associated with HLA-B8, -DR3, and -DQw2.

7) The antibody produced in the early stages of antibody responses is:

A. IgA

B. IgE

C. IgD

D. IgMCorrect Choice

E. IgG

IgM is the antibody produced in the early stages of antibody responses. It is a pentamer which can agglutinate antigen and active the classic complement pathway. IgG is the antibody that can cross the placenta and the most common antibody found in circulation. IgA is found in mucous membrane secretions and is able to agglutinate antigens and activate the alternate but not the classic complement pathway. IgD is not found in circulation other than in hyper-IgD syndrome, an autosomal recessive disorder caused by mutations in the mevalonate kinase gene. A significant elevation of serum IgD is seen in 95% of these patients. IgE is an anaphylactic antibody that is involved in nearly all immediate allergic and anaphylactic type reactions.

8) Dermatitis Herpetiformis is most commonly associated with which HLA?

A. HLA-DQ(A1*0501, B1*02) Correct Choice

B. HLA-B8

C. HLA-DR3

D. HLA-B27

E. HLA-Bw35

HLA-DQ (A1*0501, B1*02) genes are present on 90% of all patients with Dermatitis Herpetiformis. The remainder of patients have the HLA-DQ8 gene. Other associations include: HLA-B8, HLA-DR3 and DR5/DR7.

9) Which of the following dietary supplements may inhibit platelet function?

A. Vitamin K

B. Vitamin C

C. Vitamin E Correct Choice

D. Vitamin A

E. Vitamin D

Supplemental vitamin E can inhibit platelet function and predispose to hemorrhagic stroke. It can be particularly hazardous in patients with beta-thalassaemia mutations (Unchern, et al, 2003; Liu, et al, 2003).

10) All of the following statements regarding major histocompatibility complex molecules are true EXCEPT:

A. MHC class I molecules bearing viral peptides are recognized by cytotoxic T-cells that subsequently kill the infected cell

B. The MHC is located on chromosome 6 in humans

C. MHC Class II molecules bearing peptides are recognized by TH1 or TH2 cells.

D. Class I molecules such as HLA-A, B, and C, are present on all nucleated cells

E. MHC class II molecules bind stably to peptides derived from proteins sythesized and degraded in the cytosolCorrect Choice

MHC class I molecules bind stably to peptides derived from proteins sythesized and degraded in the cytosol, while MHC class II molecules bind stably to peptides derived from proteins degraded in endocytic vesicles. MHC class I molecules bearing viral peptides are recognized by cytotoxic T-cells that subsequently kill the infected cell. MHC Class II molecules bearing peptides trigger helper T-cells and are recognized by TH1 or TH2 cells. Class I molecules such as HLA-A, B, and C, are present on all nucleated cells, whereas Class II molecules are on B cells, monocytes, dendritic cells, and are inducible on keratinocytes and endothelial cells. The MHC is located on chromosome 6 in humans, its polygenic and polymorphic nature contributes to the ability of the immune system to respond to a multitude of different and rapidly evolving pathogens.

11) Which cytokine is upregulated in lesions of tuberculoid leprosy?

A. None of the answers are correct

B. IL 2Correct Choice

C. IL 10

D. IL 5

E. IL 4

Tuberculoid leprosy is characterized by a type I immune related response. Tuberculoid leprosy has increased amounts of TH1 cytokines including IL-2, interferon gamma, and IL-12. These lead to a t-cell and macrophage mediated cytotoxic response. IL-4, IL-5, and Il-10 are typically downregulated in tuberculoid leprosy.

12) Patients with a type I reaction to latex may have cross-reactions with which of the following foods?

A. Parsnips

B. Cashews

C. Avocado Correct Choice

D. Horseradish

E. Garlic

Latex allergy is a TH2 form of contact sensitivity that is IGE mediated. Using the old Gel and Coombs classification, it was classified as type I hypersensitivity (Ranta, et al, 2004; Ebo, et al, 2003).

13) Natural killer (NK) cells eliminate infected cells in all of the following ways except:

A. NK cells secrete myeloperoxidaseCorrect Choice

B. NK cells secrete perforins

C. NK cells adhere to and kill target cells coated with IgG

D. NK cells do not target cells expressing major histocompatibility (MHC) class I molecules

E. NK cells secrete granzyme

NK cells focus on the destruction of infected or malignant cells. They achieve this via recognition of IgG on target cells, the so-called 'antibody-dependent cellular toxicity.' NK cells also eliminate cells by secreting perforin, which makes holes in the cell membrane, through which granzyme is injected. Granzyme induces apoptosis by activating the caspase cascade. In addition, NK cells do not target cells expressing MHC class I molecules on their surface; some virus downregulate MHC class I molecules to evade recognition by cytotoxic T cells, which may make them susceptible to NK cell attack. Neutrophils kill ingested organims using myeloperoxidase.

14) Pemphigus is associated with which HLA type(s)?

A. HLA-B51

B. HLA-B8

C. HLA-DRw6Correct Choice

D. None of these answers are correct.

E. All of these answers are correct.

Pemphigus is associated with HLA-DR4 or DRw6.

15) Allergic contact dermatitis is caused by T-cell response to topical exposure to compounds that form complexes with host proteins (haptens). Which cell is responsible for initial sensitization of the T-cells?

A. Macrophage

B. Langerhans CellCorrect Choice

C. Mast Cell

D. B-cell

E. Melanocyte

The Langerhans cell phagocytizes the haptens in the epidermis or dermis, begins the process of maturation and migrates to the regional lymph node, where naïve T-cells are educated to expand to a clone of CLA positive memory T-cells. These cells then can expand and extravasate with subsequent exposure to the same allergen. Melanocytes, B-cells, Mast cells and macrophages are not involved in the sensitization process of allergic contact dermatitis.

16) Which of the following is associated with hepatitis C infection?

A. Relapsing polychondritis

B. Essential mixed cryoglobulinemia Correct Choice

C. Rheumatoid arthritis

D. Wegener’s granulomatosis

E. Dermatomyositis

Hepatitis C infections can present as urticaria or papable purpura and cryoglobulinemia (Lamprecht, et al, 2003).

17) All of the following statements regarding Langerhans cells are true EXCEPT:

A. They are found in some areas of lymph nodes and spleen

B. None of these answers are correct.

C. They express CD1 on their surface

D. They have a high density of Class II molecules on their surface

E. They are highly phagocyticCorrect Choice

Langerhans cells are dendritic cells found in high concentrations in epithelial surfaces and some areas of lymph nodes and spleen. They express CD1 on their surface and have a high density of Class II MHC molecules. They are poorly phagocytic.

