ABD - American Board of Dermatology Basic Science and Immunology Questions and Answers

Question 1

Which cytokine is considered central to the pathogenesis of psoriasis by acting on T cells to promote their differentiation into and maintenance of the Th17 phenotype?

Accepted Answer

Interleukin-23 (IL-23)

Answer

Interleukin-4 (IL-4)

Answer

Interleukin-10 (IL-10)

Answer

Transforming growth factor-β (TGF-β)

Question 2

A newborn presents with widespread blistering and erosions following minor trauma. A skin biopsy with immunofluorescence mapping shows a split below the lamina densa of the basement membrane zone. A mutation in the gene encoding which of the following structural proteins is the most likely cause?

Accepted Answer

Type VII collagen

Answer

Keratin 14

Answer

Plectin

Answer

Laminin 332

Question 3

A patient with a history of recurrent severe herpes simplex virus (HSV) infections is suspected of having a defect in innate immune recognition. Which of the following Toll-like receptors, located within the endosome, is most critical for recognizing viral genomic DNA and initiating an interferon response?

Accepted Answer

TLR9

Answer

TLR2

Answer

TLR4

Answer

TLR5

Question 4

Allergic contact dermatitis, such as the classic reaction to urushiol in poison ivy, is an example of which type of Gell and Coombs hypersensitivity reaction?

Accepted Answer

Type IV (Delayed-type, cell-mediated)

Answer

Type I (IgE-mediated)

Answer

Type II (Antibody-dependent cytotoxicity)

Answer

Type III (Immune complex-mediated)

Question 5

A 60-year-old fair-skinned individual with a history of extensive sun exposure develops multiple actinic keratoses. The primary type of DNA damage directly induced by the ultraviolet B (UVB) component of sunlight, which is responsible for the mutations leading to these lesions, is the formation of:

Accepted Answer

Pyrimidine dimers

Answer

Reactive oxygen species

Answer

Single-strand breaks

Answer

DNA-protein crosslinks

Question 6

The cornified cell envelope is a critical component of the epidermal barrier, formed by the cross-linking of proteins like loricrin and involucrin during terminal keratinocyte differentiation. Which enzyme is primarily responsible for catalyzing the formation of these covalent isopeptide bonds?

Accepted Answer

Transglutaminase 1

Answer

Caspase-14

Answer

Kallikrein-5

Answer

Bleomycin hydrolase