13 - Basic Principles of Immunologic Diseases in Skin (Pathophysiology of Immunologic/Inflammatory Skin Diseases) Flashcards
Typically low-molecular-weight chemicals and metals, which interact with endogeneous proteins to form immunogenic (complete) antigens
Haptens
Y/N: Evidence suggesting that genetic susceptibility to ACD is important is strong
No - not strong
Initial exposures to haptens that commonly elicit ACD inpatients signal via 2 major pathways involved in innate immunity
Inflammasomes and/or
Toll-like receptors
Phases of acute contact dermatitis/contact hypersensitivity
- Sensitization
- Elicitation
- Resolution
Cytokine, toll-like receptor and inflammasome-mediated activation of APCs
No skin inflammation
Sensitization
Cytokine, toll-like receptor and inflammasome-mediated activation of APCs
Skin inflammation elicited by T cells
Elicitation
Resident memory T cells poised for subsequent exposure
Resolution
Y/N: Because haptens easily penetrate epidermis and reach the dermis, both Langerhans cells and dermal dendritic cells encounter contact allergens
Yes
CD8alpha+ (DCs and DDCs/LCs), but not (DCs and DDCs/LCs), contribute to CD8+ T-cell responses during antiviral responses
DCs and DDCs
LCs
_____ T cells appear to be the primary mediators of skin inflammation in ACD, but _____ T-cell activation may be required for optimal _____ T-cell responses
CD8+
CD4+
CD8+
_____ T cells mediate rapid cutaneous hypersensitivity responses, whereas _____ T cells cause delayed responses
Resident memory
Central memory
_____ T cells are thought to play major roles in attenuation or termination of inflammation in cutaneous hypersensitivity
Regulatory
Severe cutaneous adverse reactions include
SJS
TEN
DiHS/DRESS
Commonly included as SCAR, but is, in general, less severe than SJS/TEN and DiHS/DRESS
AGEP
In cohorts of Han-Chinese patients, SJS/TEN that is caused by allopurinol and carbamazepine is strongly associated with the HLA haplotypes _____ and _____, respectively
B*58:01
B*15:02
Dapsone hypersensitivity syndrome, a form of DiHS/DRESS has been associated with the _____ haplotype in Asians
HLA-B*13:01
_____ T cells can be readily detected in SJS/TEN lesions, suggesting that these cells are pathogenic
Cytotoxic
Probably reflects the existence of clones of drug-reactive CD8+ resident memory T (TRM) cells that reman at sites of previous skin lesions where they are poised to respond if offending drugs are readministered
Fixed drug eruptions
Y/N: Cytotoxic responses are more prominent in DiHS/DRESS
No - less prominent
Hallmark feature of DiHS/DRESS
Peripheral eosinophila
Expansion of regulatory T cells may result in immunocompromise in the initial stage of DiHS/DRESS, allowing reactivation of _____ infections
Herpes virus
EB virus-specific CD8+ T cells are reported to be increased in the circulation and cause tissue damage in EB virus-infected tissues, including _____, that is typical of DiHS/DRESS
Liver
B cells, which serve as a reservoir for EB virus, also may be targeted because patients with DiHS/DRESS frequently experience
Hypogammaglobulinemia
_____ patients exhibit immunologic abnormalities long after resolution of the acute phase and may develop autoimmune diseases such as Hashimoto thyroiditis, SLE, and type I DM
DiHS/DRESS
Accentuated immune responses against herpes viruses and the occurrence of autoimmune diseases suggest that breakdown of peripheral tolerance is a major contributor to
DiHS/DRESS
Posits that drugs bypass classic antigen-processing mechanisms and trigger immune responses through direct, noncovalent interactions with human leukocyte antigen alleles and/or T-cell receptors that are expressed on cell surfaces
Pharmacologic interaction with immune receptors (p-i) concept
Could explain why drug reactions occur within hours to few days in patients after initial exposure to causative drugs
Pharmacologic interaction with immune receptors (p-i) concept