18) MHC Class II molecules are present on which of the following cell types:

A. NK cells

B. B cellsCorrect Choice

C. T cells

D. mast cells

E. All of the above

MHC Class II molecules are on B cells, monocytes, dendritic cells, and are inducible on keratinocytes and endothelial cells.

19) Anti Jo-1 antibodies are directed against which of the following?

A. Histidyl transfer RNA synthetase Correct Choice

B. Lysyl oxidase

C. Gyrase

D. Topoisomerase

E. Telomerase

Anti Jo-1 antibody is typical of autoimmune diseases that involve muscle, including dermatomyositis (Walker, et al, 1987; Dang, et al, 1986).

20) Which cytokine is not upregulated in atopic dermatitis patients?

A. IL-10

B. IFN-gamma Correct Choice

C. IL-5

D. IL-4

E. IL-13

Interferon gamma is Th1 cytokine which downregulates Th2 responses. The remaining are Th2 cytokines active in atopic dermatitis. IL-4 is a B-cell growth factor and active in signaling isotope switching from IgM to IgE. IL-5 is an eosinophil growth factor. IL-10 downregulates Th1 immunity and IL-13 signals isotope switching along with IL-4.

21) Subacute cutaneous lupus erythematosus has been associated with the ingestion of which of the following drugs?

A. Trimethoprim/sulfamethoxazole

B. Phenytoin

C. Allopurinol

D. Auranofin

E. Terbinafine Correct Choice

SCLE has been reported to be associated with terbinafine. This condition is often associated with anti-Ro (SS-A) and anti-La (SS-B) antibodies.

22) An 8 month-old baby with diffuse purpura is admitted to the hospital for her third episode of bacterial meningitis. Which component of her immune system is impaired?

A. Complement activationCorrect Choice

B. Natural killer cell activation

C. CD4 + T cells

D. Antibody production

E. CD8 + T cells

Predisposition to sporadic and occasionally recurrent meningococcal disease occurs in patients with congenital or acquired complement deficiencies, particularly late acting components C5-9

23) This lesion is hypoesthetic and is associated with which of the following:

A. None of these answers are correct

B. Interleukin 12

C. All of these answers are correctCorrect Choice

D. gamma interferon

E. Interleukin 2

The lesion is high immune or tuberculoid leprosy, which is associated with TH1 cytokines including IFN-gamma, IL2, IL12, IL15, IL18 and IL23.

24) The most common autoimmune disorder in patients with chronic hepatitis C infection is

A. autoimmune thyroiditis Correct Choice

B. Systemic lupus erythematosus

C. idiopathic thrombocytopenic purpura

D. rheumatoid arthritis

E. Sjögren’s syndrome

Autoimmune thrombocytopenia has been reported with hepatitis C infection but not as commonly as autoimmune thyroiditis.

25) All of the following statements regarding Natural Killer (NK) cells are true EXCEPT:

A. NK cells express CD 2 moleculesCorrect Choice

B. NK cells mediate lysis of viral-infected cells

C. NK cells have properties of innate and acquired immunity

D. NK cells mediate tumor lysis

E. NK cells are large granular lymphocytes

NK cells do not express CD 2 molecules. The other statements are true.

26) This disease is most associated with:

A. IL-5

B. gamma interferon Correct Choice

C. IL-4

D. None of these answers are correct

E. IL-13

The answer is gamma interferon, which is the TH1 cytokine associated with a hyperproliferative epidermis and with micaceous scale as seen in psoriasis.

27) Which component of the T cell receptor is associated with superantigen recognition?

A. D-beta

B. J-beta

C. V-alpha

D. V-betaCorrect Choice

E. J-alpha

Superantigens are able to bypass many elements of the normal immune response. They are not processed by antigen presenting cells. Instead, they bind directly to the MHCII complex and interact with T cells in a relatively non-specific fashion. Whereas conventional antigens require recognition in all 5 elements of the T-cell receptor (Vá, Já, Vâ, Dâ, Jâ), superantigens are recognized by Vâ alone.

28) Elaboration of which of the following cytokines is characteristic of TH2 response?

A. Interleukin-4 Correct Choice

B. Interleukin-2

C. Interleukin-1

D. Interferon-8 (gamma)

E. Interleukin-12

Interleukin-4 (IL-4) is a cytokine involved in B-cell proliferation. Along with IL-5 and IL-13, IL-4 is classified as a TH2 cytokine (Janeway, et al, 2001).

29) Immunocytomas are

A. aggressive B-cell lymphomas

B. aggressive T-cell lymphomas

C. low grade T-cell lymphomas

D. low grade B-cell lymphomas Correct Choice

E. NK cell lymphomas

These indolent tumors present as solitary or multiple nodules usually on the extremities. The cells have been reported to have CD-20 (B cell marker) and have been reported to be bcl-2 positive.

30) Naive T cells express which of the following surface molecules:

A. CD19

B. CD45RACorrect Choice

C. CD79

D. CD45RO

E. CD20

Naive T cells express CD45RA whereas memory T cells express CD45RO. CD19, 20, and 79 are B cell surface markers.

31) Eosinophils are typically seen in the cutaneous infiltrate of

A. Ki-1 lymphoma

B. Kaposiform hemangioendothelioma

C. Kawasaki’s disease

D. Krabbe’s disease

E. Kimura’s disease Correct Choice

Eotaxin, which attracts eosinophils, is produced by T cells in Kimura’s disease (Kimura, et al, 2002).

32) Which of the following diseases does not respond with a Th1-type responses?

A. Leishmaniasis which self-resolves

B. Lepromatous LeprosyCorrect Choice

C. Allergic contact dermatitis

D. Psoriasis

E. Tuberculoid Leprosy

Lepromatous leprosy is Th2 biased. The remaining conditions are Th1 predominant responses. Leishmaniasis which show strong cell-mediated immunity to the parasite and with self-resolving lesions are Th1 responses. In indolent/progressive leishmaniasis, a Th2 pattern is predominant.

33) Anti-epiligrin (laminin 5) antibodies may be seen in

A. pemphigus vegetans

B. fogo selvagem

C. pemphigoid gestationis

D. cicatricial pemphigoid Correct Choice

E. paraneoplastic pemphigus

Patients with cicatricial pemphigoid have been reported to have anti-epiligrin antibodies (Yancey, et al, 1995; Hsu, et al, 2000).

34) Which of the following cytokines, together with IL-4, promotes isotype switching from IgM to IgE?

A. IL-10

B. IFN-gamma

C. IL-13Correct Choice

D. TNF

E. IL-5

IL-5 is an eosinophil growth factor. IL-10 is a general down-regulator of TH1 immunity. IL-13 (along with IL-4) promotes an isotype switch from IgM to IgE. TNF and IFN-gamma are TH1 cytokines, TH2 cytokines. IFN-gamma is secreted by TH1 cells, and is the main macrophage-activating cytokine.

35) Which of the following is a criterion for the diagnosis of Behçet’s disease?

A. Conjunctivitis

B. Lobular panniculitis

C. Inflammatory bowel disease

D. Uveitis Correct Choice

E. Nasal septal perforation

Behçet’s is a triad that includes oral ulcerations, genital ulcerations and uveitis. Behçet’s also displays arthritis and gastrointestinal disease. Blindness is the most-feared outcome, and relates to the uveitis.

36) A disorder of melanosome transfer is

A. Piebaldism.

B. rufous albinism.

C. Hermansky-Pudlak syndrome.

D. Chédiak-Higashi syndrome. Correct Choice

E. Waardenburg’s syndrome type 1.

Also called lethal albinism, Chédiak-Higashi syndrome is a primary immunodeficiency disorder that links melanin and leukocyte granule formation. See also Hermansky-Pudlak.

37) With which HLA type is psoriasis most definitively linked?

A. HLA-Cw6Correct Choice

B. HLA-B8

C. HLA-DR4

D. HLA-DR3

E. HLA-B51

Psoriasis is linked with HLA-Cw6. Patients with this HLA type have a relative risk of having psoriasis that is 9-15 times normal.

38) Which of the following immunoglobulins cannot activate the complement pathway?

A. IgG2

B. IgG1

C. IgM

D. IgG4Correct Choice

E. IgG3

Immunoglobulins (Ig) differ in their ability to activate complement. IgM is the largest Ig, is the major Ig in the primary immune response, and consists of a pentamer that activates the classic complement pathway. IgG is the most abundant Ig and the major Ig in the secondary immune response. Four subclasses of IgG exist based on the amino acid residue sequences of their constant region, IgG1 through IgG4. IgG1 and IgG3 are potent activators of the classic complement pathway, IgG2 is less effective and IgG4 is unable to do so.

39) A patient had antibodies to desmoglein 3, but no antibodies to desmoglein 1 or desmplakin. The likely diagnosis is:

A. erythema multiforme

B. bullous pemphigoid

C. pemphigus vulgaris Correct Choice

D. pemphigus foliaceous

E. dermatitis herpetiformis

The answer is pemphigus vulgaris, which typically has autoantibodies to desmoglein 3. While mixed forms of pemphigus can occur, the histology in this case confirmed pemphigus vulgaris.

40) Which of the following TH2 cytokines is a B cell growth factor?

A. IL-4Correct Choice

B. IFN-gamma

C. IL-5

D. IL-10

E. IL-13

IL-4 is a B cell growth factor. IL-5 is an eosinophil growth factor. IL-10 is a general down-regulator of TH1 immunity. IL-13 (along with IL-4) promotes an isotype switch from IgM to IgE. IFN-gamma is not a TH2 cytokine. It is secreted by TH1 cells, and is the main macrophage-activating cytokine.

41) The human major histocompatibility complex (MHC) is located on chromosome:

A. 9

B. 11

C. 2

D. 17

E. 6Correct Choice

The MHC is highly polygenic and polymorphic, and this contributes to the ability of of the immune system to respond to a multitude of different and rapidly evolving pathogens. The MHC is located on chromosome 6 in humans.

42) Which of the following is the target antigen in pemphigus vulgaris?

A. Desmoplakin

B. Cadherin

C. Desmoglein 1

D. Type XVII collagen

E. Desmoglein 3 Correct Choice

Desmoglein 3 is the dominant target auto-antigen in pemphigus vulgaris (Hacker-Foegen, et al, 2003).

43) The pharmacologic activity of tacrolimus includes

A. inhibition of interleukin-2 gene transcription Correct Choice

B. activation of calcineurin

C. binding and inhibition of NF kappa B

D. inhibition of interleukin-1 gene transcription

E. phosphorylation of NFAT (nuclear factor of transcription)

Tacrolimus is a macrolide similar to cyclosporine and pimecrolimus (Elidel). Calcineurin is a phosphatase that dephosphorylates subunit on NFAT (nuclear factor of activated T cells).

44) The endothelial ligand for cutaneous lymphocyte antigen (CLA) is:

A. vascular cell adhesion molecule (VCAM-1)

B. Leukocyte functional antigen (LFA 3)

C. L-selectin

D. E-selectinCorrect Choice

E. intercellular adhesion molecule 1 (ICAM-1)

Cutaneous lymphocyte antigen (CLA) allow memory T cells to home to the skin, where it binds to its ligant E-selectin on cutaneous microvessels. Transmigration of memory T cells into the dermis, however, further requires interaction between leukocyte functional antigen 1 (LFA-1) and ICAM-1, and B-integrin very late antigen 4 (VLA-4) and VCAM-1. L-selectin is expressed on post-capillary venules in the lymph nodes and serves as the attachment points for naive T cells.

45) The gene for NEMO (NF-kappa bets essential modulator) is mutated in

A. Papillon-Lefévre syndrome

B. incontinentia pigmenti Correct Choice

C. dyskeratosis congenital

D. pachyonychia congenital type II

E. Noonan’s syndrome

NEMO/IKK gamma is an essential component of the nuclear factor kappa B pathway, which is a common signaling pathway for many cytokines. Mutation in this pathway have been found to cause incontinentia pigmenti.

46) Which virus is most closely associated with Kaposi’s sarcoma in HIV-infected patients?

A. Epstein-Barr virus

B. Human herpes virus 2

C. Cytomegalovirus

D. Human herpes virus 6

E. Human herpes virus 8 Correct Choice

HSV-8 has been repeatedly associated with all forms of Kaposi’s sarcoma.

47) All the following conditions exhibit a T-helper cell 1 (Th1) cytokine secretion profile except:

A. rheumatoid arthritis

B. multiple sclerosis

C. systemic lupus erythematosusCorrect Choice

D. granulomatous leprosy

E. psoriasis

Systemic lupus erythematous is associated with a Th2 cytokine profile, whereas the other conditions are associated with a Th1 cytokine profile. Th2 cells are typified by secretion of IL-4, IL-5, IL-6, IL-9, IL-10 and IL-13, whereas Th1 cells are typified by secretion of IFN-gamma, TNF-beta, and IL-2.

48) T-cell anergy occurs if:

A. MHC Class I or II is bound in the presence of IL-2

B. Stimulation by a MHC Class III molecule is involved

C. MHC/TCR engagement occurs without costimulatory moleculesCorrect Choice

D. FasL is bound on the T-cell

E. A HLA-DM facilitator is not involved with the binding

MHC/TCR engagement occurs without costimulatory molecules. MHC Class III molecules are not involved in this process. The MHC III region encodes for soluble proteins of the complement cascade and the tumor necrosis family. Fas-FasL interactions promote apoptosis on the target cell, not stimulation. IL-2 is a stimulatory molecule, produced by Th1 T-cells. It does not produce anergy. HLA-DM facilitates loading of proteins processed by antigen presenting cells into the MHC class II molecule before being brought to the cell surface.

49) Which cytokine is responsible for fever in patients with sunburn?

A. IL-1Correct Choice

B. IL-5

C. IL-10

D. TNF-beta

E. IL-11

IL-1 is a pyrogenic cytokine responsible for the fever in sunburn. It also is causes B cell maturation and proliferation and NK cell activation.

50) Sensation is intact in this lesion, but a Fite stain is positive. This lesions is associated with which of the following:

A. IL-5

B. IL-4

C. None of these answers are correct

D. IL-10

E. All of these answers are correctCorrect Choice

The lesion is low immune or lepromatous leprosy, which is associated with TH2 cytokines including IL-4, IL-5, IL-10, and IL-13.

51) Which of the following suture materials induces the least inflammation?

A. Polyglycolic acid (Dexon)

B. Silk

C. Polyglycan 910 (Vicryl)

D. Polypropylene (Prolene) Correct Choice

E. Surgical gut

Prolene is a nonabsorbable suture material that evokes only minimal inflammation.

52) Which of the following B cell receptors is involved in immunoglobulin isotype switching?

A. CD20

B. CD19

C. CD154

D. CD40Correct Choice

E. CD22

CD40 activation on B cells by CD40-ligand (CD154) on T cells induces isotype switching from an IgM to IgG response. Defects in the expression of CD40-ligand result in an immunodeficiency state (hyper-IgM syndrome) characterized by low levels of IgG, IgA and IgE, but elevated IgM. CD19, CD20, CD22 are pan-B cell markers.

53) All of the following statements regarding neutrophils are true EXCEPT:

A. None of these answers are correct.

B. Neutrophils are granulocytes

C. Neutrophils have receptors for IgG and complement

D. Neutrophils are the most abundant leukocytes

E. Neutrophils' major function is antigen presentationCorrect Choice

Neutrophils' major function is phagocytosis. The other statements are correct.

54)Calcipotriene-induced improvement in psoriasis is associated with increased lesional levels of which cytokine?

A. Interleukin-8

B. Interleukin-10 Correct Choice

C. Interluekin-12

D. Interleukin-2

E. Tumor necrosis factor

Psoriasis is generally described as a TH1 autoimmune disease where IL-12/IFN-gamma pathway is dominant. IL-10 is the prototype of TH2 and calcipotriene application results in increased levels of IL-10, thus decreasing TH1 disease.

55) Purpuric contact dermatitis is most likely to be associated with

A. nickel

B. p-phenylenediamine

C. sorbic acid

D. formaldehyde Correct Choice

E. propylene glycol

Textile dermatitis has been reported to be associated with purpuric contact dermatitis (Romaguera, et al, 1981; Garcia Bracamonte, et al, 1995).

56) The immunoglobulin most commonly found in mucous secretions is:

A. IgD

B. IgACorrect Choice

C. IgM

D. IgE

E. IgG

IgA is found in mucous membrane secretions and is able to agglutinate antigens and activate the alternate but not the classic complement pathway. IgG is the antibody that can cross the placenta and the most common antibody found in circulation. IgD is not found in circulation other than in hyper-IgD syndrome, an autosomal recessive disorder caused by mutations in the mevalonate kinase gene. A significant elevation of serum IgD is seen in 95% of these patients. IgE is an anaphylactic antibody that is involved in nearly all immediate allergic and anaphylactic type reactions. IgM is the antibody produced in the early stages of antibody responses. It is a pentamer which can agglutinate antigen and active the classic complement pathway.

57) Which systemic anti-inflammatory agent targets CD2+ activated T cells for apoptosis?

A. infliximab

B. none of the above

C. alefaceptCorrect Choice

D. efalizumab

E. etanercept

Alefacept is a soluble form of LFA-3 that blocks the immunologic synapse between CD2 on the T cell and LFA-3 on the antigen presenting cell. Furthermore, alefacept targets CD2+ activated T cells for apoptosis.

58) Which of the following causes a photoallergic contact dermatitis that is exacerbated by UVA radiation?

A. Titanium dioxide

B. Dihydroxyacetone

C. Oxybenzone Correct Choice

D. Zinc oxide

E. Ascorbic acid

Oxybenzone is the most common sunscreen agent causing photoallergic contact dermatitis. Patients sensitive should be instructed to avoid sunscreens containing oxybenzone.

59) Psoriasis affects over 2% of the world’s population and has a strong association with which HLA class I haplotype?

A. HLA-DR4

B. HLA-CW6Correct Choice

C. HLA-B27

D. HLA-DQ6

E. HLA-DR1

HLA-CW6 has been seen in up to 90% of patients with early onset psoriasis, 50% with late onset psoriasis and only 7.4% of the general population. HLA-DR1 and DR4 are both related to Rheumatoid Arthritis and have a 7x increased relative risk (RR) for developing disease. HLA-B27 is linked to ankylosing spondylitis, postinfection arthridites and Reiter’s disease, with increase relative risks of 100x, 10-20x, and 35x respectively.

60) The putative mechanism of action of topical macrolide immunomodulators is inhibition of

A. prostaglandin secretion

B. lymphocyte migration

C. lymphokine production Correct Choice

D. antigen presentation

E. neutrophil migration

Tacrolimus and pimecrolimus are topical macrolide immunomodulators that inhibit lymphokine or cytokine production via binding to macrophilin. This complex inhibits calcineurin, a phosphatase involved in the activation of NF-AT. This suppresses the production of IL-2 and IFN-gamma (TH1 cytokines) as well as IL-4, 5 and 13 (TH2 cytokines). In addition, they decrease the expression of IgE receptors on Langerhans cells and reduce mast cell degranulation.

61) This patient had antibodies to 180 kd antigen. The likely diagnosis is:

A. bullous lichen planus

B. pemphigus foliaceous

C. erythema multiforme

D. bullous pemphigoid Correct Choice

E. pemphigus vulgaris

The answer is bullous pemphigoid, which shows a characteristic antibasement membrane antibody to Bp180.

62) Chronic idiopathic urticaria is associated with which HLA type(s)?

A. HLA-DR4

B. none of the above

C. HLA-DQ8

D. all of the aboveCorrect Choice

E. HLA-DRB4 53

Chronic idiopathic urticaria is associated with HLA -DR4, -DRB4 53, and -DQ8.

63) Anti-Ro (SS-A) antibodies are most commonly found in

A. drug-induced systemic lupus erythematosus

B. eosinophilic fasciitis

C. homozygous C2 deficiency

D. mixed connective tissue disease

E. neonatal lupus erythematosus Correct Choice

Ro 60 kDa autoantigen is a major target for patients with SLE and Sjögren’s syndrome. Neonatal lupus occurs in newborns of mothers with anti-Ro antibodies and leads to children with photosensitive skin lesions and a cardiac conduction defect, a third degree heart block (Chen, et al, 2004; Costedoat-

64) The main cytokine secreted by Th1 CD8+ effector T-cells is:

A. IFN-gammaCorrect Choice

B. IL-2

C. IL-4

D. IL-1

E. IL-5

Interferon-gamma is the main cytokine secreted by Th1 CD8+ effector T-cells and is active in blocking viral replication. IL-2 is also released in Th1 reactions and causes T cell proliferation and differentiation, macrophage, NK, & Tc cell activation. It also acts as a Th1 autocrine growth factor. IL-1 is a pro-inflammatory cytokine and a pyrogen. IL-4 is a B-cell growth factor and active in signaling isotope switching from IgM to IgE. IL-5 is an eosinophil growth factor. Both IL-4 and -5 are secreted by Th2 T-cells.

65) Which is not a feature of mast cells?

A. stains with napththol chloro-acetate esterase

B. expresses c-kit

C. produces IL-8

D. responds to RANTESCorrect Choice

E. produces prostaglandin D2

Mast cells are an integral portion of immediate type hypersensitivity. RANTES is a chemoattractant for eosinphils, not mast cells.

66) A 26-year-old man presents with a history of recurrent episodes of targetoid, erythematous, edematous macules, patches, and plaques on the arms, legs, palms, and soles. The most likely etiologic agent is

A. coxsackievirus

B. herpes simplex virus Correct Choice

C. cytomegalovirus

D. parvovirus B19

E. human immunodeficiency virus

This description of the skin disorder is compatible with either erythema multiforme or erythema elevatum diutinum, both of which have been reported in association with HSV (Ng, et al, 2003; Burnett, et al, 2003)

67) This patient from New York gave a history of frequent outdoor activity. The likely diagnosis is:

A. Babesiosis

B. H. simplex erythema multiforme

C. Anthrax

D. ehrlichiosis

E. lyme disease Correct Choice

The answer is lyme disease with the typical erythema migrans appearance.

68) Oral lichen planus is most commonly associated with which HLA?

A. All of these options are correctCorrect Choice

B. DR9

C. B51

D. Bw57

E. HLA-B27

All of these HLA associations have been suggested in the literature. No specific HLA allele has been established due to patient selection and geographic heterogeneity.

69) The human leukocyte antigen that has the closet association with psoriasis is

A. HLA-B51

B. HLA-B27

C. HLA-DQ3

D. HLA-DR1

E. HLA-Cw6 Correct Choice

Human leukocyte antigens (HLA class I molecules) are designated A, B, and C and are present on all nucleated cells. Class I molecules present antigens including autoantigens to cytotoxic T cells.

70) Imiquimod induces which of the following cytokines?

A. Interleukin-5

B. Interferon-alpha Correct Choice

C. Interleukin-2

D. Interleukin-4

E. Interleukin-10

Imiquimod is an exciting new topical immunomodulator that increases a variety of cytokines including interferon-alpha (Wagner et al, 1999).

71) Which of the following best describes the mechanism of action for infliximab?

A. Inhibition of tumor necrosis factor alpha activity Correct Choice

B. Inhibition of retinoic acid 4-hydroxylase activity

C. Selective elimination of activated T cells via binding to high affinity IL-2 receptor

D. Inhibition of calcineurin-mediated dephosphorylation of transcription factors

E. Selective T-cell up-regulation of IL-4 and IL-5 production

Infliximab is a monoclonal antibody given intravenously that binds to membrane-bound and soluble TNF-alpha.

72) Of the following complement components, the most powerful neutrophil chemoattractant is:

A. C3a

B. C3

C. C5aCorrect Choice

D. C5b, C6, C7, C8, C9

E. C4a

The complement system plays an important role in innate immunity. Of this group, C5a is the most powerful neutrophil chemoattractant. C3 represents the endpoint for the classic, alternative and lectin pathways, and results in the generation of immunologically active substances. C3a and C4a cause mast cell degranulation. Assembly of C5b, C6, C7, C8, C9 components results in the membrane attack complex (MAC), which perforates cell membranes causing death by osmotic lysis.

73) The most useful pair of immunohistochemical stains to distinguish between dermatofibrosarcoma protuberans (DFSP) and a fibrous histiocytoma would be

A. synaptophysin, chromogranin

B. CD31, CD3

C. CD34, CD31

D. CD34, factor XIIIa Correct Choice

E. vimentin, synaptophysin

Dermatofibrosarcoma, the more common benign histiocytoma, is usually CD34 negative and factor XIIIa positive. DFSP is usually CD34 positive and factor XIIIa negative.

74) This skin disease has been shown to be associated with reduced Beta 2 defensin. The diagnosis is:

A. psoriasis

B. subacute cutaneous lupus erythematosus

C. lepromatous leprosy

D. atopic dermatitis Correct Choice

E. tuberculoid leprosy

The answer is atopic dermatitis. Cathelicidin 37 (LL-37) and Human Beta 2 Defensins (HBD-2) have been reported reduced in atopic dermatitis and normal or elevated in psoriasis. This could be one factor that predisposes atopics, but not psoriatics to bacterial and viral infections.

75) The most definitive HLA association with psoriasis is:

A. HLA-B17

B. HLA-B27

C. HLA-Cw6Correct Choice

D. HLA-B37

E. HLA-B13

HLA-Cw6 is associated with a 9-15x greater risk for developing psoriasis. All of the other HLA antigens listed are associated with various types of psoriasis, but at with lesser strength of association.

76) Which cytokine is the main macrophage-activating cytokine?

A. lymphotoxin

B. IFN-gammaCorrect Choice

C. IL-4

D. TNF

E. IL-10

IFN-gamma is the main macrophage-activating cytokine, and is secreted by TH1 cells.

77) The most likely target for exfoliative toxin A in bullous impetigo is

A. desmoglein 1 Correct Choice

B. collagen VII

C. desmoglein 3

D. laminin 5

E. desmocollin

Desmoglein 1, the dominant target antigen of the autoantibody involved in pemphigus foliaceus, is also the target of the exfoliative toxin of group II staphylococcus aureus that is usually responsible for bullous impetigo.

78) What is the best screening test for hereditary angioedema?

A. C3

B. C4Correct Choice

C. C2

D. CH50

E. C1 esterase

C4 is the best screening test for hereditary angioedema (Quinke's edema). There are two types of hereditary angioedema. In type I, there are low antigenic and functional levels of a NORMAL C1 esterase inhibitor protein. In type II, there is a normal or elevated level of a DYSFUNCTIONAL C1 esterase inhibitor. The low C4 level is a result of continuous activation and consumption of complement components.

79) Histamine is a biologic amine produced by which of the following cells?

A. Eosinophils

B. Monocytes

C. Platelets

D. Basophils

E. Basophils and PlateletsCorrect Choice

In the skin, histamine is mainly contained within the granules of dermal mast cells. Histamine is present in mast cells, basophils, and platelets

80) Which of the following immune-mediated events has been demonstrated in psoriasis vulgaris?

A. clonal expansion of CD8+ T cellsCorrect Choice

B. decreased production of interferon-gamma

C. decrease dermal Langerhans cells

D. increase Th2 CD4+ T cells

E. downregulation of keratin 16

The involvement of T cells in the pathophysiology of psoriasis vulgaris is well-recognized. Availability of monoclonal antibodies has allowed for extensive characterization of T cell subsets and other mediators increased in psoriasis lesions. CD8+ T cells are highly concentrated in psoriatic epidermis and studies have demonstrated increased IL-2R and HLA-DR surface molecules indicative of persistent activation. Clonal expansion of CD8+ T cells has been observed suggesting that this subset is the major antigen-reactive population.

(Krueger J. J Am Acad Dermatol 2002;46:1-23.

81) Which cytokine is predominantly responsible for the Jarish-Herxheimer reaction?

A. TNF-alphaCorrect Choice

B. IL-5

C. IL-12

D. IL-2

E. IL-6

The Jarish-Herxheimer reaction may occur after the initiation of treatment of many systemic infections including syphillis. It is an indirect drug induced effect caused by bacterial endotoxins or microbial antigens liberated by the destruction of micro-organisms. Clinical manifestations may include fever, lymphadenopathy, arthralgias, and exacerbation of pre-existing cutaneous lesions. Tumor necrosis factor-alpha is the primary cytokine that mediates this reaction.

82) Relapsing polychondritis is an autoimmune disease associated with immunity to which type of collagen?

A. VII

B. I

C. III

D. II Correct Choice

E. IV

Relapsing polychondritis has been reported to have autoantibodies to type II collage (Asadi, 2003).

83) Major histocompatibility complex class I molecules bind to:

A. Peptides derived from proteins synthesized and degraded in the cytosol Correct Choice

B. Immunoglobulin E

C. Peptides external to the cell membrane

D. Peptides derived from proteins degraded in endocytic vesicles

E. None of these answers are correct

Major histocompatibility complex (MHC) class I molecules bind to peptides derived from proteins synthesized and degraded in the cytosol. They present these processed peptides to CD8+ T-cells. MHC class II molecules bind stably to peptides derived from proteins degraded in endocytic vesicles. CD4+ T-cells recognize the MHC class II molecules. Immune activation against the foreign antigens or pathogens taken up by the cell is the result of these interactions. Peptides external to the cell are not recognized by MHC molecules. IgE does have a receptor on the cell surface, especially basophils and mast cells, but is not recognized by the MHC complex

84) Angiocentric NK/T-cell lymphoma in children may present as

A. en coup de sabre

B. acropustulosis of infancy

C. childhood dermatomyositis

D. hydroa vacciniforme Correct Choice

E. papular acrodermatitis of childhood

Hydroa vacciniforme a photodermatitis that typically occurs with sun exposure in the spring has been reported with NK/T cell lymphomas in childhood. for answer

85) Mononuclear phagocytes residing in tissues:

A. Produce cytokines, which recruit other inflammatory cells

B. All of the aboveCorrect Choice

C. Phagocytose foreign antigens and degrade them into peptides

D. Present antigen to T-cells

E. Are called macrophages

Mononuclear phagocytes are components of the innate immune system. Once in tissues they are called macrophages. All of the above are correct.

86) Efalizumab is an antibody which is directed against LFA1 on the T-cell, blocking this molecule's interaction with:

A. B7

B. P-selectin

C. CD40

D. LFA3

E. ICAM-1Correct Choice

ICAM-1 on the antigen presenting cell interacts with LFA1 on the T-cell. By interrupting this interaction, T-cell activation is blocked by preventing the pairing of LFA1 with ICAM-1. This prevents costimulatory signals from being given to the T-cell. T-cell ability to traffic into the skin is also inhibited in the arrest stage of trafficking.

87) Topical tacrolimus and pimecrolimus are used to treat atopic dermatitis and other inflammatory skin conditions. On which of the following ions is the inflammatory pathway blocked by these medications dependent?

A. Selenium

B. Potassium

C. CalciumCorrect Choice

D. Sodium

E. Zinc

Calcium. Both pimecrolimus and tacrolimus penetrate cutaneous T-cells, forming a complex with calcineurin, which blocks the activation of NF-AT, thus blocking the transcription of a variety of genes with a resultant decrease in T-cell mediated inflammation. This pathway is calcium dependent. The other ions are not involved in this process.

88) Herpes gestationis is most commonly associated with which HLA?

A. HLA-DR3Correct Choice

B. HLA-B51

C. HLA-B27

D. HLA-DQ8

E. HLA-DR9

HLA-DR3 is the most commonly found HLA association in herpes gestationis. HLA-DR4 is also found in addition to HLA-DR3 in about 50% of patients. There is nearly 100% incidence of anti-HLA antibodies patients affected by herpes gestationis

89) When attempting to identify Langerhans cells in a specimen, which marker is most helpful?

A. CD4

B. CD1 Correct Choice

C. CD7

D. CD8

E. CD20

CD1 is a surface antigen specific for epidermal Langerhans cells. It is not expressed in other epidermal structures. The other characteristic ultrastructural feature of Langerhans cells is the Birbeck granule. CD4 is found on T-helper cells and occasionally on Langerhans cells. CD7 is a T-cell marker that is often lost in cutaneous T-cell lymphoma. CD8 is found on cytotoxic T-cells. CD20 is a B-cell marker.

90) Which of the following HLA alleles is most strongly associated with Behcet’s disease?

A. HLA-DQw2

B. HLA-DR4

C. HLA-B51 Correct Choice

D. HLA-B27

E. HLA-DR1

HLA-B51 has been reported with increased relative risks in European, Asian and Middle Eastern populations (Mizuki et al 2002).

91) Which cytokine is up-regulated in this geometric, eczematous dermatitis?

A. IL-7

B. IL-5

C. IL-4

D. IL-2Correct Choice

E. IL-10

The geometric pattern of ertyhema suggests "outside job". Allergic contact dermatitis is a cell-mediated and Th1 reaction. The cytokines up-regulated in this process are IL-1, IL-2, IL-12, interferons-alpha and gamma.

92) Psoriatic arthritis is most commonly associated with which HLA?

A. HLA-Aw19

B. HLA-B27Correct Choice

C. None of these options are correct

D. HLA-Cw6

E. HLA-Bw35

HLA-B27 is associated with an increase in psoriatic arthritis as well as pustular psoriasis and acrodermatitis continua of Hallopeau.

93) A putative mechanism of action of dapsone in the treatment of inflammatory conditions relates to

A. suppression of T-cell activation

B. suppression of the halide-myeloperoxidase system

C. inhibition of neutrophil migration Correct Choice

D. enhancement of Th1 to Th2 shift

E. augmentation of interferon-alfa

Dapsone is especially effective in dermatitis herpetiformis where migration of neutrophils is seen in the dermal papillae (Zhu, et al, 2001).

94) All of the following statements are true regarding cells of the innate immune system EXCEPT:

A. IL-5 downregulates the functions of eosinophilsCorrect Choice

B. Langerhans cells are poorly phagocytic

C. Basophils are a type of granulocyte, as a neutrophils

D. Langerhans cells express CD1 on their surface

E. Neutrophils have receptors for IgG

Neutrophils, eosinophils, and basophils are collectively known as granulocytes. Neutrophils have receptors for IgG and complement. IL-5 enhances all functions of eosinophils. Langerhans cells are dendritic cells found in high concentration in epithelial surfaces and some areas of lymph nodes and spleen. They have a high density of class II MHC molecules and express CD1 on their surface. They are poorly phagocytic.

95) All of the following statements regarding mast cells are true EXCEPT:

A. Mast cells release substances that affect vascular permeability

B. Mast cells reside near small blood vessels

C. Mast cells protect mucosal surfaces against pathogens

D. Mast cells have receptors for certain fragments of complement on their surface

E. None of the above (all are true)Correct Choice

Mast cells are the central cell in immediate-type hypersenstivity, and are very important in cutaneous inflammation. They reside near small blood vessles, and when activated release substances that affect vascular permeability. They orchestrate allergic responses and protect mucosal surfaces against pathogens. They have receptors for IgE and certain fragments of complement on their cell surface.

96) In adult patients with Henoch-Schönlein purpura with IgA vasculitis, which of the following complications is most likely to occur?

A. Pulmonary hemorrhage

B. Facial edema

C. Mesangial nephropathy Correct Choice

D. Peripheral neuropathy

E. Hemorrhagic cystitis

A urinalysis should be ordered in patients with palpable purpura. Red blood cells and proteinuria are often seen in Henoch-Schönlein syndrome (Tarshish, et al, 2004).

97) Which cytokine is most important in recruiting neutrophils?

A. Interleukin-2

B. Interleukin-10

C. Interleukin-8 Correct Choice

D. Interleukin-1

E. Interleukin-4

Chemotaxis is the process of cells moving through a gradient of towards increasingly higher concentrations. IL-8 has activating and chemoattractant properties on neutrophils.

98) Which cytokine is present in Woronoff rings?

A. IL-10

B. Prostaglandin E2Correct Choice

C. IL-4

D. IL-5

E. TNF-Beta

Wornoff ring is the white halo seen surrounding some psoriatic plaques. Prostaglandin E2 is the cytokine responsible for this phenomenon.

99) The target antigen of chronic bullous disease of childhood is

A. 97 kd LAD-1 (a component of BPAG2) Correct Choice

B. alpha 6 beta 4 integrin

C. plectin

D. BPAG 1 9230 kd BPAG)

E. collagen type VII

This rare chronic bullous disease of childhood is a subepidermal blistering disease with a homogeneous IgA deposits at the epidermal basement membrane. This occurs in children usually less than 5 years of age.

100) Which antibody is most commonly found in circulation of patients with atopic dermatitis?

A. IgD

B. IgA

C. IgM

D. IgECorrect Choice

E. IgG

IgE is an anaphylactic antibody that is involved in nearly all immediate allergic and anaphylactic type reactions and commonly seen in elevated levels in patients with atopic dermatitis. Mast cells, basophils, langerhans cells, dermal dendritic cells as well as monocytes from atopic individuals all express high-affinity FcåRI receptor which can bind IgE. More recently, it became clear that can bind monomeric IgE via the high-affinity FcåRI IgG is the antibody that can cross the placenta and the most common antibody found in circulation. IgA is found in mucous membrane secretions and is able to agglutinate antigens and activate the alternate but not the classic complement pathway. IgD is not found in circulation other than in hyper-IgD syndrome, an autosomal recessive disorder caused by mutations in the mevalonate kinase gene. A significant elevation of serum IgD is seen in 95% of these patients. IgM is the antibody produced in the early stages of antibody responses. It is a pentamer which can agglutinate antigen and active the classic complement pathway.

101) Which paraprotein is found most commonly in patients with pyoderma gangrenosum?

A. IgM

B. IgG

C. IgE

D. IgA Correct Choice

E. IgD

IgA paraproteinemia has been reported in over 10-18% of pyoderma gangrenosum.

102) Which cytokine is responsible for activating natural killer cells?

A. Terferon-gamma

B. Interleukin 2Correct Choice

C. Interferon-alpha

D. Interleukin 4

E. Tumor necrosis factor-alpha

Activation of natural killer cells occurs via interleukin 2 (IL-2). IL-2 is a key component of the Th1 (cell-mediated) immunity. It acts to promote growth, proliferation and activation of T cells, B cells and natural killer cells.

103) Which cytokine is primarily responsible for stimulation of neutrophils?

A. IL-1

B. IL-6

C. IL-8Correct Choice

D. IL-5

E. IL-4

IL-8 is primarily responsible for the stimulation of neutrophils. IL-5 stimulates eosinophils. IL-4 stimulates mast cells and IgE isotype switching

104) Herpes simplex virus-related erythema multiforme has been associated with an increased frequency of

A. HLA-B8

B. HLA-B13

C. HLA-B15 Correct Choice

D. HLA-B27

E. HLA-B7

Erythema multiforme associated with herpes simplex has been reported to have an increase of HLA-B15.

105) The classical complement pathway:

A. Includes C3 and factor B.

B. Can be activated by IgG4

C. Does not cause membrane damage

D. Can be activated by IgMCorrect Choice

E. Can be activated in the absence of antibody

The classical complement pathway is activated by antigen-antibody complexes, while the alternate complement pathway can be activated in the absence of antibody. IgM and IgG are capable of activating the classical pathway, but IgG4 does not activate complement. The proteins of the classical pathway are C1, C2, C3, and C4. Factor B, Factor D, properdin, and C3 are proteins in the alternate pathway. Biologic activities of complement include opsonization, chemotaxis, anaphylaxis, immune complex solubilization, membrage damage, and B cell activation.

106) Which of the following immunoglobulin crosses the placenta?

A. IgM

B. IgA

C. IgD

D. IgGCorrect Choice

E. IgE

IgG is the antibody that can cross the placenta and the most common antibody found in circulation. IgA is found in mucous membrane secretions and is able to agglutinate antigens and activate the alternate but not the classic complement pathway. IgD is not found in circulation other than in hyper-IgD syndrome, an autosomal recessive disorder caused by mutations in the mevalonate kinase gene. A significant elevation of serum IgD is seen in 95% of these patients. IgE is an anaphylactic antibody that is involved in nearly all immediate allergic and anaphylactic type reactions. IgM is the antibody produced in the early stages of antibody responses. It is a pentamer which can agglutinate antigen and active the classic complement pathway.

107) Serum IgA antibodies to tissue transglutaminase occur in

A. pemphigus foliaceus

B. linear IgA disease

C. bullous lupus erythematosus

D. dermatitis herpetiformis Correct Choice

E. bullous pemphigoid

Autoantibodies to tissue transglutaminase are an area of active investigation in both celiac disease and dermatitis herpetiformis (Reif, et al, 2004

108) All of the following statements regarding Toll receptors are true EXCEPT:

A. Nuclear factor kappa B (NFKB) is the final common pathway of toll receptors

B. Toll 4 receptors are typically activated by gram negative bacteria

C. None of the above (all are true)

D. Toll 2 receptors are typically activated by lipopolysaccharideCorrect Choice

E. Toll receptors are present on macrophages and dendritic cells

Bacteria can induce inflammation through activation of Toll receptors, which are present on a variety of cutaneous cells including macrophages, dendritic cells, keratinocytes, and mast cells. Typically, Toll 2 receptors are activated by gram positive bacteria and Toll 4 receptors are activated by lipopolysaccharide or gram negative bacteria. Nuclear factor kappa B is a final common pathway of toll receptors and other immune receptors involved in initiating a variety of proinflammatory cytokines.

109) Which T-cell subset is commonly found in Sézary syndrome?

A. CD4+/CD7+

B. CD4-/CD7+

C. CD8+/CD7-

D. CD8+/CD7+

E. CD4+/CD7- Correct Choice

Sézary syndrome is the leukemia phase of mycosis fungoides (cutaneous T-cell lymphoma) and is usually a TH2-biased CD4+ leukemia.

110) Which of the following cytokines is a general down-regulator of TH1 immunity?

A. IL-5

B. IFN-gamma

C. TNF

D. IL-10Correct Choice

E. IL-4

IL-4 is a B cell growth factor. IL-5 is an eosinophil growth factor. IL-10 is a general down-regulator of TH1 immunity. TNF and IFN-gamma are TH1 cytokines, not TH2 cytokines. IFN-gamma is secreted by TH1 cells, and is the main macrophage-activating cytokine.

111) A deficiency of this complement component may result clinically in susceptibility to pyogenic infections, glomerulonephritis, and partial lipodystrophy.

A. C3Correct Choice

B. Properidin

C. C4

D. C50

E. C1 Esterase Inhibitor

C3 is the central component of the complement cascade. It plays a key role in the opsonization of bacteria. An autosomal recessive deficiency of C3 may result in susceptibility to pyogenic infections, glomerulonephritis, and partial lipodystrophy.

112) Proteins in the alternate complement pathway include:

A. properdin

B. Factor B

C. C3

D. Factor B and properdin

E. Factor B, properdin and C3 Correct Choice

Proteins in the alternate complement pathway are Factor B, Factor D, properdin, and C3. The alternate complement pathway is active against pathogenic microorganisms, virus-infected cells, and neoplastic cells. The proteins of the classical pathway are C1, C2, C3, and C4.

113) Which cytokine is chemotactic for neutrophils?

A. IL-2

B. IL-8Correct Choice

C. IL-3

D. IL-5

E. IL-6

IL-8 is chemotactic for neutrophils. The other cytokines elicit other types of immune cells, IL-2 (T-ells), IL-3 (mast cells), IL-5 (eosinophils), IL-6 (plasma cells).

114) Major histocompatibility complex (MHC) Class I molecules:

A. Are inducible on keratinocytes

B. All of the above

C. Are recognized by receptors on CD4+ T cells

D. Complexed with antigen trigger cytotoxic T cellsCorrect Choice

E. Bear peptides derived from pathogens taken up into vesicles

MHC Class I molecules are present on all nucleated cells. They are recognized by receptors on surfaces of CD8+ T cells, and, when complexed with antigen, trigger cytotoxic T cells. The other statements apply to MHC Class II molecules.

115) Which antibody can bind the FcER1 portion of mast cells, basophils, Langerhans cells, dermal dendritic cells?

A. IgD

B. IgA

C. IgG

D. IgM

E. IgECorrect Choice

IgE is an anaphylactic antibody that is involved in nearly all immediate allergic and anaphylactic type reactions and commonly seen in elevated levels in patients with atopic dermatitis. Mast cells, basophils, Langerhans cells, dermal dendritic cells as well as monocytes from atopic individuals all express high-affinity FcERI receptor which can bind IgE. More recently, it became clear that can bind monomeric IgE via the high-affinity FcåRI IgG is the antibody that can cross the placenta and the most common antibody found in circulation. IgA is found in mucous membrane secretions and is able to agglutinate antigens and activate the alternate but not the classic complement pathway. IgD is not found in circulation other than in hyper-IgD syndrome, an autosomal recessive disorder caused by mutations in the mevalonate kinase gene. A significant elevation of serum IgD is seen in 95% of these patients. IgM is the antibody produced in the early stages of antibody responses. It is a pentamer which can agglutinate antigen and active the classic complement pathway.

116) Langerhans cells exhibit which of the following antigenic moieties?

A. CD45

B. Langerin

C. all of the options are correctCorrect Choice

D. vimentin

E. MHC class II antigens

In addition to CD1a and S-100, Langerhans constantly express the leukocyte common antigen CD45, MHC class II antigens, vimentin and the Birbeck granule-associated molecule, Langerin.